环糊精-苯丙氨酸超分子体系的包合现象与分子识别

Inclusion Phenomena and Molecular Recognition Study on theSupramolecular System of Cyclodextrins Phenylalanine

通过紫外-可见光谱探讨了水溶液中α-环糊精(CD1),β-CD2,七(2,6-二-o-甲基)-β-CD3和γ-CD4与D-、L-、D,L-苯丙氨酸(Phe)形成超分子包合物的稳定常数(K)。手性或外消旋苯丙氨酸与同一主体结合能力的强弱顺序为:L->D,L->D-Phe,各体系的KL/KD值在1.65～3.01之间,给出了较好的异构体分离。但三种形式的苯丙氨酸与这些主体的缔合常数均较小(K<3×102mol·L-1)。就不同主体而言,K值的次序为:3>1>4>2,并不完全等同于KL/KD的顺序:2>1>3>4。

The association constant values, K, for the interaction of alpha-CD 1, beta-CD 2, heptakis (2, 6-di- o-methyl) -beta-CD 3 and gamma-CD 4 with D-, L-, D, L-phenylalanine (Phe) were determined by means of UV-vis spectroscopy. The order of the K value-is L- > D, L- > D-Phe for the same host. The K-L/K-D value is between 1.65 and 3.01, indicating that an optically active isomer can be effectively separated by means of inclusion compounds formation. The order of the K-L/K-D value (2 > 1 > 3 > 4) is different from that of the K value (3 > 1 > 4 > 2).