A novel polyether toxin, yessotoxin, was isolated from scallops implicated in diarrhetic shellfish poisoning, and its planar structrure 1 was proposed by means of modern NMR techniques.
Diarrhetic shellfish poisoning is a gastroenteritis caused by ingestion of shellfishes infested with certain dinoflagellate toxins. 1) We previously isolated the causative agents and determined their structures to be okadaic acid 2) and its derivatives, 394) and novel polyether lactones named pectenotoxin. 4,5) We now report the isolation and structural determination of a new toxic constituent named yessotoxin (YTX, l_).6) Digestive glands of the scallops Patinopecten yessoensis (84 kg) collected at Mutsu Bay, Japan, in 1986 were homogenized, extracted with acetone, and the extract was partitioned between petroleum ether and CH30H-H20 (4:l). The concentrated methanolic layer was suspended in H20 and extracted with l-BuOH. The toxic extract was loaded on an aluminum oxide (Merck, Act II-III) column and eluted successively with CH2C12-CH30H (1:l) and 1% aqueous NH3-CH30H
(1:l)to obtain pectenotoxin in the lipid, YTX and okadaic acid derivatives in the aqueous eluate. Further purification was carried out by successive chromatography with the following columns and solvents. 1) ODS-Q3 (Fuji gel) and CH30H-H20 (1:l); 2)Develosil@ODS (Nomura Chem.