Structures of ADP-Ribosylated Rifampicin and Its Metabolite: Intermediates of Rifampicin-ribosylation by Mycobacterium smegmatis DSM43756

Abstract

23-(O-ADP-Ribosyl)rifampicin [RIP-TAs (3, Na⁺ form), RIP-TAf (4, H⁺ form)] was obtained as an intermediate in the conversion process of rifampicin (1) to RIP-Mb (2) that is mediated by cell homogenates of Mycobacterium smegmatis DSM43756 or of Escherichia coli carrying a mycobacterial mono(ADP-ribosyl) transferase gene, in the presence of NADH. 23-[O-(5'-Phosphoribosyl)]rifampicin (5, RIP-TAp) was also obtained by the reaction of rifampicin with NADH in the presence of a homogenate of M. smegmatis. The structures of 3, 4, and 5 were determined by means of MS and NMR analyses.