Cytotoxic activity and DNA-binding properties of xanthone derivatives.

In this study, the interactions of different groups substituted xanthone derivatives with calf thymus DNA (ct DNA) have been investigated by spectrophotometric methods and viscosity measurements. Results indicate that xanthone derivatives can intercalate into the DNA base pairs by the plane of xanthone ring and the various substituents may influence the binding affinity with DNA according to the calculated quenching constant values and the melting temperature of DNA. Furthermore, three tumor cell lines including esophagus squamous cancer cell line (ECA109), stomach cancer cell line (SGC7901) and lung cancer cell line (GLC-82) have been used to evaluate the cytotoxic activities of xanthone derivatives by MTT (microculture tetrazolium) method. Analysis show that the oxiranylmethoxy or piperidinylethoxy substituted xanthones exhibit more effective cytotoxic activity against three cancer cells than the other substituted xanthones. The effects on the inhibition of tumor cells in vitro agree with the studies of DNA-binding.