Preparation Of Ethy(R)-2-hydroxy-4-phenybutyrate By The Method Of Microorganisms

Ethyl?R?-2-hydroxy-4-phenylbutyrate??R?-HPBE?)was prepared by asymmetric reduction of ethyl 2-oxo-4-phenylbutyrate?OPBE?wi-th the carbonyl reductase as catalyst.Dodecane was used as the in-ternal standard substance to set up the detection method.A standar-d curve of OPBE and?R?-HPBE was drew.The standard carve of glucose was established by the method of DNS.Bhycells-2 was sel-ected.The conversion and enantiometric excess of?R?-HPBE got t-o 83.4%and 81.3%.Plakett-Burman and RSM were used to optim-ize the cultivation conditions of Bhycells-2.The optimal medium w-ere as follows:glucose 32 g/L,peptone 18 g/L,KH₂PO₄ 1.5 g/L,K₂HPH₄ 1.5 g/L,MgSO₄ 0.24 g/L,NaCL 0.75 g/L,pH 6.7.Enzyme activity reached 437.6 U/L.The single factor test was used to opti-mize the conditions of the conversion.The optimal conversion cond-itions were as follows:concentrations of the substrate and cells we-re 5 mmoL/L and 0.25 g/mL,the ethanol was 2%?V/V?,pH 6,36h,180 r/min at 30?.Conversion and the enantiometric excess of?R?-HPBE reached 91.6%and 81.5%.The solubility of substrate was high in the organic phase,and the cells could maintain a high ability of transformation in the wate-r phase.The water/organic phase system was explored to transform the OPBE by Bhycells-2.It was found that the conversion reached94.5%when the substrate concentration was 40 mmoL/L.