Preparative scale conversion of gonyautoxins to neosaxitoxin

摘要

A method of preparing neosaxitoxin in quantities of a purity sufficient to allow the compound to be used as an active pharmaceutical ingredient (API) is described. The method includes the reductive desulfonation of an unresolved mixture of gonyautoxin 1 (GTX1) and gonyautoxin 4 (GTX4).