Regioselectivity of human UDP-glucuronosyl-transferase 1A1 in the synthesis of flavonoid glucuronides determined by metal complexation and tandem mass spectrometry.

ABSTRACT: A three-part tandem mass spectrometric strategy that entails MSn analysis and a post-column LC-MS cobalt complexation method is developed to identify flavonoid monoglucuronide metabolites synthesized using the 1A1 isozyme of human UDP-glucuronosyltransferase (UGT). Ten flavonoid aglycons were used as substrates, spanning the subclasses of flavones, flavonols, and flavanones. The products were characterized by LC-MS and LC-MSn, with post-column cobalt complexation employed to pinpoint the specific sites of conjugation. The dissociation of complexes of the form [Co(II) (flavonoid glucuronide - H) (4,7-diphenyl-1,10-phenanthroline)(2)]+ allowed identification of the products and differentiation of isomers. The correlation between glycosylation site and elution order is used to provide additio

SUBMITTER: Davis BD 

PROVIDER: S-EPMC2277483 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature