title: Multi-spectroscopic DNA interaction studies of sunset yellow food additive.
abstract: The use of food dyes is at least controversial due to their essential role. Synthetic color food additives occupy an important place in the food industry. Moreover many of them have been related to health problems mainly in children that are considered the most vulnerable group. The purpose of this work is to present spectrophotometric methods to analyze the interaction of native calf thymus DNA (CT-DNA) with sunset yellow (SY) at physiological pH. Considerable hyperchromism and no red shift with an intrinsic binding constant of 7 × 10(4 )M(-1) were observed in UV absorption band of SY. Binding constants of DNA with complex were calculated at different temperatures. Slow increase in specific viscosity of DNA, induced circular dichroism spectral changes, and no significant changes in the fluorescence of neutral red-DNA solutions in the presence of SY suggest that this molecule interacts with CT-DNA via groove binding mode. Furthermore, the enthalpy and entropy of the reaction between SY and CT-DNA showed that the reaction is exothermic and enthalpy favored (∆H = -58.19 kJ mol(-1); ΔS = -274.36 kJ mol(-1) ) which are other evidences to indicate that van der Waals interactions and hydrogen bonding are the main running forces in the binding of the mentioned molecule and mode of interaction with DNA.
authors: Faculty of Chemistry, Sensor and Biosensor Research Center (SBRC) & Nanoscience and Nanotechnology Research Center (NNRC), Razi University, P.O. Box 67149, Kermanshah, Islamic Republic of Iran. kashanian_s@yahoo.com
authors: Soheila
authors: S
authors: Kashanian
authors: Sahar
authors: S
authors: Heidary Zeidali
authors: Kobra
authors: K
authors: Omidfar
authors: Nahid
authors: N
authors: Shahabadi
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000737:chemistry*; D001667:Binding, Competitive; D002417:Cattle; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry; D005505:Food Coloring Agents / Q000737:chemistry*; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D009690:Nucleic Acid Conformation; D009994:Osmolar Concentration; D011789:Quantum Theory; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics; D014783:Viscosity
chemical_list: D001391:Azo Compounds; D004277:DNA, Single-Stranded; D005505:Food Coloring Agents; D004247:DNA; C427203:calf thymus DNA; C005842:6-hydroxy-5-((p- sulfophenyl)azo)-2-naphthalenesulfonic acid disodium salt