ABSTRACT
Coenzyme Q is a lipid with broad distribution in nature, present in plants, bacteria, fungi, and all animal tissues. Coenzyme Q refers to a general structure composed of a nucleus, i.e., 2,3-dimethoxy-5-methylbenzoquinone, and, substituted at position 6 of this quinone, a side chain consisting of isoprene units (5 carbons), all in trans configuration and with one double bond. In human tissues, the major part of coenzyme Q is coenzyme Q10, which has 10 isoprenoid units; only 2-7% is present as coenzyme Q9.
