title: [Spectroscopic research on the interaction of 2-(4-dimethylaminophenyl)-5-fluoro-6-(morpholin-4-yl)-1H-benzimidazole and calf thymus DNA].
abstract: UV-Vis spectra of the aqueous solutions of 2-(4-dimethylaminophenyl)-5-fluoro-6-(morpholin-4-yl)-1H-benzimidazole (1) at different pH values revealed that compound 1 is a tertiary base, which can combine three protons. Through the non-linear least square method, the logarithm of the three accumulative protonation constants of compound 1, namely, lgbeta1, lgbeta2 and lgbeta3, were determined to be 4.96 +/- 0.03, 5.72 +/- 0.07 and 7.95 +/- 0.10, respectively. UV-Vis and the steady-state fluorescence spectra indicated that a special interaction occurs between compound 1 and calf thymus DNA at the pH value of 3.40, of which thebinding constant, Kb, is (2.30 +/- 0.10) x 10(4) mol(-1) x L. Compound 1 in the concentration range of 10(-8) to 1.2 x 10(-6) mol x L(-1) has a potential application to the quantitative determination of DNA.
authors.affiliation: College of Chemistry and Molecular Enginering, Peking University, Beijing 100871, China.
authors.forename: Ling-tian
authors.initials: LT
authors.lastname: Tang
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Xin-qi
authors.initials: XQ
authors.lastname: Liu
authors.forename: Shao-wen
authors.initials: SW
authors.lastname: Hu
authors.forename: Tai-wei
authors.initials: TW
authors.lastname: Chu
authors.forename: Xiang-yun
authors.initials: XY
authors.lastname: Wang
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000032:analysis* / Q000737:chemistry; D002417:Cattle; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D009025:Morpholines / Q000032:analysis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D013053:Spectrophotometry / Q000379:methods*
chemical_list: C549149:2-(4-dimethylaminophenyl)-5-fluoro-6-(morpholin-4-yl)-1H-benzimidazole; D001562:Benzimidazoles; D009025:Morpholines; D004247:DNA; C427203:calf thymus DNA