Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Hiroyuki Furuta Last modified date:2021.06.04

Professor / Applied Fine Chemistry / Department of Applied Chemistry / Faculty of Engineering

1. TTF縮環ケイ素フタロシアニンオリゴマーの外部刺激応答性配向制御.
2. Biju Basumatary, Ikuho Hashiguchi, Shigeki Mori, Soji Shimizu, Masatoshi Ishida, Hiroyuki Furuta, Copper 1,19-Diaza-21,24-dicarbacorrole: A Corrole Analogue with an N-N Linkage Stabilizes a Ground-State Singlet Organocopper Species, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.202005167, 59, 37, 15897-15901, 2020.09, A copper complex of a heterocorrole analogue with an N-N linkage, 1,19-diaza-21,24-dicarbadibenzocorrole (Cu-5), was successfully synthesized via oxidative metalation-cyclization of a tetrapyrrolic precursor. The N-N linkage in the skeleton ofCu-5, which serves as a mediator of pi-electron delocalization, features an 18 pi aromatic system. The electronic structure ofCu-5is best described as a ground-state singlet species stabilized by the distinct NNCC coordination core. This finding shows how the ligand's design can be used to modulate the Cu3dx2-y2orbital energy, thereby making such compounds invaluable for copper-based catalytic applications..
3. Yue Wang, Koki Ogasahara, Daisuke Tomihama, Radomir Mysliborski, Masatoshi Ishida, Yongseok Hong, Yusuke Notsuka, Yoshihisa Yamaoka, Tomotaka Murayama, Atsuya Muranaka, Masanobu Uchiyama, Shigeki Mori, Yuhsuke Yasutake, Susumu Fukatsu, Dongho Kim, Hiroyuki Furuta, Near-Infrared-III-Absorbing and -Emitting Dyes: Energy-Gap Engineering of Expanded Porphyrinoids via Metallation, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.202006026, 59, 37, 16161-16166, 2020.09, The synthesis of organometallic complexes of modified 26 pi-conjugated hexaphyrins with absorption and emission capabilities in the third near-infrared region (NIR-III) is described. Symmetry alteration of the frontier molecular orbitals (MOs) of bis-Pd(II)and bis-Pt(II)complexes of hexaphyrin via N-confusion modification led to substantial metal d(pi)-p(pi)interactions. This MO mixing, in turn, resulted in a significantly narrower HOMO-LUMO energy gap. A remarkable long-wavelength shift of the lowest S-0 -> S(1)absorption beyond 1700 nm was achieved with the bis-Pt(II)complex,t-Pt-2-3. The emergence of photoacoustic (PA) signals maximized at 1700 nm makest-Pt-2-3potentially useful as a NIR-III PA contrast agent. The rigid bis-Pd(II)complexes,t-Pd-2-3andc-Pd-2-3, are rare examples of NIR emitters beyond 1500 nm. The current study provides new insight into the design of stable, expanded porphyrinic dyes possessing NIR-III-emissive and photoacoustic-response capabilities..
4. Yuta Shiina, Yuto Kage, Ko Furukawa, Heng Wang, Hirofumi Yoshikawa, Hiroyuki Furuta, Nagao Kobayashi, Soji Shimizu, TTF-Annulated Silicon Phthalocyanine Oligomers and Their External-Stimuli-Responsive Orientational Ordering, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.202011025, 59, 22721-22730, 2020.09, Orientational control of functional molecules is essential to create complex functionalities as seen in nature; however, such artificial systems have remained challenge. Herein, we have succeeded in controlling rotational isomerism of mu-oxo silicon phthalocyanine (SiPc) oligomers to achieve an external-stimuli-responsive orientational ordering using intermolecular interactions of tetrathiafulvalene (TTF). In this system, three modes of orientations, free rotation, eclipsed conformation, and staggered conformation, were interconverted in response to the oxidation states of TTF, which varied interactions from association due to formation of mixed-valence TTF dimer to dissociation due to electrostatic repulsion between TTF dications. Furthermore, a stable performance of oligomers as a cathode material in a Li-ion battery proved that the one-dimensionally stacked, rotatable structure of SiPc oligomers is useful to control the orientation of functional molecules toward molecular electronics..
5. Susumu Tanaka, Masafumi Konishi, Hiroaki Imoto, Yuma Nakamura, Masatoshi Ishida, Hiroyuki Furuta, Kensuke Naka, Fundamental Study on Arsenic(III) Halides (AsX3; X = Br, I) toward the Construction of C-3-Symmetrical Monodentate Arsenic Ligands, INORGANIC CHEMISTRY, 10.1021/acs.inorgchem.0c00598, 59, 14, 9587-9593, 2020.07, Arsenic ligands have attracted considerable attention in coordination chemistry. Arsenic(III) halides are the most important starting materials in the preparation of monodentate arsenic ligands. In this work, we optimized the synthetic methodologies of arsenic(III) halides (AsX3; X = Br, I) and examined the difference of their physical properties such as solubility to organic solvent and reactivity to nucleophiles. In addition, a wide variety of monodentate arsenic ligands were prepared with the obtained AsX3. Finally, the obtained monodentate arsenic ligands were utilized for copper-free Sonogashira cross-coupling reaction in the reaction system with porphyrin. The results showed that monodentate arsenic ligands have higher catalytic activity compared with triphenylphosphine because of the difference of the electronic features of lone pairs between arsenic and phosphorus atoms..
6. Tomoya Ishizuka, Ryuichi Sakashita, Osamu Iwanaga, Tatsuki Morimoto, Shigeki Mori, Masatoshi Ishida, Motoki Toganoh, Kiyonori Takegoshi, Atsuhiro Osuka, Hiroyuki Furuta, NH Tautomerism of N-Confused Porphyrin: Solvent/Substituent Effects and Isomerization Mechanism, JOURNAL OF PHYSICAL CHEMISTRY A, 10.1021/acs.jpca.0c04779, 124, 28, 5756-5769, 2020.07, The effects of substituents and solvents on the NH tautomerism of N-confused porphyrin (2) were investigated. The structures, electronic states, and aromaticity of NH tautomers (2-2H and 2-3H) were studied by absorption and nuclear magnetic resonance (H-1, C-13, and N-15) spectroscopies, single-crystal X-ray diffraction analysis, and theoretical calculations. The relative stability of the tautomers is highly affected by solvents, with the 3H-type tautomer being more stable in nonpolar solvents, while the 2H-type tautomer being highly stabilized in polar solvents with high donor numbers such as N,N-dimethylformamide (DMF), pyridine, and acetone. Electron-withdrawing groups on the meso-aryl substituents as well as the methyl group at the ortho position also stabilize the 2H-type tautomer. Kinetically, the tautomerism rate is significantly influenced by solvent and concentration, and a particularly large activation entropy (Delta S double dagger) is obtained in pyridine. The first-order deuterium isotope effect on the reaction rates of NH tautomerism (k(H)/k(D)) is determined to be 2.4 at 298 K. On the basis of kinetic data, the mechanism of isomerization is identified as an intramolecular process, including the rotation of the confused pyrrole in pyridine/chloroform and DMF/chloroform mixed solvent systems, and as a pyridine-mediated process in pyridine alone..
7. Ru Feng, Narumi Sato, Mayuka Nomura, Akinori Saeki, Hajime Nakanotani, Chihaya Adachi, Takuma Yasuda, Hiroyuki Furuta, Soji Shimizu, Near-infrared absorbing pyrrolopyrrole aza-BODIPY-based donor-acceptor polymers with reasonable photoresponse, JOURNAL OF MATERIALS CHEMISTRY C, 10.1039/d0tc01487g, 8, 26, 8770-8776, 2020.07, Designing near-infrared (NIR) absorbing donor-acceptor (D-A) polymers with photoresponse beyond 900 nm has remained a challenge in the area of organic photovoltaics (OPV) owing to the limited kinds of strong electron acceptors. Here we present the use of pyrrolopyrrole aza-BODIPY (PPAB) as a new acceptor group in D-A polymers in place of a conventional diketopyrrolopyrrole acceptor to achieve power conversion efficiencies up to 2.27% despite the ultra-small bandgap of 1.08 eV. The small photon energy loss of the PPAB-based D-A polymer and moderately high short-circuit current of 8.52 mA cm(-2)arising from the panchromatic visible/NIR absorption guarantee PPAB as a potential building block of D-A polymers for NIR photovoltaics..
8. Praseetha E. Kesavan, Vijayalakshmi Pandey, Masatoshi Ishida, Hiroyuki Furuta, Shigeki Mori, Iti Gupta, Synthesis, Photophysical Properties and Computational Studies of beta-Substituted Porphyrin Dyads, CHEMISTRY-AN ASIAN JOURNAL, 10.1002/asia.202000463, 15, 13, 2015-2028, 2020.07, Beta-pyrrole-substituted porphyrin dyads connected by ethynyl linkage to N-butylcarbazole or triphenylamine donors are reported. Donor-pi-acceptor type beta-substituted porphyrin dyads and their Zn(II) and Pd(II) complexes were characterized by MALDI-MS, NMR, UV-vis absorption, fluorescence and cyclic voltammetry techniques. The S-1 emission dynamics were analyzed by time-resolved spectroscopy (TCSPC); dyads exhibited efficient energy transfer up to 93% from beta-donors (N-butylcarbazole or triphenylamine group) to the porphyrin core. The efficiency of energy transfer for the beta-substituted porphyrin dyads were much higher than those of the corresponding meso-substituted porphyrin dyads, reflecting enhanced communications between the beta-donors and the porphyrin core. The Pd(II) dyads, showed characteristic phosphorescence in the near IR region and very efficient singlet oxygen quantum yields (53-60%); these dyads are promising candidates for photocatalytic oxidations of organic compounds. The donor-acceptor interaction between the porphyrin core and the beta-donors was supported by the DFT studies in the porphyrin dyads..
9. Takahide Shimada, Shigeki Mori, Masatoshi Ishida, Hiroyuki Furuta, Regioselectively alpha- and beta-alkynylated BODIPY dyes via gold(I)-catalyzed direct C-H functionalization and their photophysical properties, BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY, 10.3762/bjoc.16.53, 16, 587-595, 2020.04, A series of alpha- and beta-ethynyl-substituted BODIPY derivatives (3a, 4a, 5a, 5b, 6a, 6b) were synthesized by gold(I)-catalyzed direct C-H alkynylation reactions of dipyrromethane and BODIPY, respectively, with ethynylbenziodoxolone (EBX) in a regioselective manner. Depending on the position of the ethynyl substituent in the BODIPY skeleton, the photophysical properties of the resulting alpha- and beta-substituted BODIPYs are notably altered. The lowest S-0-S-1 transition absorbance and fluorescence bands are both bathochromically shifted as the number of substituents increases, while the emission quantum yields of the beta-ethynylated derivatives are significantly lower than those of alpha-ethynylated ones. The current method should be useful for fine-tuning of the photophysical properties of BODIPY dyes as well as for constructing BODIPY-based building cores for functional pi-materials..
10. Yue Wang, Hiroto Kai, Masatoshi Ishida, Sabapathi Gokulnath, Shigeki Mori, Tomotaka Murayama, Atsuya Muranaka, Masanobu Uchiyama, Yuhsuke Yasutake, Susumu Fukatsu, Yusuke Notsuka, Yoshihisa Yamaoka, Mamiko Hanafusa, Michito Yoshizawa, Gakhyun Kim, Dongho Kim, Hiroyuki Furuta, Synthesis of a Black Dye with Absorption Capabilities Across the Visible-to-Near-Infrared Region: A MO-Mixing Approach via Heterometal Coordination of Expanded Porphyrinoid, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/jacs.0c01824, 142, 14, 6807-6813, 2020.04, An expanded metalloporphyrin-based "black dye" Au-Pd oxohexaphyrin (AuPd1) with absorption capabilities across the visible-to-near-infrared (NIR) range was synthesized. This black dye, AuPd-1, possessed efficient light-harvesting and photostable capabilities, which were indicative of superior photothermal (PT) conversion abilities. Encapsulation of AuPd-1 with a micellar nanocapsule resulted in a compound that demonstrated intense photoacoustic (PA) properties in the NIR region in water. This finding indicated how metal (d)-ligand (pi) molecular orbital interactions in metalloporphyrins could aid in the design of visible-to-NIR light-harvesting black dyes for PT and PA applications..
11. Chengjie Li, Kai Zhang, Masatoshi Ishida, Qizhao Li, Keito Shimomura, Glib Baryshnikov, Xin Li, Mathew Savage, Xin Yan Wu, Sihai Yang, Hiroyuki Furuta, Yongshu Xie, Tripyrrin-armed isosmaragdyrins
Synthesis, heterodinuclear coordination, and protonation-triggered helical inversion, Chemical Science, 10.1039/c9sc06197e, 11, 10, 2790-2795, 2020.03, Oxidative ring closure of linear oligopyrroles is one of the synthetic approaches to novel porphyrinoids with dinuclear coordination sites and helical chirality. The spatial arrangement of the pyrrolic groups of octapyrrole (P8) affected the position of the intramolecular oxidative coupling of the pyrrolic units; tripyrrin-armed isosmaragdyrin analogue (1) containing a β,β-linked bipyrrole moiety was synthesized regioselectively in a high yield by using FeCl3. NiII-coordination at the armed tripyrrin site of 1 allowed the formation of diastereomeric helical twisted complexes (2A and 2B) and succeeding CuII-coordination at the macrocyclic core afforded heterodinuclear NiII/CuII-complexes (3A and 3B). Each of them comprised a pair of separable enantiomers, exhibiting P- and M-helices, respectively. Notably, diastereomeric interconversion from 2A to 2B was quantitatively achieved as a consequence of helical transformation under acidic conditions..
12. Keito Shimomura, Hiroto Kai, Yuma Nakamura, Yongseok Hong, Shigeki Mori, Koji Miki, Kouichi Ohe, Yusuke Notsuka, Yoshihisa Yamaoka, Masatoshi Ishida, Dongho Kim, Hiroyuki Furuta, Bis-Metal Complexes of Doubly N-Confused Dioxohexaphyrins as Potential Near-Infrared-II Photoacoustic Dyes, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/jacs.9b13475, 142, 9, 4429-4437, 2020.03, We investigated the detailed photophysical properties of a series of bis-metal (Zn and Cu) dioxohexaphyrin complexes as potential second near-infrared (NIR-II)-light responsive dyes. A cisoid-configured 28 pi-electron-conjugated dioxohexaphyrin analogue (c-3a) containing two peculiar "confused pyrrole" moieties in the framework is identified as a reduced isomer derivative of a transoid 26 pi-dioxohexaphyrin (t-2a). The symmetry-altered structure of c-3a affords a heteroleptic inner environment within the NNNN/NNOO donor core, which imparts its highly flexible electronic features and nonplanar geometry. The macrocycle c-3a can be transformed into the corresponding 26 pi-electron congener (c-2a) having a coplanar rectangular structure by unique solvent-mediated redox reactivity. Furthermore, upon metal complexation, saddle-distorted bis-metal complexes (c-M-2-2a) were formed as the 26 pi-conjugated structural isomer of the trans-dioxohexaphyrin species (i.e., t-M-2-2a). These isoelectronic dioxohexaphyrins demonstrate precise geometry-dependent photophysical properties. Broad tailing NIR-II absorption, weak emissive character, and rapid-decay of the S-1 state are observed for c-Zn-2-2a. In contrast, the coplanar t-M-2-2a exhibits efficient photoacoustic response upon laser excitation with NIR-II light (lambda > 1000 nm). To the best of our knowledge, this is the first example of an expanded porphyrin-based photoacoustic contrast agent responsive to NIR-II light..
13. Ru Feng, Narumi Sato, Takuma Yasuda, Hiroyuki Furuta, Soji Shimizu, Rational design of pyrrolopyrrole-aza-BODIPY-based acceptor-donor-acceptor triads for organic photovoltaics application, CHEMICAL COMMUNICATIONS, 10.1039/d0cc00398k, 56, 20, 2975-2978, 2020.03, Acceptor-donor-acceptor triads consisting of diketopyrrolopyrrole (DPP) or pyrrolopyrrole aza-BODIPY (PPAB) or both as acceptors and cyclopentadithiophene as a donor were rationally designed for near infrared (NIR) photovoltaics application. Among them, the PPAB-based triad exhibited the highest power conversion efficiency of 3.88% owing to the panchromatic absorption in the UV/vis/NIR regions..
14. Chengjie Li, Kai Zhang, Masatoshi Ishida, Qizhao Li, Keito Shimomura, Glib Baryshnikov, Xin Li, Mathew Savage, Xin-Yan Wu, Sihai Yang, Hiroyuki Furuta, Yongshu Xie, Tripyrrin-armed isosmaragdyrins: synthesis, heterodinuclear coordination, and protonation-triggered helical inversion, CHEMICAL SCIENCE, 10.1039/c9sc06197e, 11, 10, 2790-2795, 2020.03, Oxidative ring closure of linear oligopyrroles is one of the synthetic approaches to novel porphyrinoids with dinuclear coordination sites and helical chirality. The spatial arrangement of the pyrrolic groups of octapyrrole (P8) affected the position of the intramolecular oxidative coupling of the pyrrolic units; tripyrrin-armed isosmaragdyrin analogue (1) containing a beta,beta-linked bipyrrole moiety was synthesized regioselectively in a high yield by using FeCl3. Ni-II-coordination at the armed tripyrrin site of 1 allowed the formation of diastereomeric helical twisted complexes (2A and 2B) and succeeding Cu-II-coordination at the macrocyclic core afforded heterodinuclear Ni-II/Cu-II-complexes (3A and 3B). Each of them comprised a pair of separable enantiomers, exhibiting P- and M-helices, respectively. Notably, diastereomeric interconversion from 2A to 2B was quantitatively achieved as a consequence of helical transformation under acidic conditions..
15. Takaaki Yamamoto, Jibin Alex Abraham, Shigeki Mori, Motoki Toganoh, Soji Shimizu, Masatoshi Ishida, Hiroyuki Furuta, Tungsten(VI) Complex of N-Fused Porphyrin Absorbing Near-Infrared Light beyond 1000 nm, CHEMISTRY-AN ASIAN JOURNAL, 10.1002/asia.202000014, 15, 6, 748-752, 2020.03, Incorporating tungsten into the N3 core of a N-fused porphyrin (NFP; 1) affords high-valent tungsten(VI)-NFP complexes, WClO2-1 and 21-chlorinated WClO2-3. The X-ray structure of WClO2-1 reveals a distorted octahedral geometry with sitting atop metal coordination. The absorption spectrum of WClO2-1 displays bathochromically shifted Q-like bands beyond 1000 nm, indicating an inherently narrow HOMO-LUMO energy gap. DFT calculations show that the degeneracy of the LUMO and LUMO+1 pair of 1 is significantly resolved by the tungsten(VI) coordination. Conclusively, magnetic circular dichroism (MCD) spectroscopy and cyclic voltammetry provide a rationale for the narrow HOMO-LUMO energy gap in the "16-electron" d(0) tungsten(VI)-NFP complexes..
16. Bio-Inspired Pentadentate Metal Complexes of N-Confused Porphyrin Toward Active Catalysts.
17. Yuto Kage, Soji Shimizu, Gabriele Kociok-Kohn, Hiroyuki Furuta, G. Dan Pantos, Subphthalocyanine-Stoppered [2]Rotaxanes: Synthesis and Size/Energy Threshold of Slippage, ORGANIC LETTERS, 10.1021/acs.orglett.9b04620, 22, 3, 1096-1101, 2020.02, Subphthalocyanine (SubPc)-stoppered [2]-rotaxanes were synthesized for the first time. The rotaxane bearing unsubstituted SubPc as a stopper exhibited an equilibrium of slipping-on and slipping-off, whereas a perfluorinated SubPc stopper completely blocked slippage of the ring due to its slightly larger size. Kinetic studies revealed the Gibbs free energy of activation for the slipping-on and slipping-off processes. The optical properties of the rotaxanes, including photoinduced electron transfer, were also revealed..
