[Formation of hemichrome during reaction of hemoglobin with polar phosphatidylcholine derivatives]

Polar phosphatidylcholine derivatives [1-acyl-2-lyso-sn-glycero-3-phosphocholine, 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine (platelet-activating factor), 1-acyl-2-glutaryl-sn-glycero-3-phosphocholine, and 1-acyl-2-azelaoyl-sn-glycero-3-phosphocholine], which are formed in biological structures by enzymatic and free-radical reactions, were studied as effectors of the conversion of methemoglobin and oxyhemoglobin into an oxidized low-spin form referred to as hemichrome. It is shown that all these phosphatidylcholine derivatives act as effectors in the course of the transition of met- and oxyhemoglobin to hemichrome. Among the compounds studied, phosphatidylcholine derivatives containing glutaric and azelaic acids residues have the greatest effect on the rate of hemichrome formation.