| 1. |
梅野 圭太郎, Synthetic Study of the Northern Hemisphere of Maitotoxin, 第３回大津会議合同研究発表会, 2023.01. |
| 2. |
Keitaro Umeno, Hisaaki Onoue, Keiichi Konoki, Kohei Torikai, Yoko Yasuno, Masayuki Satake, Tohru Oishi, Convergent Synthesis of the WXYZA’B’C’D’E’F’ Ring Segment of Maitotoxin, International Congress on Pure & Applied Chemistry (ICPAC) 2022, 2022.11. |
| 3. |
Tohru Oishi, Total Synthesis and Structure–Activity Relationship Study of Amphidinol 3, International Congress on Pure & Applied Chemistry (ICPAC) 2022, 2022.11. |
| 4. |
Tohru Oishi, Total Synthesis of Amphidinol 3 and Structure-Activity Relationship Study, 2nd Edition of Chemistry International Webinar, 2022.07. |
| 5. |
Tohru Oishi, Structure Determination, Chemical Synthesis, and Evaluation of Biological Activity of Super Carbon Chain Natural Products, 日本化学会第99春季年会(2019), 2019.03. |
| 6. |
Yuma Wakamiya, Makoto Ebine, Tohru Oishi, Total Synthesis and Structure-Activity Relationship Study of Amphidinol 3, 日本化学会第99春季年会(2019), 2019.03. |
| 7. |
Tatsuya Tanaka, Kohei Torikai, Makoto Ebine, Masayuki Satake, Tohru Oishi, Synthetic Study of the VWX Ring System of Brevisulcenal-F, 日本化学会第99春季年会(2019), 2019.03. |
| 8. |
Tohru, Oishi, Structure-Activity Relationship Studies of Maitotoxin Based on the Chemical Synthesis of Partial Structures, The 14th International Kyoto Conference on New Aspects of Organic Chemistry（IKCOC-14）, 2018.10. |
| 9. |
Yuma Wakamiya, Makoto Ebine, Tohru, Oishi, Synthetic Studies of Amphidinol 3, The 14th International Kyoto Conference on New Aspects of Organic Chemistry（IKCOC-14）, 2018.10. |
| 10. |
Keitaro Umeno, Makoto Ebine, Tohru Oishi, Synthetic Study of the C30–C63 Section of Karlotoxin 2, The 14th International Kyoto Conference on New Aspects of Organic Chemistry（IKCOC-14）, 2018.10. |
| 11. |
Yuma Wakamiya, Makoto Ebine, Tohru Oishi, Synthetic studies towards the total synthesis of amphidinol 3, 19th Tetrahedron Symposium, 2018.06. |
| 12. |
Tomohiro Watanabe, Makoto Ebine, Tohru Oishi, Synthetic Studies on the Sperm-Activating and Attracting Factor from Ascidian Ascidia Sydneiensis
, The 4th International Conference on MEXT Project of Integrated Research on Chemical Synthesis & ICOMC 2014 Pre-symposium in Kyoto, 2014.07, Recently, an endogenous sperm activating and attracting factor (SAAF, 1) from eggs of ascidian Ascidia sydneiensis was isolated. SAAF was estimated to be a sulfated polyhydroxysterol: 3,7,8,26-tetrahydroxycholestane-3,26-disulfate by NMR and ESI/TOF-MS analysis using approximately 2.6 µg of the sample.
Although the stereochemistry of steroidal backbone moiety was determined, the configuration at C25 remains unknown. For elucidation of the complete structure, 25S-SAAF was synthesized and NMR data of synthetic specimen were compared with those of the natural product.
