Microtermolides A and B from Termite-Associated Streptomyces sp and Structural Revision of Vinylamycin

Microtermolides A (1) and B (2) were isolated from a.Streptomyces sp. strain associated with fungus-growing termites. The structures of 1 and 2 were determined by 1D- and 2D-NMR spectroscopy and high-resolution mass spectrometry. Structural elucidation of 1 led to the re-examination of the structure originally proposed for vinylamycin (3). Based on a comparison of predicted and experimental H-1 and C-13 NMR chemical shifts, we propose that vinylamycin's structure be revised from 3 to 4.