Glucosylquestiomycin, a novel antibiotic from Microbispora sp. TP-A0184: fermentation, isolation, structure determination, synthesis and biological activities.

Glucosylquestiomycin, a novel N-glucopyranoside of questiomycin A, was isolated from the culture broth of Microbispora sp. TP-A0184. The absolute configuration of the sugar was determined as D-configuration by chemical synthesis. The new antibiotic showed antibacterial activity against gram-positive and -negative bacteria and yeasts and cytotoxic activity against U937 cells.