Elucidation of biosynthesis of tetrodotoxin and saxitoxin based on chemical study

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02921
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 38040:Bioorganic chemistry-related
• Research Institution: Tohoku University
• Principal Investigator: Yamashita Mari 東北大学, 農学研究科, 教授 (50192430)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: テトロドトキシン / サキシトキシン / 生合成 / 構造決定 / 麻痺性貝毒 / LCMS

Outline of Final Research Achievements

Screening of new tetrodotoxin (TTX) analogues resulted to identify 9-epiTTX and Tb-242B isolated from pufferfish. Presence of these compounds suggested a shunt pathway in TTX biosynthesis. New TTX analogues, 1-hydroxy-8-epiTTX , 1-hydroxy-8-epi-5,11-dideoxyTTX, Tgr-288, Tgr-210, Cep-228A were isolated from newts and structures were elucidated. The structures of these compounds supported monoterpene origin of TTX in terrestrial environments. The ring systems different saxitoxin (STX) analogues, M5-HA and M6-HA, were isolated from the scallops and their structures were determined. These compounds were considered as the metabolites of STX. 12beta-deoxyGTX5 and 12beta-deoxySTX were synthesized and identified in the paralytic shellfish toxins producing cyanobacterium and dinoflagellate.

Free Research Field

天然物化学

Academic Significance and Societal Importance of the Research Achievements

フグ毒として知られるテトロドトキシンの生合成の解明は、食品衛生上でも重要であり、世界中で二枚貝からテトロドトキシンが検出されて以来、特に注目を集めている。その中で、化学的なアプローチにより海洋と陸上からそれぞれ新規の類縁体を単離、構造決定して、生合成経路について考察した。また、麻痺性貝毒は、現在も猛威を振るっているので、二枚貝中の新規代謝物の同定や、生合成経路の推定は学術的にも社会的にも意義がある。