title: Studies on the interaction of apigenin with calf thymus DNA by spectroscopic methods.
abstract: The interaction between apigenin and calf thymus deoxyribonucleic acid (ctDNA) in a pH 7.4 Tris-HCl buffer solution was investigated by UV-Vis spectroscopy, fluorescence spectroscopy, DNA melting techniques, and viscosity measurements. It was found that apigenin molecules could intercalate into the base pairs of DNA, forming a apigenin-DNA complex with a binding constant of K310K=6.4×10(4)Lmol(-1). The thermodynamic parameters enthalpy change (ΔH), entropy change (ΔS) and Gibbs free energy (ΔG) were calculated to be 7.36×10(4)Jmol(-1), 329JK(-1)mol(-1) and -2.84×10(4)Jmol(-1) at 310K, respectively. Hydrophobic interaction was the predominant intermolecular force in stabilizing the apigenin-DNA complex. Thermal denaturation study suggested that the stabilization of the ctDNA helix was increased when the apigenin binding to ctDNA as indicated by the increase in thermal denaturation temperature of ctDNA at around 5.0°C in the presence of apigenin. Spectroscopic techniques together with melting techniques and viscosity determination provided evidences of intercalation mode of binding for the interaction between apigenin and ctDNA.
authors.affiliation: College of Chemistry and Chemical Engineering, Qufu Normal University, Shandong, Qufu 273165, People's Republic of China. Electronic address: zhshf999@sina.com.
authors.forename: Shufang
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Chemistry and Chemical Engineering, Qufu Normal University, Shandong, Qufu 273165, People's Republic of China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Sun
authors.affiliation: College of Chemistry and Chemical Engineering, Qufu Normal University, Shandong, Qufu 273165, People's Republic of China.
authors.forename: Rongmei
authors.initials: R
authors.lastname: Kong
authors.affiliation: College of Chemistry and Chemical Engineering, Qufu Normal University, Shandong, Qufu 273165, People's Republic of China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Xu
mesh_terms: D047310:Apigenin / Q000737:chemistry / Q000493:pharmacokinetics*; D001665:Binding Sites; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D019277:Entropy; D007364:Intercalating Agents / Q000737:chemistry / Q000493:pharmacokinetics; D009691:Nucleic Acid Denaturation; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D013816:Thermodynamics; D014783:Viscosity
chemical_list: D007364:Intercalating Agents; D047310:Apigenin; D004247:DNA; C427203:calf thymus DNA
keywords: Apigenin; Binding mode; Calf thymus DNA; Fluorescence spectroscopy; UV-spectroscopy