L 156602 is a cyclic hexapeptide isolated from a strain of Streptomyces by researchers at Merck USA and reported in 1991. L 156602 belongs to the aurantimycin class and, like other members, is active against Gram positive bacteria. L 156602 was foremost discovered as a competitive binding inhibitor of the inflammatory peptide, C5a, to cell surface receptors on macrophages. In vivo, L 156602 profoundly suppresses footpad edema induced by concanavalin A and completely suppresses the infiltration of mononuclear leukocytes and neutrophils into the site of inflammation.