title: Quercetin-Iron Complex: Synthesis, Characterization, Antioxidant, DNA Binding, DNA Cleavage, and Antibacterial Activity Studies.
abstract: Quercetin-iron (II) complex was synthesized and characterized by elemental analysis, ultraviolet-visible spectrophotometry, fourier transform infrared spectroscopy, mass spectrometry, proton nuclear magnetic resonance spectroscopy, thermogravimetry and differential scanning calorimetry, scanning electron micrography and molar conductivity. The low molar conductivity value investigates the non-electrolyte nature of the complex. The elemental analysis and other physical and spectroscopic methods reveal the 1:2 stoichiometric ratio (metal:ligand) of the complex. Antioxidant study of the quercetin and its metal complex against 2, 2-di-phenyl-1-picryl hydrazyl radical showed that the complex has much more radical scavenging activity than free quercetin. The interaction of quercetin-iron (II) complex with DNA was determined using ultraviolet visible spectra, fluorescence spectra and agarose gel electrophoresis. The results showed that quercetin-iron (II) complex can intercalate moderately with DNA, quench a strong intercalator ethidium bromide and compete for the intercalative binding sites. The complex showed significant cleavage of pBR 322 DNA from supercoiled form to nicked circular form and these cleavage effects were dose-dependent. Moreover, the mechanism of DNA cleavage indicated that it was an oxidative cleavage pathway. These results revealed the potential nuclease activity of complex to cleave DNA. In addition, antibacterial activity of complex on E.coli and S. aureus was also investigated. The results showed that complex has higher antibacterial activity than ligand.
authors.affiliation: School of pharmacy, Jiangsu University, Zhenjiang, 212013, China.
authors.forename: Aun
authors.initials: A
authors.lastname: Raza
authors.affiliation: School of pharmacy, Jiangsu University, Zhenjiang, 212013, China.
authors.forename: Xiuquan
authors.initials: X
authors.lastname: Xu
authors.affiliation: School of Chemistry & Chemical Engineering, Jiangsu University, Zhenjiang, 212013, China.
authors.forename: Li
authors.initials: L
authors.lastname: Xia
authors.affiliation: School of Chemistry & Chemical Engineering, Jiangsu University, Zhenjiang, 212013, China.
authors.forename: Changkun
authors.initials: C
authors.lastname: Xia
authors.affiliation: School of pharmacy, Jiangsu University, Zhenjiang, 212013, China. jt.u@hotmail.com.
authors.forename: Jian
authors.identifier: http://orcid.org/0000-0003-3289-3352
authors.initials: J
authors.lastname: Tang
authors.affiliation: School of pharmacy, Jiangsu University, Zhenjiang, 212013, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Ouyang
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism*; D053837:DNA Cleavage / Q000187:drug effects*; D006801:Humans; D007364:Intercalating Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D011794:Quercetin / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D056831:Coordination Complexes; D007364:Intercalating Agents; D004247:DNA; D011794:Quercetin; D007501:Iron
keywords: Quercetin-iron (II) complex· anti-oxidant· DNA binding· DNA cleavage· antibacterial activity