Synthesis and antioxidant activities of new nickel(II) complexes derived from 4-benzy- loxysalicylidene-S-methyl/propyl thiosemicarbazones

Abstract

Six nickel(II) complexes of the N 2 O 2 chelating thiosemicarbazones were synthesized using N 1 -4-benzyloxysalicylidene-S-methyl/propyl thiosemicarbazone and methoxy-substitute-salicylaldehydes in the presence of Ni(II) ion by template reaction.The structures of thiosemicarbazones and nickel(II) complexes were characterized by elemental analysis, UV-Vis, IR and 1 H-NMR spectroscopies. The structure of the N 1 -4benzyloxysalicylidene-S-propyl thiosemicarbazone (2) was determined by X-ray singlecrystal diffraction method. The total antioxidant capacities of synthesized compounds were evaluated by using cupric reducing antioxidant capacity (CUPRAC) method. The thiosemicarbazones exhibited more potent antioxidant capacity than Ni(II) complexes.Trolox equivalent antioxidant capacity (TEAC) of 1c was found highest in tested 2 nickel(II) complexes. In addition, antioxidant activities of tested compounds were evaluated by using the hydroxyl radical, DPPH radical, and ABTS radical scavenging abilities of these compounds.

Novel Thiosemicarbazone Derivatives from Furan-2-Carbaldehyde: Synthesis, Characterization, Crystal Structures, and Antibacterial, Antifungal, Antioxidant, and Antitumor Activities

“…Tese compounds which contain N and S atoms usually act as bidentate or multidentate chelating ligands and can coordinate to transition metal ions through the sulfur and hydrazine nitrogen atoms [1]. Extensive investigations conducted by researchers have demonstrated that metal complexes with some thiosemicarbazone derivatives present a wide range of biological applications, such as antibacterial [2,3], antifungal [1,4], antiparasitic [5], antitubercular [6,7], antiviral [8,9], antioxidant [10,11], and antitumoral activities [12][13][14].…”