A tetrodotoxin-like substance as a minor toxin in the xanthid crab Atergatis floridus

Toxins were extracted from the xanthid crab Atergatis floridus inhabiting Ishigaki Island, Okinawa, and subjected to several types of chromatography, resulting in separation into gonyautoxin and saxitoxin fractions. Thin-layer chromatographic and electrophoretic analyses showed that the gonyautoxin fraction was composed of gonyautoxins 1-4, along with some unknown compounds. Gas chromatography-mass spectrometry demonstrated that the gonyautoxin fraction gave rise to the C9-base when alkali-hydrolyzed, indicating that this fraction contained a tetrodotoxin-like compound possessing the quinazoline skeleton specific to tetrodotoxin. The saxitoxin fraction consisted of neosaxitoxin, saxitoxin and two unknown compounds.