Identification and Characterization of Bioactive Compounds Targeting Uropathogenic Escherichia coli from Sanjin Tablets

Abstract

Sanjin Tablets are completely natural preparation with significant efficacy in treating urinary tract infection. To identify the bioactive compounds from Sanjin Tablets, we separated components capable of binding to the soluble proteins of uropathogenic Escherichia coli (UPEC) by affinity binding and characterized their identities using liquid chromatography-mass spectrometry (LC-MS) analysis. Our study discovered eight compounds with E. coli protein-binding capabilities, and all these compounds were tracked back to the original natural ingredients of Sanjin Tablets. These compounds presented essentially no antibacteria activity, indicating that they affect UPEC by means other than directly killing the cells. Further molecular modeling analysis predicted molecular targets for these compounds and mapped the residues potentially involved in compound-target interactions. All the predicted targets turned out to be critical proteins regulating the metabolisms of E. coli, suggesting that these compounds may affect metabolic pathways in UPEC and inhibit pathogenesis. These data will benefit future design of drugs with higher efficacy and specificity on targeting pathogenic bacteria.