18. Takaaki Yamamoto, Jibin Alex Abraham, Shigeki Mori, Motoki Toganoh, Soji Shimizu, Masatoshi Ishida, Hiroyuki Furuta, Tungsten(VI) Complex of N-Fused Porphyrin Absorbing Near-Infrared Light beyond 1000 nm, Chemistry - An Asian Journal, 10.1002/asia.202000014, 2020.01, Incorporating tungsten into the N3 core of a N-fused porphyrin (NFP; 1) affords high-valent tungsten(VI)-NFP complexes, WClO2-1 and 21-chlorinated WClO2-3. The X-ray structure of WClO2-1 reveals a distorted octahedral geometry with sitting atop metal coordination. The absorption spectrum of WClO2-1 displays bathochromically shifted Q-like bands beyond 1000 nm, indicating an inherently narrow HOMO-LUMO energy gap. DFT calculations show that the degeneracy of the LUMO and LUMO+1 pair of 1 is significantly resolved by the tungsten(VI) coordination. Conclusively, magnetic circular dichroism (MCD) spectroscopy and cyclic voltammetry provide a rationale for the narrow HOMO-LUMO energy gap in the “16-electron” d0 tungsten(VI)-NFP complexes..
19. Biju Basumatary, Koki Mitsuno, Masatoshi Ishida, Hiroyuki Furuta, Bis-palladium(II) complex of doubly N-confused octaphyrin( Mobius aromaticity and chiroptical properties, JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 10.1142/S1088424619501116, 24, 1-3, 416-423, 2020.01, A novel bis-palladium(II) complex of doubly N-confused octaphyrin (Pd-2-2) adopting a Mobius-twisted topological structure was synthesized and characterized. Due to the effective 36 pi-electronic delocalization over the Mobius-twisted octaphyrin scaffold, characteristic Soret and Q-like absorption features were observed in the near-infrared (NIR) region. However, the complex Pd-2-2 exhibited weak aromatic character attributed to the distinct cross-conjugated resonance contribution as inferred from the H-1 NMR chemical shifts as well as theoretical assessments (e.g. nucleus-independent chemical shift (NICS)). Since the bis-palladium(II) complexation of doubly N-confused octaphyrin 2 imparted significant conformational stability, topologically chiral enantiomers of Pd-2-2 were successfully separated as (P)- and (M)-twisted forms. The resulting isomers revealed relatively large circular dichroism (CD) responses with an absorption anisotropy factor of g(abs) = 0.009 in the NIR region (lambda = 823 nm). In addition, the cyclic voltammogram of Pd-2-2 revealed redox-rich properties due to its large pi-conjugated system..
20. Guangxian Su, Qizhao Li, Masatoshi Ishida, Chengjie Li, Feng Sha, Xin-Yan Wu, Lu Wang, Glib Baryshnikov, Dawei Li, Hans Agren, Hiroyuki Furuta, Yongshu Xie, N-Confused Phlorin-Prodigiosin Chimera: meso-Aryl Oxidation and pi-Extension Triggered by Peripheral Coordination, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201913290, 59, 4, 1537-1541, 2020.01, An N-confused phlorin isomer bearing a dipyrrin moiety at the alpha-position of the confused pyrrole ring (1) was synthesized. Pd-II and B-III coordination at the peripheral prodigiosin-like moiety of 1 afforded the corresponding complexes 2 and 3. Reflux of 2 in triethylamine (TEA) converted the meso-phenyl into the Pd-II-coordinating phenoxy group to afford 4. Under the same reaction conditions, TEA was linked to the alpha-position of the dipyrrin unit in 3 as an N,N-diethylaminovinyl group to afford 5. Furthermore, peripheral coordination of B-III in 3 and 5 improved the planarity of the phlorin macrocycle and thus facilitated the coordination of Ag-III at the inner cavity to afford 3-Ag and 5-Ag, respectively. These results provide an effective approach for developing unique porphyrinoids through peripheral coordination..
21. Akihide Nishiyama, Yuki Tanaka, Shigeki Mori, Hiroyuki Furuta, Soji Shimizu, Oxidative nitration reaction of antiaromatic 5,15-dioxaporphyrin, JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 10.1142/S108842461950113X, 24, 1-3, 355-361, 2020.01, Upon oxidation of 20 pi-electron antiaromatic 5,15-dioxaporphyrin (DOP) using nitrosonium ions as oxidants, a tetrakis-beta-nitrated compound was formed instead of the expected 18 pi-electron aromatic dication species via an oxidative nitration reaction mechanism. Compared with the original DOP, this tetranitro DOP product exhibited a blue shift of absorption and downfield shifts of the beta-pyrrolic proton signals. The unique antiaromatic electronic structure of the tetranitro DOP was disclosed experimentally by electrochemistry and theoretically by DFT and NICS calculations..
22. Tomas Torres, Jonathan L. Sessler, Dongho Kim, Hiroyuki Furuta, Preface - Special Issue in Honor of Professor Atsuhiro Osuka, JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 10.1142/S1088424620020010, 24, 1-3, I-I, 2020.01.
23. Yuto Kage, Hideaki Karasaki, Shigeki Mori, Hiroyuki Furuta, Soji Shimizu, Pyrrolopyrrole Aza-BODIPY Analogues as Near-Infrared Chromophores and Fluorophores: Red-Shift Effects of Substituents on Absorption and Emission Spectra, CHEMPLUSCHEM, 10.1002/cplu.201900226, 84, 11, 1648-1652, 2019.11, The cover feature shows how the absorption and fluorescence of an aza-BODIPY analogue bearing a diketopyrrolopyrrole moiety can be shifted to the near-infrared region by increasing the numbers of pendant thiophene units or by introducing electron-donating piperidylthiophene substituents. This challenge is likened to a Ninja ' s training of throwing a "Shuriken" further than ever. More details can be found in the Communication by H. Furuta, S. Shimizu, and co-workers (DOI: 10.1002/cplu.201900226)..
24. Ryusei Tsuruga, Narumi Uehara, Yuki Suzuki, Hiroyuki Furuta, Hiroshi Sugiyama, Masayuki Endo, Shigeyoshi Matsumura, Yoshiya Ikawa, Oligomerization of a modular ribozyme assembly of which is controlled by a programmable RNA-RNA interface between two structural modules, JOURNAL OF BIOSCIENCE AND BIOENGINEERING, 10.1016/j.jbiosc.2019.04.003, 128, 4, 410-415, 2019.10, Bimolecular ribozymes derived by physical dissection of unimolecular ribozymes consisting of two structural modules are promising platforms for the design and construction of assembled RNA nanostructures. Unit RNAs to be assembled intermolecularly into one-dimensional (1D) oligomers are designed by reconnecting the two structural modules in a manner different from the parent ribozymes. This strategy was applied to the Tetrahymena group I ribozyme. We constructed 1D ribozyme oligomers the assembly of which was observed by atomic force microscopy (AFM) and also controlled rationally to design a heterooctamer by differentiating the interface between the two modules. (C) 2019, The Society for Biotechnology, Japan. All rights reserved..
25. Yemei Wang, Shigeki Mori, Hiroyuki Furuta, Soji Shimizu, Bis(1,3-dithiol-2-ylidene)-Substituted Subtriazachlorin: A Subphthalocyanine Analogue with Redox Properties, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201905331, 58, 32, 10975-10979, 2019.08, Bis(1,3-dithiol-2-ylidene)-substituted subtriazachlorin was formed because of an unusual reaction of a 1,3-dithiole-2-one-fused subphthalocyanine in a triethylphosphite-mediated tetrathiafulvalene synthesis. In this novel molecule, the bis(1,3-dithiol-2-ylidene)ethane moiety and subtriazachlorin structure are fused, resulting in an electron-donating ability and broad absorption in the near-infrared region..
26. Ikuo Kawashima, Hiroaki Imoto, Masatoshi Ishida, Hiroyuki Furuta, Shunsuke Yamamoto, Masaya Mitsuishi, Susumu Tanaka, Toshiki Fujii, Kensuke Naka, Dibenzoarsepins: Planarization of 8 pi-Electron System in the Lowest Singlet Excited State, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201904882, 58, 34, 11686-11690, 2019.08, Dibenzo[b,f]arsepins possessing severely distorted cores compared to those of other heteropins were synthesized. These derivatives exhibited dual photoluminescence in the green-to-red region (500-700 nm) and the near-ultraviolet region (<380 nm), which could be attributed to the planarization of the arsepin core in the lowest singlet excited (S-1) state. The computational approach for the assessment of the aromatic indices revealed that the dibenzoarsepins studied show aromaticity (8 pi system) in the S-1 states in line with Baird's rule. The lone pair electrons of the arsenic atoms play a crucial role in the aromaticity in the S-1 states..
27. Ryoichi Ishimatsu, Hirosato Shintaku, Yuto Kage, Misaki Kamioka, Soji Shimizu, Koji Nakano, Hiroyuki Furuta, Toshihiko Imato, Efficient Electrogenerated Chemiluminescence of Pyrrolopyrrole Aza-BODIPYs in the Near-Infrared Region with Tripropylamine: Involving Formation of S-2 and T-2 States, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/jacs.9b05245, 141, 30, 11791-11795, 2019.07, Efficient electrogenerated chemiluminescences (ECLs) of three pyrrolopyrrole aza-BODIPYs in the near-infrared region by using tripropylamine as a coreactant are reported. Kinetic analysis based on Marcus theory indicates the direct formation of S-2 and T-2 states through the electron transfer reaction, which affects the ECL efficiencies..
28. Motoki Toganoh, Hiroyuki Furuta, N-Fused Porphyrin: A Maverick Member of the Porphyrin Family, CHEMISTRY LETTERS, 10.1246/cl.190250, 48, 7, 615-622, 2019.07, Fusion is a relatively new concept to produce unique members of the porphyrin family. A representative compound formed by fusion is N-fused porphyrin, which is synthesized from N-confused porphyrin. N-Fused porphyrin has an unusually narrow HOMO-LUMO energy gap and exhibits absorption in the near infrared region up to 1100 nm. Moreover, N-fused porphyrin serves as a versatile mono-negative tridentate ligand, which can bind a variety of metal centers tightly. While inner-core fusion is rare in tetrapyrrolic porphyrinoids, it becomes more common in expanded porphyrins, where a variety of novel structures are produced unanticipatedly..
29. Takaaki Miyazaki, Kazuki Fukuyama, Shunichi Mashita, Yuya Deguchi, Takaaki Yamamoto, Masatoshi Ishida, Shigeki Mori, Hiroyuki Furuta, Ruthenium N-Confused Porphyrins: Selective Reactivity for Ambident 2-Heteroatom-Substituted Pyridines Serving as Axial Ligands, CHEMPLUSCHEM, 10.1002/cplu.201800630, 84, 6, 603-607, 2019.06, Three types of ruthenium(II) N-confused porphyrin (NCP) complexes bearing an axial 2-thiopyridine, 2-pyridone, and 2-iminopyridine moiety at the inner carbon atom, respectively, were synthesized. The unique reactivity of the 2-substituted pyridine derivatives (2-X-pyridine; X=SH, OH, NH2) toward the inner carbon atom of the NCP allows the formation of two types of coordinated products (i. e., pyridine donor versus 2-heteroatom donors), as inferred from single-crystal X-ray structures. The selective reactivity was investigated by using density functional theory (DFT) calculations. Finally, the catalytic activity of these ruthenium complexes was demonstrated through the styrene oxidation reactions. As a result, the ruthenium(II) NCP complex bearing a 2-thiopyridine moiety, together with aqueous H2O2 as an oxidant showed the highest selectivity for benzaldehyde (benzaldehyde/styrene oxide=20 : 1)..
30. Masaya Fukuda, Shigeki Mori, Hiroyuki Furuta, Soji Shimizu, N-Confused Porphyrin-aza-Dipyrrin Chimera
A Versatile Metal Coordination Ligand Using its Unique NH Tautomerism, Chemistry - An Asian Journal, 10.1002/asia.201801750, 14, 10, 1697-1702, 2019.05, A novel N-confused porphyrin (NCP) analogue bearing an external aza-dipyrrin-like coordination site was synthesized by a Schiff-base forming reaction of N-confused oxoporphyrin and 2-aminopyridine derivatives. The chimera molecule enhances the intrinsic NH tautomerism of NCP to enable four possible tautomeric structures, three of which were identified by metal coordination..
31. Yemei Wang, Koya Uchihara, Shigeki Mori, Hiroyuki Furuta, Soji Shimizu, 1,3-Dithiole-2-one-Fused Subphthalocyanine and Subporphyrazine: Synthesis and Properties Arising from the 1,3-Dithiole-2-one Units, ORGANIC LETTERS, 10.1021/acs.orglett.9b00752, 21, 9, 3103-3107, 2019.05, Subphthalocyanine (SubPc) and its benzo ring-removed analogue, subporphyrazine (SubPz), bearing 1,3-dithiole-2-one (S2CO) groups as a new class of substituents were synthesized. In addition to the perturbed optical properties due to the presence of electron-withdrawing S2CO units, the deep bowl-shaped structure of the SubPz derivative allowed concave-convex interaction to form a unique co-crystal structure with C-6(0). Finally, using the reactivity of the peripheral S2CO units, S2CO-fused SubPc was successfully converted into tetrathiafulvalene (TTF)-annulated SubPc in a yield higher than that of the direct synthesis from a TTF-fused phthalonitrile..
32. Shota Ooi, Takayuki Tanaka, Takahisa Ikeue, Kazuhisa Yamasumi, Kento Ueta, Daiki Shimizu, Masatoshi Ishida, Hiroyuki Furuta, Atsuhiro Osuka, Bis-copper(II) Complex of Triply-linked Corrole Dimer and Its Dication, CHEMISTRY-AN ASIAN JOURNAL, 10.1002/asia.201801467, 14, 10, 1771-1776, 2019.05, Copper complexes of corroles have recently been a subject of keen interest due to their ligand non-innocent character and unique redox properties. Here we investigated bis-copper complex of a triply-linked corrole dimer that serves as a pair of divalent metal ligands but can be reduced to a pair of trivalent metal ligands. Reaction of triply-linked corrole dimer 2 with Cu(acac)(2) (acac=acetylacetonate) gave bis-copper(II) complex2Cu as a highly planar molecule with a mean-plane deviation value of 0.020 angstrom, where the two copper ions were revealed to be divalent by ESR, SQUID, and XPS methods. Oxidation of 2Cu with two equivalents of AgBF4 gave complex3Cu, which was characterized as a bis-copper(II) complex of a dicationic triply-linked corrole dimer not as the corresponding bis-copper(III) complex. In accord with this assignment, the structural parameters around the copper ions were revealed to be quite similar for 2Cu and 3Cu. Importantly, the magnetic spin-spin interaction differs depending on the redox-state of the ligand, being weak ferromagnetic in 2Cu and antiferromagnetic in 3Cu..
33. Poornenth Pushpanandan, Dong-Hoon Won, Shigeki Mori, Yuhsuke Yasutake, Susumu Fukatsu, Masatoshi Ishida, Hiroyuki Furuta, Doubly N-Confused Calix[6]phyrin Bis-Organopalladium Complexes: Photostable Triplet Sensitizers for Singlet Oxygen Generation, CHEMISTRY-AN ASIAN JOURNAL, 10.1002/asia.201801671, 14, 10, 1729-1736, 2019.05, Triplet photosensitizers that generate singlet oxygen efficiently are attractive for applications such as photodynamic therapy (PDT). Extending the absorption band to a near-infrared (NIR) region (700nm approximate to) with reasonable photostability is one of the major demands in the rational design of such sensitizers. We herein prepared a series of mono- and bis-palladium complexes(1-Pd-H-2, 2-Pd-H-2, 1-Pd-Pd, and 2-Pd-Pd) based on modified calix[6]phyrins as photosensitizers for singlet oxygen generation. These palladium complexes showed intense absorption profiles in the visible-to-NIR region (500-750nm) depending on the number of central metals. Upon photoirradiation in the presence of 1,5-dihydroxynaphthalene (DHN) as a substrate for reactive oxygen species, the bis-palladium complexes generated singlet oxygen with high efficiency and excellent photostability. Singlet oxygen generation was confirmed from the characteristic spectral feature of the spin trapped complex in the EPR spectrum and the intact O-1(2) emission at 1270nm..
34. Masaya Fukuda, Shigeki Mori, Hiroyuki Furuta, Soji Shimizu, N-Confused Porphyrin-aza-Dipyrrin Chimera: A Versatile Metal Coordination Ligand Using its Unique NH Tautomerism, CHEMISTRY-AN ASIAN JOURNAL, 10.1002/asia.201801750, 14, 10, 1697-1702, 2019.05, A novel N-confused porphyrin (NCP) analogue bearing an external aza-dipyrrin-like coordination site was synthesized by a Schiff-base forming reaction of N-confused oxoporphyrin and 2-aminopyridine derivatives. The chimera molecule enhances the intrinsic NH tautomerism of NCP to enable four possible tautomeric structures, three of which were identified by metal coordination..
35. Yufeng Yang, Masatoshi Ishida, Yuhsuke Yasutake, Susumu Fukatsu, Chihoko Fukakusa, Masa-aki Morikawa, Teppei Yamada, Nobuo Kimizuka, Hiroyuki Furuta, Hierarchical Hybrid Metal-Organic Frameworks: Tuning the Visible/Near-Infrared Optical Properties by a Combination of Porphyrin and Its Isomer Units, INORGANIC CHEMISTRY, 10.1021/acs.inorgchem.9b00251, 58, 7, 4647-4656, 2019.04, Hybrid metal organic frameworks (MOFs) with core/shell-like hierarchical structure comprised of zirconium metal and porphyrin (e.g., TPP) and its isomer, N-confused porphyrin (NCP), were synthesized through a seed-mediated reaction. The hierarchical structures of hybrid MOFs were characterized by the microscopic image analyses (e.g., scanning electron microscope (SEM), energy dispersive X-ray (EDX) spectrometry, and confocal laser scanning microscope (CLSM)). Taking advantage of the intrinsic light-harvesting properties of the porphyrin dye and the N-confused isomer, changing the core/shell layer structures of hybrid MOFs allows for tuning of the visible-to-near-infrared (NIR) absorption/emission characters, excited-state energy migrations, and photosensitization capabilities. The Forster energy transfer event occurring in the bulk MOF samples by photoexcitation enabled us to control the photoinduced singlet oxygen generation through the comprehensive light-harvesting ability of these hybrid porphyrinic MOFs. Therefore, implementation of a precisely designed porphyrin "substitute" into the MOF-based materials indeed provides a new mimic of the photosynthetic pigment system and should be potentially applicable for solar-light-driven devices..
36. Qizhao Li, Chengjie Li, Jinseok Kim, Masatoshi Ishida, Xin Li, Tingting Gu, Xu Liang, Weihua Zhu, Hans Agren, Dongho Kim, Hiroyuki Furuta, Yongshu Xie, Regioselectively Halogenated Expanded Porphyrinoids as Building Blocks for Constructing Porphyrin-Porphyrinoid Heterodyads with Tunable Energy Transfer, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/jacs.8b13148, 141, 13, 5294-5302, 2019.04, Expanded porphyrins have been attracting increasing attention owing to their unique optical and electrochemical properties as well as switchable aromaticity. Toward material applications, regioselective functionalization of the expanded porphyrins at their periphery is indeed challenging due to the presence of multiple reactive sites. Herein, a set of regioselective halogenated isomers (L5-Br-A/B/C) of neo-confused isosmaragdyrin (L5) are synthesized by a combination of the halogenation reaction of L5 and sequential macrocycleto-macrocycle transformation reactions of its halogenated isomers. On this basis, the regioselectively functionalized isosmaragdyrins are utilized as building blocks for constructing multichromophoric porphyrinoids, specifically, heterodyads L5-ZnP-A/B/C, in which a common zinc porphyrin is linked at three different pyrrolic positions of isosmaragdyrins, respectively, by Sonogashira coupling reactions. The highly efficient energy cascade from porphyrin to isosmaragdyrin is elucidated using steady-state/time-resolved spectroscopies and theoretical calculations. Notably, the energy transfer processes from the porphyrin to the isosmaragdyrin moieties as well as the excitation energy transfer rates in L5-ZnP-A/B/C are highly dependent on the linking sites by through-bond and Forster-type resonance energy transfer mechanisms. The site-selective functionalization and subsequent construction of a set of heterodyads of the expanded porphyrinoid would provide opportunities for developing new materials for optoelectronic applications..
