Rifampicin: biotransformation study using the fungus Cunninghamella elegans and monitoring through UHPLC-MS

Abstract

Drug biotransformation studies appear as an alternative to pharmacological investigations of metabolites, development of new drug candidates with reduced investment and most efficient production. The objective of this study was to evaluate the capacity of biotransformation of Rifampicin (RIF) by the filamentous fungus Cunninghamella elegans as a microbial model of mammalian metabolism. In 120 h, C. elegans transformed the drug into the following two metabolites: rifampicin quinone and novel metabolite. The products of rifampicin formed in vitro were monitored by HPLC-PDA, being identified through UHPLC–QTOF/MS. Metabolites were characterized according to their chromatographic profile, mass fragments and UV spectral data. The major metabolic pathways of rifampicin transformed by the fungus were oxidation, demethylation and mono-oxidation. The microbial transformation of RIF showed the potential of Cunninghamella species to produce RIF metabolites. This process can be used for a cost effective method for both known and unknown metabolite production.