Glucuronidation of linoleic acid diols by human microsomal and recombinant UDP-glucuronosyltransferases: identification of UGT2B7 as the major isoform involved

Arch Biochem Biophys. 2001 May 15;389(2):176-86. doi: 10.1006/abbi.2001.2344.


Recent reports suggest that linoleic acid (LA) epoxides and diols are associated with important physiological, pharmacological, and pathological events in vivo. We have shown recently that LA-diols are excellent substrates for human liver microsomal UDP-glucuronosyltransferases (UGTs); however, it is not known if other human tissues glucuronidate LA-diols or which UGT isozyme(s) is involved. The present studies with human intestinal microsomes indicate that glucuronidation of LA-diols occurs throughout the gastrointestinal tract, with the highest activity in the small intestine. LA-diols yielded exclusively hydroxyl-linked glucuronides, whereas LA yielded the carboxyl-linked glucuronide. Studies with human recombinant UGTs demonstrated that only UGT2B7 glucuronidated LA and LA-diols. Kinetic analysis with UGT2B7 yielded apparent K(m) values in the range of 40-70 microM and V(max) values from 4.5 to 5.4 nmol/mg x min. These studies indicate that LA and LA-diols are excellent substrates for intestinal UGTs and provide the first evidence for UGT2B7 being the major isoform involved.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Female
  • Glucuronides / chemistry
  • Glucuronides / metabolism*
  • Glucuronosyltransferase / metabolism*
  • Humans
  • In Vitro Techniques
  • Intestines / enzymology
  • Isoenzymes / metabolism
  • Kinetics
  • Linoleic Acids / chemistry
  • Linoleic Acids / metabolism*
  • Male
  • Microsomes / enzymology
  • Microsomes, Liver / enzymology
  • Middle Aged
  • Molecular Structure
  • Recombinant Proteins / metabolism


  • Glucuronides
  • Isoenzymes
  • Linoleic Acids
  • Recombinant Proteins
  • UGT2B7 protein, human
  • Glucuronosyltransferase