m-6-m型Gemini双季铵盐表面活性剂与DNA的相互作用

合成了5种m-6-m型Gemini双季铵盐表面活性剂,在对产物结构和表面活性进行分析的基础上,分别采用紫外分光光度法和荧光分光光度法考察了m-6-m型Gemini双季铵盐表面活性剂与DNA的相互作用.结果表明,m-6-m型Gemini表面活性剂的CMC随烷基疏水链的增长呈逐渐下降趋势.几种表面活性剂均没有使DNA的紫外吸收峰发生红移或蓝移现象,说明复合物无嵌插作用或氢键形成,表面活性剂与DNA作用后的吸光度随表面活性剂浓度的增大而增强,当表面活性剂的浓度相同时,吸光度随疏水链的增大而逐渐减弱.Gemini表面活性剂浓度增大导致荧光强度降低,表面活性剂与DNA作用时的猝灭为静态猝灭,随着疏水链长度的增长,荧光猝灭常数降低,表面活性剂与DNA之间的作用力减弱.

Interaction of DNA with m-6-m Gemini quaternary ammonium salt surfactant

Five kinds of Gemini quaternary ammonium salt surfactants,m-6-m,were synthesized and characterized.On the basis of the surveyed values of the surface tension,the interaction between these surfactants and DNA was studied by ultraviolet spectrum and fluorescence spectra.The results showed that the Gemini quaternary ammonium salt surfactants with a longer hydrophobic chain had smaller CMC values.Red shift or blue shift of UV absorption peak was not observed in the experiment,it indicated that there is no intercalation on the compounds or hydrogen bond formation.Absorbance of interaction between Gemini surfactants and DNA increased with the increase of surfactant concentration.When the surfactant concentration is the same,the absorbance became weaker with increasing of hydrophobic chain.The fluorescence interaction of DNA with Gemini surfactants was a static quenching process.What's more,high surfactant concentration and long hydrophobic chains contributed to the decreasing of fluorescence intensity and quenching constants.Meanwhile,the interaction between Gemini surfactants and DNA became weak.