title: Structure elucidation of the adducts formed by fjord region Dibenzo[a,l]pyrene-11,12-dihydrodiol 13,14-epoxides with deoxyguanosine.
abstract: (+/-)-anti-Dibenzo[a,l]pyrene-11,12-dihydrodiol 13,14-epoxide {(+/-)-anti-DB[a,l]PDE} was reacted with deoxyguanosine (dG) in dimethylformamide at 100 degrees C for 30 min, and two sets of adducts were isolated: a mixture of (+/-)-anti-cis- & -trans-N(2)dG (43%) and a mixture of (+/-)-anti-cis- & -trans-N7Gua (45%). Both are mixtures of four stereoisomers that cannot be separated by HPLC. Similarly, (+/-)-syn-DB[a,l]PDE was reacted with dG under the same conditions, and (+/-)-syn-cis- & -trans-N(2)dG (38%) and (+/-)-syn-cis- & -trans-N7Gua (59%) were obtained. The structures of the adducts were determined by a combination of NMR and fast atom bombardment mass spectrometry. By reacting (-)-anti-DB[a,l]PDE or (+)-syn-DB[a,l]PDE with dG under the same conditions, however, optically pure N(2)dG and N7Gua isomers were obtained: (-)-anti-cis-N(2)dG (12%), (-)-anti-trans-N(2)dG (17%), (-)-anti-trans-N7Gua (43%), (+)-syn-cis-N(2)dG (7%), (+)-syn-trans-N(2)dG (3%), (+)-syn-cis-N7Gua (36%), and (+)-syn-trans-N7Gua (22%). The structures of the optically pure adducts were assigned by NMR. syn- and anti-DB[a,l]PDE-N(2)dG adducts can be distinguished by fluorescence line-narrowing spectroscopy (FLNS). Moreover, distinction between cis- and trans-stereochemistry of the adducts is also straightforward by FLNS, because the FLN spectra for the four DB[a,l]PDE-N(2)dG adducts, anti-cis, anti-trans, syn-cis, and syn-trans, are spectroscopically unique.
authors.affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, Nebraska 68198-6805,USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: George
authors.forename: M L
authors.initials: ML
authors.lastname: Gross
authors.forename: C H
authors.initials: CH
authors.lastname: Lin
authors.forename: R
authors.initials: R
authors.lastname: Jankowiak
authors.forename: G J
authors.initials: GJ
authors.lastname: Small
authors.forename: A
authors.initials: A
authors.lastname: Seidel
authors.forename: H
authors.initials: H
authors.lastname: Kroth
authors.forename: E G
authors.initials: EG
authors.lastname: Rogan
authors.forename: E L
authors.initials: EL
authors.lastname: Cavalieri
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000737:chemistry*; D018736:DNA Adducts / Q000138:chemical synthesis*; D003849:Deoxyguanosine / Q000737:chemistry*; D004101:Dihydroxydihydrobenzopyrenes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
chemical_list: D018736:DNA Adducts; D004101:Dihydroxydihydrobenzopyrenes; C071371:dibenzo(a,l)pyrene 11,12-dihydrodiol; D004247:DNA; D003849:Deoxyguanosine