Dumulmycin, an Antitubercular Bicyclic Macrolide from a Riverine Sediment-Derived <i>Streptomyces</i> sp.

Abstract

Dumulmycin (<b>1</b>) was isolated from <i>Streptomyces</i> sp. DM28, a bacterial strain from a riverine sediment sample. The structure of <b>1</b> was elucidated as a bicyclic macrolide possessing 19-membered and 5-membered rings by spectroscopic analysis. The stereochemistry of <b>1</b> was determined by <i>J</i>-based configuration analysis, ROESY NMR data, DP4 calculations, and the modified Mosher's method. Genetic analysis identified a <i>trans</i>-acyltransferase polyketide biosynthetic gene cluster for <b>1</b>. Dumulmycin exhibited <i>in vitro</i> antitubercular activity (MIC₅₀ = 27.1 μM).