Ciguatoxin, chemical structure

The membrane ion channels are the molecular targets for several toxins that induce fast effects in cells. The chemical structure ofYTX [5-7] resembles those of brevetoxins and ciguatoxins, with more than ten contiguous ether rings. These two groups of toxins are fast and potent activators of voltagegated sodium channels, therefore some interaction of YTX with cellular ion channels could be expected. However, YTX did not interact with sodium channels and did not induce any competitive displacement of brevetoxins from site five of sodium channels [8]. 

Because the chemical structures of the toxins and metabolites are not known, it is impossible to state that ciguatoxin extracted from fish is derived solely from G. toxicus or any other dinoflagellate. It is more likely that the diverse symptoms of the illness are a consequence of a combination of several toxins (Tindall et al. 1984) and/or metabolites of these toxins produced by one or more organisms. 

As this book goes to press, two events have occurred that bear mention. First, the structure of ciguatoxin has just been published in the Journal of the American Chemical Society (1989, 111, 8929-8931). Despite the determined efforts of many scientists over several years, the structure of this important marine toxin, discussed in Chapters 8,11, and 13, has resisted elucidation. Its publication marks a notable achievement, attained through the cooperation of investigators with different, complementary skills. 

Nukina M, Tachibana K, Koyagani LM, Scheuer PI (1983) Structural studies of ciguatoxin. Presented at Symposium on Seafood Toxins, Washington D.C. American Chemical Society, (Abst 135). 

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