Interaction of a novel antitumor agent TAS-103 with DNA.

Interaction of a novel antitumor agent TAS-103 with DNA has been studied by a variety of methods including thermal melting study, UV-Visible spectroscopy, 1H- and 31P-NMR spectroscopy. Thermal melting study indicated that TAS-103 stabilizes the double stranded form of DNA and the relative binding strength of TAS-103 is equal to that of ethidium bromide (EtBr). UV-Visible spectroscopy demonstrated that titration curves are nearly identical with all DNA oligomers producing a hypochromic and hypsochromic effect. A hypsochromic effect of TAS-103 is differ from typical intercalators such as EtBr and Actinomycin D that exhibit a bathochromic effect. 1H- and 31P-NMR spectroscopy revealed that TAS-103 has mainly two binding modes. Major binding mode is outside binding and minor binding mode is intercalation.