Metal-Based Biologically Active Compounds

A series of cobalt, nickel, copper, and zinc complexes of bidentate Schiff bases derived from the condensation reaction of 4-amino-5-mercapto-3-methyl/ethyl-1,2,4-triazole with 2,4-dichlorobenzaldehyde were synthesized and tested as antimicrobial agents. The synthesized Schiff bases and their metal complexes were characterized with the aid of elemental analyses, magnetic moment measurements, spectroscopic and thermogravimetric techniques. The presence of coordinated water in metal complexes was supported by infrared and thermal gravimetric studies. A square planar geometry was suggested for Cu(II) and octahedral geometry proposed for Co(II), Ni(II), and Zn(II) complexes. The Schiff bases and their metal complexes have been screened for antibacterial (Pseudomonas aeruginosa, Bacillus subtilis) and antifungal activities (Aspergillus niger, A. flavus). The metal complexes exhibited significantly enhanced antibacterial and antifungal activity as compared to their simple Schiff bases. Metal complexes may be subjected for the design and synthesis of such possibilities having such biological activities. Metal complexes may be subjected for the design and synthesis of such possibilities having such biological activities. The chemistry of Schiff bases and their structural analogues has occupied a place of considerable importance [4] as they easily form stable complexes with most transition metal ions. 1,2,4-triazoles nucleus and their derivatives emerge rapidly with the advances of modern heterocyclic chemistry, promising a variety of medical applications such as antibacterial, antifungal, anticancer, antitumor, anticonvulsant, anti-inflammatory, and analgesic properties. The incorporation of the 1,2,4-triazole unit into Schiff base macrocycles is of considerable current interest as complexes of 1,2,4-triazoles are being developed for potential use in applications such as magnetic materials and photo chemically driven molecular devices. The synthesized Schiff bases and their metal complexes were characterized with the aid of elemental analyses, magnetic moment measurements, spectroscopic, and thermogravimetric techniques. The Schiff bases and their metal complexes have been screened for antibacterial (Pseudomonas aeruginosa, Bacillus subtilis) and antifungal activities (Aspergillus niger, A. flavus). 1Department of Chemistry, Kurukshetra University, Kurukshetra 136 119, India2Department of Microbiology, Kurukshetra University, Kurukshetra 136 119, India Received 19 July 2011; Accepted 20 September 2011 http://www.hindawi.com/journals/bca/2011/901716/