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.
Keywords: Amycolatopsis alba DSM 44262Δabm9; N-acetyl-D-glucosamine; carbamothioic S-acid; elicitation; kigamicins.