Dinoflagellate neurotoxins related to saxitoxin: Structures of toxins C3 and C4, and confirmation of the structure of neosaxitoxin

Article abstract of DOI:10.1016/S0040-4039(01)91069-X

By x-ray crystallography of the 11β epimer, toxins C3 and C4 are shown to be 21-sulfo-N-1-hydroxysaxitoxin-11α- and 11β-hydroxysulfate, confirming the position and identity of the 3 substituents which, with the parent compound, form the array of 12 saxitoxins found in Protogonyaulax.