Cytotoxic Veraguamides, Alkynyl Bromide-containing cyclic Depsipeptides from the marine Cyanobacterium cf. Osciallatoria margaritifera. EmilyCytotoxic Veraguamides, Alkynyl Bromide-containing cyclic Depsipeptides from the marine Cyanobacterium cf. Osciallatoria margaritifera.

Abstract

A family of cancer cell cytotoxic cyclodepsipeptides, veraguamides A-C( 1-3) and H-L( 4-8), were isolated from a collection of cf. Oscillatoria margaritifera obtained from the Coiba National Park, Panama, as part of the Panama International Cooperation Biodiversity Group program. The planar structure of veraguamide A (1) was deduced by 2D NMR spectroscopy and mass spectrometry, whereas the structures of 2-8 were mainly determinedbyacombinationof 1HNMRandMS2/MS3techniques. These new compounds are analogous to the mollusk-derived kulomo’opunalidenaturalproducts,withtwooftheveraguamides(Cand H) containing the same terminal alkyne moiety. However, four veraguamides, A, B, K, and L, also feature an alkynyl bromide, a functionality that has been previously observed in only one other marine natural product, jamaicamide A. Veraguamide A showed potent cytotoxicity to the H-460 human lung cancer cell line (LD50 = 141 nM).