Occurrence of tetrodotoxin in a gastropod mollusk, "araregai" Niotha clathrata.

Paralytic toxicity was detected in a small gastropod mollusk, “araregai” Niotha clathrata. The toxin was partially purified from digestive glands of the gastropod by a method which essentially consisted of activated charcoal treatment, followed by chromatography on CM-Sephadex C-25 and Bio-Rex 70. Araregai toxin thus purified was indistinguishable from tetrodotoxin in thin-layer chromatographic and electrophoretic behaviors. In addition, gas chromatography-mass spectrometry of the alkali hydrolyzate of araregai toxin indicated the presence of quinazoline skeleton specific to tetrodotoxin. Araregai toxin was identified as tetrodotoxin from these results.