中文摘要：

采用光谱法研究了抗癌药物喜树碱与DNA的相互作用。DNA引起喜树碱的吸收光谱轻微的红移和减色并导致喜树碱的荧光猝灭,说明喜树碱和DNA形成基态复合物。通过计算确定了二者的结合常数,结合位点数及主要结合力。同时考察了离子强度、磷酸根浓度、猝灭剂KI对二者相互作用的影响并比较了单、双链DNA和喜树碱相互作用的程度。变性实验确定了喜树碱-DNA复合物的熔点为60℃,比纯DNA的熔点低18℃。实验结果表明喜树碱和DNA之间主要是沟槽作用模式。

英文摘要：

The interaction of an anti-cancer drug camptothecin with salmon sperm DNA was studied by spectroscopic techniques.DNA induced slight hypochromic and bathochromic effects on the UV-Vis absorption spectra of camptothecin,but strong fluorescence quenching of camptothecin,which suggest the formation of ground-state camptothecin-DNA complex.The binding constant and number of binding site were calculated and the main interaction force was determined.The effect of salt,phosphate and negatively charged quencher KI on camptothecin-DNA interaction was investigated and the interaction of camptothecin with double-stranded DNA and single-stranded DNA was compared.The melting temperature of camptothecin-DNA complex was 60 ℃,which is 18 ℃ lower than that of pure DNA.All the results indicate that groove binding mode is the main interaction mode between camptothecin and DNA.