37. Qizhao Li, Masatoshi Ishida, Hiroto Kai, Tingting Gu, Chengjie Li, Xin Li, Glib Baryshnikov, Xu Liang, Weihua Zhu, Hans Agren, Hiroyuki Furuta, Yongshu Xie, Skeletal Rearrangement of Twisted Thia-Norhexaphyrin: Multiply Annulated Polypyrrolic Aromatic Macrocycles, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201900010, 58, 18, 5925-5929, 2019.04, A hybrid thia-norhexaphyrin comprising a directly linked N-confused pyrrole and thiophene unit (1) revealed unique macrocycle transformations to afford multiply inner-annulated aromatic macrocycles. Oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone triggered a cleavage of the C-S bond of the thiophene unit, accompanied with skeletal rearrangement to afford unique pi-conjugated products: a thiopyrrolo-pentaphyrin embedded with a pyrrolo[1,2]isothiazole (2), a sulfur-free pentaphyrin incorporating an indolizine moiety (3), and a thiopyranyltriphyrinoid containing a 2H-thiopyran unit (4). Furthermore, 2 underwent desulfurization reactions to afford a fused pentaphyrin containing a pyrrolizine moiety (5) under mild conditions. Using expanded porphyrin scaffolds, oxidative thiophene cleavage and desulfurization of the hitherto unknown N-confused core-modified macrocycles would be a practical approach for developing unique polypyrrolic aromatic macrocycles..
38. Neha Manav, Praseetha E. Kesavan, Masatoshi Ishida, Shigeki Mori, Yuhsuke Yasutake, Susumu Fukatsu, Hiroyuki Furuta, Iti Gupta, Phosphorescent rhenium-dipyrrinates: efficient photosensitizers for singlet oxygen generation, DALTON TRANSACTIONS, 10.1039/c8dt04540b, 48, 7, 2467-2478, 2019.02, A series of rhenium(i) dipyrrinato complexes (Re1-Re8) have been prepared and characterized; their crystal structures, phosphorescence and singlet oxygen generation studies are reported. The aromatic substituents, such as thienyl, p-bromophenyl, p-fluorophenyl, m-fluorophenyl, pentaflurophenyl, N-butylcarbazole, N-phenylcarbazole, and N-butylphenothiazine, are linked to the C5 position of Re-dipyrrinates. Varying the electronic nature of the substituents from electron donating (e.g., carbazole) to electron withdrawing (e.g., pentaflurophenyl) allowed the change in the structural, electrochemical, and spectroscopic properties of these complexes. In particular, the rhenium dipyrrinates showed phosphorescence in the near IR region with sufficiently longer triplet state lifetimes ((T) = 9-29 s). Also, a large Stokes shift ( = 5682-6957 cm(1)) was witnessed for all the rhenium dipyrrinates. Triplet emission was reflected in the efficient singlet oxygen generation yields (phi approximate to 0.75-0.98) along with the distinct photo-stability. Density functional theory (DFT) calculations revealed that the electron density is spread over the dipyrrin unit in most complexes. Rhenium dipyrrinate having a phenothiazine substituent exhibited the smallest HOMO-LUMO band gap (2.820 eV) among all Re-complexes..
39. Jayaprakash Ajay, Sriram Shirisha, Masatoshi Ishida, Kosuke Ito, Shigeki Mori, Hiroyuki Furuta, Sabapathi Gokulnath, Planar Antiaromatic Core-Modified 24 pi Hexaphyrin( and 32 pi Octaphyrin( Bearing Alternate Hybrid Diheterole Units, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201805861, 25, 11, 2859-2867, 2019.02, The Lewis acid catalyzed self-condensation of hybrid diheterole (furan-pyrrole and thiophene-pyrrole) precursors has afforded novel Huckel antiaromatic 24 pi hexaphyrin( and 32 pi octaphyrin( structures without beta-annulated bridges. Single-crystal X-ray diffraction analysis of the hybrid porphyrinoids (S3N3-ox and O4N4-ox) revealed a nearly planar conformation and the H-1 NMR spectra suggest the presence of paratropic ring currents. These antiaromatic macrocycles show characteristic optical features and underwent reversible two-electron reduction to Huckel aromatic 26 pi- and 34 pi-electron species, respectively, as is evident from the results of spectroscopic and theoretical studies (nucleus-independent chemical shift (NICS) and anisotropy of the current-induced density (ACID) calculations). The incorporation of hybrid diheteroles alternately into expanded porphyrin skeletons provides a novel approach to the fine-tuning of the electronic structures of planar antiaromatic macrocycles..
40. Akihide Nishiyama, Masaya Fukuda, Shigeki Mori, Ko Furukawa, Heike Fliegl, Hiroyuki Furuta, Soji Shimizu, Rational Synthesis of Antiaromatic 5,15-Dioxaporphyrin and Oxidation into beta,beta-Linked Dimers, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201804648, 57, 31, 9728-9733, 2018.07, 5,15-Dioxaporphyrin was synthesized for the first time by a nucleophilic aromatic substitution reaction of a nickel bis(,-dibromodipyrrin) complex with benzaldoxime, followed by an intramolecular annulation of the -hydroxy-substituted intermediate. This unprecedented molecule is a 20-electron antiaromatic system, in terms of Huckel's rule of aromaticity, because lone pair electrons of oxygen atoms are incorporated into the 18-electron conjugated system of the porphyrin. A theoretical analysis based on the gauge-including magnetically induced current method confirmed its antiaromaticity and a dominant inner ring pathway for the ring current. The unique reactivity of 5,15-dioxaporphyrin forming a ,-linked dimer upon oxidation was also revealed..
41. Yogesh Kumar Maurya, Katsuya Noda, Kazuhisa Yamasumi, Shigeki Mori, Tomoki Uchiyama, Kazutaka Kamitani, Tomoyasu Hirai, Kakeru Ninomiya, Maiko Nishibori, Yuta Hori, Yoshihito Shiota, Kazunari Yoshizawa, Masatoshi Ishida, Hiroyuki Furuta, Ground-State Copper(III) Stabilized by N-Confused/N-Linked Corroles: Synthesis, Characterization, and Redox Reactivity, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/jacs.8b01876, 140, 22, 6883-6892, 2018.06, Stable square planar organocopper(III) complexes (CuNCC2, CuNCC4, and CuBN) supported by carbacorrolebased tetradentate macrocyclic ligands with NNNC coordination cores were synthesized, and their structures were elucidated by spectroscopic means including X-ray crystallographic analysis. On the basis of their distinct planar structures, X-ray absorption/photoelectron spectroscopic features, and temperature-independent diamagnetic nature, these organocopper complexes can be preferably considered as novel organocopper(III) species. The remarkable stability of the high-valent Cu(III) states of the complexes stems from the closed-shell electronic structure derived from the peculiar NNNC coordination of the corrolemodified frameworks, which contrasts with the redox-noninnocent radical nature of regular corrole copper(II) complexes with an NNNN core. The proposed structure was supported by DFT (B3LYP) calculations. Furthermore, a pi-laminated dimer architecture linked through the inner carbons was obtained from the one-electron oxidation of CuNCC4. We envisage that the precise manipulation of the molecular orbital energies and redox profiles of these organometallic corrole complexes could eventually lead to the isolation of yet unexplored high-valent metal species and the development of their organometallic reactions..
42. Saki Inuzuka, Hitoshi Kakizawa, Kei-ichiro Nishimura, Takuto Naito, Katsushi Miyazaki, Hiroyuki Furuta, Shigeyoshi Matsumura, Yoshiya Ikawa, Recognition of cyclic-di-GMP by a riboswitch conducts translational repression through masking the ribosome-binding site distant from the aptamer domain, GENES TO CELLS, 10.1111/gtc.12586, 23, 6, 435-447, 2018.06, The riboswitch is a class of RNA-based gene regulatory machinery that is dependent on recognition of its target ligand by RNA tertiary structures. Ligand recognition is achieved by the aptamer domain, and ligand-dependent structural changes of the expression platform then usually mediate termination of transcription or translational initiation. Ligand-dependent structural changes of the aptamer domain and expression platform have been reported for several riboswitches with short (<40 nucleotides) expression platforms. In this study, we characterized structural changes of the Vc2 c-di-GMP riboswitch that represses translation of downstream open reading frames in a ligand-dependent manner. The Vc2 riboswitch has a long (97 nucleotides) expression platform, but its structure and function are largely unknown. Through mutational analysis and chemical probing, we identified its secondary structures that are possibly responsible for switch-OFF and switch-ON states of translational initiation..
43. Takaaki Yamamoto, Koki Mitsuno, Shigeki Mori, Shuhei Itoyama, Yoshihito Shiota, Kazunari Yoshizawa, Masatoshi Ishida, Hiroyuki Furuta, Two Discrete RuCp* (Cp* = Pentamethylcyclopentadienyl) Binding Modes of N-Confused Porphyrins: Peripheral pi Complex and Sitting Atop Ruthenocenophane Complex by Skeletal Transformation, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201801237, 24, 26, 6742-6746, 2018.05, Complexation of a RuCp* cation with N-confused tetraarylporphyrins (NCPs) forms directly bound ruthenium(II) pentamethylcyclopentadienyl (Cp*) pi-Complex on a specific meso-aryl group (e.g., phenyl) neighboring peripheral imino nitrogen of NCPs in high yields. In contrast, in the case of NCPs bearing bulky meso-substituents (e.g., 3,5-di-tert-butylphenyl), new ruthenocenophane-like complex embedded on an N-confused calix[4]-phyrin was formed through multiple C-H bond activation of methyl groups of Cp* ligand. The mechanistic insight into the formation of the ruthenocenophane was derived from DFT calculations..
44. Yutaka Hisamune, Taeyeon Kim, Keiichi Nishimura, Masatoshi Ishida, Motoki Toganoh, Shigeki Mori, Dongho Kim, Hiroyuki Furuta, Switch-ON Near IR Fluorescent Dye Upon Protonation: Helically Twisted Bis(Boron Difluoride) Complex of -Extended Corrorin, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201705516, 24, 18, 4628-4634, 2018.03, A novel helically twisted -extended corrorin derivative having two boron dipyrrin (BODIPY) moieties at the periphery, a BODIPY DYEmer (6-BF2) cross-bridged with -conjugated dipyrrinylidene unit, was synthesized and characterized. The neutral 6-BF2 is nonfluorescent due to the internal photoinduced charge transfer (CT) character in the excited state as inferred from the femtosecond transient absorption spectroscopy. However, upon protonation, the CT process is suppressed and the species H6-BF2+ becomes near infrared (IR) emissive. With the aid of rigid helical conformations in 6-BF2, the helical isomers (P- and M-forms) were resolved and their chiroptical property was investigated. The distinct circular dichroism (CD) spectral changes of the enantiomers were observed in the presence of acids, which demonstrates that 6-BF2 can be utilized for potential acid-responsive chiroptical materials..
45. Takaaki Miyazaki, Takaaki Yamamoto, Shunichi Mashita, Yuya Deguchi, Kazuki Fukuyama, Masatoshi Ishida, Shigeki Mori, Hiroyuki Furuta, N-Confused Porphyrin Metal Complexes with an Axial Pyridine Directly Tethered from an Inner Carbon
A Bioinspired Ligand as a Versatile Platform for Catalysis, European Journal of Inorganic Chemistry, 10.1002/ejic.201701494, 2018, 2, 203-207, 2018.01, Bioinspired pentadentate ligand N-confused porphyrin (NCP) bearing a 2-mercaptopyridine group and its RuII and CoIII complexes were synthesized. Their structures were revealed by single-crystal X-ray crystallographic analysis. Installation of an axial thiopyridine ligand shifts the redox potentials negatively and enhances the catalytic activity largely, which was demonstrated in the cyclopropanation reaction using the Co complex..
46. Takaaki Yamamoto, Koki Mitsuno, Shigeki Mori, Shuhei Itoyama, Yoshihito Shiota, Kazunari Yoshizawa, Masatoshi Ishida, Hiroyuki Furuta, Two Discrete RuCp* (Cp*=Pentamethylcyclopentadienyl) Binding Modes of N-Confused Porphyrins
Peripheral π Complex and Sitting Atop Ruthenocenophane Complex by Skeletal Transformation, Chemistry - A European Journal, 10.1002/chem.201801237, 2018.01, Complexation of a RuCp* cation with N-confused tetraarylporphyrins (NCPs) forms directly bound ruthenium(II) pentamethylcyclopentadienyl (Cp*) π-complex on a specific meso-aryl group (e.g., phenyl) neighboring peripheral imino nitrogen of NCPs in high yields. In contrast, in the case of NCPs bearing bulky meso-substituents (e.g., 3,5-di-tert-butylphenyl), new ruthenocenophane-like complex embedded on an N-confused calix[4]phyrin was formed through multiple C-H bond activation of methyl groups of Cp* ligand. The mechanistic insight into the formation of the ruthenocenophane was derived from DFT calculations..
47. Yuto Kage, Shigeki Mori, Marina Ide, Akinori Saeki, Hiroyuki Furuta, Soji Shimizu, Blackening of aza-BODIPY analogues by simple dimerization: panchromatic absorption of a pyrrolopyrrole aza-BODIPY dimer, MATERIALS CHEMISTRY FRONTIERS, 10.1039/c7qm00438a, 2, 1, 112-120, 2018.01, Dimerization of the so-called pyrrolopyrrole aza-BODIPY, which is a new class of aza-BODIPY analogues exhibiting intense absorption and emission in the visible (Vis) and near infrared (NIR) region, via a bithienyl linkage led to the creation of a novel black dye with dual emission and panchromatic absorption properties in the Vis/NIR region. The role of the linkage in the dye was unambiguously elucidated by comparison of the optical properties with those of its biphenyl-linked counterpart..
48. Takaaki Miyazaki, Takaaki Yamamoto, Shunichi Mashita, Yuya Deguchi, Kazuki Fukuyama, Masatoshi Ishida, Shigeki Mori, Hiroyuki Furuta, N-Confused Porphyrin Metal Complexes with an Axial Pyridine Directly Tethered from an Inner Carbon: A Bioinspired Ligand as a Versatile Platform for Catalysis, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, 10.1002/ejic.201701494, 2, 203-207, 2018.01, Bioinspired pentadentate ligand N-confused porphyrin (NCP) bearing a 2-mercaptopyridine group and its Ru-II and Co-III complexes were synthesized. Their structures were revealed by single-crystal X-ray crystallographic analysis. Installation of an axial thiopyridine ligand shifts the redox potentials negatively and enhances the catalytic activity largely, which was demonstrated in the cyclopropanation reaction using the Co complex..
49. Kazuhisa Yamasumi, Keiichi Nishimura, Yutaka Hisamune, Yusuke Nagae, Tomoki Uchiyama, Kazutaka Kamitani, Tomoyasu Hirai, Maiko Nishibori, Shigeki Mori, Satoru Karasawa, Tatsuhisa Kato, Ko Furukawa, Masatoshi Ishida, Hiroyuki Furuta, Bis-Copper(II)/pi-Radical Multi-Heterospin System with Non-innocent Doubly N-Confused Dioxohexaphyrin( Ligand, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201704321, 23, 61, 15322-15326, 2017.11, A contracted doubly N-confused dioxohexaphyrin( complex consisting of two paramagnetic copper metals and open-shell pi-radical ligand was synthesized as a new multi-heterospin motif. X-ray spectroscopy supported the divalent character of the inner copper centers, and electron paramagnetic resonance and magnetometric studies suggested the presence of unpaired delectrons strongly antiferromagnetically coupled with pi-radicals delocalized on the macrocycle. The 25 pi non-innocent dioxohexaphyrin ligand allowed the facile interconversion between antiaromatic 24 pi and aromatic 26 pi species, respectively, upon redox reactions..
50. Koki Mitsuno, Takafumi Yoshino, Iti Gupta, Shigeki Mori, Satoru Karasawa, Masatoshi Ishida, Hiroyuki Furuta, Doubly N-Confused [36]Octaphyrin( Isomerization, Bis-Metal Coordination, and Topological Chirality, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201708253, 56, 45, 14252-14256, 2017.11, A novel [36]octaphyrin analogue embedding two Nconfused pyrrole units demonstrated unique prototropy-coupled isomerization between the Figure-of-eight and dumbbell conformers. Upon bis-metal coordination, fixation of fully pconjugated Figure-of-eight structures was achieved as referred from the X-ray crystal structure. Chirogenesis of the helical enantiomers was proved by intense circular dichroism (CD) response in the near infrared (NIR) region..
51. Hideaki Matsuo, Motoki Toganoh, Masatoshi Ishida, Shigeki Mori, Hiroyuki Furuta, Stereoretentive Ligand Exchange Reactions of N-Fused Porphyrin Ruthenium(II) Complexes, INORGANIC CHEMISTRY, 10.1021/acs.inorgchem.7b01972, 56, 22, 13842-13851, 2017.11, The ligand exchange reactions of the ruthenium(II) complex of N-fused tetraphenylporphyrin, Ru(NFp)(CO)(2)Cl (2), with various anions were investigated. The chloride ligand of the isomers 2a-c was stereoretentively exchanged with bromide (Br-), iodide (I-), and acetate (AcO-) anions in toluene at 100 degrees C, structures of which were confirmed by H-1 NMR as well as single crystal X-ray diffraction analysis. The silver (AgOAc, AgOTf) and boron (NaBPh4) reagents also afforded the corresponding stereoretentive products. On the other hand, the reaction with NaBH4 afforded the hydride complex Ru(NFp)(CO)(2)H (7) with low stereospecificity, showing a higher reactivity of 2c than other isomers. The ligand dissociation mechanism was proposed with the help of theoretical calculations on the plausible five-coordinated intermediates..
52. Poornenth Pushpanandan, Yogesh Kumar Maurya, Toshihiro Omagari, Ryuji Hirosawa, Masatoshi Ishida, Shigeki Mori, Yuhsuke Yasutake, Susumu Fukatsu, John Mack, Tebello Nyokong, Hiroyuki Furuta, Singly and Doubly N-Confused Calix[4]phyrin Organoplatinum(II) Complexes as Near-IR Triplet Sensitizers, INORGANIC CHEMISTRY, 10.1021/acs.inorgchem.7b02047, 56, 20, 12572-12580, 2017.10, Organoplatinum(II) complexes of calix[4]phyrin analogues, singly N-confused calix[4]phyrin (Pt-2), and doubly N-confused calix[4]phyrin (Pt-3), were synthesized and characterized. The explicit structures of these organoplatinum(II) complexes were elucidated by single-crystal X-ray diffraction and spectroscopic studies. The introduction of N-confused pyrrole rings to the parent calix[4]phyrin scaffold was found to have profound effects on the photophysical properties, such as the bathochromic shifts of both the absorption and phosphorescence maxima. The triplet excited state properties of these platinum complexes were analyzed by DFT calculations at the B3LYP level. The organoplatinum(II) complexes derived from the deformed scaffolds can serve as potent triplet sensitizers for singlet oxygen generation under aerobic conditions..
53. Ryuichi Sakashita, Yasutaka Oka, Hisanori Akimaru, Praseetha E. Kesavan, Masatoshi Ishida, Motoki Toganoh, Tomoya Ishizuka, Shigeki Mori, Hiroyuki Furuta, Tautomerism-Induced Cis-Trans Isomerization of Pyridylethenyl N-Confused Porphyrin, Journal of Organic Chemistry, 10.1021/acs.joc.7b01770, 82, 16, 8686-8696, 2017.08, Pyridylethenyl-substituted N-confused porphyrins (NCPs) were synthesized, and their cis-trans isomerization was studied. Among four possible isomers, trans-3H and cis-2H types of structures, of which aromaticity and absorption/emission properties differ largely, were isolated. The cis-isomer was largely stabilized by the intramolecular hydrogen bonding between the pyrrolic-NH and the pyridinic-N in the vicinity. The thermal cis-trans isomerization proceeded even at 30 °C, which was significantly accelerated by the pyridine added to the system. The kinetic studies revealed that the isomerization reaction was second-order and the activation energy of the thermal isomerization from cis to trans isomer was ΔG0cis→trans = 35.7 kcal/mol at 298 K, which is significantly smaller than that of Ni complex (42.3 kcal/mol). An intermolecular proton transfer induced cis-trans isomerization mechanism was proposed..
54. Yufeng Yang, Xin Wu, Nathalie Busschaert, Hiroyuki Furuta, Philip A. Gale, Dissecting the chloride-nitrate anion transport assay, CHEMICAL COMMUNICATIONS, 10.1039/c7cc04912a, 53, 66, 9230-9233, 2017.08, A systematic study of chloride vs. nitrate selectivity across six anion transporters has revealed a good correlation between the selectivities of their anion binding and membrane transport properties. This work reveals the limitations of the chloride-nitrate exchange assay and shows how new approaches can be used to measure anion uniport..
