Synthesis Of Cefprozil Using Penicillin G Acylase In Recyclable Aqueous Two-Phase Systems

Cefprozil is an important kind of cephalosporin antibiotics. In this study, recyclable aqueous two-phase systems (ATPS) were applied to conduct the enzymatic synthesis of Cefprozil. The enzyme used was Immobilized penicillin G acylase (PGA). The nucleus was7-Amino-3-(1-propenyl)-4-cephalosporanic acid (7-APRA), and the side chain was4-Hydroxyphenylglycine methyl ester (HPGME). The adjustment of partition coefficient and the selection of optimum reaction conditions in aqueous system and ATPS were investigated in this study.Two recyclable aqueous two phase systems were tested, namely thermo-pH response system of PNB/PADB and pH-pH response system of PADB/PADBA-In thermo-pH response system, the partition coefficient of Cefprozil reached2.24with60mmol/L (NH4)2SO4and1.41with60mmol/L MgSO4, and in pH-pH response system, the partition coefficient of Cefprozil reached1.72with100mmol/L MgSO4. The partition coefficient of nucleus7-APRA was0.11in thermo-pH response system and0.12in pH-pH response system. The partition coefficient of side chain HPGME was0.85and0.72in thermo-pH response system and pH-pH response system respectively.The enzymatic reaction conditions in aqueous system were studied. The optimal conditions are pH6.5,20℃,78u/mL enzyme usage,30mmol/L nucleus7-APRA,90mmol/L side chain HPGME. The final yield reached56.02%under these conditions.The reactions in ATPS show higher yield and more stability. In PNB/PADB system, the final yield was65.01%while in PDAB/PADBA system, the final yield reached60.32%.60mmol/L (NH4)2SO4, MgSO4and KC1were added to the reaction system separately and the results show that in PNB/PADB system, the reaction with (NH4)2SO4reached the highest yield of75.81%, and the reaction with MgSO4showed the lowest yield of36.01%. Meanwhile, in PADB/PADBA system, the existence of MgSo4decreased the reaction yield to32.40%.