Kinetics of Schiff base formation between the cholesterol ozonolysis product 3β-hydroxy-5-oxo-5,6-secocholestan-6-al and phosphatidylethanolamine

The kinetics of Schiff base formation between the cholesterol ozonolysis product 3β-hydroxy-5-oxo-5,6-secocholestan-6-al and dimyristoyl phosphatidylethanolamine was investigated. The activation energy of Schiff base formation at temperatures above and below the phase transition of the phospholipid was calculated. Increase in the activation energy derived from perturbation of the surface structure by the process of Schiff base formation was demonstrated. The presence of the Schiff base with the aldolization product of the oxysterol was also observed and its significance is discussed.