Synthesis,characterization and in vitro biological activity of new zinc(II) complexes of the nonsteroidal anti‐inflammatory drug sulindac and nitrogen‐donor ligands

Metal carboxylate compounds with nitrogen‐ and/or oxygen‐donor ligands with various carboxylate coordination modes, monodentate, bidentate and bridging bidentate, have been shown to be important from biological and chemical aspects. Five zinc ion binary compounds, diaqua‐bis‐(2‐((E )‐5‐fluoro‐2‐methyl‐1‐(4‐(methylsulfinyl)benzylidene)‐1H –inden‐3‐yl)acetato)zinc(II) ( 1 ), aqua‐bis‐(2‐((E )‐5‐fluoro‐2‐methyl‐1‐(4‐(methylsulfinyl)benzylidene)‐1H –inden‐3‐yl)acetato)pyridin‐2‐aminezinc(II) ( 2 ), (2‐((E )‐5‐fluoro‐2‐methyl‐1‐(4‐(methylsulfinyl)benzylidene)‐1H –inden‐3‐yl)acetato) pyridin‐2‐ylmethanaminezinc(II) (2‐((E )‐5‐fluoro‐2‐methyl‐1‐(4‐(methylsulfinyl)benzylidene)‐1H –inden‐3‐yl)acetate) ( 3 ), bis‐(2‐((E )‐5‐fluoro‐2‐methyl‐1‐(4‐(methylsulfinyl)benzylidene)‐1H –inden‐3‐yl)acetato)‐1,10‐phenanthrolinezinc(II) ( 4 ) and bis‐(2‐((E )‐5‐fluoro‐2‐methyl‐1‐(4‐(methylsulfinyl)benzylidene)‐1H –inden‐3‐yl)acetato)‐1,10‐phenanthrolinezinc(II) ( 5 ), have been prepared and fully characterized. In addition, the complexes were evaluated for their antibacterial activity using the in vitro agar diffusion method against two Gram‐positive (Staphylococcus epidermidis , Staphylococcus aureus ) and two Gram‐negative (Bordetella , Escherichia coli ) bacteria and yeast species (Saccharomyces and Candida ). Complex 5 showed reasonable activity against yeast. All compounds showed greater antibacterial activity against Gram‐positive than Gram‐negative bacteria. Results indicated that the efficiency of complex 5 in preventing the formation of β‐hematin was 67.6%. The efficiency of chloroquine as a standard drug was reported as 93%. Furthermore, the phosphatase activity of the Zn(II) complexes was studied and results indicated an effect of the zinc complexes on phosphatase activity.