小分子化合物与DNA嵌插作用的研究——不同酰胺侧链对结合强度的影响

A STUDY ON THE SMALL-MOLECULE AND DNA INTERCALATION——THE EFFECT OF DIFFERENT AMIDE SIDE CHAINS ON BINDING STRENGTH

本文报道不同侧链萘并噻吩类化合物(a、b、c)的合成及其与DNA的结合。粘度测定及光谱研究表明化合物与DNA以嵌插络合的方式结合。通过紫外、可见光谱法测定了3个化合物与DNA络合的表观稳定常数。结果表明,随着侧链的增长,化合物与DNA结合的强度逐渐减弱。通过微量热实验数据对小分子化合物与DNA结合的本质进行了初步分析。

For the purpose of maknig clear the DNA binding of naphthothiophene derivatives especially theeffect of side chain structure, three naphthothiophenes with different side chains (compounds a, b andc) have been designed and synthesized. The compounds were bound to DNA by intercalation based onincrease in viscosity of DNA. The Binding strength was evaluated by spectroscopic and calorimetricmeasurements. The binding constants of three compounds are in the order b>a>c. Thermal meltingexperiments were performed with the same results. Calorimetric titration data show a limited correl-ation between △H and △S for binding of the compounds to DNA grooves, i. e., an increase in entropy(2.7 cal/deg mol) is accompanied by a decrease in enthalpy (1.1 kcal/mol) and the overall effect onthe binding affinity is small.