X-14873H

Streptomyces sp. X-14873 (ATCC 31679) has been found to produce a number of secondary metabolites. Three have been identified as the novel actinomycins, X-14873B, C and D, each of which contains both proline and 3-hydroxy-5-methylproline. Potentially, the most important microbial product from this fermentation is the novel polyether antibiotic X-14873A which differs from lysocellin only in the substituents at carbons C-4 and C-5 in the tetrahydropyranyl ring. The methyl group and proton in lysocellin are replaced by an ethyl and hydroxyl group, respectively in X-14873A. In addition, two other novel polyethers, X-14873H and G, were isolated and shown to differ from 1 in lacking a carboxyl group and in the case of 3, possessing an ether bridge across the terminal tetrahydrofuranyl ring system.

Novel polyether antibiotics X-14873A, X-14873G, and X-14873H are produced by the fermentation of Streptomyces sp. X-14873 (ATCC 31679). This report presents taxonomic studies and fermentation conditions for the antibiotic producing culture. The antibiotics are mainly active against Gram-positive bacteria. The ionophore properties of X-14873A are also characterized.