Schiff base zinc(II) complex ofthioacetamide derivatives. Synthesis, characterization and evaluation of interaction with human serum albumin

Amongst the various metal ions, zinc is an attractive prospect, being a bioessential trace element whichplays a vital role in biological processes like electron transfer, endogenous oxidative DNA damageassociated with aging and cancer and its complexes are preferred molecules for cancer inhibition bychemotherapy. In this study, a new water soluble zinc(II) complex 1 (Fig. 1) derived from thioacetamideand 2,3-Butanedione monoxime was synthesized and characterized by elemental analysis (CHN), molarconductance measurements and spectroscopic methods. The interaction of complex 1 with Human SerumAlbumin (HSA) was investigated under like physiological condition in Tris–HCl buffer solution at pH 7.4by means of spectroscopic methods (fluorescence, and UV-Vis).The results of fluorescence titrationrevealed that the complex 1 strongly quench the intrinsic fluorescence of HSA through a static quenchingprocedure. Binding constants (Kb) and the number of binding sites (n ~ 1) were calculated using modifiedStern–Volmer equations. The thermodynamic parameters ΔG at different temperatures (298, 307, 317 K)were calculated subsequently the value of ΔH and ΔS was also calculated which revealed that thehydrophobic and hydrogen bonding interactions play a major role in HSA–complex 1 association. Thedistance r between donor (HSA) and acceptor (complex 1) was obtained according to fluorescenceresonance energy transfer and the alterations of HSA secondary structure induced by complex 1 wereconfirmed by UV-Vis measurements.

کلیدواژه ها:

Schiff base ، human serum albumin ، fluorescence quenching ، UV-Vis spectroscopy