55. Takahiro Tanaka, Yusuke Hirata, Yuto Tominaga, Hiroyuki Furuta, Shigeyoshi Matsumura, Yoshiya Ikawa, Heterodimerization of GroupI Ribozymes Enabling Exon Recombination through Pairs of Cooperative trans-Splicing Reactions, CHEMBIOCHEM, 10.1002/cbic.201700053, 18, 16, 1659-1667, 2017.08, GroupI (GI) self-splicing ribozymes are attractive tools for biotechnology and synthetic biology. Several trans-splicing and related reactions based on GI ribozymes have been developed for the purpose of recombining their target mRNA sequences. By combining trans-splicing systems with rational modular engineering of GI ribozymes it was possible to achieve more complex editing of target RNA sequences. In this study we have developed a cooperative trans-splicing system through rational modular engineering with use of dimeric GI ribozymes derived from the Tetrahymena groupI intron ribozyme. The resulting pairs of ribozymes exhibited catalytic activity depending on their selective dimerization. Rational modular redesign as performed in this study would facilitate the development of sophisticated regulation of double or multiple trans-splicing reactions in a cooperative manner..
56. Jiaying Yan, Yufeng Yang, Masatoshi Ishida, Shigeki Mori, Bao Zhang, Yaqing Feng, Hiroyuki Furuta, Organometallic Group 11 (Cu-III, Ag-III, Au-III) Complexes of a trans-Doubly N-Confused Porphyrin: An "Expanded Imidazole" Structural Motif, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201701958, 23, 47, 11375-11384, 2017.08, Complexation of group 11 metal cations with an alpha-bis(phenylthio)-substituted trans-doubly N-confused porphyrin (trans-N2CPSPh : 4) afforded a series of square-planar trivalent organometallic complexes (i.e., Cu-H4, Ag-H4, and Au-H4). The X-ray crystal structures of the complexes revealed highly planar core geometries along with the presence of peripheral amine and imine nitrogen sites of the pyrrolic moieties. NMR, UV/Vis absorption, and magnetic circular dichroism (MCD) spectroscopies suggested the 18 pi-electron aromaticity of the complexes. The aromaticity was also fully analyzed by various theoretical methodologies such as nucleus-independent chemical shift (NICS) and anisotropic induced current density (ACID) calculations. The central metal affects the amphiprotic character of the complexes possessing both pyrrolic amino nitrogen and imino nitrogen atoms at the periphery, which was examined by the photometric titration with trifluoroacetic acid (TFA) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), respectively. The inherent acidity of the complexes was followed in the order; Cu-H4 > Au-H4 > Ag-H4 and that of basicity was Au-H4 > Ag-H4 > Cu-H4. The complexes could be considered as an "expanded imidazole" structural motif..
57. Ryuichi Sakashita, Yasutaka Oka, Hisanori Akimaru, Praseetha E. Kesavan, Masatoshi Ishida, Motoki Toganoh, Tomoya Ishizuka, Shigeki Mori, Hiroyuki Furuta, Tautomerism-Induced Cis-Trans Isomerization of Pyridylethenyl N-Confused Porphyrin, JOURNAL OF ORGANIC CHEMISTRY, 10.1021/acs.joc.7b01770, 82, 16, 8686-8696, 2017.08, Pyridylethenyl-substituted N-confused porphyrins (NCPs) were synthesized, and their cis-trans isomerization was studied. Among four possible isomers, trans-3H and cis-2H types of structures, of which aromaticity and absorption/emission properties differ largely, were isolated. The cis-isomer was largely stabilized by the intramolecular hydrogen bonding between the pyrrolic-NH and the pyridinic-N in the vicinity. The thermal cis-trans isomerization proceeded even at 30 degrees C, which was significantly accelerated by the pyridine added to the system. The kinetic studies revealed that the isomerization reaction was second-order and the activation energy of the thermal isomerization from cis to trans isomer was Delta G(0)(cis -> trans)(double dagger) = 35.7 kcal/mol at 298 K, which is significantly smaller than that of Ni complex (42.3 kcal/mol). An intermolecular proton transfer induced cis-trans isomerization mechanism was proposed..
58. Yufeng Yang, Ryuichi Sakashita, Kazuhisa Yamasumi, Masatoshi Ishida, Teppei Yamada, Hiroyuki Furuta, Zirconium-based Metal-Organic Frameworks with N-Confused Porphyrins: Synthesis, Structures, and Optical Properties, CHEMISTRY LETTERS, 10.1246/cl.170461, 46, 8, 1230-1232, 2017.08, Metal-organic frameworks (MOFs) composed of zirconium (Zr-6) and N-confused porphyrins (NCPs) were synthesized. The cubic structures with ftw topology were determined by powder X-ray diffraction and microscopic analyses. These complexes represent high chemical stability toward various pH ranges and NIR absorption/emission derived from the NCP moieties..
59. Masamichi Tamada, Taku Iino, Yemei Wang, Marina Ide, Akinori Saeki, Hiroyuki Furuta, Nagao Kobayashi, Soji Shimizu, Facile synthesis of dimeric aza-BODIPY analogues from electron-deficient bislactams and their intriguing optical and electrochemical properties, Tetrahedron Letters, 10.1016/j.tetlet.2017.06.088, 58, 32, 3151-3154, 2017.07, Electron-deficient bislactams, isoindigo and benzodipyrrolidone, were converted into dimeric aza-BODIPY analogues by a Schiff base forming reaction. These novel aza-BODIPY analogues exhibited bathochromically-shifted absorption and anodic shifts of the reduction potentials, implying their potential application as n-type chromophores in optoelectronics..
60. Fumiya Iizuka, Yuto Kage, Nagao Kobayashi, Hiroyuki Furuta, Soji Shimizu, Phenylene-Bridged Expanded Porphyrazines, CHEMPLUSCHEM, 10.1002/cplu.201600482, 82, 7, 1021-1024, 2017.07, Novel expanded porphyrazines comprising o- and p-phenylene units were synthesized from self-condensation reactions of acyclic [2+1]-type precursors prepared from 1,3-diiminoisoindoline and the corresponding phenylenediamines. Mobius and Huckel topological structures of [4+2]-type and [3+2]-type expanded porphyrazines, respectively, were elucidated by X-ray crystallography. Despite the Mobius and Huckel [4n] p-electron systems, these expanded porphyrazines are virtually nonaromatic as a result of their flexible structures in solution, which may diminish intrinsic aromaticity and antiaromaticity..
61. Sudipta Das, Haamid R. Bhat, Naresh Balsukuri, Prakash C. Jha, Yutaka Hisamune, Masatosi Ishida, Hiroyuki Furuta, Shigeki Mori, Iti Gupta, Donor-acceptor type A(2)B(2) porphyrins: synthesis, energy transfer, computational and electro-chemical studies, INORGANIC CHEMISTRY FRONTIERS, 10.1039/c6qi00558f, 4, 4, 618-638, 2017.04, A series of donor-acceptor type trans-A(2)B(2) porphyrins and their Zn(II) and Pd(II) complexes 5-13 have been synthesized and characterized by various spectroscopic techniques. The effect of the donor moieties (e.g., N-butylcarbazole, N-butylphenothiazine, and triphenylamine) on the spectroscopic properties of the porphyrins has been studied. The structural changes indeed affected the optical and electro-chemical properties of these porphyrins. Higher energy shifts of the Soret bands were observed for porphyrins upon varying the donor moieties. The electrochemical studies of all the derivatives indicated increased interactions between the donor groups and the porphyrin core, which in turn are reflected in the anodic shifts in their reduction potentials. Both steady-state and time-resolved fluorescence studies revealed effective energy transfer (EET; up to 87%) from donor groups to the porphyrin core in the porphyrins, 5-10. The palladium(II) porphyrin complexes, 11-13, showed characteristic phosphorescence in the near IR region. Density functional theory (DFT) studies support the presence of donor-acceptor interaction between the porphyrin core and the meso-substituents in the dyads. Density functional theory (DFT) and time dependent-density functional theory (TD-DFT) studies showed that in 5, 8 and 11, the transitions are of pi -> pi(star) type; whereas in the other molecules viz. 6, 7, 9, 10, 12 and 13 intramolecular charge transfer (ICT) is involved in all the respective highest intensity absorption transitions..
62. Jonathan L. Sessler, Zeev Gross, Hiroyuki Furuta, Introduction: Expanded, Contracted, and Isomeric Porphyrins, CHEMICAL REVIEWS, 10.1021/acs.chemrev.7b00036, 117, 4, 2201-2202, 2017.02.
63. Airi Furukawa, Takahiro Tanaka, Hiroyuki Furuta, Shigeyoshi Matsumura, Yoshiya Ikawa, Use of a fluorescent aptamer RNA as an exonic sequence to analyze self-splicing ability of a group i intron from structured RNAs, Biology, 10.3390/biology5040043, 5, 4, 43-43, 2016.12, Group I self-splicing intron constitutes an important class of functional RNA molecules that can promote chemical transformation. Although the fundamental mechanism of the auto-excision from its precursor RNA has been established, convenient assay systems for its splicing activity are still useful for a further understanding of its detailed mechanism and of its application. Because some host RNA sequences, to which group I introns inserted form stable three-dimensional (3D) structures, the effects of the 3D structures of exonic elements on the splicing efficiency of group I introns are important but not a fully investigated issue. We developed an assay system for group I intron self-splicing by employing a fluorescent aptamer RNA (spinach RNA) as a model exonic sequence inserted by the Tetrahymena group I intron. We investigated self-splicing of the intron from spinach RNA, serving as a model exonic sequence with a 3D structure..
64. Furukawa, A, Tanaka, T, Furuta, H, Matsumura, S, Ikawa, Y, Use of a Fluorescent Aptamer RNA as an Exonic Sequence to Analyze Self-Splicing Ability of a Group I Intron from Structured RNAs , Biology, 10.3390/biology5040043, 5, 43-43, 2016.11.
65. Masatoshi Ishida, Toshihiro Omagari, Ryuji Hirosawa, Keisuke Jono, Young Mo Sung, Yuhsuke Yasutake, Hidemitsu Uno, Motoki Toganoh, Hajime Nakanotani, Susumu Fukatsu, Dongho Kim, Hiroyuki Furuta, Boron Difluoride Complexes of Expanded N-Confused Calix[n]phyrins That Demonstrate Unique Luminescent and Lasing Properties, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201606246, 55, 39, 12045-12049, 2016.09, Complexation of novel multiply N-confused expanded calix[n]phyrins with boron difluoride afforded a new class of cyclic BODIPY (boron-dipyrromethene) arrays. The structures of circularly arranged BODIPY subunits linked in an N-confused fashion give rise to such photophysical properties unique to the macrocycles as red-shifted emission wavelengths along with apparent large Stokes shifts, long emission lifetimes, and solid-state lasing. The DFT calculations support the size-dependent excited-state dynamics of the macrocycles..
66. Saki Inuzuka, Kei-Ichiro Nishimura, Hitoshi Kakizawa, Yuki Fujita, Hiroyuki Furuta, Shigeyoshi Matsumura, Yoshiya Ikawa, Mutational analysis of structural elements in a class-I cyclic di-GMP riboswitch to elucidate its regulatory mechanism, JOURNAL OF BIOCHEMISTRY, 10.1093/jb/mvw026, 160, 3, 153-162, 2016.09, The Vc2 riboswitch possesses an aptamer domain belonging to the class-I c-di-GMP riboswitch family. This domain has been analysed and the molecular mechanism by which it recognizes the c-di-GMP ligand has been elucidated. On the other hand, the regulatory mechanism of the full-length Vc2 riboswitch to control its downstream open reading frame (ORF) remains largely unknown. In this study, we performed in vivo reporter assays and in vitro biochemical analyses of the full-length riboswitch and its aptamer domain. We evaluated the results of in vivo and in vitro analyses to elucidate the regulatory mechanism of the Vc2 riboswitch. The present results suggest that recognition of c-di-GMP ligand by the Vc2 riboswitch aptamer domain downregulates expression of its downstream ORF primarily at the translational level..
67. Shiina, Y.; Karasaki, H.; Mori, S.; Kobayashi, N.; Furuta, H.; Shimizu, S. , A Novel Isoindole-Containing Polyaromatic Hydrocarbon Unexpectedly Formed during the Synthesis of Meso-2,6-Dichlorophenyl-Substituted Tribenzosubporphyrin, J. Porphyrin Phthalocyanines,, 2016.08.
68. Ikawa, Y.; Katsumata, S.; Sakashita, R.; Sato, S.; Takenaka, S.; Furuta, H. , Water-Soluble Porphyrinoids as G-Quadruplex Binders and Telomerase Inhibitors , J. Porphyrins Phthalocyanines ,, 2016.08.
69. Tanaka, Takahiro, Matsumura, Shigeyoshi, Furuta, Hiroyuki, Ikawa, Yoshiya, Tecto-GIRz: Engineered Group I Ribozyme the Catalytic Ability of Which Can Be Controlled by Self-Dimerization, CHEMBIOCHEM, 10.1002/cbic.201600190, 17, 15, 1448-1455, 2016.08.
70. Yuta Shiina, Hideaki Karasaki, Shigeki Mori, Nagao Kobayashi, Hiroyuki Furuta, Soji Shimizu, A novel isoindole-containing polyaromatic hydrocarbon unexpectedly formed during the synthesis of meso-2,6-dichlorophenyl-substituted tribenzosubporphyrin, JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 10.1142/S1088424616500541, 20, 8-11, 1049-1054, 2016.08, A novel isoindole-containing polyaromatic hydrocarbon was unexpectedly formed during the synthesis of meso-2,6-dichlorophenyl-substituted tribenzosubporphyrin from a reaction of phthalimide and 2,6-dichlorophenylacetic acid in the presence of boric acid. Due to the highly annulated structure, this molecule exhibited blue color in solution, which was theoretically well reproduced by the HOMO-LUMO transitions based on the time-dependent DFT calculation. In this manuscript, the synthesis and properties of this polyaromatic hydrocarbon and meso-2,6-dichlorophenyl-substituted tribenzosubporphyrin are reported..
71. Takahiro Tanaka, Shigeyoshi Matsumura, Hiroyuki Furuta, Yoshiya Ikawa, Tecto-GIRz: Engineered Group I Ribozyme the Catalytic Ability of Which Can Be Controlled by Self-Dimerization, CHEMBIOCHEM, 10.1002/cbic.201600190, 17, 15, 1448-1455, 2016.08, RNA is a promising biomaterial for self-assembly of nano-sized structures with a wide range of applications in nanotechnology and synthetic biology. Several RNA-based nanostructures have been reported, but most are unrelated to intracellular RNA, which possesses modular structures that are sufficiently large and complex to serve as catalysts to promote sophisticated chemical reactions. In this study, we designed dimeric RNA structures based on the Tetrahymena group I ribozyme. The resulting dimeric RNAs (tecto group I ribozyme; tecto-GIRz) exhibit catalytic ability that depended on controlled dimerization, by which a pair of ribozymes can be activated to perform cleavage and splicing reactions of two distinct substrates. Modular redesign of complex RNA structures affords large ribozymes for use as modules in RNA nanotechnology and RNA synthetic biology..
72. Yoshiya Ikawa, Sho Katsumata, Ryuichi Sakashita, Shinobu Sato, Shigeori Takenaka, Hiroyuki Furuta, Water-soluble porphyrinoids as G-quadruplex binders and telomerase inhibitors, JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 10.1142/S108842461650053X, 20, 8-11, 1041-1048, 2016.08, Water-soluble derivatives of three kinds of expanded porphyrins (N-fused pentaphyrin, hexaphyrin, and heptaphyrin) were synthesized and their binding ability to G-quadruplex (G4-) DNA was evaluated. The inhibitory effects on enzymatic telomere extension were also investigated together with other tetrapyrrolic porphyrinoids. While expanded porphyrins increased the melting temperature of G4-DNA more effectively than the regular porphyrins, a porphyrin isomer (N-confused porphyrin) showed the highest inhibitory effect on telomerase activity..
73. Yogesh Kumar Maurya, Takahiro Ishikawa, Yasunori Kawabe, Masatoshi Ishida, Motoki Toganoh, Shigeki Mori, Yuhsuke Yasutake, Susumu Fukatsu, Hiroyuki Furuta, Near-Infrared Phosphorescent Iridium(III) Benzonorrole Complexes Possessing Pyridine-based Axial Ligands, INORGANIC CHEMISTRY, 10.1021/acs.inorgchem.6b00853, 55, 12, 6223-6230, 2016.06, Novel near-infrared phosphorescent iridium(III) complexes based on benzo-annulated N-linked corrole analogue (termed as benzonorrole) were synthesized. The structures of the complexes revealed octahedral coordination geometries involving an organometallic iridium-carbon bond with two external axial ligands. Interestingly, the iridium(III) complex exhibits near-infrared phosphorescence at room temperature at wavelengths beyond 900 nm. The significant redshift of the emission, as compared to the corrole congener, is originated from the ligand-centered triplet character. The fine-tuning of the photophysical properties of the complexes was achieved by introducing electron-donating and electron-withdrawing substituents on the axial pyridine ligands..
74. Shota Nakano, Yuto Kage, Hiroyuki Furuta, Nagao Kobayashi, Soji Shimizu, Pyrene-Bridged Boron Subphthalocyanine Dimers: Combination of Planar and Bowl-Shaped pi-Conjugated Systems for Creating Uniquely Curved pi-Conjugated Systems, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201600548, 22, 23, 7706-7710, 2016.06, Pyrene-bridged boron subphthalocyanine dimers were synthesized from a mixed-condensation reaction of 2,7-di-tert-butyl-4,5,9,10-tetracyanopyrene and tetrafluorophthalonitrile, and their syn and anti isomers arising from the result of connecting two bowl-shaped boron subphthalocyanine molecules were successfully separated. Expansion of the conjugated system of boron subphthalocyanine through a pyrene bridge caused a redshift of the Q band absorption relative to the parent pyrene-fused monomer, whereas combining the curved pi-conjugation of boron subphthalocyanine with the planar pi-conjugation of pyrene enabled facile embracement of C-60 molecules, owing to the enhanced concave-convex pi-pi stacking interactions..
75. Motoki Toganoh, Hideaki Matsuo, Ayumi Sato, Hiroyuki Furuta, Ruthenocene-Type Complexes of N-Fused Porphyrins, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201600813, 22, 24, 8316-8322, 2016.06, Ruthenocene-type hybrid complexes with N-fused porphyrinato ligands, [Ru(NFp)Cp] (NFp=N-fused porphyrin, Cp=cyclopentadienyl), have been prepared and characterized by NMR and UV/Vis/NIR spectroscopy, cyclovoltammetry, and X-ray crystallography. [Ru(NFp)Cp] is a common low-spin ruthenium(II)complex and shows strong aromaticity. The Ru-Cp distance (1.833 angstrom) in [Ru(NFp)Cp] is comparable to that in [RuCp2] (1.840 angstrom). DFT calculations on [Ru(NFp)Cp] showed the unequivocal contribution of the RuCp moiety as well as the NFp moiety to both the HOMO and LUMO, constructing a three-dimensional d-pi conjugated system. The HOMO-LUMO gaps of [Ru(NFp)Cp] are insensitive to the substituents on the NFp ligand, which is illustrated spectroscopically as well as theoretically. This is in sharp contrast to the ligand precursor, the N-fused porphyrin, in which the HOMO-LUMO gap is affected by substituents in a similar manner to standard porphyrins and related macrocycles..
76. Jung-Ho Hong, Adil S. Aslam, Masatoshi Ishida, Shigeki Mori, Hiroyuki Furuta, Dong-Gyu Cho, 2-(Naphthalen-1-yl)thiophene as a New Motif for Porphyrinoids: Meso-Fused Carbaporphyrin, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/jacs.6b01063, 138, 15, 4992-4995, 2016.04, The first synthesis of meso-fused carbaporphyrin via a premodification method was accomplished by substituting two pyrrole moieties and one meso-carbon with 2-(naphthalen-1-yl)thiophene. The obtained global pi-conjugation pathway of the macrocycle noticeably disturbs the 10 pi local aromaticity of naphthalene, and its aromatic nature was supported NMR spectroscopy together with nucleus-independent chemical shift, anisotropy of the induced current density, and harmonic oscillator stabilization energy calculations. In addition, the meso-fused carbaporphyrin also allowed the formation of a square planar Pd-II complex..
77. Abhijit Mallick, Juwon Oh, Dongho Kim, Masatoshi Ishida, Hiroyuki Furuta, Harapriya Rath, Induced Correspondence of a Local -Aromatic Sextet in Heteroannulenes: Synthesis and Characterization, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201600380, 22, 16, 5504-5508, 2016.04, Acid-catalyzed [3+3] condensation reactions of two hitherto unknown tripyrrane moieties with pentafluorobenzaldehyde has led to the formation of new generation heteroannulene ( and mutant heteroannulene ( Inclusion of local -aromatic sextets, namely the N-methyl pyrrole rings through ,-linkages and ,-linkages, has led to the isolation of first ever heteroannulenes cross-conjugated at four points and two points respectively within the macrocycles..
