目的 研究非水相体系中反式头孢丙烯的酶法合成工艺条件.方法 以7-氨基-3-E-丙烯基-3-头孢菌素-4-羧酸(trans-7-APRA)与对羟基苯甘氨酸(HPG)为底物,利用单甲氧基聚乙二醇修饰化的蛋白酶为催化剂,在非水相体系中合成反式头孢丙烯.采用单因素实验确定影响反式头孢丙烯相对产率的主要因素及其取值范围.以此为基础,应用响应面法对底物配比、酶用量、溶剂配比和温度4因素进行优化.结果 非水相体系中反式头孢丙烯均有一定量的合成,以DMSO和甘油的混合非水相体系为最佳合成体系.蛋白酶非水相合成反式头孢丙烯的最佳工艺参数:底物配比ntrans-7-APRA∶nHPG=7∶10,酶用量HPG∶Enzyme=1∶1,溶剂比率VDMSO∶V甘油=2∶1,温度30℃,在此反应条件下相对产率可达到63.6%,与理论预测值相比相对误差在2%左右.结论 修饰化中性蛋白酶在非水相体系中可有效合成反式头孢丙烯,该工艺可为酶法制取头孢丙烯的实际应用提供理论依据.
Objective The technical process for enzymatic synthesis of trans-cefprozil in non-aqueous phase system was researched. Methods The single-methoxy polyethylene glycol modified protease was used to catalyze 7-amino-3-E-3-propylene cephalosporin 4-carboxylic acid and hydroxyphenylglycine into cefprozil in non-aqueous phase system. Firstly, main factors and the values affecting the yield of trans-cefprozil were confirmed by single factor experiment. Based on this, ratio of substrates, enzyme dosage, solution ratio and reaction temperature were optimized via response surface method. Results Trans-cefprozil can be synthesized in various non-aqueous phase system and the mixture of DMSO and Glycerol was selected as the optimal reaction system. The optimum parameters to synthesize trans-cefprozil in non-aqueous phase system by neutral protease was as following: nAPRA: nHPG=7:10, HPG:Enzyme=1:1, VDMSO:VGlycerol=2:1 and at 30℃, under which the relative yield was up to 63.6% and had 2% of relative error compared with the theoretical prediction. Conclusion The modified protease can effectively synthesize trans-cefprozil in non-aqueous phase system, which would provide a theoretical basis for the enzymatic preparation of cefprozil.