menaquinone-6 and ubiquinone-6

Coenzyme Q

Topics: Animals; Ataxia; Drosophila melanogaster; Electron Transport; HeLa Cells; Humans; Mitochondria; Mitochondrial Diseases; Muscle Weakness; Mutation; Ubiquinone; Vitamin K 2

A novel analytical method was applied for identification of isoprenoid quinones in Escherichia coli by liquid chromatography atmospheric press chemical ionization mass spectrometry in negative mode (LC-NI-APCI-MS). Extraction and clean-up of sample were carried out on Sep-Pak Plus Silica solid-phase extraction cartridges. Ubiquinone-7 (UQ-7), Ubiquinone-8 (UQ-8) and Mequinone-8 (MK-8) were determined directly using combined information on retention time, molecular ion mass, fragment ion masses and UV characteristic spectrometry without any standard reagent. It was found that UQ-8 was the major component of isoprenoid quinones in Escherichia coli under aerobic condition. Compared with UQ-8, the relative abundance of UQ-7 and MK-8 is only 15% and 14%, respectively. The average recoveries of UQ-6, UQ-10 and vitamin K(1) in Escherichia coli were investigated by standard spiking experiment. The recoveries were achieved in the range from 94 to 106%, and the relative standard deviations (RSD) of the triplicate analysis of the spiked samples (UQ-6, UQ-10 and vitamin K(1)) ranged from 3 to 8%. The detection limits of LC-NI-APCI-MS were estimated to be 5, 40 and 0.8 microg/g dry cell for UQ-6, UQ-10 and vitamin K(1), respectively.

Topics: Chromatography, Liquid; Escherichia coli; Mass Spectrometry; Quinones; Sensitivity and Specificity; Terpenes; Ubiquinone; Vitamin K 1; Vitamin K 2