78. Yong Ni, Sangsu Lee, Minjung Son, Naoki Aratani, Masatoshi Ishida, Animesh Samanta, Hiroko Yamada, Young-Tae Chang, Hiroyuki Furuta, Dongho Kim, Jishan Wu, A Diradical Approach towards BODIPY-Based Dyes with Intense Near-Infrared Absorption around lambda=1100 nm, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201511151, 55, 8, 2815-2819, 2016.02, A diradical approach to obtain stable organic dyes with intense absorption around lambda= 1100 nm is reported. The para- and meta-quinodimethane-bridged BODIPY dimers BD-1 and BD-2 were synthesized and were found to have a small amount of diradical character. These molecules exhibited very intense absorption at lambda= 1088 nm (epsilon= 6.65 x 10(5) m(-1)cm(-1)) and 1136 nm (epsilon= 6.44 x 10(5) m(-1)cm(-1)), respectively, together with large two-photon-absorption cross-sections. Structural isomerization induced little variation in their diradical character but distinctive differences in their physical properties. Moreover, the compounds showed a selective fluorescence turn-on response in the presence of the hydroxyl radical but not with other reactive oxygen species..
79. Miao Li, Pingchun Wei, Masatoshi Ishida, Xin Li, Mathew Savage, Rui Guo, Zhongping Ou, Sihai Yang, Hiroyuki Furuta, Yongshu Xie, Macrocyclic Transformations from Norrole to Isonorrole and an N-Confused Corrole with a Fused Hexacyclic Ring System Triggered by a Pyrrole Substituent, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201510879, 55, 9, 3063-3067, 2016.02, Three kinds of fused porphyrinoids, L2-L4, possessing different types of corrole-based frameworks were synthesized from a pyrrole-substituted corrole isomer (norrole L1). Oxidation of L1 afforded a unique N-C-meso-fused pyrrolyl isonorrole L2, involving the fusion of an auxiliary pyrrolic NH moiety with a meso-sp(3)-hybridized carbon atom. Subsequently, L2 underwent macrocycle transformations to give singly and doubly N-C-Ar-fused N-confused corroles, L3 and L4, respectively. L3 and L4 contain fused []-tetra- and []-hexacyclic structures, respectively, prepared through lateral annulation. These skeletal transformation reactions from norrole to its isomer isonorrole and finally to N-confused corrole indicate that multiply fused porphyrinoids could be readily synthesized from pyrrole-appended confused porphyrinoids..
80. Ni, Y.; Lee, S.; Son, M.; Aratani, N.; Ishida, M.; Yamada, H.; Furuta, H.; Kim, D.; Wu, J., Diradical Approach towards BODIPY Based Near-infrared Dyes with Intense Absorption around 1100 nm , Angew. Chem. Int. Ed. , 10.1002/anie.201511151, 55, 2815-2819, 2016.01.
81. Kai Zhang, Junda Zhang, Xin Li, Rui Guo, Hans Agren, Zhongping Ou, Masatoshi Ishida, Hiroyuki Furuta, Yongshu Xie, Synthesis of a Neo-Confused Octaphyrin and the Formation of Its Mononuclear Complexes, ORGANIC LETTERS, 10.1021/acs.orglett.5b02363, 17, 19, 4806-4809, 2015.10, Novel neo-confused octaphyrin( (1) was synthesized by oxidative ring closure of an octapyrrane bearing two terminal "confused" pyrroles. Crystal structures of its Zn(II) and Cu(II) complexes (2 and 3) show a figure-of-eight conformation with unique mononuclear coordination structures. Photophysical data and theoretical calculations suggest that the neo-confused octaphyrin 1 is a 34 pi electron conjugated species showing nonaromaticity. Coordination of pocopper and zinc ions results in the further narrowing of the HOMO-LUMO gaps..
82. Zhang, K.; Zhang, J.; Li, X.; Guo, R.; Agren, H.; Ou, Z.; Ishida, M.; Furuta, H.; Xie, Y., Synthesis of a Neo-Confused Octaphyrin and the Formation of Its Mononuclear Complexes, Org. Lett. , 10.1021/acs.orglett.5b02363, 17, 4806-4809, 2015.09.
83. Soji Shimizu, Ai Murayama, Takuya Haruyama, Taku Iino, Shigeki Mori, Hiroyuki Furuta, Nagao Kobayashi, Benzo[c,d]indole-Containing Aza-BODIPY Dyes: Asymmetrization-Induced Solid-State Emission and Aggregation-Induced Emission Enhancement as New Properties of a Well-Known Chromophore, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201501464, 21, 37, 12996-13003, 2015.09, A series of symmetric and asymmetric benzo[c,d]indole-containing aza boron dipyrromethene (aza-BODIPY) compounds was synthesized by a titanium tetrachloride-mediated Schiff-base formation reaction of commercially available benzo[c,d]indole-2(1H)-one and heteroaromatic amines. These aza-BODIPY analogues show different electronic structures from those of regular aza-BODIPYs, with hypsochromic shifts of the main absorption compared to their BODIPY counterparts. In addition to the intense fluorescence in solution, asymmetric compounds exhibited solid-state fluorescence due to significant contribution of the vibronic bands to both absorption and fluorescence as well as reduced fluorescence quenching in the aggregates. Finally, aggregation-induced emission enhancement, which is rare in BODIPY chromophores, was achieved by introducing a nonconjugated moiety into the core structure..
84. Yutaka Hisamune, Keiichi Nishimura, Koji Isakari, Masatoshi Ishida, Shigeki Mori, Satoru Karasawa, Tatsuhisa Kato, Sangsu Lee, Dongho Kim, Hiroyuki Furuta, Stable pi Radical from a Contracted Doubly N-Confused Hexaphyrin by Double Palladium Metalation, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201502285, 54, 25, 7323-7327, 2015.06, A contracted doubly N-confused dioxohexaphyrin derivative served as a dinucleating metal ligand for unsymmetrical coordination. The complexation of two palladium(II) cations led to the formation of pi-radical species that were persistent in atmospheric air in the presence of moisture. Effective delocalization of an unpaired electron over the hexaphyrin backbone could contribute to the distinct chemical stability..
85. Ryuichi Sakashita, Masatoshi Ishida, Hiroyuki Furuta, Spectroscopic and Theoretical Studies of Acid-Base Behaviors of N-Confused Porphyrins: Effects of meso-Aryl Substituents, JOURNAL OF PHYSICAL CHEMISTRY A, 10.1021/jp512229k, 119, 6, 1013-1022, 2015.02, The acid-base properties of a series of meso-aryl-substituted N-confused porphyrins (NCPs) were examined in aqueous sodium dodecyl sulfate (SDS) micellar solutions by both spectrophotometric methods and theoretical calculations. Reflecting the unsymmetrical structure of NCP having an outward-pointing pyrrolic nitrogen atom, the first and second protonations were distinguishable in the absorption and H-1 NMR spectra, unlike for porphyrins, and the pK(3) and pK(4) values were determined discretely. The individual basicities of the NCPs were directly related to the inductive effect of para substituents on the meso-phenyl groups: A linear relationship between the pK(3) (pK(4)) and Hammett sigma(para) parameters was revealed. In the case of deprotonation, the structure of monoanionic NCP species was similarly characterized by the absorption and H-1 NMR spectra. For the second deprotonation, the pK(1) value was determined to be 11.39 for the NCP derivative with pentafluorophenyl groups. DFT calculations support the changes in electronic structures and aromaticity of the cationic and anionic species. It is demonstrated that NCPs are easily protonated and deprotonated compared to the corresponding regular congeners..
86. Arghya Basu, Motoki Kitamura, Shigeki Mori, Masatoshi Ishida, Yongshu Xie, Hiroyuki Furuta, Near-infrared luminescent Sn(IV) complexes of N-confused tetraphenylporphyrin: Effect of axial anion coordination, JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 10.1142/S1088424615500212, 19, 1-3, 361-371, 2015.01, Novel tin(IV) halo complexes of an N-confused tetraphenylporphyrin with different axial ligands have been synthesized and characterized by various spectroscopic methods including X-ray crystallographic analysis. The molecular structures of the dichloro and dibromo derivatives possess perfect octahedral geometries, which are nearly comparable to the corresponding regular porphyrin complexes. In contrast, the iodide/triiodide complex obtained by a same reaction manner, demonstrated that the tin(IV) cation is slightly displaced towards axially coordinated iodide anion, giving rise to the different electronic structure due to the tautomeric form of N-confused porphyrin ligand. These structural differences reflected to the distinct photophysical and electrochemical properties. The Sn(IV) complexes are near IR luminescent, however the unsymmetrical axial coordination of iodide and triiodide anions in the tin(IV) N-confused porphyrin complex allows, in particular, the longer emission lifetimes and a smaller singlet-triplet energy gap, which were investigated by steady-state and time-resolved spectroscopies as well as theoretical calculations..
87. Pingchun Wei, Kai Zhang, Xin Li, Deying Meng, Hans Agren, Zhongping Ou, Seikweng Ng, Hiroyuki Furuta, Yongshu Xie, Neo-Fused Hexaphyrin: A Molecular Puzzle Containing an N-Linked Pentaphyrin, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 10.1002/anie.201408307, 53, 51, 14069-14073, 2014.12, The first neo-confused hexaphyrin( was synthesized by oxidative ring closure of a hexapyrrane bearing two terminal "confused" pyrroles. The new compound displays a folded conformation with a short interpyrrolic C center dot center dot center dot N distance of 3.102 angstrom, and thus it readily underwent ring fusion to afford a neo-fused hexaphyrin with an unprecedented 5,5,5,7-tetracyclic ring structure. Furthermore, coordination of Cu-II triggered a ring opening/contracting reaction to afford a Cu-II complex of an N-linked pentaphyrin derivative. The roles of reactive N-C bonds in the porphyrinoid macrocycles were demonstrated..
88. Yoshiya Ikawa, Sho Katsumata, Ryuichi Sakashita, Hiroyuki Furuta, Spectrometric Detection of DNA by the Bis-Zn(II) Complex of a Water-soluble Doubly N-Confused Hexaphyrin, CHEMISTRY LETTERS, 10.1246/cl.140765, 43, 12, 1929-1931, 2014.12, A water-soluble derivative of meso-hexaaryl doubly N-confused hexaphyrin 1 was synthesized by appending pyridinium groups to the meso-aryl moieties of the hexapyrrolic macrocycle. Hexaphyrin 1 and its bis-Zn(II) complex 1-Zn interacted with DNA in aqueous buffer solution, which were detectable by the absorption changes and by the turn-off fluorescence response..
89. Masatoshi Ishida, Kensuke Nakahara, Ryuichi Sakashita, Tomoya Ishizuka, Motonori Watanabe, Hidemitsu Uno, Atsuhiro Osuka, Hiroyuki Furuta, N-confused phlorin: a stable dihydroporphyrin isomer containing a confused pyrrole ring, JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 10.1142/S1088424614500692, 18, 10-11, 909-918, 2014.10, Synthesis of bona fide N-confused phlorin derivatives through simple chemical reduction of N-confused porphyrin precursors using sodium borohydride, p-toluenesulfonyl hydrazide, etc. is described. Spectroscopic, X-ray diffraction analyses and DFT-assisted calculations of these species support the nonaromatic phlorin electronic structure..
90. Takahiro Tanaka, Hiroyuki Furuta, Yoshiya Ikawa, Installation of orthogonality to the interface that assembles two modular domains in the Tetrahymena group I ribozyme, JOURNAL OF BIOSCIENCE AND BIOENGINEERING, 10.1016/j.jbiosc.2013.10.008, 117, 4, 407-412, 2014.04, Two modular elements (P5abc and Delta P5) in the Tetrahymena group I ribozyme can be separated physically to generate a two-piece ribozyme derivative consisting of a separately prepared P5abc (P5 RNA) and the rest of the intron (Delta P5 RNA). Molecular recognition in the interface assembling P5 RNA and Delta P5 RNA is strong and specific, and the catalytic ability of the two-piece ribozyme is comparable to that of the parent unimolecular ribozyme. We designed alternative P14 (L5c-L2) interacting modules participating in the assembly of P5 and Delta P5 and investigated their ability in the context of complex formation of the two-piece ribozyme and in vivo splicing of the unimolecular intron ribozyme. Combined use of alternative P14 and L5b-P6 interacting modules provided robust orthogonality to the P5/Delta P5 assembly interface of the bimolecular complex. (c) 2013, The Society for Biotechnology, Japan. All rights reserved..
91. Yongshu Xie, Pingchun Wei, Xin Li, Tao Hong, Kai Zhang, Hiroyuki Furuta, Macrocycle Contraction and Expansion of a Dihydrosapphyrin Isomer, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/ja4112644, 135, 51, 19119-19122, 2013.12, Cyclization of a pentapyrrane with two terminal beta-linked pyrroles afforded a dihydrosapphyrin isomer (1) with the pyrroles linked in a unique beta,alpha-alpha,beta mode, which was rather reactive, and thus it readily underwent a ring-contracted rearrangement to a pyrrolyl norrole (2), and succeeding ring expansion to a terpyrrole-containing isosmaragdyrin analogue (4). 1, 2, and 4 contain the internal ring pathways with a minimum of 17, 15, and 16 atoms, respectively. 1, 2, and 4 are almost nonfluorescent, whereas the complex of 2 with Zn2+ shows a distinct NIR emission peak at 741 nm. The unprecedented pyrrole transformation chemistry by confusion approach is illustrated..
92. Yoshiya Ikawa, Satoshi Touden, Sho Katsumata, Hiroyuki Furuta, Colorimetric/fluorogenic detection of thiols by N-fused porphyrin in water, BIOORGANIC & MEDICINAL CHEMISTRY, 10.1016/j.bmc.2013.08.037, 21, 21, 6501-6505, 2013.11, A water-soluble derivative of N-fused porphyrin (NFP) possessing four cationic side-arms (pPyNFP) serves as a unique class of colorimetric/fluorogenic reporters that selectively react with biothiols in aquaous media to afford N-confused porphyrin (NCP) derivatives, while other nucleophilic amino acids were inert under a wide range of pH conditions. Owing to the large difference of the optical properties between NCP and NFP, the transformation enabled selective detection of biothiols in colorimetric/fluorogenic manner, especially in the near-infrared region. To the best our knowledge, this is the first example of porphyrin-based thiol detection systems that use the direct attack of thiol group on the optical reporter. (C) 2013 Elsevier Ltd. All rights reserved..
93. Junya Ishikawa, Hiroyuki Furuta, Yoshiya Ikawa, RNA Tectonics (tectoRNA) for RNA nanostructure design and its application in synthetic biology, WILEY INTERDISCIPLINARY REVIEWS-RNA, 10.1002/wrna.1185, 4, 6, 651-664, 2013.11, RNA molecules are versatile biomaterials that act not only as DNA-like genetic materials but also have diverse functions in regulation of cellular biosystems. RNA is capable of regulating gene expression by sequence-specific hybridization. This feature allows the design of RNA-based artificial gene regulators (riboregulators). RNA can also build complex two-dimensional (2D) and 3D nanostructures, which afford protein-like functions and make RNA an attractive material for nanobiotechnology. RNA tectonics is a methodology in RNA nanobiotechnology for the design and construction of RNA nanostructures/nanoobjects through controlled self-assembly of modular RNA units (tectoRNAs). RNA nanostructures designed according to the concept of RNA tectonics are also attractive as tools in synthetic biology, but in vivoRNA tectonics is still in the early stages. This review presents a summary of the achievements of RNA tectonics and its related researches in vitro, and also introduces recent developments that facilitated the use of RNA nanostructures in bacterial cells. WIREs RNA 2013, 4:651-664. doi: 10.1002/wrna.1185 For further resources related to this article, please visit the WIREs website. Conflict of interest: The authors have declared no conflicts of interest for this article..
94. Toganoh, Motoki; Furuta, Hiroyuki, Theoretical Study on the Conformation and Aromaticity of Regular and Singly N-Confused [28]Hexaphyrins, JOURNAL OF ORGANIC CHEMISTRY, 10.1021/jo401531w, 78, 18, 9317-9327, 2013.09.
95. Motoki Toganoh, Hiroyuki Furuta, Theoretical Study on the Conformation and Aromaticity of Regular and Singly N-Confused [28]Hexaphyrins, JOURNAL OF ORGANIC CHEMISTRY, 10.1021/jo401531w, 78, 18, 9317-9327, 2013.09, Structures and electronic states of regular and singly N-confused [28]hexaphyrins( were thoroughly studied with the aid of DFT calculations. To obtain systematic information, all the conceivable structures (450 structures in total) were examined. Unlike the [26]hexaphyrins( reported previously (J. Org. Chem. 2010, 75, 8213-8223), the electronic states of [28]hexaphyrins were highly affected by their conformations. The planar conformers (dumbbell, rectangular, triangular) show Huckel antiaromaticity, while the singly twisted conformers show Mobius aromaticity. Figure-eight structures correspond to the doubly twisted structures and show non-aromaticity. Disruption of annulenic circuits in singly N-confused [28]hexaphyrins caused weakening of both aromatic and antiaromatic characteristics. Relative stabilities among conformers were mainly governed by the intramolecular hydrogen bonds and secondarily affected by the steric factors. In addition, interconversion pathways among conformers were proposed on the basis of calculations on singly N-confused [28]hexaphyrins..
96. Motoki Toganoh, Hideaki Matsuo, Ayumi Sato, Yuya Hirashima, Hiroyuki Furuta, Synthesis and Isomerization of N-Fused Tetraphenylporphyrin Ruthenium(II) Complexes, INORGANIC CHEMISTRY, 10.1021/ic401314a, 52, 16, 9613-9619, 2013.08, Three possible isomers of N-fused tetraphenylporphyrin ruthenium complexes, Ru(NFTPp)Cl(CO)(2) (2a-c), were isolated and fully characterized by NMR, IR, CV, UV-vis-NIR absorption, and X-ray crystallographic analyses. Each isomer was stable at ambient conditions and isomerization among 2a-c occurred at elevated temperature both in solution and in a solid state, through the intramolecular rotational pathways. Electronic structures of 2a-c were analyzed in detail by DFT study to reveal appreciable differences in the interaction between the NFTPp ligand and the Ru-Cl moiety..
97. Junya Ishikawa, Hiroyuki Furuta, Yoshiya Ikawa, An in vitro-selected RNA receptor for the GAAC loop: modular receptor for non-GNRA-type tetraloop, NUCLEIC ACIDS RESEARCH, 10.1093/nar/gkt040, 41, 6, 3748-3759, 2013.04, Although artificial RNA motifs that can functionally replace the GNRA/receptor interaction, a class of RNA-RNA interacting motifs, were isolated from RNA libraries and used to generate designer RNA structures, receptors for non-GNRA tetraloops have not been found in nature or selected from RNA libraries. In this study, we report successful isolation of a receptor motif interacting with GAAC, a non-GNRA tetraloop, from randomized sequences embedded in a catalytic RNA. Biochemical characterization of the GAAC/receptor interacting motif within three structural contexts showed its binding affinity, selectivity and structural autonomy. The motif has binding affinity comparable with that of a GNRA/receptor, selectivity orthogonal to GNRA/receptors and structural autonomy even in a large RNA context. These features would be advantageous for usage of the motif as a building block for designer RNAs. The isolated motif can also be used as a query sequence to search for unidentified naturally occurring GANC receptor motifs..
98. Motoki Toganoh, Naoyuki Harada, Hiroyuki Furuta, Flexible coordination of hetero-scorpionate ligands composed of pyrrole/pyridines hybrid in rhenium(I) tricarbonyl complexes, POLYHEDRON, 10.1016/j.poly.2012.06.053, 52, 1153-1158, 2013.03, Rhenium(I) coordination of hetero-scorpionate ligands composed of pyrrole/pyridines hybrid with four coordination sites on a single carbon atom afforded a variety of rhenium(I) tricarbonyl complexes. X-ray analyses on the rhenium(I) complexes revealed the flexible coordination of such hetero-scorpionate ligands. Presence of an additional coordinative site adjacent to the tridentate ligands lead to a unique supramolecular complex, anion recognizing complex, and bis-metal complex. (C) 2012 Elsevier Ltd. All rights reserved..
