染料木素及其钐配合物与DNA的相互作用

DNA-binding properties of genistein and it′s Sm (Ⅲ) complex

在合成染料木素钐(Ⅲ)配合物的基础上,以荧光光谱法、紫外吸收光谱法和粘度法研究了染料木素及其钐(Ⅲ)配合物与DNA的作用.结果发现,该配合物的荧光强度在加入DNA后增大,而染料木素则降低;配合物使DNA-EB体系的荧光强度降低要明显强于染料木素;配合物相较于配体与DNA相互作用之后,其紫外光谱的减色效应以及红移现象均强于配体;配合物使DNA粘度的增加的程度也大于配体.结果显示,染料木素及其钐(Ⅲ)配合物都能与DNA发生插入结合作用,但配合物与DNA结合得更加紧密.抗肿瘤活性体外测试的结果表明,无论染料木素还是配合物对于筛选的瘤株均具有一定的抑制作用,但是配合物对瘤株的抑制强于配体.

Absorption, fluorescence spectra and viscometric studies have been carried out on the interactions between genistein and its Sm （ Ⅲ ） complexes, SmL2·OAc·4H2O [ L = genistein （5-OH group deprotonated）] with calf thymus DNA. The increase in fluorescence was observed for the Sm （Ⅲ） complex in the presence of DNA, whereas the decrease in fluorescence appeared for genistein. Fluorescence quenching was observed for the DNA-EB system when the Sin （ Ⅲ ） complex was added, whereas slightly quenched fluorescence was seen for the DNA-EB system with addition of genistein. The relative viscosity of DNA system increased with the addition of the complex. Hypochromism and a small shift were observed in the UV spectra of Sm （ Ⅲ ） complex in the presence of DNA. The above results suggested that genistein and SmL2·OAc· 4H2O could both bind to DNA, but the binding affinity of Sm （ Ⅲ ） complex much higher than that of genistein. Antitumor activities for the Sm （ Ⅲ ） complex and genistein were tested by the MTT method. The results show that the inhibitory ratio of the Sm （ Ⅲ ） complex against the tested tumor cells was higher than that of genistein.