Zn(II)-complexes of diisatin dihydrazones as effective catalysts in the oxidation protocol of benzyl alcohol and effective reagents for biological studies

Two new dinuclear complexes of Zn2+ ion (ZnLC2 and ZnLC6, respectively) with two novel diisatin dihydrazone ligands of succinyl (H2LC2) and terephthalyl (H2LC2) derivatives were constructed. Their structure confirmation was achieved by different spectroscopic tools. The catalytic action of two ZnLCX was estimated under an aerobic atmosphere in the selective oxygenation protocol of benzyl alcohol within hydrogen peroxide. ZnLC6 represented more significant action by 88 % awarding of the monooxo-product, i.e. benzaldehyde, (with loaded catalyst amount = 0.005 mmol, at reaction temperature 70 degrees C for about 3 h), whereas ZnLC2 showed less reactivity with 87 % of the monooxo-product (with the same supplied amount, at 70 degrees C for 5 h). The biochemical action of H2LCX and ZnLCX was studied spectroscopically with some microbial-series and three human cancer cells. In addition, their biological action was studied through the interacting mode with calf thymus DNA (ctDNA) through viscometric and spectrophotometric assays. Both ZnLCX complexing reagents manifested a regarded inhibiting action versus the titled microbial (bacterial and fungal) series and with three human cancer cells growth (according to the zone values in mm of inhibition, MIC in mu M, and IC50 values in mu M) than that of free H2LCX ligands. ZnLC6 exhibited a distinguished interacting ability with ctDNA more than that interaction behavior of ZnLC2 based on the derived magnitudes of Kb (the binding constants), and Delta G/=b (the Gibbs' free energy), respectively. Such results referred to the lipophilic feature of the terphthalyl derivative compare to that of the succinyl one of the bonded ligands. Also, both ZnLC2 and ZnLC6 exhibited an observable higher reactivity over their both H2LC2 and H2LC6 ligands pointing to the function of Zn2+ ion and the structural effect of the free ligands for their progressing reactivity against the studied bacterial series, fungal series, human cancer cell lines and ctDNA.