Occurrence of tetrodotoxin in the gastropod mollusk Tutufa lissostoma (frog shell).

Paralytic toxicity was detected in gastropod mollusk Tutufa lissostoma (frog shell) specimens collected from Suruga Bay, Shizuoka Prefecture, Japan. Seventeen of the 22 digestive glands removed were toxic; the highest toxicity, expressed as tetrodotoxin (TTX), being as high as 700 mouse units (MU) per gram. Attempts were made to isolate the toxin from pooled digestive glands by activated charcoal treatment and column chromatography on Amberlite IRC-50, CM-Sephadex C-25 and Bio-Rex 70. The toxin showed a specific toxicity (as TTX) of 4200 MU/mg. It exhibited the same thin-layer chromatographic and electrophoretic behaviors and 1H-NMR spectrum as TTX. The toxin gave the same pattern as the TTX standard when alkali-hydrolyzed and analyzed by GC--MS, indicating that it contains the quinazoline skeleton specific to TTX. From these results the frog shell toxin was identified as TTX.