title: Differentiation of isomeric 2'-, 3'- and 5'-deoxynucleosides by electron ionization and chemical ionization-linked scanning mass spectrometry.
abstract: A comparative mass spectral examination of the trimethylsilyl (TMS) derivatives of 2'-, 3'- and 5'-deoxyadenosine, 2'-, 3'- and 5'-deoxyguanosine, 2'-, 3'- and 5'-deoxyxanothosine and 2'- and 5'-deoxy-2-fluoroadenosine is presented. A general compilation of the major fragment ions found in the low-resolution electron ionization (EI) spectra of the eleven deoxynucleosides is given. Chemical ionization (CI)-collisional activation (CA) daughter ion spectra are reported using the deoxyadenosines as model compounds. Ion structures and fragmentation pathways are proposed for those ions characteristic of each of the isomers. Significant differences in fragmentation exist between the isomeric 2'-, 3'- and 5'-purine deoxynucleosides. The formation and structures of ten ions important in this differentiation are discussed. The CI-CA linked scan spectra provide complementary structural information relative to the EI mass spectra.
authors: Department of Pharmaceutical Sciences, College of Pharmacy, University of Arizona, Tucson 85721.
authors: M L
authors: ML
authors: Reimer
authors: T D
authors: TD
authors: McClure
authors: K H
authors: KH
authors: Schram
mesh_terms: D003853:Deoxyribonucleosides / Q000032:analysis*; D004563:Electrochemistry; D008401:Gas Chromatography-Mass Spectrometry; D007536:Isomerism; D008970:Molecular Weight; D014297:Trimethylsilyl Compounds / Q000032:analysis
chemical_list: D003853:Deoxyribonucleosides; D014297:Trimethylsilyl Compounds