Analysis of vitamin E metabolites including carboxychromanols and sulfated derivatives using LC/MS/MS - PubMed (original) (raw)

Analysis of vitamin E metabolites including carboxychromanols and sulfated derivatives using LC/MS/MS

Qing Jiang et al. J Lipid Res. 2015 Nov.

Abstract

Tocopherols and tocotrienols are metabolized via hydroxylation and oxidation of their hydrophobic side chain to generate 13'-hydroxychromanols (13'-OHs) and various carboxychromanols, which can be further metabolized by conjugation including sulfation. Recent studies indicate that long-chain carboxychromanols, especially 13'-carboxychromanol (13'-COOH), appear to be more bioactive than tocopherols in anti-inflammatory and anticancer actions. To understand the potential contribution of metabolites to vitamin E-mediated effects, an accurate assay is needed to evaluate bioavailability of these metabolites. Here we describe an LC/MS/MS assay for quantifying vitamin E metabolites using negative polarity ESI. This assay includes a reliable sample extraction procedure with efficacy of ≥ 89% and interday/intraday variation of 3-11% for major metabolites. To ensure accurate quantification, short-chain, long-chain, and sulfated carboxychromanols are included as external/internal standards. Using this assay, we observed that sulfated carboxychromanols are the primary metabolites in the plasma of rodents fed with γ-tocopherol or δ-tocopherol. Although plasma levels of 13'-COOHs and 13'-OHs are low, high concentrations of these compounds are found in feces. Our study demonstrates an LC/MS/MS assay for quantitation of sulfated and unconjugated vitamin E metabolites, and this assay will be useful for evaluating the role of these metabolites in vivo.

Keywords: liquid chromatography tandem mass spectrometry; metabolism; sulfation; tocopherol; tocotrienol.

Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

PubMed Disclaimer

Figures

Fig. 1.

Fig. 1.

Structures of vitamin E forms.

Fig. 2.

Fig. 2.

Vitamin E (γT) metabolism and metabolites. Vitamin E forms are metabolized via ω-hydroxylation and oxidation to generate 13′-OH and 13′-COOH, which is subsequently metabolized via β-oxidation to form 11′-, 9′-, 7′-, 5′-, and 3′-COOH. Sulfation of intermediate carboxychromanols appears to take place in parallel with β-oxidation in response to supplementation of vitamin E forms.

Fig. 3.

Fig. 3.

LC/MS/MS fragmentation of vitamin E metabolites.

Similar articles

Cited by

References

    1. Jiang Q. 2014. Natural forms of vitamin E: metabolism, antioxidant, and anti-inflammatory activities and their role in disease prevention and therapy. Free Radic. Biol. Med. 72: 76–90. - PMC - PubMed
    1. Birringer M., Pfluger P., Kluth D., Landes N., Brigelius-Flohe R. 2002. Identities and differences in the metabolism of tocotrienols and tocopherols in HepG2 cells. J. Nutr. 132: 3113–3118. - PubMed
    1. Sontag T. J., Parker R. S. 2002. Cytochrome P450 omega-hydroxylase pathway of tocopherol catabolism. Novel mechanism of regulation of vitamin E status. J. Biol. Chem. 277: 25290–25296. - PubMed
    1. Jiang Q., Freiser H., Wood K. V., Yin X. 2007. Identification and quantitation of novel vitamin E metabolites, sulfated long-chain carboxychromanols, in human A549 cells and in rats. J. Lipid Res. 48: 1221–1230. - PMC - PubMed
    1. Freiser H., Jiang Q. 2009. Gamma-tocotrienol and gamma-tocopherol are primarily metabolized to conjugated 2-(beta-carboxyethyl)-6-hydroxy-2,7,8-trimethylchroman and sulfated long-chain carboxychromanols in rats. J. Nutr. 139: 884–889. - PMC - PubMed

Publication types

MeSH terms

Substances

Grants and funding

LinkOut - more resources