99. Nana Isomoto, Yuri Maeda, Takahiro Tanaka, Hiroyuki Furuta, Yoshiya Ikawa, Fixation and Accumulation of Thermotolerant Catalytic Competence of a Pair of Ligase Ribozymes Through Complex Formation and Cross Ligation, JOURNAL OF MOLECULAR EVOLUTION, 10.1007/s00239-012-9536-x, 76, 1-2, 48-58, 2013.02, In the early stages of the hypothetical RNA world, some primitive RNA catalysts (ribozymes) may have emerged through self-assembly of short RNA oligomers. Although they may be unstable against temperature fluctuations and other environmental changes, ligase ribozymes (ribozymes with RNA strand-joining activity) may resolve structural instability of self-assembling RNAs by converting them to the corresponding unimolecular formats. To investigate this possibility, we constructed a model system using a cross-ligation system composed of a pair of self-assembling ligase ribozymes. Their abilities to act as catalysts, substrates, and a cross-ligation system were analyzed with or without thermal pretreatment before the reactions. A pair of self-assembling ligase ribozymes, each of which can form multiple conformations, demonstrated that thermotolerance was acquired and accumulated through complex-formation that stabilized the active forms of the bimolecular ribozymes and also cross-ligation that produced the unimolecular ribozymes..
100. Won-Young Cha, Jong Min Lim, Min-Chul Yoon, Young Mo Sung, Byung Sun Lee, Sho Katsumata, Masaaki Suzuki, Hirotaka Mori, Yoshiya Ikawa, Hiroyuki Furuta, Atsuhiro Osuka, Dongho Kim, Deprotonation-Induced Aromaticity Enhancement and New Conjugated Networks in meso-Hexakis(pentafluorophenyl)[26]hexaphyrin, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201200991, 18, 49, 15838-15844, 2012.12, meso-Hexakis(pentafluorophenyl)-substituted neutral hexaphyrin with a 26p-electronic circuit can be regarded as a real homolog of porphyrin with an 18p-electronic circuit with respect to a quite flat molecular structure and strong aromaticity. We have investigated additional aromaticity enhancement of meso-hexakis(pentafluorophenyl)[26]hexaphyrin( by deprotonation of the inner N?H groups in the macrocyclic molecular cavity to try to induce further structural planarization. Deprotonated mono- and dianions of [26]hexaphyrin display sharp B-like bands, remarkably strong fluorescence, and long-lived singlet and triplet excited-states, which indicate enhanced aromaticity. Structural, spectroscopic, and computational studies have revealed that deprotonation induces structural deformations, which lead to a change in the main conjugated p-electronic circuit and cause enhanced aromaticity..
101. Takaaki Yamamoto, Motoki Toganoh, Shigeki Mori, Hidemitsu Uno, Hiroyuki Furuta, Rhenium complexes of peripherally pi-extended N-confused porphyrins, CHEMICAL SCIENCE, 10.1039/c2sc20708g, 3, 11, 3241-3248, 2012.11, Peripherally pi-extended N-confused porphyrin rhenium complexes were synthesized by the rhenium-mediated reactions of N-confused porphyrins with 2-methyl azaarene and the structures were elucidated by X-ray crystallographic analyses. Extension of the pi-conjugation in the complexes was supported by the absorption spectra, electrochemical measurements and theoretical calculations..
102. Satoshi Touden, Yoshiya Ikawa, Ryuichi Sakashita, Motoki Toganoh, Shigeki Mori, Hiroyuki Furuta, Sulfur-assisted interconversion between N-confused porphyrin and N-fused porphyrin, TETRAHEDRON LETTERS, 10.1016/j.tetlet.2012.08.131, 53, 45, 6071-6074, 2012.11, The ring-opening reaction of N-fused tetraphenylporphyrin (NFTPP-H, 2) to C3-substituted N-confused tetraphenylporphyrin (NCTPP-S-Ar, 4) proceeded efficiently in 85-95% yields. Furthermore, removal of the C3-arylthio-substituents in 4 was achieved by the two types of desulfurization reactions. The Ni2B-mediated desulfurization afforded C3-free N-confused tetraphenylporphyrin (NCTPP-H, 1) whereas the radical-mediated desulfurization with (n-Bu)(3)Sn-H and AIBN promoted the ring-fusion to afford 2. (C) 2012 Elsevier Ltd. All rights reserved..
103. Yamashita Kohei, Tanaka Takahiro, Hiroyuki Furuta, Ikawa Yoshiya, TectoRNP: self-assembling RNAs with peptide recognition motifs as templates for chemical peptide ligation, JOURNAL OF PEPTIDE SCIENCE, 10.1002/psc.2444, 18, 10, 635-642, 2012.10.
104. Kohei Yamashita, Takahiro Tanaka, Hiroyuki Furuta, Yoshiya Ikawa, TectoRNP: self-assembling RNAs with peptide recognition motifs as templates for chemical peptide ligation, JOURNAL OF PEPTIDE SCIENCE, 10.1002/psc.2444, 18, 10, 635-642, 2012.10, TectoRNA, an artificial RNA with self-assembling ability, has been employed as a structural platform for RNA nanotechnology and RNA synthetic biology. In this study, tectoRNA was applied as a specific template for chemical peptide ligation. On the basis of a self-assembling tectoRNA, we designed and constructed a template RNA that facilitates peptide ligation depending on controlled dimer formation. Two RNA-binding peptides were recognized by two peptide-binding RNA motifs embedded in the template RNA, and chemical ligation was promoted because of the entropic effect of Mg2+-dependent dimerization. In a series of biochemical analyses, we determined the relationship between the structures of the tectoRNA-based templates and the extent of acceleration in peptide ligation. Copyright (c) 2012 European Peptide Society and John Wiley & Sons, Ltd..
105. Takahiro Tanaka, Hiroyuki Furuta, Ikawa Yoshiya, A two-piece derivative of a group I intron RNA as a platform for designing self-assembling RNA templates to promote peptide ligation, Journal of Nucleic Acids, 0.1155/2012/305867, 2012, 2012.08.
106. Bottom-up Construction of RNA 3D-Structures for Design and Engineering of Ribozymes/Riboswitches.
107. Motoki Toganoh, Gokulnath Sabapathi, Kawabe Yasunori, Hiroyuki Furuta, Synthesis and Reactivity of 5,10,15-Triaryl Doubly N-Confused Bilanes, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201103034, 18, 14, 4380-4391, 2012.04.
108. Motoki Toganoh, Sabapathi Gokulnath, Yasunori Kawabe, Hiroyuki Furuta, Synthesis and Reactivity of 5,10,15-Triaryl Doubly N-Confused Bilanes, CHEMISTRY-A EUROPEAN JOURNAL, 10.1002/chem.201103034, 18, 14, 4380-4391, 2012.04, A series of 5,10,15-tris(pentafluorophenyl) doubly N-confused bilanes were synthesized in a stepwise manner with the aid of sterically demanding N-protecting groups, in which the difference in reactivity between regular pyrrole and N-confused pyrrole plays a crucial role in the synthetic strategy. Some doubly N-confused bilanes were converted into porphyrinoids or a unique 2:2 copper(II) complex with a helical structure. In addition, the conformations and electronic states of the doubly N-confused bilanes were investigated theoretically, giving fruitful information about the effect of confusion on the bilane skeleton..
109. Toganoh, M.; Gokulnath, S.; Kawabe, Y.; Furuta, H. , Synthesis and Reactivity of 5,10,15-Triaryl Doubly N-Confused Bilanes , Chem. Eur. J. , 18, 4380–4391, 2012.02.
110. Ikawa, Y.; Touden, S.; Katsumata, S.; Furuta, H. , Water-soluble N-Confused Porphyrinoids for Bio-related Chemistry , G-COE J. , 2012, 5, 6–8 ., 2012.02.
111. Yuki Fujita, Takahiro Tanaka, Hiroyuki Furuta, Yoshiya Ikawa, Functional roles of a tetraloop/receptor interacting module in a cyclic di-GMP riboswitch, JOURNAL OF BIOSCIENCE AND BIOENGINEERING, 10.1016/j.jbiosc.2011.10.004, 113, 2, 141-145, 2012.02, Riboswitches are a class of structural RNAs that regulate transcription and translation through specific recognition of small molecules. Riboswitches are attractive not only as drug targets for novel antibiotics but also as modular tools for controlling gene expression. Sequence comparison of a class of riboswitches that sense cyclic di-GMP (type-I c-di-GMP riboswitches) revealed that this type of riboswitch frequently shows a GAAA loop/receptor interaction between P1 and P3 elements. In the crystal structures of a type-I c-di-GMP riboswitch from Vibrio cholerae (the Vc2 riboswitch), the GNRA loop/receptor interaction assembled P2 and P3 stems to organize a ligand-binding pocket. In this study, the functional importance of the GAAA loop-receptor interaction in the Vc2 riboswitch was examined. A series of variant Vc2 riboswitches with mutations in the GAAA loop/receptor interaction were assayed for their switching abilities. In mutants with mutations in the P2 GAAA loop, expression of the reporter gene was reduced to approximately 40% - 60% of that in the wild-type. However, mutants in which the P3 receptor motif was substituted with base pairs were as active as the wild-type. These results suggested that the GAAA loop/receptor interaction does not simply establish the RNA 3D structure but docking of P2 GAAA loop reduces the flexibility of the GAAA receptor motif in the P3 element. This mechanism was supported by a variant riboswitch bearing a theophylline aptamer module in P3 the structural rigidity of which could be modulated by the small molecule theophylline. (C) 2011, The Society for Biotechnology, Japan. All rights reserved..
112. Yoshiya Ikawa, Satoshi Touden, Sho Katsumata, Hiroyuki Furuta, Water-soluble N-Confused Porphyrinoids for Bio-related Chemistry, Science for Future Molecular Systems, 5, 6-8, 2012.02.
113. Motoki Toganoh, Hiroyuki Furuta, Blooming of confused porphyrinoids-fusion, expansion, contraction, and more confusion, CHEMICAL COMMUNICATIONS, 10.1039/c1cc14633e, 48, 7, 937-954, 2012.01, This article introduces an overview of progressively developing chemistry of N-confused porphyrin and related macrocycles. Study on confusion results in discovery of fusion and combination with expansion or contraction has provided uniquely important classes of porphyrinoids. Syntheses, properties and coordination chemistry of such porphyrinoids are briefly described. Possibilities in applications are also mentioned..
114. Ikumi Kawahara, Kaichiro Haruta, Yuta Ashihara, Daichi Yamanaka, Mituhiro Kuriyama, Naoko Toki, Yoshinori Kondo, Kenta Teruya, Junya Ishikawa, Hiroyuki Furuta, Yoshiya Ikawa, Chojiro Kojima, Yoshiyuki Tanaka, Site-specific isotope labeling of long RNA for structural and mechanistic studies, NUCLEIC ACIDS RESEARCH, 10.1093/nar/gkr951, 40, 1, 2012.01, A site-specific isotope labeling technique of long RNA molecules was established. This technique is comprised of two simple enzymatic reactions, namely a guanosine transfer reaction of group I self-splicing introns and a ligation with T4 DNA ligase. The trans-acting group I self-splicing intron with its external cofactor, 'isotopically labeled guanosine 5'-monophosphate' (5'-GMP), steadily gave a 5'-residue-labeled RNA fragment. This key reaction, in combination with a ligation of 5'-remainder non-labeled sequence, allowed us to prepare a site-specifically labeled RNA molecule in a high yield, and its production was confirmed with N-15 NMR spectroscopy. Such a site-specifically labeled RNA molecule can be used to detect a molecular interaction and to probe chemical features of catalytically/structurally important residues with NMR spectroscopy and possibly Raman spectroscopy and mass spectrometry..
115. Kohei Yamashita, Norimasa Kashiwagi, Hiroyuki Furuta, Yoshiya Ikawa, Turnover Ability of a Designed RNA Acting as a Template for Chemical Peptide Ligation, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 10.1271/bbb.110255, 75, 10, 2021-2024, 2011.10, A designed self-folding RNA possessing two peptide-recognition motifs served as a template for the chemical ligation of two RNA-binding peptides under stoichiometric conditions. In this study, we investigated the turnover ability of this template RNA in facilitation of peptide ligation and found that the RNA exhibited modest turnover ability under conditions in which its 3D structure was marginally stable..
116. Kohei YAMASHITA, Norimasa KASHIWAGI, Hiroyuki FURUTA, Yoshiya IKAWA , Turnover Ability of a Designed RNA Acting as a Template for Chemical Peptide Ligation
, Biosci. Biotechnol. Biochem, , Vol.75, , pp.2020-2024, , 2011.09.
117. Motold Toganoh, Yasunori Kawabe, Hiroyuki Furuta, C-Fused Norrole: A Fused Corrole Isomer Bearing a N,C-Linked Bipyrrole Unit, JOURNAL OF ORGANIC CHEMISTRY, 10.1021/jo2014017, 76, 18, 7618-7622, 2011.09, Oxidative cyclization of a doubly N-confused bilane afforded a N-confused N,C-linked corrole (N-confused norrole), which was readily oxidized to form a C-fused N,C-linked corrole (C-fused norrole)..
118. Jong Min Lim, Iti Gupta, Hiroyuki Furuta, Dongho Kim, Comparative photophysics of sapphyrin derivatives: effects of confused and fused pyrrole rings, JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 10.1142/S1088424611003719, 15, 9-10, 858-864, 2011.09, We have investigated the photophysical properties of [22] pi-conjugated pentapyrrolic systems, sapphyrin, N-confused and N-fused sapphyrins, with a particular focus on the effects of confused and fused pyrrole rings on their electronic structures using steady-state and time-resolved spectroscopic methods, two-photon absorption cross-section (sigma((2))) measurements and quantum mechanical calculations. The absorption spectra of N-confused and N-fused sapphyrins exhibit relatively red-shifted features compared to sapphyrin. In parallel with these spectral features, the reduced HOMO-LUMO gaps were observed in going from sapphyrin to N-fused sapphyrin. In the analysis of the anisotropy of the induced current density (AICD), N-confused and N-fused sapphyrins show that extra pi-electrons in confused and fused pyrrole rings contribute to the extension of their pi-conjugation pathways. Slightly larger two-photon absorption cross-section values of N-confused and N-fused sapphyrins (3250 and 3900 GM) than that of sapphyrin (2900 GM) also reflect an enhanced pi-conjugation effect due to bicyclic and endocyclic extensions in pi-conjugation pathways, respectively. The excited singlet and triplet state lifetimes of N-confused sapphyrin were determined to be 60 ps and 1 mu s, respectively, due to conformational change and acceleration of nonradiative decay processes, being in a sharp contrast with those of sapphyrin (2.4 ns and 13 mu s, respectively). In the case of N-fused sapphyrin, very short singlet excited-state lifetime of 5 ps was detected probably due to the excited-state NH-tautomerization process which enhances nonradiative decay processes..
119. Motoki Toganoh, Takumi Takayama, Nandy Ritesh, Nobuo Kimizuka, Hiroyuki Furuta, Synthesis and Properties of Acetylene-bridged N-Confused Porphyrin Dimers, CHEMISTRY LETTERS, 10.1246/cl.2011.1021, 40, 9, 1021-1023, 2011.09, Acetylene-bridged N-confused porphyrin (NCP) dimers were synthesized by Stille coupling reactions. Moderate electronic interaction between the NCP chromophores was observed in the inner-3H tautomers while strong interaction was observed in the inner-2H tautomers..
120. Motoki TOGANOH, Takumi TAKAYAMA, Nandy RITESH, Nobuo KIMIZUKA, Hiroyuki FURUTA , Synthesis and Properties of Acetylene-Bridged N-Confused Porphyrin Dimers
, Chem. Lett, , Vol.40, , pp.1021-1023,, 2011.07.
121. Shinya Ikeda, Motoki Toganoh, Hiroyuki Furuta, Synthesis, Reactivity, and Properties of N-Fused Porphyrin Manganese(I) Tricarbonyl Complexes, INORGANIC CHEMISTRY, 10.1021/ic2000393, 50, 13, 6029-6043, 2011.07, The reactions of N-fused tetraphenylporphyrin (NFTPP, 1a) and its 21-substituted derivatives, 21-Br-NFTPP (1b), 21-NO2-NFTPP (1c), and 21-Bz-NFTPP (1d), with Mn(CO)(5)Br gave the manganese(I) tricarbonyl complexes bearing N-fused tetraphenylporphyrinato ligands (2a-d), respectively, in 46-99% yields. The complexes were characterized by mass, IR, H-1 and C-13 NMR spectroscopy, and the final structural proof was evident from the X-ray crystallographic analysis for 2a. The crystals of 2a center dot CH2Cl2 belong to the monoclinic space group P2(1)/n (#14), with a = 15.007(2) angstrom, b = 12.5455(19) angstrom, c = 21.150(3) angstrom, beta = 102.227(4)degrees, and Z = 4. The lengths (angstrom) of three manganese nitrogen and three manganese-carbon bonds are inequivalent respectively [Mn - N(2), 2.007(2); Mn - N(23), 2.033(2); Mn - N(24), 1.988(3); and Mn - CO, 1.798(4), 1.804(4), 1.841(3)] reflecting the asymmetric structure of the NFp ligand. The aromatic substitution reactions of 2a, such as nitration, formylation, and chlorination, proceeded without a loss of center metal to give the corresponding 21-nitro (2c), 21-formyl (2e), and 21-chloro (2f) derivatives, regioselectively. In the electrochemical measurements of 2, one reversible oxidation and two reversible reduction waves were observed. The redox potentials of 2 indicate the narrow energy gaps between the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO-LUMO) being consistent with the electronic absorption spectra that display the absorption edges over 1000 nm. Protonation occurred at the inner core nitrogen of 2a upon the addition of acids, which is inferred from the H-1 NMR spectra as well as theoretical calculations. By a treatment with amine N-oxides, demetalation of 2 proceeded to afford the corresponding NFP free-bases (1)..
122. Shinya IKEDA, Motoki TOGANOH, Hiroyuki FURUTA , Synthesis, Reactivity, and Properties of N-Fused Porphyrin Manganese(I)Tricarbonyl Complexes
, Inorg. Chem, , Vol.50, , pp.6029-6043,, 2011.06.
123. Junya Ishikawa, Yuki Fujita, Yuri Maeda, Hiroyuki Furuta, Yoshiya Ikawa, GNRA/receptor interacting modules: Versatile modular units for natural and artificial RNA architectures, METHODS, 10.1016/j.ymeth.2010.12.011, 54, 2, 226-238, 2011.06, Interactions between GNRA tetraloops and their receptors are found frequently as modular units in various types of naturally occurring structured RNAs. Due to their functional importance, GNRA/receptor interactions have been studied extensively with regard to their 3D structures and biochemical and biophysical properties. Artificial non-natural GNRA/receptor modules have also been generated not only to obtain a better understanding of this class of motifs in natural RNA structures but also for application of these modular units to the design and construction of artificial RNA structures that can be used as platforms to generate functional RNAs applicable for nanobiotechnology. In this review, we present a survey of structures, functions, and analyses as well as artificial generation and application of GNRA/receptor interacting modules. (C) 2010 Elsevier Inc. All rights reserved..
124. Maeda, Y.; Furuta, H.; Ikawa, Y. , Trans-Acting RNAs as Molecular Probes for Monitoring Time-Dependent Structural Change of an RNA Complex Adapting Two Structures, J. Biosci. Bioeng., in press, 2011.03.
125. Yuri Maeda, Hiroyuki Furuta, Yoshiya Ikawa, Trans-acting RNAs as molecular probes for monitoring time-dependent structural change of an RNA complex adapting two structures, JOURNAL OF BIOSCIENCE AND BIOENGINEERING, 10.1016/j.jbiosc.2010.11.007, 111, 3, 370-376, 2011.03, As dynamic structural changes are pivotal for the functions of some classes of RNA molecule, it is important to develop methods to monitor structural changes in RNA in a time-dependent manner without chemical modification. Based on previous reports that trans-acting RNAs can be used as probes for analysis and control of 3D structures of target RNAs, we applied this method to monitor time-dependent structural changes in RNA. We designed and performed a proof-of-principle study using a simple model RNA complex that adopts two different structures as a target. The time-dependent structural changes in the target RNA were successfully monitored using two trans-acting RNAs, which stably form a ternary complex with the bimolecular target RNA and act as a catalyst to join two RNA fragments of the target complex, respectively. (C) 2010, The Society for Biotechnology, Japan. All rights reserved..
