title: Lipase catalyzed acetylation of 3,5,4'-trihydroxystilbene: optimization and kinetics study.
abstract: The use of immobilized lipase from Candida antarctica (Novozym(®) 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 °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 °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.
authors.affiliation: Biotechnology Center, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kuo
authors.forename: Fang-Wen
authors.initials: FW
authors.lastname: Hsiao
authors.forename: Shu-Mei
authors.initials: SM
authors.lastname: Dai
authors.forename: Chieh-Ming J
authors.initials: CM
authors.lastname: Chang
authors.forename: Chih-Chen
authors.initials: CC
authors.lastname: Lee
authors.forename: Yung-Chuan
authors.initials: YC
authors.lastname: Liu
authors.forename: Chwen-Jen
authors.initials: CJ
authors.lastname: Shieh
mesh_terms: D000107:Acetylation; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D004800:Enzymes, Immobilized / Q000378:metabolism; D006358:Hot Temperature; D007700:Kinetics; D008049:Lipase / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D000077185:Resveratrol; D013267:Stilbenes / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D004800:Enzymes, Immobilized; D013267:Stilbenes; D008049:Lipase; D000077185:Resveratrol