title: Fluorescence and photoelectron studies of the intercalative binding of benz(a)anthracene metabolite models to DNA.
abstract: DNA binding of nonreactive metabolite models derived from benz(a)anthracene was studied. The molecules investigated include 1,2,3,4-tetrahydrobenz(a)anthracene (1), 5,6-dihydrobenz(a)anthracene (2), and 8,9,10,11-tetrahydrobenz(a)anthracene (3), as well as anthracene and phenanthrene. Measurements of the effects of DNA binding upon fluorescence intensities and fluorescence lifetimes indicate that molecules 1 and 3 (KA = 1.5 - 2.5 x 10(3) M-1) bind more strongly to native DNA than does molecule 2 (KA congruent to 0.5 x 10(3) M-1). Furthermore, molecules 1 and 3 bind to DNA much more effectively than do the two less sterically hindered pi electron metabolite models, anthracene and phenanthrene. Photoelectron data suggests that the enhanced binding of molecules 1 and 3 is due to increases in polarizability. Experiments carried out with denatured DNA indicate that the binding of molecule 1 entails the greatest intercalation.
mesh_terms: D001551:Benz(a)Anthracenes / Q000378:metabolism*; D001665:Binding Sites; D004247:DNA / Q000378:metabolism*; D004583:Electrons; D010777:Photochemistry; D013050:Spectrometry, Fluorescence
chemical_list: D001551:Benz(a)Anthracenes; D004247:DNA