PT  - JOURNAL ARTICLE
AU  - N R Niemeijer
AU  - T K Gerding
AU  - R A De Zeeuw
TI  - Glucuronidation of labetalol at the two hydroxy positions by bovine liver microsomes. Isolation, purification, and structure elucidation of the glucuronides of labetalol.
DP  - 1991 Jan 01
TA  - Drug Metabolism and Disposition
PG  - 20--23
VI  - 19
IP  - 1
4099  - http://dmd.aspetjournals.org/content/19/1/20.short
4100  - http://dmd.aspetjournals.org/content/19/1/20.full
SO  - Drug Metab Dispos1991 Jan 01; 19
AB  - Glucuronidation is known to be a major metabolic pathway for labetalol. As the drug contains a phenolic and an alcoholic hydroxy group, in principle two regio isomeric glucuronides can be formed. By incubating the substrate labetalol with bovine liver microsomes, in the presence of the co-substrate UDP-glucuronic acid, both hydroxy positions were glucuronidated. The different glucuronides were isolated from the incubation mixture using Bond-Elut extraction cartridges and separated by means of high performance liquid chromatography. The formation of glucuronides was confirmed by performing reference incubations using radiolabeled UDP-glucuronic acid. Structure elucidation of the various glucuronides was done by nuclear magnetic resonance, ultraviolet spectroscopy, and mass spectrometry.