Novel ligand 1-((8-hydroxyquinolin-5-yl)methyl)-3-(thiazol-2-ylimino)indolin-2-one was synthesized by condensation of 5-(chloromethyl)-1,8a-dihydroquinolin-8-ol with 3-(thiazol-2-ylimino)indolin-2-one. Metal complexes of this ligand were prepared using various transition metal ion salts, viz., Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II). All synthesized compounds were characterized by various spectroscopic techniques. Thermogravimetric analysis of metal complexes was also carried out. Geometry of the metal complexes was carried out by electronic spectral analysis and magnetic measurement studies. The ligand and metal complexes were screened for their antibacterial activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Proteus vulgaris, and Pseudomonas aeruginosa. The metal complexes are found more potent bactericides than the ligand. The interaction of ligand and its complexes with plasmid (pUC 19) DNA and calf thymus DNA was investigated by gel electrophoresis measurements. The superoxide dismutase mimetic activity of the ligand and its metal complexes has also been assessed for their ability to inhibit the reduction of nitrobluetetrazolium chloride.