Permethylated, mass spectrometry

Keywords Carbohydrate Linkage analysis Permethylation Mass spectrometry... 

The development of mass spectrometry (MS) procedures for the study of C-glycosylflavo-noids is particularly significant because of the resistance of the C-glycosidic bond to hydrolysis. It is important, from the structural point of view, to determine the molecular mass and to localize the sugar substituents on the aglycone moiety. This has been achieved in the past by electron impact EI-MS of permethylated derivatives. 

The carbohydrate sequence of the major tetrasaccharlde was determined by examining the nitrous acid deamination products (25) as permethylated disaccharides by chemical ionization mode of gas chromatography/mass spectrometry. The products were identified as hexosyl-2,5-anhydromannitol and hexosyl-myoinositol,indicating that the major tetrasaccharide had the sequence Galp(l->4)GlcNAcp(l->4)Glcp(l- -2)Inos (Figure 5). 

Figure 3. Selected ion monitoring from mass spectrometry of a permethylated-reduced mixture of non-acid glycolipids from non-epithelial residue of the white rat...

Figure 11. Selected ion monitoring from mass spectrometry of glycolipids of epithelial cells of the two rat strains. A total of 200 fig each of the permethylated-reduced mixture was evaporated by a temperature rise of 5°C/min, and mass spectra were recorded each 38 sec. Electron energy was 34 eV, acceleration voltage 4 kV, trap current 500 fiA, and ion source temperature 290°C.

Direct probe mass spectrometry. Glycosphingolipids (30-100 pg) were permethylated as described (12). The samples (less than 5 p g) were subjected to electron impact/desorption analysis with a Varian MAT CH-5 DF mass spectrometer under the following conditions emission current, 300pA electron energy, 70 eV acceleration voltage, 3KV ion source temperature, 160° C emitter wire current, programed from 0 to 35mA. 

A. Dell, Preparation and desorption mass spectrometry of permethyl and peracetyl derivatives of oligosaccharide, Meth. Enzymol., 193 (1990) 647-660. 

E. Yoon and R. A. Laine, Linkage position determination in a novel set of permethylated neutral trisaccharides by collisional-induced dissociation and tandem mass spectrometry. Biol. Mass Spectrom., 21 (1992) 479-485. 

P. Juhasz and C. E. Costello, Matrix-assisted laser desorption ionization time-of-flight mass-spectrometry of underivatized and permethylated gangliosides, J. Am. Soc. Mass Spectrom., 3 (1992) 785-796. 

Viseux, N., de Hoffmann, E. and Domon, B. (1997) Structural assignment of permethylated oligosaccharide subunits using sequential tandem mass spectrometry. Anal. Chem., 69, 3193-8. 

Solouki, T., Reinhold, B.B., Costello, C.E. et al. (1998) Electrospray ionization and matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry of permethylated oligosaccharides. Anal. Chem., 70 (5), 857-64. 

M. Guillard, J. Gloerich, H. J. C. T. Wessels, E. Morava, R. A. Wevers, and D. J. Lefeber, Automated measurement of permethylated serum A-glycans by MALDI-linear ion trap mass spectrometry, Carbohydr. Res., 344 (2009) 1550-1557. 

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