Thermodynamic study of interaction between phthalocyanines with calf thymus DNA
نویسندگان
چکیده
The experimental determination of formation constant for interaction of two water soluble phthalocyanines, Cobalt (II) 4,4',4",4'"-tetrasulpho phthalocyanine (CoTsPc ) and Manganese(II) 4,4',4",4"-tetrasulpho phthalocyanine (MnTsPc ) , with calf thymus DNA have been studied by UV-Vis spectrophotometric method at lrnM phosphate buffer , pH 7.4 and at 5 different temperatures 20,25,30,35 and 400 C . The changes of UvVis absorption spectra during the titration of these phthalocyanines with calf thymus DNA revealed a large hypochromicity (up to 45%) of the phthalocyanines maximum bands, usually considered as proof of phthalocyanine intercalation in to DNA. The calculated formation constants, Ks , according to the SQUAD software were in the range of 104-105 M-1.By using the Van't Hoff equation. The values of enthalpy and entropy changes associated to the (CoTsPc +DNA) and (MnTsPc+DNA) were determined .Then by using AG°=-RTLIIK, we calculated the values of AG° at considered temperatures. Our results showed strong electrolytic effects on phthalocyanines behavior and increasing NaCl concentration induced self-aggregation of the CoTsPc and MnTsPc.
منابع مشابه
Thermodynamic study of interaction between phthalocyanines with calf thymus DNA
The experimental determination of formation constant for interaction of two water soluble phthalocyanines,Cobalt (II) 4,4',4",4'"-tetrasulpho phthalocyanine (CoTsPc ) and Manganese(II) 4,4',4",4"-tetrasulphophthalocyanine (MnTsPc ) , with calf thymus DNA have been studied by UV-Vis spectrophotometric methodat lrnM phosphate buffer , pH 7.4 and at 5 different temperatures 20,25,30,35 and 400CC ....
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