Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1999 Feb;27(2):309-16.

Identification of (-)-epicatechin metabolites and their metabolic fate in the rat

Affiliations
  • PMID: 9929521

Identification of (-)-epicatechin metabolites and their metabolic fate in the rat

K Okushio et al. Drug Metab Dispos. 1999 Feb.

Abstract

After oral administration of (-)-epicatechin to rats, three kinds of metabolites (M-1, M-2, and M-3) were detected in the urine. After isolation of the compounds by preparative high-performance liquid chromatography, structural analysis was carried out by mass spectrometry and NMR. As a result, two compounds, M-1 and M-2, were identified as (-)-epicatechin and 3'-O-methyl-(-)-epicatechin, respectively. M-3 was suggested to be a monomethylated (-)-epicatechin, but definitive elucidation was not possible because of its small quantity. Methylation of (-)-epicatechin with rat liver homogenates and subsequent structural analysis showed that M-3 was 4'-O-methyl-(-)-epicatechin. Identification of conjugated forms of the urinary metabolites also was attempted. Two conjugates in the urine were purified and analyzed by mass spectrometry and NMR. These conjugates were shown to be (-)-epicatechin-5-O-beta-glucuronide and 3'-O-methyl-(-)-epicatechin-5-O-beta-glucuronide, respectively. Metabolism and excretion of (-)-epicatechin were examined. (-)-Epicatechin and its methylated derivatives in the free forms were detected in plasma and urine, but not in bile. Significant differences in the excretion ratio of the conjugated forms of (-)-epicatechin and 3'-O-methyl-(-)-epicatechin were observed between urine and bile. Time-course analysis of (-)-epicatechin metabolites showed that the most predominant metabolites in plasma and urine were the conjugates of (-)-epicatechin and 3'-O-methyl-(-)-epicatechin, respectively, and the cumulative amount of the urinary metabolites excreted during the 24-h period was about 8% of the administered (-)-epicatechin.

PubMed Disclaimer

Similar articles

Cited by

LinkOut - more resources

-