Chapter 12 - Identification of coenzyme Q (ubiquinone) homologs

Abstract

This chapter describes the various methods used for identifying coenzyme Q (ubiquinone) homologs in yeasts and yeastlike fungi. In the reversed-phase paper chromatography method, a filter paper strip is impregnated with 3.0% silicon oil in chloroform. The paper strip is developed with ethanol/ethyl acetate/water, and similarly, another filter paper strip is impregnated with 2.5% white vaseline in toluene. After developing and drying the paper strips, the coenzyme Q homologs are located as yellowish-brown spots on the chromatograms by oxidation with 0.3% KMnO4 in water. In the reversed-phase thin-layer chromatography method, the samples are spotted on a reversed-phase thinlayer plate, which is developed with acetone/acetonitrile. The spots of the coenzyme Q homologs are visualized under a shortwave UV light or by spraying 50% H2SO4(v/v), followed by heating the plate in an oven at 120–150° C for 2–5 minutes. In the case of high performance liquid chromatography, the separation of the coenzyme Q homologs is performed on a Novapak C18 column. The mobile phase is methanol/isopropanol, and the flow rate is l.0 ml/minutes. Detection is done at 275 nm and then, the sample peaks are compared with those of known reference standards.