Metabolism of olaquindox in rat and identification of metabolites in urine and feces using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry
Article first published online: 14 MAR 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Rapid Communications in Mass Spectrometry
Volume 25, Issue 7, pages 889–898, 15 April 2011
How to Cite
Bi, Y., Wang, X., Xu, S., Sun, L., Zhang, L., Zhong, F., Wang, S., Ding, S. and Xiao, X. (2011), Metabolism of olaquindox in rat and identification of metabolites in urine and feces using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry. Rapid Commun. Mass Spectrom., 25: 889–898. doi: 10.1002/rcm.4928
- Issue published online: 17 MAR 2011
- Article first published online: 14 MAR 2011
- Manuscript Revised: 30 DEC 2010
- Manuscript Accepted: 30 DEC 2010
- Manuscript Received: 28 OCT 2010
Olaquindox (OLA), N-(2-hydroxyethyl)-3-methyl-2-quinoxalincarboxamide-1,4-dioxide, is an antimicrobial and growth-promoting agent for animals, which has been banned or allowed only limited use for its potential toxicity. To thoroughly understand the metabolic pathways, metabolism of OLA in rat was studied using ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry with MSE and mass defect filtering techniques. Twenty metabolites (M1–M20) were detected in rat feces and urine, of which nine phase I metabolites (M6, M7, M11–M16) and four phase II metabolites (M17–M20) were found in vivo for the first time. The structures of metabolites were reliably characterized on the basis of accurate mass and fragment ions in MSE spectra. The major metabolic pathways reported previously in pigs, including reduction of NO groups, oxidation of the alcohol and hydrolysis, were also confirmed in this study. In addition, hydroxylation of the methyl group, N-dehydroxyethylation and glucuronidation were also proved to be the important metabolic pathways, which contribute to improving our knowledge about in vivo metabolism of OLA. Copyright © 2011 John Wiley & Sons, Ltd.