A new arabinomannan from the cell wall of the chlorococcal algae Chlorella vulgaris.

A new arabinomannan has been isolated from the cell wall of the green algae Chlorella vulgaris by extraction with 0.1 M NaOH, dialysis and SEC fractionation. M(w) was about 8000 u.

Simultaneous determination of substituent patterns in partially acid hydrolyzed O-Me/O-Me-d(3)-cellulose and quantification of the obtained oligomers by HPLC-ESI-MS.

Substituent patterns in oligosaccharide derivatives obtained from methyl cellulose were determined up to DP10 by electrospray ionization mass spectrometry employing separation of the oligomer fractions by HPLC. Oligosaccharides were labeled with meta-aminobenzoic acid after perdeuteromethylation and partial hydrolysis of methyl cellulose, enabling simultaneous quantification according to DP by HPLC/UV. Control of the HPLC-method was performed with a defined oligomer mixture obtained from β-cyclodextrin.

Quantitative aspects in electrospray ionization ion trap and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of malto-oligosaccharides.

Mass spectrometry is widely applied in carbohydrate analysis, but still quantitative evaluation of data is critical due to different ionization efficiencies of the constituents in a mixture. Different size and chemical structure of the analytes cause their uneven distribution in droplets (electrospray ionization, ESI) or matrix spots (matrix-assisted laser desorption/ionization, MALDI). In addition, instrumental parameters affect final ion yields.

Labeling of oligosaccharides for quantitative mass spectrometry.

Quantitative analysis of oligosaccharide mixtures and their derivatives by electrospray ionization mass spectrometry (ESI MS) is challenging, for example, due to different affinities of the analytes to alkali ions. To overcome this source of discrimination and to enhance signal intensity, labeling studies with cellobiose as model compound were performed with the goal to develop a rapid, easy, and robust method. Hydrazone formation with the permanently charged Girard's T reagent as well as reductive amination with five different charge providing amines were studied under various conditions.