J.J. de Ridder

Mass spectrometry of pertrimethylsilyl aldosyl oligosaccharides

Abstract The mass spectra of 18 trimethylsilyl disaccharides containing only aldohexoses, connected via all possible linkages (1 → 1) to (1 → 6), were compared. These spectra could be divided into three main groups: (1 → 1) disaccharides, (1 → 2), (1 → 3), (1 → 4) disaccharides and (1 → 5), (1 → 6) disaccharides. (1 → 2), (1 → 3) and (1 → 4) disaccharides could be distinguished on the basis of two ratios of peak intensities. (1 → 5) and (1 → 6) disaccharides could not be distinguished. Also, the mass spectra of 4 trimethylsilyl trisaccharides built up from aldohexoses only were recorded. The spectra of three aldopentose containing disaccharides showed that the monosaccharide sequence as well as the position of the glycosidic link could be determined.

Mass spectrometry of pertrimethylsilyl oligosaccharides containing fructose units

Abstract Mass spectra of 6 TMS-disaccharides of type aldohexosyl-(1→ x)-fructose, in which x varies from 1 to 6, were compared and could be divided into two main groups i.e. (1 ar 1), (1 ar 2) disaccharides and (1 ar 3), (1 ar 4), (1 ar 5), (1 ar 6) disaccharides. Within both groups a further differentiation was possible. Also the mass spectra of 2 di-, 6 tri- and 3 tetrasaccharides containing one or more (x ar 2)-β- d -fructofuranose units (x = 1 or 6) were studied. The presence of such a unit gives rise to very abundant ions at m/e 437 and/or m/e 815. A number of other fragment ions e.g. m/e 671, m/e 811, m/e 1049 and m/e 1427 are also of great importance for the characterization of the latter fructosyl oligosaccharides.

Mass spectrometry of 2-acetamido-2-deoxyglycose containing disaccharides

Abstract The mass spectra of six trimethylsilyl 2-acetamido-2-deoxy-aldohexosyl-aldohexoses with (1 → 2), (1 → 3), (1 → 4) and (1 → 6) glycosidic linkages were compared. The spectra could be divided in two main groups on the basis of the ratio of the intensities of the peaks at m/e 217 and m/e 204 ( 217 204 ): (1 → 2), (1 → 3) disaccharides and (1 → 4), (1 → 6) disaccharides. (1 → 2) and (1 → 3) disaccharides could be distinguished on the basis of some ratios of peak intensities, (1 → 4) and (1 → 6) disaccharides on the basis of the presence or absence of one intense peak ( m/e 552). Further, the mass spectrum of an aldohexosyl-(1 → 6)-2-acetamido-2-deoxy-aldohexose is discussed. In all cases the sequence of the monomers could be determined by using the sum of the intensities of two related peaks.

Identification of some stereoisomeric disaccharides by mass spectrometry

Abstract The mass spectra of the trimethylsilyl derivatives of the disaccharides α-lactose, β-lactose, β-cellobiose and the equilibrium mixtures α, β-lactose and α, β-cellobiose have been recorded. A close investigation of peak intensity ratios shows persistent differences for the compounds investigated, allowing a new method of identification. The configuration of the anomeric C-atom of the reducing unit turned out to be the most important factor influencing the relative intensity of several peaks in the mass spectra.

Mass spectrometric investigation of copper chelates with 1-(2-pyridylazo)-2-naphthol

The mass spectra of copper chelates of 1-(2-pyridylazo)-2-naphthol, HX, prepared by different methods, are discussed. Peaks due to Cu(2)X(2)(+), CuX(2)(+) and CuXCl(+) have been positively identified and all copper-containing species have the expected isotopic ratios. The significance of probe temperature and impurities are discussed and it is concluded that the spectra are more in accordance with the known chemical facts than those reported earlier by Betteridge and John.