Studies on paralytic shellfish poison from the oyster cultured in Senzaki Bay, Yamaguchi prefecture.

Attempts were made to search the cause of food poisoning in which 16 persons developed numbness in the mouth by ingestion the oyster Crassostrea gigas from Senzaki Bay, Yamaguchi Prefecture. The midgut glands of the oyster collected from Senzaki Bay, soon after the poisoning (mid-Jan., 1979) were extracted with acidified 80% ethanol. The extract was defatted three times with chloroform, treated with activated charcoal, and then purified by chromatography on Bio-Gel P-2 and Bio-Rex 70. The toxic fractions obtained were analyzed by cellulose acetate strip electrophoresis and thin layer chromatography on silica gel . The results showed that the fractions contained gonyautoxins-1, 2, 3, and 5, together with saxitoxin and neosaxitoxin. It was concluded from these results that the poisoning was caused by the paralytic shellfish poison which had accumulated in the oyster.