两相体系中固定化黏红酵母CCZU-G5催化合成(R)-2-羟基-4-苯基丁酸乙酯

摘要

A strain capable of reducing ethyl-2-oxo-4-phenylbutanoate (OPBE) into ethyl (R)-2-hydroxy-4-phenylbutyrate [(R)-HPBE] was screened and identified as Rhodotorula mucilaginosa. In an isooctane /organic solvent biphasic system, reaction conditions of the asymmetric reduction of OPBE for synthesizing optically active (R)-HPBE with immobilized Rhodotorula mucilaginosa CCZU-G5 cell were investigated. The results showed that the optimum reaction conditions were: ratio of isooctane 10%, concentration of OPBE 100 mmol/L, catalyst dosage 0.45 g/mL and 40 g/L glucose as co-substrate. After 16 h of biotransformation under the optimum conditions, the yield of (R)-HPBE was as high as 83.5% and enantiomeric excess (e.e.). value was more than 99%. These immobilized catalysts could be repeatedly used for seven times, and the yield and e.e. value were all over 70% and 99%, respectively.%通过筛选得到一株高立体选择性还原2-氧代-4-苯基丁酸乙酯(OPBE)合成(R)-2-羟基-4-苯基丁酸乙酯[(R)-HPBE]的菌株并鉴定为黏红酵母.研究了在异辛烷/水两相体系中固定化黏红酵母CCZU-G5不对称还原OPBE合成(R)-HPBE的反应条件.结果表明最适的反应条件为:在异辛烷比例为10％条件下,底物浓度为100mmol/L,催化剂用量为0.45 g/mL,辅底物为40 g/L的葡萄糖.在建立的反应体系中反应16h,(R)-HPBE产率最高,达83.5％,e.e.值99％以上.固定化酵母经7次重复使用后,产率和e.e.值分别维持在70％和99％以上.