Studies on Paralytic Shellfish Poisons Contained in the Mussel Mytilus edulis from Funka Bay, Hokkaido

Abstract

Attempts were made to reveal the composition of paralytic shellfish poisons (PSP) in the mussel Mytilus edulis from Funka Bay, Hokkaido. The shucked mussels were extracted with 80% ethanol (pH 2.0). The extract was defatted with chloroform, treated with activated charcoal, and then purified by column chromatography on Bio-Gel P-2 and Bio-Rex 70. Each fraction thus obtained was analyzed by fluorescence intensity monitoring and mouse assay. PSP components contained in toxic fractions were identified by using cellulose acetate membrane electrophoresis and thin layer chromatography on silica gel. The mussel from Funka Bay was found to contain gonyautoxin VIII and its epimer, together with gonyautoxin I-V, saxitoxin and neosaxitoxin. The ratios of each PSP component in the total toxicity were as follows ; gonyautoxin I (31%), gonyautoxin II (12%), gonyautoxin III (15%), gonyautoxin IV (16%), gonyautoxin V (3%), gonyautoxin VIII plus its epimer (2%), saxitoxin plus neosaxitoxin (21%). This is the first time that gonyautoxin VIII and its epimer, which have been mainly detected in the bivalves from the western part of Japan, are detected in Hokkaido. It was revealed from these results that low toxic components having N-sulfonato carbamoyl group such as gonyautoxin V and VIII are present not only in the western part of Japan but also in the eastern part of Japan, particularly in Hokkaido.