Kuo_2012_Bioprocess.Biosyst.Eng_35_1137

The use of immobilized lipase from Candida antarctica Novozym((R 435 to catalyze acetylation of trans-3,5,4'-trihydroxystilbene was investigated in this study Response surface methodology and 5-level-4-factor central composite rotatable design were adopted to evaluate the effects of synthesis variables including reaction time 24-72 h temperature 25-65 degrees C substrate molar ratio 1:15-1:75 and enzyme amount 600-3,000 PLU on the percentage molar conversion of trans-4'-O-acetyl-3,5-dihydroxystilbene The results showed that reaction temperature and enzyme amount were the most important parameters on percentage molar conversion Based on ridge max analysis the optimum conditions for synthesis were reaction time 60 h reaction temperature 64 degrees C substrate molar ratio 1:56 and enzyme amount 2,293 PLU The molar conversion of actual experimental values was 95 under optimal conditions The synthesis product was analyzed using HPLC mass and NMR The results revealed that the major product was trans-4'-O-acetyl-3,5-dihydroxystilbene The reaction kinetics was found to follow the Ping-Pong mechanism substrate inhibition was not found at high vinyl acetate concentration.