Rhodopeptins (Mer-N1033), novel cyclic tetrapeptides with antifungal activity from Rhodococcus sp. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities.

Five novel cyclic tetrapeptides, named rhodopeptin C1, C2, C3, C4 and B5, were isolated from a strain named Rhodococcus sp. Mer-N1033. They are a novel type of cyclic tetrapeptide composed of a beta-amino acid and three usual alpha-amino acids. Rhodopeptins show high in vitro antifungal activity against Candida albicans and Cryptococcus neoformans, whereas they show no activity against bacteria.