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| 13. |
Takeshi Tsuruda, Makoto Ebine, Yuri Takada, Tohru Oishi, Studies toward Total Synthesis of Amphidinol 3
, The 4th International Conference on MEXT Project of Integrated Research on Chemical Synthesis & ICOMC 2014 Pre-symposium in Kyoto, 2014.07, Amphidinol 3 (AM3, 1) is a marine natural product produced by the dinoflagellate Amphidinium klebsii. AM3 has attracted considerable attention of synthetic chemists because of the unique structure and potent antifungal activity. It was difficult to determine the absolute configuration of AM3 because of the presence of a number of stereogenic centers on the acyclic long carbon chain, therefore revisions of stereochemistry at C2 and C51 have been made. In order to confirm the absolute configuration, synthetic studies toward total synthesis of AM3 were performed.. |
| 14. |
Tohru Oishi, Synthesis of Ladder-shaped Polyethers by Using Microflow Reactors
, The Eighth International Symposium on Integrated Synthesis (ISIS-8), 2013.11. |
| 15. |
Tohru Oishi, Makoto EBINE, Synthesis of the C31-C67 Part of Amphidinol 3, The 8th International Conference on Cutting-Edge Organic Chemistry in Asia & The 4th New Phase International Conference on Cutting-Edge Organic Chemistry in Asia, 2013.11, Amphidinol 3 (AM3, 1) is a marine natural product isolated from dinoflagellate Amphidinium klebsii.1 AM3 elicits potent antifungal activity (MIC = 4.0 g/disk),2 but its mode of action remains to be elucidated. Because of the presence of a number of stereogenic centers on the acyclic long carbon chain, it was difficult to determine the molecular structure of AM3. Although the stereochemistry of AM3 was determined by extensive NMR analysis and degradation of the natural product,3 total synthesis of AM3 is necessary for the structure confirmation. As a part of our studies on structure confirmation of AM3 based on the chemical synthesis of the partial structures,4,5 the C31-C67 part of AM3 has been synthesized. Both the C43-C52 and the C31-C42 THP fragments were prepared from common THP intermediate.6 Coupling of these fragments and introduction of the polyene group via Julia-Kocienski olefination successfully afforded the C31-C67 part of AM3. . |
| 16. |
Tohru Oishi, Synthesis of Partial Structures of Maitotoxin
, 14th Tetrahedron Symposium - Asian Edition: Challenges in Organic and Bioorganic Chemistry, 2013.10, Maitotoxin (MTX) is a causative toxin of ciguaetra seafood poisoning produced by the dinoflagellate Gambierdiscus toxicus. MTX is one of the largest non-biopolymer (MW 3422) and most toxic against mammals (50 ng/kg) known to date. MTX elicits remarkable biological activities at extremely low concentration, for instance, hemolysis of red blood cells (15 nM) and calcium ion influx in various cell lines (0.3 nM). Despite a large number of investigations, the precise mode of action at the molecular level has not been elucidated. During the course of our synthetic studies of MTX for developing its antagonists, partial structure of MTX corresponding to the WXYZA’B’C’ ring system was synthesized based on the -cyano ether method via successive coupling of the W- and Z-ring giving the WXYZ-ring fragment, followed by coupling with the C’-ring through the construction of the A’B’-ring systems. Syntheses of the C’D’E’F’ ring and the QRS ring system will be also reported.. |
| 17. |
Tohru Oishi, Makoto EBINE, Synthesis of the C31-C67 Part of Amphidinol 3
, 3rd International Congress on Natural Sciences with Sisterhood Universities (ICNS 2013), 2013.10, Amphidinol 3 (AM3, 1) is a marine natural product isolated from dinoflagellate Amphidinium klebsii.1 AM3 elicits potent antifungal activity (MIC = 4.0 g/disk),2 but its mode of action remains to be elucidated. Because of the presence of a number of stereogenic centers on the acyclic long carbon chain, it was difficult to determine the molecular structure of AM3. Although the stereochemistry of AM3 was determined by extensive NMR analysis and degradation of the natural product,3 total synthesis of AM3 is necessary for the structure confirmation. As a part of our studies on structure confirmation of AM3 based on the chemical synthesis of the partial structures,4,5 the C31-C67 part of AM3 has been synthesized. Both the C43-C52 and the C31-C42 THP fragments were prepared from common THP intermediate.6 Coupling of these fragments and introduction of the polyene group via Julia-Kocienski olefination successfully afforded the C31-C67 part of AM3.. |
| 18. |
Hisaaki Onoue, Tomomi Baba, Kohei TORIKAI, Makoto EBINE, Tohru Oishi, Synthetic Study of the QRS Ring System of Maitotoxin
, 3rd International Congress on Natural Sciences with Sisterhood Universities (ICNS 2013), 2013.10, Maitotoxin (MTX) is a ladder shaped polyether compound produced by dinoflagellate Gambierdiscus toxicus, and it was found as one of the causative toxins of ciguatera seafood poisoning. MTX elicits remarkable biological activities at extremely low concentrations, for instance, MTX causes hemolysis of red blood cells and a profound influx of Ca2+ into cells. As a part of our structure-activity relationship studies based on chemical synthesis of the partial structures of MTX,1 the QRS ring system (1) of MTX was designed. The synthesis of 1 began with coupling reaction of Weinreb amide 2 with furyllithium 3, followed by Achmatowicz reaction and methylation to afford pyranone 4. Chemoselective methylation on the methoxy group of 4 was achieved in a stereoselective manner, and then tricyclic compound 6 was synthesized via methylation. After conversion of compound 6 to ketone 7, the synthesis of the QRS ring system 1 was achieved via ring expansion.. |
| 19. |
Makoto EBINE, Nobuaki Matsumori, Michio Murata, Tohru Oishi, Synthesis of the C31-C67 part of amphidinol 3
, 14th Tetrahedron Symposium, 2013.06, Amphidinol 3 (AM3) is a marine natural product isolated from dinoflagellate Amphidinium klebsii. AM3 elicits potent antifungal activity (MIC = 4.0 g/disk), but its mode of action remains to be elucidated. Because of the presence of a number of stereogenic centers on the acyclic long carbon chain, it was difficult to determine the molecular structure of AM3. Although the stereochemistry of AM3 was determined by extensive NMR analysis and degradation of the natural product, total synthesis of AM3 is necessary for the structure confirmation.
