STUDIES ON POLYETHERIN A. I ISOLATION AND CHARACTERIZATION

Abstract

A new antibiotic polyetherin A was isolated from cultures of Streptomyces hygroscopicus strain E-749. The antibiotic is active against Gram positive bacteria including mycobacteria, and phytopathogenic fungi. The substance is obtained as colorless needles, m. p. 183.5-185°C, and is a lipophilic acid with the molecular formula C42-43H72-74O12.It is dextrorotatory active and has no absorption in the ultraviolet and visible regions. The infrared and n. m.r. spectra of the antibiotic and some derivatives revealed a carboxyl, a methoxyl and two vicinal hydroxyl groups but no carbonyl function. This information suggested polycyclic polyether structure for the antibiotic.