Umezawamides, new bioactive polycyclic tetramate macrolactams isolated from a combined-culture of Umezawaea sp. and mycolic acid-containing bacterium.

New polycyclic tetramate macrolactams, Umezawamides A (1) and B (2) were isolated from a combined-culture of Umezawaea sp. RD066910 and mycolic-acid containing bacterium Tsukamurella pulmonis TP-B0596. Their planar structures and partial stereochemistries were determined based on the spectroscopic analysis, MMFF conformational search, and ECD calculations. Umezawamides are the first secondary metabolites isolated from the genus Umezawaea and they exhibited cytotoxicities to P388 murine leukemia cells. Furthermore, umezawamide A (1) showed growth inhibitory activity against Candida albicans.