title: Synthesis, spectral characterization and antioxidant activity studies of a bidentate Schiff base, 5-methyl thiophene-2-carboxaldehyde-carbohydrazone and its Cd(II), Cu(II), Ni(II) and Zn(II) complexes.
abstract: A new Schiff base bidentate ligand (L), 5-methyl thiophene-2-carboxaldehyde-carbohydrazone and its metal (Cu(II), Cd(II), Ni(II) and Zn(II)) complexes with general stoichiometry [M(L)2X2] (where X=Cl) were synthesized. The ligand and its metal complexes were characterized by elemental analyses, IR, 1H NMR, ESR spectral analyses, and molar conductance studies. The molar conductance data revealed that all the metal chelates are non-electrolytes. IR spectra showed that ligand (L) is coordinated to the metal ions in a bidentate manner with N and O donor sites of the azomethine-N, and carbonyl-O. ESR and UV-Vis spectral data showed that the geometrical structure of the complexes are Orthorhombic. Furthermore, the antioxidant activity of the ligand and its complexes was determined by hydroxyl radical scavenging, DPPH, NO, reducing power methods in vitro. The obtained IC50 value of the DPPH activity for the copper complex (IC50=66.4 μm) was higher than other compounds. Microbial assay of the above complexes against Staphylococcus aureus, Escherichia coli, Rhizocotonia bataticola and Alternaria alternata showed that copper complex exhibited higher activity than the other complexes.
authors.affiliation: Inorganic and Analytical Chemistry Division, Department of Chemistry, Sri Venkateswara University, Tirupati 517 502, India.
authors.forename: Y
authors.initials: Y
authors.lastname: Harinath
authors.forename: D Harikishore
authors.initials: DH
authors.lastname: Kumar Reddy
authors.forename: B Naresh
authors.initials: BN
authors.lastname: Kumar
authors.forename: Ch
authors.initials: Ch
authors.lastname: Apparao
authors.forename: K
authors.initials: K
authors.lastname: Seshaiah
mesh_terms: D000447:Aldehydes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001424:Bacterial Infections / Q000188:drug therapy; D002104:Cadmium / Q000737:chemistry / Q000494:pharmacology; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D003300:Copper / Q000737:chemistry / Q000494:pharmacology; D005658:Fungi / Q000187:drug effects; D006801:Humans; D006835:Hydrazones / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D009181:Mycoses / Q000188:drug therapy; D009532:Nickel / Q000737:chemistry / Q000494:pharmacology; D012545:Schiff Bases / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D013876:Thiophenes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D015032:Zinc / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000447:Aldehydes; D000890:Anti-Infective Agents; D000975:Antioxidants; D056831:Coordination Complexes; D006835:Hydrazones; D012545:Schiff Bases; D013876:Thiophenes; D002104:Cadmium; D003300:Copper; D009532:Nickel; C509177:thiophene-2-carboxaldehyde; D015032:Zinc