title: Study of DNA light switch Ru(II) complexes: synthesis, characterization, photocleavage and antimicrobial activity.
abstract: The three Ru(II) complexes of [Ru(phen)(2)dppca](2+) (1) [Ru(bpy)(2)dppca](2+) (2) and [Ru(dmb)(2)dppca](2+) (3) (where phen = 1,10 phenanthroline, bpy = 2,2-bipyridine, dmb = 2 ,2-dimethyl 2',2'-bipyridine and polypyridyl ligand containing a single carboxylate functionality dppca ligand (dipyridophenazine-11-carboxylic acid) have been synthesized and characterized. These complexes have been shown to act as promising calf thymus DNA intercalators and a new class of DNA light switches, as evidenced by UV-visible and luminescence titrations with Co(2+) and EDTA, steady-state emission quenching by [Fe(CN)(6)](4-) and KI, DNA competitive binding with ethidium bromide, viscosity measurements, and DNA melting experiments. The results suggest that 1, 2, and 3 complexes bind to CT-DNA through intercalation and follows the order 1 > 2 > 3. Under irradiation at 365 nm, the three complexes have also been found to promote the photocleavage of plasmid pBR322 DNA.
authors.affiliation: Department of Chemistry, Osmania University, Hyderabad, Andhra Pradesh, India.
authors.forename: Praveen Kumar
authors.initials: PK
authors.lastname: Yata
authors.forename: M
authors.initials: M
authors.lastname: Shilpa
authors.forename: P
authors.initials: P
authors.lastname: Nagababu
authors.forename: M Rajender
authors.initials: MR
authors.lastname: Reddy
authors.forename: Laxma Reddy
authors.initials: LR
authors.lastname: Kotha
authors.forename: Nazar Md
authors.initials: NM
authors.lastname: Gabra
authors.forename: S
authors.initials: S
authors.lastname: Satyanarayana
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001231:Aspergillus flavus / Q000187:drug effects; D001234:Aspergillus niger / Q000187:drug effects; D002417:Cattle; D004247:DNA / Q000737:chemistry*; D053837:DNA Cleavage; D004926:Escherichia coli / Q000187:drug effects; D008027:Light; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009492:Neurospora crassa / Q000187:drug effects; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012428:Ruthenium / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D009942:Organometallic Compounds; D012428:Ruthenium; D004247:DNA; C427203:calf thymus DNA