Spectral, biological screening, and DNA studies of metal chelates of 4-[N,N-bis-(3,5-dimethyl-pyrazolyl-1-methyl)]aminoantipyrine

Abstract

Tridentate chelate complexes of Co(II), Ni(II), and Cu(II) have been synthesized from 4-[N,N-bis-(3,5-dimethyl-pyrazolyl-1-methyl)]aminoantipyrine. Microanalytical data, UV-Vis, magnetic susceptibility, Infrared, ¹H- ¹³C-NMR, mass, thermal gravimetric analysis and electron paramagnetic resonance (EPR) techniques were used to confirm the structures. The electronic absorption spectra and magnetic susceptibility measurements suggest a distorted octahedral geometry for the metal. EPR spectra of the copper(II) complex at 77 K confirm the distorted octahedral geometry of the copper(II) complex. The antimicrobial activities of the ligand and metal complexes against the bacteria such as Xanthomonas maltophilia, Chromobacterium violaceum, Acinetobacter, Staphylococci, Streptococci, and the fungus Candida albicans have been carried out. A comparative study of minimum inhibitory concentration values of the ligand and its metal complexes indicates that metal complexes exhibit higher antibacterial and antifungal activity than the free ligand. The electrochemical behavior of copper(II) complex was studied by cyclic voltammetry. The complexes show nuclease activity in the presence of oxidant.

Keywords:

• Pyrazolyl aminoantipyrine
• Metal complexes
• Biological screening
• DNA cleavage studies

Acknowledgments

The authors thank the Management of Thiagarajar College, Madurai, and one of the authors (MK) thanks the UGC, SERO, Hyderabad for awarding Teacher Fellowship and SAIF-IIT-Bombay, USIC-MKU-Madurai, SAIF-IIT-Madras-Chennai and CDRI (SAIF), Lucknow for providing analytical facilities.