ON THE SODIUM AND LITHIUM ION AFFINITIES OF SOME ALPHA-AMINO-ACIDS

被引:95
作者
BOJESEN, G
BREINDAHL, T
ANDERSEN, UN
机构
[1] Department of Chemistry, Odense University, Odense M
来源
ORGANIC MASS SPECTROMETRY | 1993年 / 28卷 / 12期
关键词
D O I
10.1002/oms.1210281215
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
The decomposition of 59 different cluster ions (generated by fast atom bombardment) consisting of two different amino acids and a sodium ion was analysed. The only fragment ions of significant abundance could be assigned to sodium ion-bound amino acids. Assuming that the most abundant ion in the fragment ion spectrum corresponds to the amino acid with the highest sodium ion affinity (SIA), the 20 common alpha-amino acids could be ordered with increasing sodium ion affinity as follows: Gly, Ala, Cys, Val, (Leu, Ile), Ser, Met, Thr, (Phe, Pro), Asp, Tyr, (Glu, Lys), Trp, Asn, Gln, His, Arg. Quantitative determinations were carried out by comparison of the lithium ion affinity (LIA) of Ala with that of dimethylformamide (DMF) in a fragment ion scan of the ion-bound dimer Ala-Li+-DMF. LIA(Ala) was calculated from LIA(Ala) = LIA(DMF) -(1/C)ln[I(AlaLa+)/I(DMF-Li+), where the constant C was estimated from measurements of proton-bound amine-amino acid clusters. From fragment ion analysis of nine other Li+-bound alpha-amino acid dimers, the following lithium ion affinities were obtained: Gly 51.0, Ala 52.6, Sar 53.5, alpha-aminobutyric acid 53.7, glycine methyl ester 54.7 and Val 54.8. SIA(Ala) was estimated to be 75% of the lithium ion affinity and from fragment ion analysis of ten Na+-bound alpha-amino acid dimers the following sodium ion affinities were obtained: Gly 37.9, Ala 39.4, alpha-aminobutyric acid 40.3, Val 41.0, glycine methylster 41.0 and Sar 41.2.
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页码:1448 / 1452
页数:5
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  • [1] Kebarle P., Hogg A.M., J. Chem. Phys., 42, (1965)
  • [2] Hogg A.M., Kebarle P., J. Chem. Phys., 43, (1965)
  • [3] Staley R.H., Beauchamp J.L., J. Am. Chem. Soc., 97, (1975)
  • [4] Woodin R.L., Beauchamp J.L., J. Am. Chem. Soc., 100, (1978)
  • [5] Gaffney J.S., Pierce R.C., Friedman L., J. Am. Chem. Soc., 99, (1977)
  • [6] Meot-Ner (Mautner) M., Hunter E.P., Field F.H., J. Am. Chem. Soc., 101, (1979)
  • [7] Locke M.J., McIver R.T., J. Amer. Chem. Soc., 105, (1983)
  • [8] Taft R.W., Anvia F., Gal J.-F., Walsh S., Capon M., Holmes M.C., Hosn K., Oloumi G., Vasanwala R., Yazdani S., Free energies of cation-molecule complex formation and cation-solvent transfers, Pure and Applied Chemistry, 62, (1990)
  • [9] Castleman A.W., Peterson K.I., Upshulte B.L., Schelling F.J., Int. J. Mass Spectrom. Ion Phys., 47, (1983)
  • [10] Guo B.C., Conklin B.J., Castleman A.W., J. Am. Chem. Soc., 111, (1989)