Caprazamycins, Novel Lipo-nucleoside Antibiotics, from Streptomyces sp: II. Structure Elucidation of Caprazamycins

Novel antibiotics, active against acid-fast bacteria, caprazamycins, were isolated from the culture broth of Streptomyces sp. MK730-62F2. The planar structures of the compounds were determined by 2D NMR spectroscopic study. Furthermore, the absolute structure of caprazamycin B ( 2 ) was established by NMR spectroscopy and X-ray crystallography of its degradation products and by total synthesis of the 5-amino-5-deoxy- D -ribose moiety. In the course of degradation studies of 2 under alkaline and acidic conditions, we obtained the two core components, caprazene ( 11 ) and caprazol ( 14 ), respectively, in high yield.Structurally, caprazamycins belong to a family of lipo-uridyl antibiotics, which have been discovered as specific inhibitors of a bacterial translocase.