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Biosynthesis of Alky Gallates Catalyzed by Tannase in Reverse Micelle |
WANG Zheng;TIAN Yun;LU Xiang-yang;YU Hua-zhong;LUO Ze-min |
Department of Bioengineering, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China |
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Abstract Alky gallate is a kind of antioxidant and processes patient therapy value. However, it is synthesized by chemical method, which brings serious circumstance containment and low productivity. To avoid the defects, the method of biosynthesis for alky gallates was established in reversed micelles reaction system, in which propyl gallate (PG), butyl gallate (BG) and amyl gallate (AG) were successfully synthesized. The reverse micelle consisted of docusate sodium salt (AOT), isooctane and water; the tannase concentration was 0.6 mg/mL. In the reverse micelle reaction systems for PG, BG and AG, when W0 (the mole ratio of water to AOT) was respectively 15,15 and 12.5; reaction temperatures were 30, 40 and 45 ℃, respectively; AOT concentrations were 0.1, 0.2 and 0.2 mol/L respectively; pH values all were 6, conversion of gallic acid reached the highest in the different systems. The highest conversion rates of gallic acid reached 87.4%, 90.3% and 92.5% respectively. Various factors had different effects on tannase catalytic activity due to three different alky alcohol isomers.
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Received: 05 March 2005
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Corresponding Authors:
WANG Zheng
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