Methods for purifying phycotoxins, pharmaceutical compositions containing purified phycotoxins, and methods of use thereof

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.