Rhodopeptins, novel cyclic tetrapeptides with antifungal activities from Rhodococcus sp II.: Structure elucidation

The structures of rhodopeptins. novel antifungal peptides. were determined on the basis of physico-chemical analyses of the intact molecules and their acid hydrolysates. The structures of rhodopeptins C1, C2, C3, C4 and B5 were determined to be cyclo (-Gly-L-Orn-L-Val-3-amino-10-methyldodecanoyl-) cyclo (-Gly-L-Orn-L-Ile-3-amino-10-methyldodecanoyl-) cyclo (-Gly-L-Orn-L-Val-3-amino- 12-methyltridecanoyl-), cyclo (-Gly-L-Orn-L-Val-3-amino-12-methyltetradecanoyl-) and cyclo (-Gly-L-Lys-L-Val-3-amino-13-methyltetradecanoyl-) respectively. They are novel cyclic tetrapeptides containing a lipophilic beta-amino acid.