126. Shinya Ikeda, Motoki Toganoh, Shanmugam Easwaramoorthi, Jong Min Lim, Dongho Kim, Hiroyuki Furuta, Synthesis and Photophysical Properties of N-Fused Tetraphenylporphyrin Derivatives: Near-Infrared Organic Dye of [18]Annulenic Compounds, JOURNAL OF ORGANIC CHEMISTRY, 10.1021/jo102128m, 75, 24, 8637-8649, 2010.12, A variety of N-fused porphyrin derivatives were prepared and their photophysical properties were investigated. Although intact N-fused tetraarylporphyrins showed almost no emission, introduction of electron-withdrawing groups such as a nitro group and a cyano group on the macrocycles caused significant refinements in their emission efficiency. Long emission wavelengths (900-1000 nm) as well as fairly large Stokes shifts (similar to 1200 cm(-1)) are exceptionally unique photophysical properties among [18]annulenic compounds, which could be rationalized by the excited state intramolecular proton transfer (ESIPT) process. Relatively weak emission quantum yields (similar to 5.0 x 10(-4)) and unusually short SI state lifetimes (similar to 13.5 ps) are in good agreement with the ESIPT process. The solvent and substituent effects on the photophysical properties are also discussed in conjunction with the theoretical studies, where the mesityl groups at the meso-positions play a unique role..
127. Motoki Toganoh, Hiroyuki Furuta, Theoretical Study on Conformation and Electronic State of Huckel-Aromatic Multiply N-Confused [26]Hexaphyrins, JOURNAL OF ORGANIC CHEMISTRY, 10.1021/jo101856h, 75, 23, 8213-8223, 2010.12, Conformations and electronic states of Huckel-aromatic regular, singly, doubly, and triply N-confused [26]hexaphyrins were investigated using density functional theory (DFT) calculations. A comparison of the molecular energies of 754 structures in all revealed that the most stable conformers depend on the degree of confusion, where ring strain and intramolecular hydrogen bonding would play a critical role. Consequently, regular and singly N-confused hexaphyrins prefer a dumbbell conformation, doubly N-confused hexaphyrin prefers a rectangular conformation, and triply N-confused hexaphyrin prefers a triangular conformation. Introduction of N-confused pyrrole rings into the hexaphyrin framework causes narrower HOMO-LUMO energy gaps, while it does not affect the NICS values or aromaticity significantly. The steric repulsion imposed by meso-aryl substituents largely affects the relative energies among the conformers..
128. Toganoh, M.; Furuta, H., Theoretical study on conformation and electronic state of Hükel-aromatic multiply N-confused [26]hexaphyrins, J. Org. Chem., in press, 2010.11.
129. Yuki Fujita, Junya Ishikawa, Hiroyuki Furuta, Yoshiya Ikawa, Generation and Development of RNA Ligase Ribozymes with Modular Architecture Through "Design and Selection", MOLECULES, 10.3390/molecules15095850, 15, 9, 5850-5865, 2010.09, In vitro selection with long random RNA libraries has been used as a powerful method to generate novel functional RNAs, although it often requires laborious structural analysis of isolated RNA molecules. Rational RNA design is an attractive alternative to avoid this laborious step, but rational design of catalytic modules is still a challenging task. A hybrid strategy of in vitro selection and rational design has been proposed. With this strategy termed "design and selection," new ribozymes can be generated through installation of catalytic modules onto RNA scaffolds with defined 3D structures. This approach, the concept of which was inspired by the modular architecture of naturally occurring ribozymes, allows prediction of the overall architectures of the resulting ribozymes, and the structural modularity of the resulting ribozymes allows modification of their structures and functions. In this review, we summarize the design, generation, properties, and engineering of four classes of ligase ribozyme generated by design and selection..
130. Motoki Toganoh, Takayoshi Hihara, Hiroyuki Furuta, N-Heterocyclic Carbene Embedded in an N-Confused Porphyrin Framework, INORGANIC CHEMISTRY, 10.1021/ic1016356, 49, 18, 8182-8184, 2010.09, A rhenium(I) complex of an N-heterocyclic carbene ligand embedded in an N-confused porphyrin core was serendipitously synthesized by the reaction of an inner-methylated N-confused porphyrin with Re-2(CO)(10)..
131. Yuki Fujita, Hiroyuki Furuta, Yoshiya Ikawa, Evolutionary optimization of a modular ligase ribozyme: a small catalytic unit and a hairpin motif masking an element that could form an inactive structure, NUCLEIC ACIDS RESEARCH, 10.1093/nar/gkq018, 38, 10, 3328-3339, 2010.06, The YFL ribozyme is an artificial ligase ribozyme isolated by a 'design and selection' strategy, in which a modular catalytic unit was generated on a rationally designed modular scaffold RNA. This ligase ribozyme has a versatile catalytic unit that accepts not only beta-nicotinamide mononucleotide (beta-NMN) but also inorganic pyrophosphate as leaving groups for template-dependent RNA ligation. Although this property is interesting from an evolutionary viewpoint regarding primitive RNA ligation/polymerization systems in the RNA world, structural analysis of the YFL ribozyme has not been continued due to apparent structural nonuniformity of its folded state. To elucidate the active structure of the YFL ribozyme, we performed in vitro evolution experiments to improve its folding ability. Biochemical and phylogenetic analyses of evolved variants indicated that the catalytic unit of the YFL ribozyme is compact and the 3' single-stranded region of the parent YFL-1 ribozyme contributes to mask an element that could form an inactive structure..
132. Junya Ishikawa, Nana Isomoto, Yuki Fujita, Hiroyuki Furuta, Yoshiya Ikawa, The transDSL Ligase Ribozyme Can Utilize Various Forms of Modules to Clamp Its Substrate and Enzyme Units, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 10.1271/bbb.90849, 74, 4, 872-874, 2010.04, TransDSL, is an RNA ligase ribozyme whose enzyme unit joins two RNA fragments constituting a substrate. The enzyme unit recognizes the substrate by means of two clamp modules. We constructed active variants by replacing the original clamp module with various types of interactions. Such flexible modularity would be advantageous in the application of this ribozyme in nanobiotechnology..
133. Motoki Toganoh, Hiroyuki Harada, Yoshiya Ikawa, Hiroyuki Furuta, Self-assembly of Zn(II) Porphyrin-1,2,3-Triazole Conjugate with Alcohol Glue, CHEMISTRY LETTERS, 10.1246/cl.2010.252, 39, 3, 252-253, 2010.03, A Zn(II) porphyrin 1,2,3-triazole conjugate (1-Zn), which can be prepared by click chemistry, afforded a unique self-assembled structure with methanol molecules as glue in the crystals and in toluene solution. The resulting assembled units form a zigzag architecture due to multipoint CH-pi interactions in the solid state..
134. Motoki Toganoh, Hiroyuki Furuta, Theoretical Study on Rotation of Pyrrole Rings in Porphyrin and N-Confused Porphyrin, JOURNAL OF PHYSICAL CHEMISTRY A, 10.1021/jp906126g, 113, 50, 13953-13963, 2009.12, Rotation of pyrrole rings in regular porphyrins and N-confused porphyrins is theoretically investigated by DFT calculations. While the inversion of the pyrrole rings in the regular porphyrins requires high activation energies (36.5-49.1 kcal/mol), the inversion of the Confused pyrrole rings in the N-confused porphyrins requires Much lower activation energies (18.1-24.5 kcal/mol). This marked difference can be explained by the intramolecular hydrogen bondings and aromatic stabilization due to the [18]annulenic Substructures, where confusion and NH tautomerism play ail important role. In both of the macrocycles, 360 degrees rotation of their pyrrole rings Would be difficult possibly due to the small cavity. Alternatively, a reaction pathway for the production of N-fused porphyrin from N-confused porphyrin is obtained, which is consistent with the experimental observation..
135. Norimasa Kashiwagi, Kohei Yamashita, Hiroyuki Furuta, Yoshiya Ikawa, Designed RNAs with Two Peptide-Binding Units as Artificial Templates for Native Chemical Ligation of RNA-Binding Peptides, ChemBioChem, 10.1002/cbic.200900392, 10, 17, 2745-2752, 10, 2745-2752., 2009.11, The template effect plays important roles not only in modern synthetic and enzymatic catalysis but also in the ancient "RNA polypeptide (RNP) world which has been postulated to be a crucial stage in the origin of life. To mimic primitive template catalysis of peptide ligations by RNAs, we previously reported the design and synthesis of a ternary RNP complex in which the ligation of two peptides was significantly facilitated by a template RNA with two peptide binding units. However, RNA molecules also promoted the ligation reaction in a nonspecific manner through electrostatic interactions between RNA and basic peptides. In this study, we suppressed this effect by reducing the length of the original template derived from the Tetrahymena intron RNA. This modification however decreased the template ability for the specific reaction. As an alternative RNA that was as effective as the original template, we found that a self dimerizing RNA was a promising template for peptide ligation without a nonspecific effect..
136. Toganoh, M.; Furuta, H. , Theoretical Study on Rotation of Pyrrole Rings in Porphyrin and N-Confused Porphyrin, J. Phys. Chem. A., 113, 13953-13963., 2009.10.
137. Junya Ishikawa, Shigeyoshi Matsumura, Luc Jaeger, Tan Inoue, Hiroyuki Furuta, Yoshiya Ikawa, Rational optimization of the DSL ligase ribozyme with GNRA/receptor interacting modules, ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 10.1016/, 490, 2, 163-170, 2009.10, The DSL ribozyme is a class of artificial ligase ribozymes with a highly modular architecture, which catalyzes template-directed RNA ligation on a helical substrate module that can be either covalently connected (cis-DSL) or physically separated (trans-DSL) from the catalytic module. Substrate recognition by the catalytic module is promoted by one or two sets of GNRA/receptor interactions acting as clamps in the cis or trans configurations, respectively. In this study, we have rationally designed and analyzed the catalytic and self-assembly properties of several trans-DSL ribozymes with different sets of natural and artificial GNRA-receptor clamps. Two variants newly designed in this study showed significantly enhanced catalytic properties with respect of the original trans-DSL construct. While this work allows dissection of the turnover and catalytic properties of the trans-DSL ribozyme, it also emphasizes the remarkable modularity of RNA tertiary structure for nano-construction of complex functions. (C) 2009 Elsevier Inc. All rights reserved..
138. Ikawa, Y.; Harada, H.; Toganoh, M.; Furuta, H. , Synthesis and Protonation Behavior of A Water-Soluble N-Fused Porphyrin: Conjugation with An Oligoarginine by Click Chemistry, Bioorg. Med. Chem. Lett. , 19, 2448-2452., 2009.05.
139. Fujita, Y.; Furuta, H.; Ikawa, Y., Tailoring RNA Modular Units on A Common Scaffold: A Modular Ribozyme with A Catalytic Unit for b-Nicotinamide Mononucleotide-activated RNA Ligation, RNA, 15, 877−888, 2009.05.
140. Norimasa Kashiwagi, Hiroyuki Furuta, Yoshiya Ikawa, Primitive templated catalysis of a peptide ligation by self-folding RNAs, NUCLEIC ACIDS RESEARCH, 10.1093/nar/gkp111, 37, 8, 2574-2583, 2009.05, RNApolypeptide complexes (RNPs), which play various roles in extant biological systems, have been suggested to have been important in the early stages of the molecular evolution of life. At a certain developmental stage of ancient RNPs, their RNA and polypeptide components have been proposed to evolve in a reciprocal manner to establish highly elaborate structures and functions. We have constructed a simple model system, from which a cooperative evolution system of RNA and polypeptide components could be developed. Based on the observation that several RNAs modestly accelerated the chemical ligation of the two basic peptides. We have designed an RNA molecule possessing two peptide binding sites that capture the two peptides. This designed RNA can also accelerate the peptide ligation. The resulting ligated peptide, which has two RNA-binding sites, can in turn function as a trans-acting factor that enhances the endonuclease activity catalyzed by the designed RNA..
141. Yoshiya Ikawa, Hiroyuki Harada, Motoki Toganoh, Hiroyuki Furuta, Synthesis and protonation behavior of a water-soluble N-fused porphyrin: Conjugation with an oligoarginine by click chemistry, BIOORGANIC & MEDICINAL CHEMISTRY LETTERS, 10.1016/j.bmcl.2009.03.066, 19, 9, 2448-2452, 2009.05, A water-soluble derivative of N-fused porphyrin (NFP) possessing a nona-arginine (R9) peptide tail was synthesized for the first time by a Cu(I)-catalyzed azide-alkyne 'click' reaction. In aqueous solution, at pH 8, the conjugated molecule (NFP-R9) exists as free base and protonated below pH < 6.5 to form monoprotonated species dominantly, and diprotonated one below pH < 2.3, while such clear two-step protonation behavior was not observed in the DMF solution. (c) 2009 Elsevier Ltd. All rights reserved..
142. Yuki Fujita, Hiroyuki Furuta, Yoshiya Ikawa, Tailoring RNA modular units on a common scaffold: A modular ribozyme with a catalytic unit for beta-nicotinamide mononucleotide-activated RNA ligation, RNA, 10.1261/rna.1461309, 15, 5, 877-888, 2009.05, A novel ribozyme that accelerates the ligation of beta-nicotinamide mononucleotide (beta-NMN)-activated RNA fragments was isolated and characterized. This artificial ligase ribozyme (YFL ribozyme) was isolated by a "design and selection'' strategy, in which a modular catalytic unit was generated on a rationally designed modular scaffold RNA. Biochemical analyses of the YFL ribozyme revealed that it catalyzes RNA ligation in a template-dependent manner, and its activity is highly dependent on its architecture, which consists of a modular scaffold and a catalytic unit. As the design and selection strategy was used for generation of DSL ribozyme, isolation of the YFL ribozyme indicated the versatility of this strategy for generation of functional RNAs with modular architectures. The catalytic unit of the YFL ribozyme accepts not only beta-NMN but also inorganic pyrophosphate and adenosine monophosphate as leaving groups for RNA ligation. This versatility of the YFL ribozyme provides novel insight into the possible roles of beta-NMN (or NADH) in the RNA world..
143. Motoki Toganoh, Takayoshi Hihara, Kentaro Yonekura, Yuichi Ishikawa, Hiroyuki Furuta, Synthesis and characterization of novel azo-embedded N-confused tetraphenylporphyrin, JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, 10.1142/S1088424609000292, 13, 2, 215-222, 2009.02, A unique class of azo porphyrin, 5,10,15,20-tetraphenyl-21-phenylazo-(2-aza-21-carbaporphyrin 1, in which an azophenyl group is embedded in N-confused porphyrin, was synthesized and characterized by H-1 NMR, C-13 NMR, UV-vis absorption, MS, and X-ray crystallographic analysis. Synthesis of 1 was achieved through a coupling reaction of 21-amino N-confused tetraphenylporphyrin with nitrosobenzene and subsequent deoxygenation of resulting azoxy derivative with a trioxo rhenium(VII) N-fused porphyrinato catalyst. The azo-conjugate molecule was exclusively obtained as a trans-isomer and no isomerization to the cis-isomer was observed under thermal or photoirradiation. The absorption spectrum of I shows a moderate red-shift due to the effective interaction between the porphyrinic pi-system and the connecting azophenyl group. Upon protonation, this effect is essentially lost as a result of removing degeneracy of LUMO and LUMO+1..
144. Toganoh, M.; Furuta, H., New Development of Porphyrin-Boron Complex, Kagaku (Chemistry), 63, 68−69, 2008.12.
145. Yoshiya Ikawa, Hiroaki Ogawa, Hiroyuki Harada, Hiroyuki Furuta, N-confused porphyrin possessing glucamine-appendants: Aggregation and acid/base properties in aqueous media, BIOORGANIC & MEDICINAL CHEMISTRY LETTERS, 10.1016/j.bmcl.2008.10.079, 18, 24, 6394-6397, 2008.12, A water-soluble derivative of N-confused porphyrin (NCP: 5,10,15,20-tetraaryl-2-aza-21-carbaporphyrin) was synthesized by introducing glucamine groups at the para-position of meso-aryl groups. The tetraglucamine-appended NCP (TG-NCP) exists as monocation in aqueous solution containing 6 mM sodium dodecyl sulfate (SDS) but exists as freebase to form aggregates in pure water. These properties are distinct from those of corresponding regular porphyrin, which exists as freebase in the micellar solution and practically insoluble in water. (C) 2008 Elsevier Ltd. All rights reserved..
146. Alagar Srinivasan, Motoki Toganoh, Teppel Niino, Atsuhiro Osuka, Hiroyuki Furuta, Synthesis of N-Confused Tetraphenylporphyrin Rhodium Complexes Having Versatile Metal Oxidation States, INORGANIC CHEMISTRY, 10.1021/ic061093+, 47, 23, 11305-11313, 2008.12, A variety of N-confused tetraphenylporphyrin rhodium complexes were synthesized, and their structures and physical properties were investigated. Depending on the reaction conditions, the rhodium(I), -(III), and -(IV) complexes were produced, which exemplified the versatile coordination mode of N-confused porphyrin ligands..
147. Srinivasan, A.; Toganoh, M.: Niino, T.; Osuka, A.; Furuta, H., Synthesis of N-Confused Tetraphenylporphyrin Rhodium Complexes Having Versatile Metal Oxidation States, Inorg. Chem. 2008, 47, 11305−11313, 2008.10.
148. Motoki Toganoh, Naoyuki Harada, Hiroyuki Furuta, Hydrogen-bonding network in new scorpionate-type ligand composed of pyridine/pyrrole hybrid and anion-binding behavior of the corresponding rhodium complexes in alkyne cyclotrimerization reaction, JOURNAL OF ORGANOMETALLIC CHEMISTRY, 10.1016/j.jorganchem.2008.07.005, 693, 19, 3141-3150, 2008.09, New heteroscorpionate ligands (1 and 2) having a di(pyridin-2-yl)(1H-pyrrol-2-yl) methane substructure are synthesized. X-ray crystallographic analysis on 1 and 2 reveals that they form unique hydrogen bonding networks depending on the size of neighboring groups in solid states. 1 and 2 can form cationic rhodium( I) complexes, wherein the counter anions form hydrogen bondings with the pyrrolic NH moiety. In alkyne cyclotrimerization reactions using those complexes as catalyst, the catalytic activity is significantly enhanced when electron-donating counter anions is placed near the metal center. (C) 2008 Elsevier B.V. All rights reserved..
149. Motoki Toganoh, Teppei Niino, Hiroyuki Furuta, Luminescent Au(III) organometallic complex of N-confused tetraphenylporphyrin, CHEMICAL COMMUNICATIONS, 10.1039/b807922f, 34, 4070-4072, 2008.09, An organometallic Au(III) complex of N-confused tetraphenylporphyrin has been synthesized and its electrochemical and photophysical properties investigated, unique emission is observed in solution at ambient temperature..
150. Ikawa, Y.; Moriyama, S.; Furuta, H., Facile Syntheses of BODIPY Derivatives for Fluorescent Labeling of the 3’ and 5’ Ends of RNAs, Anal. Biochem., 378, 166−170, 2008.07.
151. Atsuya Muranaka, Shigetsugu Homma, Hiromitsu Maeda, Hiroyuki Furuta, Nagao Kobayashi, Detection of unusual Delta HOMO < Delta LUMO relationship in tetrapyrrolic cis- and trans-doubly N-confused porphyrins, CHEMICAL PHYSICS LETTERS, 10.1016/j.cplett.2008.06.037, 460, 4-6, 495-498, 2008.07, A plus-to-minus MCD sign in ascending energy has been detected for the Q bands of the copper(III) complexes of doubly N-confused porphyrin (cis- and trans-1). An unusual Delta HOMO < Delta LUMO relationship for tetrapyrrolic porphyrins was calculated using the HF, DFT, and semi-empirical methods. By applying the Michl's perimeter model, the observed MCD pattern was successfully explained by the computational results. (c) 2008 Published by Elsevier B. V..
152. Yoshiya Ikawa, Shoji Moriyama, Hiroyuki Furuta, Facile syntheses of BODIPY derivatives for fluorescent labeling of the 3 ' and 5 ' ends of RNAs, ANALYTICAL BIOCHEMISTRY, 10.1016/j.ab.2008.03.054, 378, 2, 166-170, 2008.07, As inexpensive and readily available fluorophores for 3' and 5' end labeling of RNA molecules, symmetrical BODIPY (boron dipyrromethene: 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) derivatives having a primary amino group were designed, and their facile synthetic route was established. Novel BODIPY derivatives exhibited photophysical properties comparable to commercially available BODIPY FL EDA (4,4-difluoro-5,7-dimethyl-4-bora-3 a,4a-diaza-s-indacene-3-propionyl ethylenediamine). To confirm utility of new derivatives, specific labeling of the 3' and 5' ends of in vitro transcribed RNAs was carried out. Furthermore, the 3 ' end of the 5 ' fragment of the bimolecular Tetrahymena ribozyme was labeled, and its catalytic activity was investigated. (C) 2008 Elsevier Inc. All rights reserved..
