1. DNA binding, prominent photonuclease activity and antibacterial PDT of cobalt(II) complexes of phenanthroline based photosensitizers
- Author
-
D. Girija, Halehatty S. Bhojya Naik, Manju Giridhar, Kalligundi R. Sangeetha Gowda, and C.N. Sudhamani
- Subjects
Magnetic Resonance Spectroscopy ,Absorption spectroscopy ,Stereochemistry ,Phenanthroline ,Phenazine ,Drug Evaluation, Preclinical ,chemistry.chemical_element ,Phot ,010402 general chemistry ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Quinoxaline ,Quinoxalines ,Escherichia coli ,Organometallic Compounds ,Genetics ,Binding Sites ,Photosensitizing Agents ,Viscosity ,010405 organic chemistry ,Singlet oxygen ,Cobalt ,DNA ,General Medicine ,Anti-Bacterial Agents ,0104 chemical sciences ,Photochemotherapy ,chemistry ,Quinolines ,Molecular Medicine ,Triazenes ,Phenanthrolines - Abstract
The chemistry of Co(II) complexes showing efficient light induced DNA cleavage activity, binding propensity to calf thymus DNA and antibacterial PDT is summarized in this article. Complexes of formulation [Co(mqt)(B)2]ClO4 1–3 where mqt is 4-methylquinoline-2-thiol and B is N,N-donor heterocyclic base, viz. 1,10-phenanthroline (phen 1), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq 2) and dipyrido[3,2-a:2′,3′-c]phenazine (dppz 3) have been prepared and characterized. The DNA-binding behaviors of these three complexes were explored by absorption spectra, viscosity measurements and thermal denaturation studies. The DNA binding constants for complexes 1, 2 and 3 were determined to be 1.6 × 103 M−1, 1.1 × 104 M−1 and 6.4 × 104 M−1 respectively. The experimental results suggest that these complexes interact with DNA through groove binding mode. The complexes show significant photocleavage of supercoiled (SC) DNA proceeds via a type-II process forming singlet oxygen as the reactive species. Antimicrobial photodynamic therapy was studied using photodynamic antimicrobial chemotherapy (PACT) assay against E. coli and all complexes exhibited significant reduction in bacterial growth on photoirradiation.
- Published
- 2018