Lipase Catalyzed Synthesis Of Natural Vitamin E Esters

This paper focus on the tocopherol esters synthesis catalyzed by immobilized lipase Candida sp.99-125established in our lab. Tocopherol esters can be synthesized easily with vinyl acetate as acyl-donor in organic solvent system, so it is with acetic anhydride as acyl-donor in a solvent free system. Different parameters in the two systems had been optimized to achieve maximum yield and the results are as follows:(1) with petroleum ether as solvent, the reciprocal shaker controlled at40℃and180rpm, the molar ratio of tocopherol and vinyl acetate is1:2, the concentration of a-tocopherol is0.043g/mL, the lipase amount used is0.02g/mL,3.0g5A molecular sieve added into the system, more than85%of tocopherol was converted into tocopherol acetate after72hours reaction;(2) in a solvent free system, the optimal conditions are that:0.6g a-tocopherol,4mL acetic anhydride, temperature70℃,0.6g immobilized lipase. The maximum conversion is95%with13X molecular sieve added to adsorb water in the system.Scale-up of the production of tocopherol esters in organic solvent is also optimized and it have the same results as former flask experiments. After separation and purification of vitamin E ester, the pure product is determined by IR spectra, GC-Mass.This synthesis using immobilized lipase has great potential for industrialization for its simple routine, less energy consumption and environmental friendship during the whole process.