Comprehensive Investigations About the Binding Interactions of Sudan Dyes with DNA by Spectroscopy and Docking Methods.

Sudan dyes are recognized as carcinogens, which are strictly determined whether there are them in food for food safety. Hence, in order to understand the mechanism at the molecular level, this work investigated the binding interactions of Sudan I-IV with calfthy mus DNA. The synchronous fluorescence and UV-vis spectral results suggested the complex formation between Sudan I-IV and ct-DNA. EB and Hoechst 33258 displacement experimental results confirmed the binding sites of Sudan I-IV in ct-DNA and the minor groove-binding mode of Sudan I-IV with ct-DNA. The molecular modeling computational method also proved binding mode, which is consistent with the spectral experiments. In addition, the aromatic rings of Sudan I-IV play important roles in binding with DNA. Compared to Sudan I and II, the increase of molecular conjugation system enhances the binding abilities of Sudan III and Sudan IV with DNA. Vdm + Hbond + desolv energies of them are the main contribution of their combined energies.