Influence of kaolinite on chiral hydrolysis of methyl dichlorprop enantiomers  

作　　者：方兆华 文岳中 刘维屏 

机构地区：[1]Institute of Environmental Science, Zhejiang University, Hangzhou 310029, China

出　　处：《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》2005年第10期1028-1032,共5页浙江大学学报（英文版）B辑（生物医学与生物技术）

基　　金：Project supported by the National Natural Science Foundation of China (No. 30270767) and the National Nature Science Foundation of China for the Distinguished Young Scholars Program (No. 20225721)

摘　　要：The effect of kaolinite on the enzymatic chiral hydrolysis of methyl dichlorprop enantiomers ((R,S)-methyl-2-(2,4- dichlorophenoxy) propanoic acid, 2,4-DPM) was investigated using chiral gas chromatography. Compared with the control without kaolinite, the enantiomeric ratio (ER) increased from 1.35 to 8.33 and the residual ratio of 2,4-DPM decreased from 60.89% to 41.55% in the presence of kaolinite. Kaolinite likely had emotion influence on lipase activity and its enantioselectivity. Moreover, the amount of kaolinite added was also found to be a sensitive factor affecting the enantioselective hydrolysis of 2,4-DPM. Fourier transform infrared (FTIR) spectroscopy studies of the interaction of lipase with kaolinite provided insight into the molecular structure of the complex and offered explanation of the effects of kaolinite on enzymatic hydrolysis of 2,4-DPM. Spectra showed that the effect of kaolinite on the hydrolysis of 2,4-DPM was affected by adsorption of lipase on kaolinite and changes of adsorbed lipase conformation, which led to the modified enantioselectivity.The effect of kaolinite on the enzymatic chiral hydrolysis of methyldichlorprop enantiomers ((R,S)-methyl-2-(2,4-dichlorophenoxy) propanoic acid, 2,4-DPM) wasinvestigated using chiral gas chromatography. Compared with the control without kaolinite, theenantiomeric ratio (ER) increased from 1.35 to 8.33 and the residual ratio of 2,4-DPM decreased from60.89 percent to 41.55 percent in the presence of kaolinite. Kaolinite likely had emotion influenceon lipase activity and its enantioselectivity. Moreover, the amount of kaolinite added was alsofound to be a sensitive factor affecting the enantioselective hydrolysis of 2,4-DPM. Fouriertransform infrared (FTIR) spectroscopy studies of the interaction of lipase with kaolinite providedinsight into the molecular structure of the complex and offered explanation of the effects ofkaolinite on enzymatic hydrolysis of 2,4-DPM. Spectra showed that the effect of kaolinite on thehydrolysis of 2,4-DPM was affected by adsorption of lipase on kaolinite and changes of adsorbedlipase conformation, which led to the modified enantioselectivity.

关 键 词：Enantioselectivity  Kaolinite  CHIRAL gas chromatography  METHYL dichlorprop  LIPASE 

分 类 号：X131.3[环境科学与工程—环境科学]