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.