title: Study binding of Al-curcumin complex to ds-DNA, monitoring by multispectroscopic and voltammetric techniques.
abstract: In this work a complex of Al3+ with curcumin ([Al(curcumin) (EtOH)2](NO3)2) was synthesized and characterized by UV-vis, FT-IR, elemental analysis and spectrophotometric titration techniques. The mole ratio plot revealed a 1:1 complex between Al3+ and curcumin in solution. For binding studies of this complex to calf thymus-DNA various methods such as: UV-vis, fluorescence, circular dichroism (CD), FT-IR spectroscopy and cyclic voltammetry were used. The intrinsic binding constant of ACC with DNA at 25°C was calculated by UV-vis and cyclic voltammetry as 2.1×10(4) and 2.6×10(4), respectively. The thermodynamic studies showed that the reaction is enthalpy and entropy favored. The CD results showed that only the Δ-ACC interacts with DNA and the Δ-ACC form has not any tendency to interact with DNA, also the pure curcumin has not any stereoselective interaction with CT-DNA. Fluorimetric studies showed that fluorescence enhancement was initiated by a static process in the ground state. The cyclic voltammetry showed that ACC interact with DNA with a binding site size of 2. From the FT-IR we concluded that the Δ-ACC interacts with DNA via partial electrostatic and minor groove binding. In comparison with previous works it was concluded that curcumin significantly reduced the affinity of Al3+ to the DNA.
authors.affiliation: Department of Medicinal Chemistry, Faculty of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah 67145-1673, Islamic Republic of Iran. fahmadi@kums.ac.ir
authors.forename: F
authors.initials: F
authors.lastname: Ahmadi
authors.forename: A A
authors.initials: AA
authors.lastname: Alizadeh
authors.forename: N
authors.initials: N
authors.lastname: Shahabadi
authors.forename: M
authors.initials: M
authors.lastname: Rahimi-Nasrabadi
mesh_terms: D000535:Aluminum / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002942:Circular Dichroism; D003474:Curcumin / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D004247:DNA; C427203:calf thymus DNA; D000535:Aluminum; D003474:Curcumin