title: Characterization of photo-induced pyrimidine cyclobutane dimers by laser desorption Fourier transform mass spectrometry.
abstract: Laser desorption Fourier transform mass spectrometry was used to characterize the cis-syn cyclobutane photodimers of uracil-uracil, uracil-thymine and thymine-thymine. This soft ionization technique generated [M-H]- ions as well as some fragment ions. Investigation of the laser desorption process indicated that gas-phase dimerization reactions do not occur for pyrimidine monomers and dimers under these experimental conditions. Collisional dissociation of the [M-H]- ions provided structural information for the pyrimidine rings of the dimers. The fragment ions observed in the collisional dissociation spectra of these cyclobutane dimers suggested rearrangement of the [M-H]- parent ions to a macrocycle prior to dissociation.
authors.affiliation: Analytical Chemistry Division, Oak Ridge National Laboratory, Tennessee 37831-6120.
authors.forename: R L
authors.initials: RL
authors.lastname: Hettich
authors.forename: M V
authors.initials: MV
authors.lastname: Buchanan
authors.forename: C H
authors.initials: CH
authors.lastname: Ho
mesh_terms: D003503:Cyclobutanes; D005583:Fourier Analysis; D007834:Lasers; D013058:Mass Spectrometry; D010777:Photochemistry; D011740:Pyrimidine Dimers / Q000032:analysis* / Q000528:radiation effects; D013941:Thymine / Q000032:analysis; D014466:Ultraviolet Rays; D014498:Uracil / Q000032:analysis
chemical_list: D003503:Cyclobutanes; D011740:Pyrimidine Dimers; D014498:Uracil; D013941:Thymine