title: [Structure of a psoralen-thymine photoproduct: model for the interaction with DNA on the pyrone ring of psoralen].
abstract: Photoadduct 4-ethoxypsoralen-thymine (4a-methyl-11,1-epoxyethanofuro [3'',2'',:6',7']chromeno-[2',3':1,2]cyclobutal[4,3-d]pyrimid in e-2,4, 5-trione), C18-H14N2O6, Mr = 354.1, monoclinic, P21/c, a = 9.021 (3), b = 11.504 (1), c = 16.397 (3) A, beta = 110.45 (1) degrees, V = 1594.4 A 3, Z = 4, Dm = 1.46, D chi = 1.475 Mg m-3, lambda (Mo K alpha) = 0.71069 A, mu = 0.072 mm-1, F(000) = 736, T = 298 K, R = 0.032 for 1442 observed reflections. This original structure of an intramolecular photoproduct obtained photochemically gives structural information about the cycloaddition of the thymine base on the pyrone ring of the psoralen. The crystal structure displays deformations of the planes of the two rings which form a dihedral angle of 40.5 degrees and a cis-anti conformation relative to the cyclobutane bridging component.
authors.affiliation: Laboratoire de Cristallographie et de Physique Cristalline, UA 114 CNRS, Université de Bordeaux I, Talence, France.
authors.forename: P A
authors.initials: PA
authors.lastname: Salahou
authors.forename: C
authors.initials: C
authors.lastname: Courseille
authors.forename: J L
authors.initials: JL
authors.lastname: Decout
authors.forename: J
authors.initials: J
authors.lastname: Lhomme
mesh_terms: D003432:Cross-Linking Reagents; D004247:DNA / Q000187:drug effects*; D004249:DNA Damage; D005363:Ficusin / Q000494:pharmacology*; D011564:Furocoumarins / Q000494:pharmacology*; D008968:Molecular Conformation; D010777:Photochemistry; D013237:Stereoisomerism; D013941:Thymine / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D003432:Cross-Linking Reagents; D011564:Furocoumarins; D004247:DNA; D005363:Ficusin; D013941:Thymine
vernacular_title: Structure d'un photoproduit psoralène-thymine: modèle pour l'interactio avec l'ADN sur le cycle pyrone du psoraléne.