title: Determination of reduced and total ubiquinones in biological materials by liquid chromatography with electrochemical detection.
abstract: A convenient and reliable liquid chromatographic (LC) method with electrochemical detection (ED) was developed for the determination of reduced (ubiquinol) and total ubiquinones in biological materials. After extraction of samples with n-hexane, ubiquinol was separated on a reversed-phase column and assayed directly by ED. In order to determine the total amount of a ubiquinone in biological samples, the unbiquinone was converted into the corresponding reduced form by treatment with sodium borohydride. No significant interfering peak (plastoquinol-9, ubichromenol-9, etc.) was observed in the elution areas of ubiquinol-7 to -11. This LC-ED method was about 70 times more sensitive than the previous LC-UV method and was able to detect 150 pg of ubiquinol-10. The method was applied satisfactorily to the determination of the contents of ubiquinol homologues in biological materials. The content of ubiquinols is a major component of the total ubiquinones in human plasma and urine and rat plasma and liver, but a minor component in rat heart and kidney.
authors.affiliation: Faculty of Pharmaceutical Sciences, Kobe-Gakuin University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Okamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Fukunaga
authors.forename: Y
authors.initials: Y
authors.lastname: Ida
authors.forename: T
authors.initials: T
authors.lastname: Kishi
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D003404:Creatinine / Q000652:urine; D004563:Electrochemistry; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014451:Ubiquinone / Q000031:analogs & derivatives / Q000032:analysis* / Q000097:blood / Q000652:urine
chemical_list: D014451:Ubiquinone; D003404:Creatinine; C003741:ubiquinol