title: Synthesis, DNA interactions and antibacterial PDT of Cu(II) complexes of phenanthroline based photosensitizers via singlet oxygen generation.
abstract: Cu(II) complexes [Cu(mqt)(B)H2O]ClO4(1-3) of 2-thiol 4-methylquinoline and phenanthroline bases (B), viz 1,10-phenanthroline (phen in 1), Dipyrido[3,2-d:2',3'-f]quinoxaline (dpq in 2) and Dipyrido[3,2-a:2',3'-c]phenazine (dppz in 3) have been prepared and characterized by elemental analysis, IR, UV-Vis, magnetic moment values, EPR spectra and conductivity measurements. The spectral data reveal that all the complexes exhibit square-pyramidal geometry. The DNA-binding behaviors of the three complexes were investigated by absorption spectra, viscosity measurements and thermal denaturation studies. The DNA binding constants for complexes (1), (2) and (3) were determined to 2.2×10(3), 1.3×10(4) and 8.6×10(4)M(-1) respectively. The experimental results suggest that these complexes interact with DNA through groove-binding mode. The photo induced cleavage studies shows that the complexes possess photonuclease property against pUC19 DNA under UV-Visible irradiation via a mechanistic pathway involving formation of singlet oxygen as the reactive species. Antimicrobial photodynamic therapy was studied using photodynamic antimicrobial chemotherapy (PACT) assay against Escherichiacoli and all complexes exhibited significant reduction in bacterial growth on photoirradiation.
authors.affiliation: Department of Studies and Research in Industrial Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577 451, India.
authors.forename: C N
authors.initials: CN
authors.lastname: Sudhamani
authors.affiliation: Department of Studies and Research in Industrial Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577 451, India. Electronic address: hsb_naik@rediffmail.com.
authors.forename: H S
authors.initials: HS
authors.lastname: Bhojya Naik
authors.affiliation: Department of Studies and Research in Industrial Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577 451, India.
authors.forename: K R
authors.initials: KR
authors.lastname: Sangeetha Gowda
authors.affiliation: Department of Studies and Research in Industrial Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577 451, India.
authors.forename: M
authors.initials: M
authors.lastname: Giridhar
authors.affiliation: Department of Studies and Research in Industrial Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577 451, India.
authors.forename: D
authors.initials: D
authors.lastname: Girija
authors.affiliation: Department of Studies and Research in Industrial Chemistry, School of Chemical Sciences, Kuvempu University, Shankaraghatta 577 451, India.
authors.forename: P N
authors.initials: PN
authors.lastname: Prashanth Kumar
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D002417:Cattle; D015169:Colony Count, Microbial; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism; D053837:DNA Cleavage / Q000187:drug effects; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D009691:Nucleic Acid Denaturation; D010618:Phenanthrolines / Q000138:chemical synthesis / Q000494:pharmacology*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000138:chemical synthesis* / Q000494:pharmacology*; D026082:Singlet Oxygen / Q000378:metabolism*; D014783:Viscosity
chemical_list: D000900:Anti-Bacterial Agents; D056831:Coordination Complexes; D010618:Phenanthrolines; D017319:Photosensitizing Agents; D026082:Singlet Oxygen; D003300:Copper; D004247:DNA; C427203:calf thymus DNA; C025205:1,10-phenanthroline
keywords: Cleavage; Groove-binding; Metal complexes; PACT assay; Photonuclease activity