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Oxidative catabolism of alpha-tocopherol in rat liver microsomes

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Van Houte, H de Hoffmann, Edmond [UCL] Van Veldhoven, PP Mannaerts, GP. Carchon, H. Baes, Michel [UCL] Declercq, PE

The goal of this study was to clarify the mechanism responsible for the catabolism of a-tocopherol. The vitamin, bound to albumin, was incubated with rat liver microsomes and appeared to be broken down. Optimal production of the metabolite was obtained when 1 mg of microsomal protein was incubated with 36 muM of alpha -tocopherol in the presence of 1.5 mM of NADPH. Chromatographic and mass spectrometric analyses of the metabolite led to the conclusion that it consists of an omega -acid with an opened chroman ring, although we could not perform nuclear magnetic resonance analysis to confirm this. Our data show that ol-tocopherol is omega -oxidized to a carboxylic acid and that this process can occur in rat liver microsomes in the presence of NADPH and O-2. The oxidation to the quinone structure appears to be a subsequent event that may be artifactual and/or catalyzed by a microsomal enzyme(s).

Document type Article de périodique (Journal article) – Article de recherche
Access type Accès restreint
Publication date 2001
Language Anglais
Journal information "Lipids" - Vol. 36, no. 4, p. 367-372 (2001)
Peer reviewed yes
Publisher Amer Oil Chemists Soc A O C S Press (Champaign)
issn 0024-4201
e-issn 1558-9307
Publication status Publié
Affiliation UCL
Links
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Bibliographic reference Van Houte, H ; de Hoffmann, Edmond ; Van Veldhoven, PP ; Mannaerts, GP. ; Carchon, H. ; et. al. Oxidative catabolism of alpha-tocopherol in rat liver microsomes. In: Lipids, Vol. 36, no. 4, p. 367-372 (2001)
Permanent URL http://hdl.handle.net/2078.1/42749