title: Chemiluminescence assay for quinones based on generation of reactive oxygen species through the redox cycle of quinone.
abstract: A sensitive and selective chemiluminescence assay for the determination of quinones was developed. The method was based on generation of reactive oxygen species through the redox reaction between quinone and dithiothreitol as reductant, and then the generated reactive oxygen was detected by luminol chemiluminescence. The chemiluminescence was intense, long-lived, and proportional to quinone concentration. It is concluded that superoxide anion was involved in the proposed chemiluminescence reaction because the chemiluminescence intensity was decreased only in the presence of superoxide dismutase. Among the tested quinones, the chemiluminescence was observed from 9,10-phenanthrenequinone, 1,2-naphthoquinone, and 1,4-naphthoquinone, whereas it was not observed from 9,10-anthraquinone and 1,4-benzoquinone. The chemiluminescence property was greatly different according to the structure of quinones. The chemiluminescence was also observed for biologically important quinones such as ubiquinone. Therefore, a simple and rapid assay for ubiquinone in pharmaceutical preparation was developed based on the proposed chemiluminescence reaction. The detection limit (blank + 3SD) of ubiquinone was 0.05 microM (9 ng/assay) with an analysis time of 30 s per sample. The developed assay allowed the direct determination of ubiquinone in pharmaceutical preparation without any purification procedure.
authors.affiliation: Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Kishikawa
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ohkubo
authors.forename: Kaname
authors.initials: K
authors.lastname: Ohyama
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Nakashima
authors.forename: Naotaka
authors.initials: N
authors.lastname: Kuroda
mesh_terms: D049449:Luminescence; D010084:Oxidation-Reduction; D004364:Pharmaceutical Preparations / Q000737:chemistry; D011809:Quinones / Q000032:analysis*; D017382:Reactive Oxygen Species / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D004364:Pharmaceutical Preparations; D011809:Quinones; D017382:Reactive Oxygen Species