Camptothecin (CPT) and 10-hydroxycamptothecin (HCPT) are two anti-tumor agents that cause the tumor cell death by inhibiting the degradation of the cleaved DNA strand. In the current study, we researched the interactions of CPT/HCPT and bovine serum albumin (BSA) with the multi-spectroscopy method, electrochemical method and molecular docking method. The inverse ratio of K_sv and K_a to temperature and the difference in UV–vis absorption indicated that there was a formed complex in both CPT-BSA system and HCPT-BSA system when they titrated into BSA solution, cyclic voltammetry and AC impedance experiments confirmed this phenomenon. The thermodynamic data demonstrated that hydrogen bonding as well as electrostatic interactions might be the leading force when they bound to BSA. The experiments of site competition and molecular docking showed that both CPT and HCPT bind to BSA on site I. Furthermore, the three-dimensional fluorescence, synchronous fluorescence and circular dichroism spectroscopy demonstrated that presence of CPT/HCPT changed the conformation of BSA.

喜树碱（CPT）和10-羟基喜树碱（HCPT）是两种抗肿瘤药物，它们通过抑制裂解的DNA链的降解而导致肿瘤细胞死亡。在本研究中，我们用多光谱法，电化学法和分子对接法研究了CPT / HCPT和牛血清白蛋白（BSA）的相互作用。K _sv和K _a的反比温度和紫外可见吸收率的差异表明，当将CPT-BSA系统和HCPT-BSA系统滴定到BSA溶液中时，它们都形成了复合物，循环伏安法和交流阻抗实验证实了这一现象。热力学数据表明，氢键和静电相互作用在与BSA结合时可能是主导力。现场竞争和分子对接的实验表明，CPT和HCPT均与I部位的BSA结合。此外，三维荧光，同步荧光和圆二色光谱表明CPT / HCPT的存在改变了BSA的构象。