A study of metal chelation of dinucleotide analogs in the gas phase by fast-atom bombardment mass spectrometry

✍ Scribed by Mandapati Saraswathi; Jack M. Miller

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 863 KB
• Volume: 7
• Category: Article
• ISSN: 1044-0305
• DOI: 10.1016/1044-0305(96)84506-5

✦ Synopsis

Fast-atom bombardment (FAB) mass spectrometry was used to investigate the interaction of proton and alkali metal ions with dinucleotide analogs such as T-n-T (T = thymine moiety, n = polyether chain, e.g., triethylene, tetraethylene, pentaethylene, and hexaethylene ether l-4), A-n-T (A = adenine unit 5-8), and T-n-OMe (9-12) in 3nitrobenzyl alcohol matrix. The [M + HI" ion is the most abundant ion for the A-n-T series, whereas in l-4 and 9-12 the (TCzHJ+ ion is the most abundant. Formation of [M + H -C,H,O]+ ions, a characteristic fragmentation of crown ethers under electron ionization, is observed for compounds 1-12 and is more pronounced in 6 and 7. An abundant [M -HI-ion is observed for all the compounds studied under negative ion FAB due to the presence of the (-CO-NH-CO-) group of thymine, an indication of existence of intramolecular H bonding. The FAB mass spectra of l-12 with alkali metal ions (Li+, Na+, K+, Rb+, and Cs+) showed formation of abundant metal-coordinated ions (EM + Met]" and [TC,H, + Met]+).

Compounds 3,4,6,7, and lo-12 showed ions due to the substitution of the thymine moiety