Cyclomarins A-C, new antiinflammatory cyclic peptides produced by a marinebacterium (Streptomyces sp.)

Three new cyclic heptapeptides, cyclomarins A-C (1-3), were isolated from e xtracts of a cultured marine bacterium collected in the vicinity of San Die go, CA. The major metabolite, cyclomarin A (1), contains three common and f our unusual (or unique) amino acids. The structures of the new metabolites were determined using 1D and 2D NMR methods, and the stereochemistry was de termined from an X-ray crystal structure of the diacetate derivative of 1. Cyclomarin A (1) displays significant antiinflammatory activity in both in vivo and in vitro assays.