Abstract: Methods for producing phycotoxins from natural sources, wherein the phycotoxins have a definite compositional profile are described herein. In one embodiment, the phycotoxins are produced by cyanobacteria. In one embodiment, the phycotoxins are produced by continuously culturing cyanobacteria under strictly controlled conditions in order to produce a definite compositional profile. In another embodiment, organic nutrients are added to the culture that allows for higher concentrations of neosaxitoxin and saxitoxin or gonyaulatoxins 2 and 3 per weight of the algae. The phycotoxins are isolated primarily from the bacteria but can also be isolated from the culture medium. In one embodiment, the cyanobacteria produce only neosaxitoxin and saxitoxin in a ratio of about 6:1, 5:1, 4:1, or 3:1. In a preferred embodiment, the amount of saxitoxin is less than 20% by weight of the total amount of neosaxitoxin and saxitoxin produced. In another embodiment, the cyanobacteria produce only GTX2 and GTX 3.

Abstract: Phycotoxins are purified from a mixture of phycotoxins produced in a continuous process. Cyanobacteria are produced in a continuous culture, then lyzed, the cells pelleted and extracted, and the extract purified using an organic solvent-aqueous mixture and repeated passage through a diatomaceous earth column. The column is washed with acetic acid, then the neosaxitoxin extracted with an alcohol-water mixture. The eluate is passed through activated charcoal columns, which are washed with distilled water to remove the retained pigments and impurities, the further purified by HPLC. In one embodiment, the process produces only neosaxitoxin and saxitoxin. In another embodiment, the process produces only GTX2/3.