ArticleAnalytical biochemistry2009
Optimization of the enzymatic hydrolysis and analysis of plasma conjugated gamma-CEHC and sulfated long-chain carboxychromanols, metabolites of vitamin E.
Article in Analytical biochemistry, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.
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Who cites it
10 citing papers in PubMed, 32 citations in OpenAlex.
- Combining vitamin E metabolite 13'-carboxychromanol and a lactic acid bacterium synergistically mitigates colitis and colitis-associated dysbiosis in mice.Free radical biology & medicine · 2025Article
- Metabolism of natural forms of vitamin E and biological actions of vitamin E metabolites.Free radical biology & medicine · 2022Article
- Gamma-tocopherol, a major form of vitamin E in diets: Insights into antioxidant and anti-inflammatory effects, mechanisms, and roles in disease management.Free radical biology & medicine · 2022Article
- Concise Synthesis of (ACS omega · 2021Article
- Tocopherols and Tocotrienols Are Bioavailable in Rats and Primarily Excreted in Feces as the Intact Forms and 13'-Carboxychromanol Metabolites.The Journal of nutrition · 2020Article
- Complexity of vitamin E metabolism.World journal of biological chemistry · 2016Review
- Analysis of vitamin E metabolites including carboxychromanols and sulfated derivatives using LC/MS/MS.Journal of lipid research · 2015Article
- Natural forms of vitamin E: metabolism, antioxidant, and anti-inflammatory activities and their role in disease prevention and therapy.Free radical biology & medicine · 2014Review
- Mechanisms for the prevention of vitamin E excess.Journal of lipid research · 2013Review
- α-Tocopherol injections in rats up-regulate hepatic ABC transporters, but not cytochrome P450 enzymes.Free radical biology & medicine · 2011Article
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Authors and funding
2 authors at 1 institution in 1 country.
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Abstract
Natural forms of vitamin E are metabolized by omega-hydroxylation and beta-oxidation of the hydrophobic side chain to generate urinary-excreted 2-(beta-carboxyethyl)-6-hydroxychroman (CEHC) and CEHC conjugates (sulfate, glucuronide, or glucoside). We recently showed that sulfated long-chain carboxychromanols, the conjugated intermediate beta-oxidation products, are formed from tocopherols and tocotrienols in human cells and in rats. CEHC conjugates have been quantified after being converted to its unconjugated counterpart by sulfatase/glucuronidase. Although the enzymatic hydrolysis is critical for appropriate quantification of conjugated CEHC, it is not clear whether brief incubation of the plasma with sulfatases/glucuronidases results in complete deconjugation of conjugated CEHC. Here we show that quantitative hydrolysis of the conjugated vitamin E metabolites in the plasma requires an extraction procedure using methanol/hexane (2 ml/5 ml) and an overnight sulfatase/glucuronidase hydrolysis. Using this procedure, we demonstrate that conjugated gamma-CEHC and some sulfated long-chain carboxychromanols are fully deconjugated. In contrast, direct enzymatic hydrolysis of the whole plasma underestimates the conjugated metabolites by at least threefold. This protocol may be also useful for the analysis of other conjugated phenolic compounds in complicated biological matrices such as plasma.
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