Identification and formation pattern of metabolites of cyazofamid by soil fungus Cunninghamella elegans

Abstract

This study was performed to investigate the formation of microbial metabolites from cyazofamid by the soil fungus Cunninghamella elegans. The incubation of cyazofamid with C. elegans was conducted for 10 days. Cyazofamid disappeared after 7 days of incubation, producing three metabolites. Metabolites identified by liquid chromatography-tandem mass spectrometry were 4-chloro-5-(4-(hydroxymethyl) phenyl)-imidazole-2-carbonitrile (CHCN), 4-(4-chloro-2-cyanoimidazole-5yl) benzoic acid (CCBA) and 4-chloro-2-cyano-5-(4-(hydroxymethyl) phenyl) N,N-dimethyl-1H-imidazole-1-sulfonamide (CCHS). A new metabolite, CCHS, was further confirmed by H-1-C-13 HSQC (heteronuclear single-quantum correlation) using nuclear magnetic resonance. As a possible metabolic pathway, cyazofamid could be oxidized to CCHS, degraded to CHCN and further oxidized to CCBA. The metabolic system of C. elegans would be a powerful tool for predicting and identifying phase I metabolites that could be formed in mammalian systems.