title: A novel control of enzymatic enantioselectivity through the racemic temperature influenced by reaction media.
abstract: The influence of reaction media on the racemic temperature (T(r)) in the lipase-catalyzed resolution of ketoprofen vinyl ester was investigated. An effective approach to the control of the enzymatic enantioselectivity and the prediction of the increasing tendency was developed based on the T(r) influenced by reaction media. The T(r) for the resolution catalyzed by Candida rugosa lipase (CRL) was found at 29 °C in aqueous and S-ketoprofen was obtained predominantly at 40 °C. However, CRL showed R-selectivity at 40 °C in diisopropyl ether because the T(r) was changed to 56 °C. CRL, lipase from AYS Amano(®) and Mucor javanicus lipase were further applied for the investigation of the enzymatic enantioselectivity in dioxane, DIPE, isooctane and their mixed media with water. The effects of the reaction medium on T(r) could be related to the solvent hydrophobicity, the lipase conformational flexibility and the interaction between the enantiomers and the lipase.
authors: Department of Chemistry, Zhejiang University, Hangzhou 310027, People's Republic of China.
authors: Xin
authors: X
authors: Jin
authors: Bokai
authors: B
authors: Liu
authors: Zhong
authors: Z
authors: Ni
authors: Qi
authors: Q
authors: Wu
authors: Xianfu
authors: X
authors: Lin
mesh_terms: D055162:Biocatalysis; D002175:Candida / Q000201:enzymology; D005656:Fungal Proteins / Q000378:metabolism*; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D007202:Indicators and Reagents; D007660:Ketoprofen / Q000031:analogs & derivatives / Q000378:metabolism; D008049:Lipase / Q000378:metabolism*; D008968:Molecular Conformation; D009089:Mucor / Q000201:enzymology; D009795:Octanes; D011487:Protein Conformation; D012997:Solvents; D013237:Stereoisomerism; D013696:Temperature; D014867:Water
chemical_list: D005656:Fungal Proteins; D007202:Indicators and Reagents; D009795:Octanes; D012997:Solvents; D014867:Water; D007660:Ketoprofen; C428110:Lip4 protein, Candida rugosa; D008049:Lipase; C045798:2,2,4-trimethylpentane