用木瓜蛋白酶及固定化木瓜蛋白酶拆分DL-苯丙氨酸

为了将手性化合物D-苯丙氨酸和L-苯丙氨酸进行分离，利用木瓜蛋白酶及固定化木瓜蛋白酶催化的方法对其拆分．试验结果表明，用DL-苯丙氨酸合成N-乙酰-DL-苯丙氨酸，得率为88.7％．木瓜蛋白酶、海藻酸钠 壳聚糖固定化木瓜蛋白酶(IPSAC)、尼龙布固定化木瓜蛋白酶(IPN)催化合成N-乙酰-L-苯丙氨酰苯胺时，对催化合成过程影响最大的因素分别是溶液中的离子强度、溶液中的离子强度、反应温度；溶液中的离子强度与pH对合成的影响较大．本试验得出分别用木瓜蛋白酶、IPSAC、IPN催化合成N-乙酰-L-苯丙氨酰苯胺的3个最佳方案；用此3个方案合成时，产率分别为61.2%、54.7%、36.3%．N-乙酰-L-苯丙氨酰苯胺水解生成L-苯丙氨酸，产率59.2%，光学纯度为96.6％．N-乙酰-D-苯丙氨酸水解生成D-苯丙氨酸，产率61.7%，光学纯度为95.7％．

Resolution of DL-Phenylalanine by Papain and Immobilized Papain

In order to separate chiral D-phenylalanine from L-phenylalanine, the enzyme catalytic method by papain and immobilized papain were used in this investigation. It indicated that the yield rate of N-acetyl-DL-phenylalanine synthesized from DL-phenylalanine was 88.7%. The ionic strength was the strongest influencing factor in the synthesis of N-acetyl-L-phenylalanylaniline by both papain and immobilized papain on sodium alginate-chitosan (IPSAC). But the reaction temperature was the strongest influencing factor in the synthesis by immobilized papain on nylon cloth (IPN). The ionic strength and the pH were the important influencing factors in the synthesis. The yield rates of the best synthesis system of N-acetyl-L-phenylalanylaniline by papain, IPSAC, IPN were 61.2%, 54.7%, 36.3%, respectively. The yield rate of L-phenylalanine from N-acetyl-L-phenylalanylaniline hydrolyzation was 59.2%. The optical purity of the product was 96.6%. The yield rate of D-phenylalanine from N-acetyl-D-phenylalanine hydrolyzation was 61.7%. The optical purity was 95.7%.