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糖淀粉对不同链长的对位取代苯酚羧酸酯在1:1(V/V)Me_2SO-H_2O 中的水解有显著的加速作用,乙酸酯的水解是二级反应;十二酸酯和十六酸酯则均呈 Michaelis-Menten 型饱和动力学.讨论了受物的链长和取代基对络合物解离常数 K_d 和催化速度常数 k_c 的影响.乙酸酯及十二酸酯水解反应的 k_(un),k_(obs),k_2和 k_o 均符合 Hammett 方程,而十六酸酯则不符合.包结过程以不利的熵变、有利的焓变为特征.比较(?)专和自发水解的(?)表明,糖淀粉加速长链酯水解的主要原因是形成了螺旋包结络合物.还讨论了由于十六酸酯分子间簇集和自身绕曲对包结和催化过程的影响.
Glycated starch can accelerate the hydrolysis of para-substituted phenol carboxylic acid esters with different chain lengths in 1: 1 (V / V) Me_2SO-H_2O, and the hydrolysis of acetate is the second-order reaction. The laurate and The hexadecanoic acid ester showed Michaelis-Menten type saturation kinetics. The influences of the length of the acceptor and the substituents on the dissociation constant K_d and the catalytic rate constant k_c of the complex were discussed. The hydrolysis of acetate and dodecanoate The responses of k un, k obs, k 2 and k o are all in accordance with the Hammett equation, while the hexadecanoic acid esters are not in agreement. The entrapment process is characterized by unfavorable entropy change and favorable enthalpy change. And spontaneous hydrolysis (?) Showed that the main reason for the accelerated hydrolysis of long chain esters was the formation of helix inclusion complexes. It was also discussed that due to the intercalation of hexadecanoate esters and the self-wrapping, The impact of the process.