The purified D-hydantoinase was immobilized on EAH sepharose 4B via the carbodiimide method with a yield of enzyme activity up to 79.44%.The immobilized hydantoinase showed remarkable stability at 4℃.An integrated pr...The purified D-hydantoinase was immobilized on EAH sepharose 4B via the carbodiimide method with a yield of enzyme activity up to 79.44%.The immobilized hydantoinase showed remarkable stability at 4℃.An integrated process of N-carbamoyl-D-phenylalanine(N-D-Phe)synthesis from D,L-5-benzylhydantoin(D,L-BH)catalyzed by immobilized D-hydantoinase coupled with an ion-exchange unit for in situ product removal(ISPR)was established.The variation of pH and conversion in the fixed-bed reactor with or without ISPR was compared at different temperatures,initial substrate concentrations and volumes of adsorbent.Within 24 h,the pH value in the reactor with ISPR could be kept at the alkaline range,which was beneficial to the enzymatic conversion and racemization of L-5-benzyl hydantoinase.This led to a higher overall conversion of 62.725% under optimal operation conditions,an increase of 89.3% compared with the fixed-bed reactor without ISPR.展开更多
采用N,N-二甲基-2-氯乙酰胺、4-羟基苯乙酸、三乙胺等为原料,于乙腈中反应,HPLC跟踪检测合成对羟基苯乙酸-N,N-二甲基甲酰氨基甲酰甲酯(简称化合物B)。结果表明,最佳合成工艺参数为:反应时间12 h,反应温度60℃,溶剂用量为2 200 m L,物...采用N,N-二甲基-2-氯乙酰胺、4-羟基苯乙酸、三乙胺等为原料,于乙腈中反应,HPLC跟踪检测合成对羟基苯乙酸-N,N-二甲基甲酰氨基甲酰甲酯(简称化合物B)。结果表明,最佳合成工艺参数为:反应时间12 h,反应温度60℃,溶剂用量为2 200 m L,物料比为n(4-羟基苯乙酸)∶n(N,N-二甲基-2-氯乙酰胺)=1∶1.10。在最佳条件下,收率86%,纯度98%以上。展开更多
文摘The purified D-hydantoinase was immobilized on EAH sepharose 4B via the carbodiimide method with a yield of enzyme activity up to 79.44%.The immobilized hydantoinase showed remarkable stability at 4℃.An integrated process of N-carbamoyl-D-phenylalanine(N-D-Phe)synthesis from D,L-5-benzylhydantoin(D,L-BH)catalyzed by immobilized D-hydantoinase coupled with an ion-exchange unit for in situ product removal(ISPR)was established.The variation of pH and conversion in the fixed-bed reactor with or without ISPR was compared at different temperatures,initial substrate concentrations and volumes of adsorbent.Within 24 h,the pH value in the reactor with ISPR could be kept at the alkaline range,which was beneficial to the enzymatic conversion and racemization of L-5-benzyl hydantoinase.This led to a higher overall conversion of 62.725% under optimal operation conditions,an increase of 89.3% compared with the fixed-bed reactor without ISPR.
文摘采用N,N-二甲基-2-氯乙酰胺、4-羟基苯乙酸、三乙胺等为原料,于乙腈中反应,HPLC跟踪检测合成对羟基苯乙酸-N,N-二甲基甲酰氨基甲酰甲酯(简称化合物B)。结果表明,最佳合成工艺参数为:反应时间12 h,反应温度60℃,溶剂用量为2 200 m L,物料比为n(4-羟基苯乙酸)∶n(N,N-二甲基-2-氯乙酰胺)=1∶1.10。在最佳条件下,收率86%,纯度98%以上。
