Study of the Interaction of Dinucleotide Analogs with Alkaline Earth Metal Ions by Fast Atom Bombardment Mass Spectrometry

✍ Scribed by Saraswathi, Mandapati; Miller, Jack M.

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 663 KB
• Volume: 31
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(199609)31:9<1011::aid-jms387>3.0.co;2-8

✦ Synopsis

The fast atom bombardment (FAB)mass spectra of a series of dinucleotide analogs, compounds 1-8 with alkaline earth metal chlorides (CaCI,, MgCI,, SrCI, and BaCI,) were studied in a thioglycerol matrix. The positive-ion FAB mass spectra of 1-8 with CaCI, gave [ M + Ca -HI +, [ M + CaClj + and [ M + Ca,CI -2HI + ions. The formulae of [ M + Ca -H I + and [ M + Ca,CI -2HI + ions from 2 were confirmed with high-resolution measurements. Compounds 1-8 with alkaline earth metal ions also give metal chelated dimerized species [ 2 M + Ca,CI -4H]+, I t M + Ca, -3Hj + and [2M + Ca -HI +], a process which is independent of the size of the polyether chain. The negative-ion FAB spectra also produce bimetallic ions with all substrates studied. Experiments with D,O addition using CaCI, with compounds 2 and 6 suggested the elimination of acidic protons (amide and/or amine) in the formation of [M + Met,CI, -nH) ions in either positive or negative modes. The site of the metal chelation was the same in both positive-and negative-ion mass spectra. The collision-activated dissociation data suggest the covalent bonding of the metal to the nitrogen base and coordination with the polyether chain.