PROMOINDUCIN, A NOVEL THIOPEPTIDE PRODUCED BY STREPTOMYCES SP SF2741

Our continued screening to find tipA promoter-inducing substances resu lted in the isolation of promoinducin from a mycelial extract of Strep tomyces sp, SF2741, Based on various 1D- and 2D-NMR studies, including field gradient (FG)-COSY, HSQC, FG-HMBC, phase-sensitive. C-13-decoup led HMBC and NOESY experiments, promoinducin's structure was establish ed to be a thiopeptide composed of threonine, some unusual amino acids masked at their carboxyl groups by thiazole or methyloxazole rings, s ulfomycinamate and five dehydroalanine residues. Promoinducin induced the tipA promoter at 40 ng/ml, and also exhibited strong antibacterial activity against some Gram-positive bacteria.