ABSTRACT
Phospholipids are functionally active components of biological membranes. The wonderful properties of living membranes—their structural stability together with the dynamic equilibrium of membranous components involved in metabolic processes—are based on the chemical structure of phospholipids. The chemical bonds in phospholipids are of three types only, carbon-carbon bonds, ester bonds, and phosphoester bonds. Phospholipids can be regarded as asymmetric phosphoric acid diesters. The stability of phospholipids depends strongly on the nature of the constituent acyl and alkyl residues. Phospholipids carrying unsaturated bonds tend to change their structure under the action of the air oxygen; they are especially prone to undergo nonenzymatic reactions of autooxidation and photooxygenation, resulting in hydroperoxide formation with concomitant acyl migration and stereomutation of the double bonds. Epoxidation of unsaturated compounds is a reaction well known in organic chemistry. In oxidative metabolism of phospholipids epoxidation also plays an important role.
