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利用紫外-可见吸收和荧光发射光谱,结合非线性最小二乘法拟合曲线以及分子力学(MM2)模拟系统地研究了手性分子N-[4-(1-芘基)]丁酰-D/L-苯丙氨酸(PDP和PLP,总称PPs)与β-环糊精(-βCD)、2-位硒桥联双-βCD(2-SeCD)和2-位碲桥联双-βCD(2-TeCD)的包结能力大小及这3个环糊精对PPs手性识别能力的差异和识别机理.研究结果表明,PPs不能与单疏水空腔的-βCD形成很好的包结复合物,与具有较长桥联链的2-TeCD结合能力最强.2-TeCD与PDP和PLP的结合常数分别为2.33×104和6.07×103L/mol,对PPs的手性识别比达到KD/KL=3.84,高于2-SeCD(KD/KL=2.61).用MM2模拟得出了PPs与这两个双环糊精形成复合物的三维结构:PPs的绝大部分位于双环糊精两个空腔之间,但是在这两个复合物中,苯环与芘环所成的二面角不同.此外,PPs与这两个双环糊精作用时均存在明显的氢键相互作用,且2-TeCD强于2-SeCD.
The chiral molecule N- [4- (1-pyrenyl)] butyryl-D / D-ascorbic acid was studied systematically by UV-vis absorption and fluorescence emission spectroscopy combined with the nonlinear least squares fitting curve and molecular dynamics (MM2) Phenylalanine (PDP and PLP, collectively PPs) with β-cyclodextrin (β-CD), 2-position selenium bridged bis-βCD 2-TeCD), and the recognition mechanism of these three cyclodextrins on the chiral recognition ability of PPs.The results show that PPs can not form a good inclusion complex with -βCD in a single hydrophobic cavity , Which had the strongest binding ability to 2-TeCD with longer bridge.The binding constants of 2-TeCD with PDP and PLP were 2.33 × 104 and 6.07 × 103L / mol respectively, and the chiral recognition ratio of PPs reached KD / KL = 3.84, higher than that of 2-SeCD (KD / KL = 2.61). The three-dimensional structure of PPs complexed with these two bicyclodextrins was obtained by MM2 simulation: most of the PPs were located in the two cavities , But in these two complexes, the benzene ring and pyrene ring dihedral angle is different.In addition, PPs and the two double cyclodextrin obvious interaction exists when hydrogen bonds, and 2-TeCD Stronger than 2-SeCD.