Hydrolysis Of Vitamin E Acetate In Reverse Micelle Systems

The effects of ingredients that constitute reverse micelle systems on stability and activity of cholesterol esterase which catalyze the hydrolysis of vitamin E acetate in reverse micelle systems have been studied. It was found that organic solvent, surfactant, and water content (Wo) have great impact on the catalysis behaviors of enzyme in reverse micelle systems. The reverse micelle system that consists of 0.014mol/L lecithin / 0.006 mol/L cholesterol/ cyclohexane is the optimal reaction system.The effects of temperature and other reaction conditions on the activity of cholesterol esterase in reverse micelle systems have been studied, and the reaction conditions were optimized.The stability, behavior of kinetics and optical selectivity of the cholesterol esterase in reverse micelle systems have been systematically studied, and compared with those in micelle solutions. The results showed that the stability, activity and optical selectivity of the enzyme in reverse micelle systems are much higher than in micelle solutions.Using the reverse micelle systems that consists of 0.014mol/L lecithin / 0.006mol/L cholesterol/ cyclohexane as biomembrane-simulating systems, the optical selectivity in the courses of hydrolysis of vitamin E acetate has been studied. The antioxidation activity of d-vitamin E acetate, d,l-vitamin Eacetate, d-a-tocopherol and d,l-#-tocopherol in the reverse micelle systems have been studied. The result indicated that the in vivo optical activity of vitamin E acetate was caused by (1) the optical selectivity in the courses of hydrolysis of vitamin E acetate in vivo, the velocity of hydrolysis of d -vitamin E acetate is much higher than that of 1- vitamin E acetate, which can produce more a-tocopherol that protect the lipids from oxidation ; (2) the hydrolysis product of d -vitamin E acetate ,d -a-tocopherol, have a higher antioxidation activity in vivo than 1-a-tocopherol which is the hydrolysis product of 1 -vitamin E acetate when they display cooperate antioxidation with SOD.