Kinetic aspects of ultrasound-accelerated lipase catalyzed acetylation and optimal synthesis of 4¡ä-acetoxyresveratrol

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• 作者：Chia-Hung Kuo ; Fang-Wen Hsiao ; Jiann-Hwa Chen ; Chang-Wei Hsieh ; Yung-Chuan Liu ; Chwen-Jen Shieh
• 关键词：Acetylation ; Resveratrol ; Ultrasound ; Ping&ndash ; Pong kinetics ; Lipase ; Response surface methodology
• 刊名：Ultrasonics Sonochemistry
• 出版年：2013
• 出版时间：January, 2013
• 年：2013
• 卷：20
• 期：1
• 页码：546-552
• 全文大小：694 K

文摘

Ultrasonic assistance of lipase (Candida antarctica; Novozym? 435) catalyzed synthesis of 4¡ä-acetoxyresveratrol from resveratrol and vinyl acetate was investigated. Response surface methodology and a three-level-three-factor Box-Behnken design were adopted to evaluate the effects of synthesis variables, including reaction time (4-12 h), enzyme amount (2500-4500 PLU), and ultrasonic power (90-150 W) on the percentage molar conversion of 4¡ä-acetoxyresveratrol. Based on ridge max analysis, the optimum conditions for synthesis were: reaction time 10.78 h, enzyme amount 5492 PLU, and ultrasonic power 147.8 W. With ultrasound assistance, not only the phenolic compound acetylation time decreased, but also a high yield (95.2 % ) was achieved. The reaction kinetic model agreed with Ping-Pong mechanism, and the apparent kinetic constant ratio related to enzyme performance was 2.4 times higher in the ultrasound-assisted reaction than in the mechanical-mixing reaction. The apparent kinetic constant K₂ indicated that ultrasound enhanced the vinyl acetate affinity to the enzyme. The simplified Ping-Pong kinetic model was employed to simulate 4¡ä-acetoxyresveratrol production in batch reaction. It was found that a good prediction existed between the fitting results and the experimental data.