ISOLATION OF CYLINDROSPERMOPSIN FROM A CYANOBACTERIUM UMEZAKIA NATANSAND ITS SCREENING METHOD

In 1987 a cyanobacterium (blue-green alga) Umezakia natans was isolate d from Lake Mikata, Fukui, Japan, as a new member of the family of Sti gonemataceae. The crude extract of U. natans showed hepatotoxicity to mice, from which a toxic compound was isolated. The toxin was identica l in all respects to a recently reported hepatotoxin, cylindrospermops in, isolated from an Australian tropical cyanobacterium Cylindrospeimo psis raciborskii. Because cylindrospermopsin causes fatty liver and ce ntral necroses in mice and is suspected of being an agent causing huma n hepatoenteritis, its monitoring in drinking water supplies has been required. So a rapid screening method including four steps, extraction , clean-up, separation, and determination, has been proposed for cylin drospermopsin. A combination of a clean-up using HP-20 and C-18-cartri dge, and HPLC with photodiode array detector made it possible to estab lish a screening method for the toxin. The established method was appl ied to five samples and cylindrospermopsin was traced in one of them.