Seasonal changes of paralytic toxicity in purple clam, Soletellina diphos, and identification of the responsible toxin. In：P. Gopalakrishnakone and C.K. Tan (eds.)

Abstract

Attempts were made to elucidate the responsible toxin in the cultured purple clam Soletellina diphos which caused food poisoning incidents in South Taiwan in January 1986. Clam specimens were collected from the culture pond eight days after the outbreak and assayed for the anatomical distribution of lethal potency (as paralytic shellfish poison=PSP). The digestive gland showed the highest potency of 2,000±1,600 (mean±S.E.) MU/g, followed by other parts (160±110 MU/g) and siphon (33±24 MU/g). The lethal potency of the purple clam gradually decreased over one year, resulting in a value of 6±4 MU/g digestive gland in December. The toxin was partially purified from the ethanolic extract of toxic digestive glands, by ultrafiltration and Bio-Gel P-2 column chromatography. TLC, cellulose acetate membrane electrophoresis and !IPLC analyses demonstrated that the toxin consisted almost exclusively of gonyautoxiris 1-4. It was concluded from these results that the causative agent of the above food poisoning was nothing else than PSP.