Toxins of a blue-green alga: similarity to saxitoxin.

Toxins were isolated from the freshwater blue-green alga Aphanizomenon flos-aquae. The toxic fractions were characterized by paper and thin-layer chromatography, isolation characteristics, infrared spectra, physiological activity, and reactivity with specific color reagents. The toxic fractions appear to be similar, if not identical, to saxitoxin (paralytic shellfish toxin), which is produced by the marine dinoflagellate Gonyaulax catenella.