环方铂立体异构体与小牛胸腺DNA作用的研究(英文)

Interactions of Dioxycyclobutenedione.(1, 2-cyclohexanediamine) Platinum(Ⅱ) with Calf Thymus DNA

研究了环方铂三种立体异构体（ＳＳ，ＲＳ和ＲＲ）与小牛胸腺ＤＮＡ的作用，差示扫描量热法（ＤＳＣ）测得的数据显示出三种化合物与ＤＮＡ作用的结果分别使其熔融温度下降了０．６，１．４和２．２Ｋ．有无ＤＮＡ存在时三种化合物及方酸（ｐＨ＝７．０）的^（１３）Ｃ核磁共振谱表明，当三种化合物与ＤＮＡ作用时，先释放出方酸根生成水铂，而后再与ＤＮＡ结合．综合上述实验结果，对三种化合物与ＤＮＡ的作用强度、方式及机理进行了讨论．

The interaction of a group of new synthetic compounds, dioxycyclobutenedione- (1, 2 -cyclohexanedindne ) platinum (Ⅱ) (DCP ) and its stereoisomers, with calf thymus DNA was investigated by DSC and NMR methods. In the presence of three stereoisomers of the compounds, the melting temperatures of DNA are 350. 45 (SS, trans-d-l-DCP), 349. 65 (RS, cis-DCP) and 348.85(RR, trans-1-DCP) )K respectively, while the melting temperature of DNA is 351.05 K. Comparing the ^(13)C NMR spectra of three stereoisomers of the compounds with and without DNA to that of squaric acid at pH = 7. 0 and room temperature, it can be obviously seen that square acid bases dropped out of the compound molecules as leaving group and got into the solutions as they bound to DNA. On the basis of the above experimental results, the binding strength and the model of the compounds with DNA have been discussed.