title: Regioselectivity of human UDP-glucuronosyltransferase isozymes in flavonoid biotransformation by metal complexation and tandem mass spectrometry.
abstract: Based on reactions with five flavonoids, the regioselectivities of twelve human UDP-glucuronosyltransferase (UGT) isozymes were elucidated. The various flavonoid glucuronides were differentiated based on LC-MS/MS fragmentation patterns of [Co(II)(flavonoid-H)(4,7-diphenyl-1,10-phenanthroline)(2)](+) complexes generated upon post-column complexation. Glucuronide distributions were evaluated to allow a systematic assessment of the regioselectivity of each isozyme. The various UGT enzymes, including eight UGT1A and four UGT2B, displayed a remarkable range of selectivities, both in terms of the positions of glucuronidation and relative reactivity with flavanones versus flavonols.
authors: Department of Chemistry and Biochemistry, University of Texas at Austin, 1 University Station A5300, Austin, TX 78712, USA.
authors: Scott A
authors: SA
authors: Robotham
authors: Jennifer S
authors: JS
authors: Brodbelt
mesh_terms: D001711:Biotransformation; D003035:Cobalt; D056831:Coordination Complexes / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry*; D020719:Glucuronides / Q000737:chemistry; D014453:Glucuronosyltransferase / Q000737:chemistry*; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry
chemical_list: D056831:Coordination Complexes; D005419:Flavonoids; D020719:Glucuronides; D007527:Isoenzymes; D003035:Cobalt; D014453:Glucuronosyltransferase