Verification of biooxidation of ciguatoxins leading to species specific toxin profiles

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07594
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic life science
• Research Institution: Fisheries Research and Education Agency (2016-2017); National Fisheries University (2015)
• Principal Investigator: Ikehara Tsuyoshi 国立研究開発法人水産研究・教育機構, 水産大学校, 教授 (90359951)
• Co-Investigator(Renkei-kenkyūsha): OSHIRO Naomasa 国立医薬品食品衛生研究所, 食品衛生管理部第二室, 室長 (20507032)
• Research Collaborator: YASUMOTO Takeshi
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: シガテラ / シガトキシン / 酸化酵素

Outline of Final Research Achievements

Ciguatera fish poisoning is a clinical syndrome that causes neurological symptoms in patients and affects more than 50,000 people per year. This foodborne illness results from eating fish from warm water regions around the world that contain natural marine toxins that are collectively known as ciguatoxins (CTXs). In the Pacific, these toxins are produced by the dinoflagellate Gambierdiscus toxicus, which accumulates in fish through the food chain and undergoes oxidative modification, giving rise to numerous analogs. In this study, we aimed to verify the biooxidation process of CTXs in vitro using CTX4A/4B and CTX3C as substrates, and recombinant human CYP3A4, fish liver S9 fractions, and microsomal fractions as oxidizing enzymes. The reaction products were identified by LC-MS/MS analysis using reference toxins, which unambiguously confirmed the production of CTX1B, 54-deoxyCTX4B, 52-epi-54-deoxyCTX1B, 2-hydroxyCTX3C, and 2,3-dihydroxyCTX3C.

Free Research Field

海洋自然毒