As a part of our studies on structure confirmation of AM3, synthesis of the C31-C67 part of AM3 was achieved. Both the C31-C42 (3) and the C43-C52 (4) fragments were prepared from common THP intermediate 2. Coupling of these fragments and introduction of the polyene unit via Julia-Kocienski olefination using sulfone 5 successfully afforded the C31-C67 part of AM3 (6).
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| 20. |
Takeshi Tsuruda, 海老根 真琴, Tohru Oishi, Synthetic Study of the C1-C20 Part of Amphidinol 3
, 第21回日本化学会九州支部・韓国化学会釜山支部合同セミナー, 2013.06, Amphidinol 3 (AM3, 1) is a marine natural product produced by the dinoflagellate Amphidinium klebsii. AM3 has attracted considerable attention of synthetic chemists because of the unique structure and potent antifungal activity. As a part of our studies on total synthesis of AM3, the C1-C20 part of AM3 (5) has been synthesized via chemoselective cross metathesis1 as a key step. . |
| 21. |
Hisaaki Onoue, 鳥飼 浩平, 海老根 真琴, Tohru Oishi, Synthetic Study of the QRS Ring System of Maitotoxin
, 第21回日本化学会九州支部・韓国化学会釜山支部合同セミナー, 2013.06, Maitotoxin (MTX) is a biotoxin produced by dinoflagellate Gambierdiscus toxicus and it was found as one of the causative toxins of ciguatera seafood poisoning. As a part of our structure-activity relationship studies based on chemical synthesis of the partial structures of MTX,1 the QRS ring system of MTX was designed and synthesized via chemoselective methylation of a pyranone and ring expansion giving seven-membered S-ring.. |
| 22. |
Makoto EBINE, Tohru Oishi, Synthesis of the C31-C67 Part of a Antifungal Marine Natural Product Amphidinol 3
, The 23rd French-Japanese Symposium on Medicinal and Fine Chemistry, 2013.05, Amphidinol 3 (AM3, 1) is a marine natural product isolated from dinoflagellate Amphidinium klebsii.1) AM3 elicits potent antifungal activity (MIC = 4.0 g/disk),2) but its mode of action remains to be elucidated. Because of the presence of a number of stereogenic centers on the acyclic long carbon chain, it was difficult to determine the molecular structure of AM3. Although the stereochemistry of AM3 was determined by extensive NMR analysis and degradation of the natural product,3) total synthesis of AM3 is necessary for the structure confirmation.
As a part of our studies on structure confirmation of AM3, the C31-C67 part of AM3 has been synthesized. Both the C43-C52 and the C31-C42 THP fragments were prepared from common THP intermediate. Coupling of these fragments and introduction of the polyene group via Julia-Kocienski olefination successfully afforded the C31-C67 part of AM3. In the poster presentation, we will present a synthesis and structure analysis of the C31-C67 part of AM3.
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| 23. |
Tohru Oishi, Synthesis of Fluorine Labeled Natural Products for Solid-State NMR Measurements
, 4 th International Fluorine Workshop, Tokyo, 2013.04. |
| 24. |
Makoto Ebine, Aya Umeda, Takeshi Tsuruda, Tohru Oishi, Studies toward Total Synthesis of Amphidinol 3, The 2nd International Conference on MEXT Project of Integrated Research on Chemical Synthesis “Molecular Functions in Complex Systems”, 2012.12. |
| 25. |
Makoto Ebine, Aya Umeda, Takeshi Tsuruda, Yoshiyuki Manabe, Nobuaki Matsumori, Michio Murata, Tohru Oishi, Studies toward Total Synthesis of Amphidinol 3, the 1 2th International Kyoto Conference (IKCOC-12), 2012.11. |
| 26. |
Hajime Shibata, Hiroshi Tsuchikawa, Nobuaki Matsumori, Michio Murata, Tohru Oishi, Yuki Hiradate, Manabu Yoshida, Masaaki Morisawa, Synthetic study for the structure elucidation of an endogenous sperm activating and attracting factor isolated from eggs of the ascidian Ascidia sydneiensis
, Gordon Research Conference, 2012.02. |
| 27. |
Kohei TORIKAI, Satoru Ujihara, Nobuaki Matsumori, Keiichi Konoki, Saburo Aimoto, Michio Murata, Tohru Oishi, Design and Synthesis of Artificial Ladder-Shaped Polyethers that Interact with Transmembrane Proteins, 2011.11. |
| 28. |
Yoshiyuki Manabe, Mitsunori Kanemoto, Nobuaki Matsumori, Michio Murata, Tohru Oishi, Design and Synthesis of Artificial Ladder-Shaped Polyethers that Interact with Transmembrane Proteins, 2011.11. |
| 29. |
Tohru Oishi, Synthetic Approach toward Structure Confirmation of Amphidinol 3
, The Sixth Korea-Japan Young Scientists Meeting on Natural Products Chemistry and Bioorganic Chemistry, 2011.06. |
