Coenzyme Q (Ubiquinone)

Hatefi, Youssef

doi:10.1002/9780470122709.ch5

Cited by 33 publications

(14 citation statements)

References 121 publications

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“…Stock solutions of CoQ 9 and CoQ 10 were prepared in 1-propanol and stored at −70°C. The concentrations of both stock solutions were calculated by reading the absorbance on a spectrophotometer (275 nm wavelength; 1 cm quartz cuvette), using a molar absorptivity (ε) of 14,700 for CoQ 9 and 14,200 for CoQ 10 (Hatefi, 1963). A series of CoQ 10 calibration standards (at concentrations of 0.06, 0.29, 0.579, 1.158 and 2.317 µmol L −1 ) were prepared in 1-propanol from the stock solution.…”

Section: Methodsmentioning

confidence: 99%

Determination of coenzyme Q10 in human breast milk by high-performance liquid chromatography

Tang

Miles

Steele

et al. 2006

Biomed. Chromatogr.

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An isocratic HPLC method was developed for the determination of coenzyme Q(10) (CoQ(10)) in human breast milk. After a single-step liquid-liquid extraction, the milk extract was injected directly into the HPLC system. The analytical method is based on pre-column inline treatment of CoQ(10). Chromatographic separation of CoQ(10) and coenzyme Q(9) (CoQ(9)) internal standard was achieved using a reversed-phase Microsorb-MV C(18) analytical column. CoQ(10) and CoQ(9) were monitored by an electrochemical detector (ECD). An excellent linearity (r = 0.999) was observed for CoQ(10) in the concentration range 0.06-2.5 micromol L(-1) in breast milk. The limit of quantitation (LOQ) was 60 nmol L(-1). Coefficients of variations (CVs) for intra-day and inter-day assay precisions were less than 5%. A total of 194 breast milk samples were analyzed for the CoQ(10) concentration; the mean value was 0.32 +/- 0.21 micromol L(-1).

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Section: Methodsmentioning

confidence: 99%

Determination of coenzyme Q10 in human breast milk by high-performance liquid chromatography

Tang

Miles

Steele

et al. 2006

Biomed. Chromatogr.

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“…The reduced form of CoQ10 (ubiquinol-10) was prepared from the parent ubiquinone-10, according to the method of Lang et al (1986). Purity and stability of the standard solutions were checked every month by using the known molar extinction coefficient for ubiquinone-10 (e ¼ 14 240 L mol À1 cm À1 ) (Hatefi, 1963) and measuring the absorbance E 1% at 275 nm with an Ultrospec 2100 pro UV/visible spectrophotometer (Biochrom Ltd, Cambridge, England). Standard solutions were sealed under nitrogen and stored at À40 1C in amber glass vials.…”

Section: Standardsmentioning

confidence: 99%

“…Ubiquinones are found as ubiquinol/ubiquinone redox couples which function as electron carriers in mitochondria and have an essential role in the energy metabolism (Lester and Crane, 1959). They contain a chromogenic nucleus (2,3-dimethoxy-5-methyl-1,4-benzoquinone) and a polyisoprenoid side chain in the 6-position which differs only in the number of isoprenoid units (Hatefi, 1963). The predominant form of ubiquinone in humans, animals, and fish is Co-enzyme Q10 (2,3-dimethoxy-5-methyl-6-decaprenylbenzoquinone), containing 10 isoprenoid units in the side chain (Fig.…”

Section: Introductionmentioning

confidence: 99%

Seasonal variation of Co-enzyme Q10 content in pelagic fish tissues from Eastern Quebec

Souchet

Laplante

2007

Journal of Food Composition and Analysis

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“…Ubiquinone is important as an electron carrier in the mitochondrial electron transport system (1,3,4) and is useful for producing ATP. Ubiquinone-10, which has 10 isoprene units, is particularly important because it is found in the human mitochondrial respiratory chain.…”

mentioning

confidence: 99%

“…Ubiquinone, also known as coenzyme Q, belongs to the fat-soluble component in aerobic organisms and is widely distributed in nature with varying lengths of the side chain isoprene units (1,2). Ubiquinone is important as an electron carrier in the mitochondrial electron transport system (1,3,4) and is useful for producing ATP.…”

mentioning

confidence: 99%

Specific and rapid analysis of ubiquinones using Craven's reaction and HPLC with postcolumn derivatization

Shimada

Kodjabachian

Ishida

2007

Journal of Lipid Research

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A new method for the analysis of ubiquinones in various samples was developed using an HPLC system with postcolumn derivatization. Craven's reaction, a specific color reaction for the analysis of ubiquinones, was used in the system. Because the reaction progressed in organic solvents that contained ubiquinones and ethylcyanoacetate under an alkaline condition, the selectivity for ubiquinone detection was higher than that for ubiquinone detection using the nonderivatized ultraviolet detection system at 275 nm, a system widely used for the analysis of ubiquinones. The new detection system can avoid the adverse effects of impurities. Furthermore, it can confirm specificity by stopping the color reaction under a neutral condition. The detection limit for ubiquinone-10 was 1 ng (1.2 pmol). A good linearity for the calibration curve was observed in the range of 11.7 pmol to 11.7 nmol. To investigate the possible application of this method, various samples, such as soybean capsules used as a dietary supplement and biological materials (rice as well as bovine plasma and liver samples), were applied to the system and their ubiquinone contents were quantified. This method is thought to be widely and conveniently applicable for determining the level of ubiquinones because of its high selectivity for ubiquinone detection.-Shimada, H., D. Kodjabachian, and M. Ishida. Specific and rapid analysis of ubiquinones using Craven's reaction and HPLC with postcolumn derivatization. J. Lipid

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Coenzyme Q (Ubiquinone)

Cited by 33 publications

References 121 publications

Determination of coenzyme Q10 in human breast milk by high-performance liquid chromatography

Determination of coenzyme Q10 in human breast milk by high-performance liquid chromatography

Seasonal variation of Co-enzyme Q10 content in pelagic fish tissues from Eastern Quebec

Specific and rapid analysis of ubiquinones using Craven's reaction and HPLC with postcolumn derivatization

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