In this study, the interactions of two benzoxanthones 1,3-dihydroxy-12H-benzo[b]xanthen-12-one (1) and 9,11-dihydroxy-12H-benzo[a]xanthen-12-one (2) with calf thymus DNA (ct DNA) have been investigated by absorption spectroscopy, fluorescence spectroscopy, circular dichroism spectroscopy and viscosity measurements. Experimental results suggested an intercalative mode with DNA for the two compounds; Furthermore, the binding affinity with DNA of 1 bearing linearly fused aromatic rings was higher than that of 2 bearing angularly fused aromatic rings according to the calculated binding constant values. In addition, three cell lines, the human cervical cancer cell line (HeLa), human hepatocellular liver carcinoma cell line (HepG2) and human normal liver cell line (L02) were used to evaluate the cytotoxic activities of the two benzoxanthones in vitro. As the results, they showed significant cytotoxic activity against the tumor cell lines HeLa and HepG2, but weak cytotoxic activity against normal liver cell line L02.

中文翻译：

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两种苯并黄酮衍生物的细胞毒活性和DNA结合研究。

在这项研究中，两种苯并氧杂蒽酮1,3-二羟基-12H-苯并[b]黄嘌呤-12-（1）和9,11-二羟基-12H-苯并[a]黄嘌呤-12-（2）的相互作用用吸收光谱法，荧光光谱法，圆二色性光谱法和粘度测量法研究了带有小牛胸腺DNA（ct DNA）的人。实验结果表明，这两种化合物均具有DNA的插入模式；此外，根据计算的结合常数值，具有1个线性稠合的芳族环的DNA的亲和力高于具有2个具有角稠合的芳族环的DNA的亲和力。此外，使用三种细胞系，人宫颈癌细胞系（HeLa），人肝细胞肝癌细胞系（HepG2）和人正常肝细胞系（L02）来评估两种苯并氧杂蒽酮的体外细胞毒活性。