153. Tomoya Ishizuka, Shinya Ikeda, Motoki Toganoh, Ichiro Yoshida, Yuichi Ishikawa, Atsuhiro Osuka, Hiroyuki Furuta, Substitution, dimerization, metalation, and ring-opening reactions of N-fused porphyrins, TETRAHEDRON, 10.1016/j.tet.2008.02.041, 64, 18, 4037-4050, 2008.04, A variety of reactions such as substitution, dimerization, rhenium(I) metalation, and ring-opening reactions of N-fused porphyrin (NFP) and optical properties of the products are presented. Palladium-catalyzed cross-coupling reactions under Suzuki or Stille conditions afford aryl and arylethynyl-substituted NFPs (12, 14) and an ethynyl-bridged dimer (15) from 3-bromo-substituted NFP (3b) in 40-98% yields. Treatment of NFP with silver(I) trifluoroacetate in CHCl3 affords a dimer (22) linked at both C21-positions of the fused rings and its bis-Re(I) metal complex (24) is synthesized. X-ray structures of the 3-trifluoromethyl and 3-phenyl NFP derivatives (9e and 12a) reveal the three-center hydrogen bondings in the core. All the new NFP derivatives display unique absorption spectra, and particularly, ethyne-bridged NFP-dimer (15) shows a remarkable bathochromic shift into a near-infrared region showing an absorption band at 1020 nm with tailing up to 1100 nm. Moreover, alkoxide nucleophiles convert NFP into NCP derivatives by the cleavage of C-N bond in the fused ring, which is useful for the preparation of various C3-substituted NCPs and C21,C21'-linked NCP dimers from NFPs. (c) 2008 Elsevier Ltd. All rights reserved..
154. Motoki Toganoh, Keitaro Fujino, Shinya Ikeda, Hiroyuki Furuta, Catalytic deoxygenation of pyridine N-oxides with N-fused porphyrin rhenium complexes, TETRAHEDRON LETTERS, 10.1016/j.tetlet.2007.12.117, 49, 9, 1488-1491, 2008.02, Deoxygenation reactions of pyridine N-oxide derivatives catalyzed by N-fused porphyrin rhenium(VII) trioxo complexes are developed, affording the corresponding pyridine derivatives in quantitative yields with excellent turnover numbers up to 340,000. (c) 2007 Elsevier Ltd. All rights reserved..
155. Masashi Fukuchi, K. Takegoshi, Tomoya Ishizuka, Hiroyuki Furuta, N-15 solid-NMR and X-ray diffraction studies of N-confused porphyrins, MAGNETIC RESONANCE IN CHEMISTRY, 10.1002/mrc.2066, 45, S56-S60, 2007.12, Using N-15 high-resolution solid-state NMR and X-ray diffraction, the structure of N-confused porphyrin (NCP) in the solid state was studied. A ID N-15 magic angle spinning (MAS) experiment and a 2D dipolar assisted rotational resonance (DARR) N-15-N-15 spin exchange experiment of N-confused tetratolylporphyrin (Tol) crystallized from CH2Cl2/hexane indicate that Tol is the inner 3H-type tautomer and has two magnetically different molecules in the unit cell. Further, a FSLG-2 (4) over bar2 H-1-N-15 dipolar recoupling NMR measurement indicates no fast ring flipping motion which is consistent with the planar structure in the X-ray analysis. The planarity of Tol is ascribed to crystal packing enforced by pi-pi stacking and CH-pi interactions. Copyright (c) 2007 John Wiley & Sons, Ltd..
156. Motoki Toganoh, Shinya Ikeda, Hiroyuki Furuta, Synthesis, reactivity, and properties of N-fused porphyrin rhenium(l) tricarbonyl complexes, INORGANIC CHEMISTRY, 10.1021/ic701208g, 46, 23, 10003-10015, 2007.11, The thermal reactions of N-fused tetraarylporphyrins or N-confused tetraarylporphyrins with Re-2(CO)(10) gave the rhenium(l) tricarbonyl complexes bearing N-fused porphyrinato ligands (4) in moderate to good yields. The rhenium complexes 4 are characterized by mass, IR, H-1, and C-13 NMR spectroscopy, and the structures of tetraphenylporphynato complex 4a and its nitro derivative 15 are determined by X-ray single crystal analysis. The rhenium complexes 4 show excellent stability against heat, light, acids, bases, and oxidants. The aromatic substitution reactions of 4 proceed without a loss of the center metal to give the nitro (15), formyl (16), benzoyl (17), and cyano derivatives (19), regioselectively. In the electrochemical measurements for 4, one reversible oxidation wave and two reversible reduction waves are observed. Their redox potentials imply narrow HOMO-LUMO band gaps of 4 and are consistent with their electronic absorption spectra, in which the absorption edges exceed 1000 nm. Theoretical study reveals that the HOMO and LUMO of the rhenium complexes are exclusively composed of the N-fused porphyrin skeleton. Protonation of 4 takes place at the 21-position regioselectively, reflecting the high coefficient of the C21 atom in the HOMO orbital. The skeletal rearrangement reaction from N-confused porphyrin Re(l) complex (8) to N-fused porphyrin Re(l) complex (4) is suggested from the mechanistic study as well as DFT calculations..
157. Tatsuki Morimoto, Hiroyuki Furuta, Supramolecular interaction of keto-substituted pyrroles, SUPRAMOLECULAR CHEMISTRY, 10.1080/10610270601132129, 19, 7, 493-500, 2007.10, Several types of pyrrole derivatives bearing carbonyl groups were synthesized and their structures in the solid states were elucidated by single crystal X-ray analysis. In the case of alpha-ketopyrroles, the molecules exist as hydrogen bonding dimers between the pyrrole NH and carbonyl groups, while in the case of beta-ketopyrrole derivatives, hydrogen bonding networks are formed. Both the alpha,beta'-diketo-substituted pyrroles and their derivatives are suggested to be suitable for the construction of 1-D chain networks. Overall, the effects of substituents on the supramolecular interactions are discussed in detail..
158. Jang-Hyun Ryu, Fuyuki Ito, Toshihiko Nagamura, Kiyohisa Nakamura, Hiroyuki Furuta, Yutaka Shibata, Shigeru Itoh, Excited-state dynamics of normal and doubly N-confused type hexaphyrin derivatives studied by time-resolved fluorescence measurements, CHEMICAL PHYSICS LETTERS, 10.1016/j.cplett.2007.06.097, 443, 4-6, 274-279, 2007.08, The excited-state dynamics of two expanded porphyrin derivatives which have six pyrrole rings of normal and doubly N-confused types was studied by time-resolved fluorescence and transient absorption measurements. We have found that their dynamics is very different due to four substituents in the doubly N-confused hexaphyrin derivative. The bleaching recovery of the free-base doubly N-confused hexaphyrin shows the double exponential fiinction with time constants of tau = 80 +/- 10 ps and 47 +/- 10 ps. The fluorescence decay curve, on the other hand, shows single-exponential function. To explain such behavior, we propose a model that the recovery process originates from two conformers in the S-1 state. It is plausible that the two excited-state conformers are deactivated independently to the ground state with radiative and nonradiative processes, respectively. (C) 2007 Elsevier B.V. All rights reserved..
159. Fukuchi, M.; Takegoshi, K.; Ishizuka, T.; Furuta, H. , 15N Solid-NMR and and X-ray Diffraction Studies of N-Confused Porphyrins, Magn. Reson. Chem. , 45, s56–s60, 2007.07.
160. Kashiwagi, N.; Furuta, H.; Ikawa, Y., Design and Analysis of a Structural RNA that Act as a Template for Peptide Ligation, Nucleic Acids Symp. Ser., 51, 387–388, 2007.06.
161. Toganoh, M.; Ikeda, S.; Furuta, H. , Synthesis, Reactivity, and Properties of N-Fused Porphyrin Rhenium(I) Tricarbonyl Complexes , Inorg. Chem. , 46, 10003–10015., 2007.06.
162. Tomoya Ishizuka, Hiroki Yamasaki, Atsuhiro Osuka, Hiroyuki Furuta, Syntheses of aryl- and arylethynyl-substituted N-confused porphyrins, TETRAHEDRON, 10.1016/j.tet.2007.04.007, 63, 24, 5137-5147, 2007.06, Palladium-catalyzed cross-coupling reactions under Suzuki, Sonogashira, and Stille conditions afford 3-aryl (9-12) and 3-arylethynyl N-confused porphyrin (NCP) silver(III) complexes (13-15) from the 3-bromo NCP complex (4) in ca. 70% yields along with the transmetalated products, 3-substituted NCP palladium(II) complexes (11-Pd to 15-Pd), in 10-30% yields. Substitution at 3-position was confirmed by the single crystal X-ray structures of 9, 13-Ag, and 13-Pd. The arylethynyl groups or five-membered heterocyclic aromatic rings at 3-position largely affected the optical properties of N-confused porphyrin, in which the longest absorption maxima of the Q-bands are shifted bathochromically by 30-120 nm. The electronic effect of substituent differs largely between palladium and silver complexes reflecting the different pi-electron delocalization pathway of NCP cores. 3-Aryl- and 3-arylethynyl NCP silver(III) complexes were easily demetalated to afford the corresponding free base porphyrins by the treatment of sodium borohydride. (c) 2007 Elsevier Ltd. All rights reserved..
163. Norimasa Kashiwagi, Takeshi Akeda, Tatsuki Morimoto, Tomoya Ishizuka, Hiroyuki Furuta, Synthesis and isomerization of imino-fused N-confused porphyrin, ORGANIC LETTERS, 10.1021/ol0703534, 9, 9, 1733-1736, 2007.04, A set of mutually interconvertable inner-bridged-type porphyrinoids, imino-fused N-confused porphyrins (IF-NCPs), which possess a [5.7.5] tricyclic ring in the core, were synthesized from a condensation reaction of 21-amino-substituted NCP and an arylaldehyde, and the structures were characterized by X-ray single-crystal analysis..
164. Fuyuki Ito, Takayasu Nagai, Yuki Ono, Keisuke Yamaguchi, Hiroyuki Furuta, Toshihiko Nagamura, Photophysical properties of 2-picolinoylpyrrole boron complex in solutions, CHEMICAL PHYSICS LETTERS, 10.1016/j.cplett.2007.01.001, 435, 4-6, 283-288, 2007.02, Photophysical properties of boron 2-picolinoylpyrrole complex (BOPPY) were investigated by UV-Vis absorption, fluorescence spectra and fluorescence lifetime measurements in various solutions. The absorption peak of BOPPY was shifted to blue with increasing the solvent polarity. The fluorescence peak, on the other hand, was shifted to red with increasing the solvent polarity. The electronic structure of BOPPY was calculated by the molecular orbital method to reveal the charge transfer character. The magnitude of change in the dipole moment was calculated by the Lippert-Mataga equation. The fluorescence lifetime and fluorescence quantum yield were measured in solvents as a function of dielectric constant. These results suggest that the BOPPY has an intramolecular charge transfer (ICT) character in the excited state. (c) 2007 Elsevier B.V. All rights reserved..
165. Kashiwagi, N.; Akeda, T.; Morimoto, T.; Ishizuka, I.; Furuta, H., Synthesis and Isomerization of Imino-Fused N-Confused Porphyrin, Org. Lett., in press, 2007.01.
166. Hiromitsu Maeda, Tatsuki Morimoto, Atsuhiro Osuka, Hiroyuki Furuta, Halide-anion binding by singly and doubly N-confused porphyrins, CHEMISTRY-AN ASIAN JOURNAL, 10.1002/asia.200600182, 1, 6, 832-844, 2006.12, The halide-binding properties of N-confused porphyrin (NCP, 1) and doubly N-confused porphyrins (trans-N2CP (2), cis-N2CP (3)) were examined in CH2Cl2. In the free-base forms, cis-N2CP (3) showed the highest affinity to each anion (Cl-, Br-, I-) with association constants K-a = 7.8 x 10(3), 1.9 x 10(3), and 5.8 x 10(2) M-1, respectively. As metal complexes, on the other hand, trans-N2CP 2-Cu exhibited the highest affinity to Cl-, Br, and I- with K-a = 9.0 x 10(4), 2.7 x 10(4), and 1.9 x 10(3) M-1, respectively. The corresponding Ka values for cis-N2CP 3-Cu and NCP 1-Cu were about 1/10 and 1/2, respectively, of those of 2-Cu. With the help of density functional theory (DFT) calculations and complementary affinity measurements of a series of trisubstituted N-confused porphyrins, the efficient anion binding of NCPs was attributed to strong hydrogen bonding at the highly polarized NH moieties owing to the electron-deficient C6F5 groups at meso positions as well as the ideally oriented dipole moments and large molecular polarizability. The orientation and magnitude of the dipole moments in NCPs were suggested to be important factors in the differentiation of the affinity for anions..
167. Motoki Toganoh, Teppei Niino, Hiromitsu Maeda, Bruno Andrioletti, Hiroyuki Furuta, Unprecedented formation of a rhodium cluster triggered by rhodium-fastened N-confused gable porphyrin, INORGANIC CHEMISTRY, 10.1021/ic061741p, 45, 26, 10428-10430, 2006.12, Thermal reaction of N-confused porphyrin (NCP) with [RhCl(CO)(2)](2) caused unprecedented formation of tetranuclear rhodium complex Rh-4(NCP)(2)(CO)(4) having a gable-porphyrin-type structure, where two porphyrin pi systems were electronically connected by the rhodium cluster..
168. Yuki Ono, Hiroyuki Furuta, 2-picolinoylpyrrole: A new entry to metal-complexing agent, CHEMISTRY LETTERS, 10.1246/cl.2006.750, 35, 7, 750-751, 2006.07, The Pd(II) and Pt(II) complexes of 2-picolinoylpyrrole were synthesized and the 2:1 square-planar coordination, wherein each pyrrole and pyridine moieties are in trans positions, respectively, were characterized by means of X-ray single-crystal analyses..
169. Jung Ho Kwon, Tae Kyu Ahn, Min-Chul Yoon, Deok Yun Kim, Mi Kyoung Koh, Dongho Kim, Hiroyuki Furuta, Masaaki Suzuki, Atsuhiro Osuka, Comparative photophysical properties of free-base, Bis-Zn(II), Bis-Cu(II), and Bis-Co(II) doubly N-confused hexaphyrins(, JOURNAL OF PHYSICAL CHEMISTRY B, 10.1021/jp056083t, 110, 24, 11683-11690, 2006.06, We have comparatively investigated the photophysics of a series of bis-metal doubly N-confused hexaphyrins( using time-resolved fluorescence, femtosecond transient absorption, two-photon absorption measurements, and geometry-optimized ab initio calculations. Bis-Zn( II) and free-base doubly N-confused hexaphyrins exhibit well-resolved and red-shifted B- and Q-like absorption bands compared with porphyrins. Their allowed transitions are (pi, pi*) transitions of the hexaphyrin ring, as confirmed by the HOMO and LUMO frontier orbitals based on ab initio calculations at the B3LYP/6-31G level. On the other hand, the absorption spectra of bis-Cu(II) and bis-Co(II) doubly N-confused hexaphyrins are relatively broad, presumably due to large couplings between the metal d-orbitals and pi-electrons of the hexaphyrin ring. Owing to these couplings, bis-Cu( II) and bis-Co( II) doubly N-confused hexaphyrins have much shorter excited-state lifetimes of 9.4( 0.3 ps and 670 fs, respectively, than those (267 +/- 16 and 62.4 +/- 1.2 ps, respectively) of bis- Zn( II) and free-base doubly N-confused hexaphyrins. The two-photon absorption cross section (sigma((2))) values, which are believed to depend strongly on the ring planarity (pi-conjugation), are in line with the excited-state lifetime trends..
170. Motoki Toganoh, Jo Konagawa, Hiroyuki Furuta, Bis[iridium(I)] complex of inverted N-confused porphyrin, INORGANIC CHEMISTRY, 10.1021/ic060203+, 45, 10, 3852-3854, 2006.05, The reaction of N-confused tetraphenylporphyrin with IrCl(CO)(2)(p-toluidine) gave a novel bis[iridium(I)] complex, wherein the confused pyrrole ring took an inverted conformation..
171. Toganoh, M.; Niino, T.; Maeda, H.; Andrioletti, B.; Furuta, H, Unprecedented Formation of Rhodium Cluster Triggered by Rhodium-Fastened N-Confused Gable Porphyrin, Inorg. Chem., 45, 10428-10430, 2006.01.
172. Synthesis and Reaction of N-Confused Porphyrinatoantimony(V).
173. JC Liu, T Ishizuka, A Osuka, H Furuta, Modulation of axial coordination in N-confused porphyrin-antimony(v) dibromide complex by proton stimulus, CHEMICAL COMMUNICATIONS, 10.1039/b301539b, 15, 1908-1909, 1908-1909, 2003.08, The change of the axial bond length in the antimony( V) N-confused tetraphenylporphyrin dibromide complex was demonstrated by protonation and confirmed from X-ray single crystal analyses..
174. Chemistry of N-Confused Porphyrin : A Novel Porphyrin Isomer.
175. Liu, J.-C.; Ishizuka, T.; Osuka, A.; Furuta, H., "Modulation of Axial Coordination in N-Confused Porphyrin-Antimony(V) Dibromide Complex by Proton Stimulus", Chem. Commun., 10.1039/b301539b, 15, 1908-1909, 1908-1909, 2003.01.
176. Sessler, J. L.; Maeda, H.; Mizuno T.; Lynch, V. M.; Furuta H., "Quinoxaline-oligopyrroles: Improved Pyrrole-based Anion Receptors", Chem. Commun., 2002, 862-863., 2002.01.
177. Lin, X. M.; Umezawa, K.; Tohda, K.; Furuta, H.; Sessler, J. L.; Umezawa, Y., "Potentiometric Responses of Expanded Porphyrin Incorporated Liquid Membrane Electrodes toward a Series of inorganic and Organic Anions", Anal. Sci., 14, 99-108, 1998.01.
178. Kazunori Odashima, Ryuichi Naganawa, Hanna Radecka, Masamitsu Kataoka, Eiichi Kimura, Tohru Koike, Koji Tohda, Masahiro Tange, Hiroyuki Furuta, Jonathan L. Sessler, Kenichi Yagij, Yoshio Umezawa, Chemical Sensing Based on Membrane Potential Change Induced by Host-Guest Complexation at a Membrane Surface, Supramolecular Chemistry, 10.1080/10610279408029869, 4, 2, 101-113, 1994.12, Three new principles for discrimination of organic guests by the membrane potential change are described, which are based on the host-guest recognition of charged groups, hydrogen bonding groups, or steric shapes of nonpolar moieties, (i) Potentiometric discrimination by the recognition of charged groups has been attained by liquid membrane type electrodes containing lipophilic macrocyclic polyamines as the sensory elements. These electrodes displayed potentiometric selectivities for organic anions according to the amount or proximity of negative charges. Thus, the strongest responses were observed for such guests as ATP4- having a large number of negative charges as well as maleate2- and phthalate2-having negative charges at the closest distance within the molecule, (ii) Potentiometric discrimination by the recognition of hydrogen bonding groups has been attained by an electrode containing a lipophilic cytosine-pendant triamine, which functions as a ditopic receptor for guanine nucleotides by an electrostatic interaction with the phosphate group and a complementary base pairing with the guanine base. This electrode displayed nearly all-or-nothing selectivities between guanine and adenine nucleotides. Selective responses to guanine nucleotides were also obtained by double receptor type electrodes containing a macrocyclic tetraamine and a neutral cytosine derivative despite the fact that both of these hosts, when existed separately, showed only weak responses to these guests, (iii) Potentiometric discrimination by the recognition of steric shapes of nonpolar moieties has been attained by an electrode containing a lipophilic hexaester of calix[6]arene having an inclusion cavity for organic guests. At pH 7.0, the strongest responses were obtained for primary amine guests such as 2-phenylethyiamine and 1-octylamine having no bulky substituent at the a-carbon that could sterically hinder the formation of tripodal hydrogen bonds between the NH3 + group of the guest and the ester carbonyl groups of the host. A comparison of potentiometric selectivities with those of the electrode containing dibenzo-18-crown-6, as well as !H-NMR results on the geometry of the host-guest complex, strongly supported a potentiometric shape discrimination effect based on the inclusion of guests within the calix[6]arene cavity having a well-defined structure. © 1994, Taylor &
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