Carbamothioic S-acid derivative and kigamicins, the activated production of silent metabolites in Amycolatopsis alba DSM 44262Δabm9 elicited by N-acetyl-D-glucosamine

One new carbamothioic S-acid derivative (1) and five known kigamicin derivatives (2–6) were isolated from the fermentation extract of Amycolatopsis alba DSM 44262Δabm9 elicited by N-acetyl-D-glucosamine. HPLC-DAD-UV analyses indicated that the DSM 44262Δabm9 strain did not produce these metabolites originally and the production of 1–6 was induced by adding 25 mM N-acetyl-D-glucosamine in the culture medium. The structures of 1–6 were identified on the basis of NMR spectroscopic data and high-resolution ESIMS. These results highlight that addition of N-acetyl-D-glucosamine in the microbial culture medium could activate cryptic gene expression, induce and increase the production of new or known secondary metabolites.