Barbamide, a chlorinated metabolite with molluscicidal activity from the Caribbean cyanobacterium Lyngbya majuscula.

The lipid extract from a Curaçao collection of the marine cyanobacterium Lyngbya majuscula was toxic to the mollusc Biomphalaria glabrata. Subsequent bioassay-guided fractionation of this extract yielded a novel lipopeptide, barbamide, as the active compound (LC100 = 10 micrograms/mL). The structure of barbamide was determined by spectroscopic methods and was found to contain several unique structural features, including a trichloromethyl group and the methyl enol ether of a beta-keto amide.