Spectroscopic and thermodynamic approach to the interaction of nonperipherally substituted cationic phthalocyanines with calf thymus (CT)-DNA

Authors: SEVGİCAN TUNCER, İBRAHİM ÖZÇEŞMECİ, BEHİCE ŞEBNEM SESALAN, AYFER KALKAN BURAT

Abstract: Novel, nonperipherally tetrasubstituted cationic metal-free and metallophthalocyanines (Zn, In) were synthesized in the present study. The binding constants, the disappearance of quenching effect of all cationic phthalocyanines on the fluorescence intensity of SYBR Green--disodium salt of deoxyribonucleic acid (DNA) from calf thymus complex, and the changes in T$_{m}$ of double helix DNA with thermal denaturation profile were investigated by UV-Vis and fluorescence spectrophotometric methods. To investigate the spontaneity of the reactions between DNA and novel quaternized phthalocyanines in buffer, thermodynamic parameters were employed.

Keywords: Calf thymus (CT)-DNA, morpholine, quaternized phthalocyanines, Gibbs, entropy

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