Lipase-mediated asymmetric hydrolysis of D,L-phenylglycine methyl ester in the aqueous solution of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate

ORGN 659

Yu-Ying Liu, liuyuying29@hotmail.com1, Wen-Yong Lou, scutlou@hotmail.com1, Hong Wu, bbhwu@scut.edu.cn2, and Min-Hua Zong, btmhzong@scut.edu.cn1. (1) Department of Biotechnology, South China University of Technology, 1 Wushan Street, Guangzhou, 510640, China, (2) College of Biological Sciences and Biotechnology, South China University of Technology, 1 Wushan Street, Guangzhou, 510640, China
Novozym 435 (lipase B from Candida antarctica)-catalyzed asymmetric hydrolysis of D,L-phenylglycine methyl ester (D,L-PGME) was examined in the aqueous solution of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM•BF4). The enzyme exhibited excellent activity and enantioselectivity in the system compared to in phosphate buffer or organic solvents. L-PGME with an enantiomeric excess of 93.8% at substrate conversion of 53.0% could be obtained after a reaction time of 60 min when the reaction was performed in the phosphate buffer solution (50 mM, pH8.0) of 20%(v/v) BMIM•BF4. The apparent kinetic parameters Km, Vmax and the activation energy Ea for the reaction are 37.7 mM, 3.58 mM•min-1 and 39.18 kJ•mol-1, respectively. When the reaction was conducted under reduced pressure to in situ remove methanol formed, improved reaction rate and enantioselectivity could be achieved. This study might provide an alternative way for the preparation of enantiopure L-phenylglycine, a key compound for the synthesis of taxol.
 

Asymmetric Reactions, Heterocycles, Aromatics, Combinatorial, and Physical Organic Chemistry
8:00 PM-10:00 PM, Wednesday, 31 August 2005 Washington DC Convention Center -- Hall A, Poster

Division of Organic Chemistry

The 230th ACS National Meeting, in Washington, DC, Aug 28-Sept 1, 2005