Simple and Fast Method for Recognition of Reducing and Nonreducing Neutral Carbohydrates by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Abstract

Negative-ion mode matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry (TOF-MS) was used for the characterization of storage, neutral oligosaccharides extracted from Jerusalem artichoke, red onion, and wheat. The oligosaccharides from the real samples were analyzed with 2,4,6-trihydroxyacetophenone as the most convenient matrix that was selected in advance with the standard carbohydrate samples (inulin and maltooligosaccharides). The oligosaccharides from Jerusalem artichoke and red onion (similarly as inulin) produced [M - H](-) peaks as the main distribution, which reflects their nonreducing composition. On the contrary, the cross-ring fragmentations [M - H - 120](-) formed the main distribution in the mass spectra of hydrolyzed wheat starch similarly to reducing maltooligosaccharides and dextrans. The negative-ion mode MALDI-TOF MS is capable of recognizing reducing and nonreducing oligosaccharides. Such a simple differentiation of malto or inulin type of oligosaccharides is not possible in the positive-ion mode.

Structural analysis and differentiation of reducing and nonreducing neutral model starch oligosaccharides by negative-ion electrospray ionization ion-trap mass spectrometry

“…This phenomenon, as well preferential fragmentation of [M−H] − ions on glycosidic bond between glucose and fructose, can also facilitate the differentiation of reducing and nonreducing saccharides with a terminal fructose unit. The same conclusions were deduced from MALDI measurements of reducing and nonreducing saccharides [24].…”

“…The number of the ionic species recorded in the negative-ion mode was rather high: ring and glycosidic fragments of the deprotonated molecules were found in the negative-ion mass spectra of the reducing saccharides [24]. On the contrary, positive-ion mass spectra were simpler with regard to the variety of the ion species.…”

Structure and degree of polymerisation of fructooligosaccharides present in roots and leaves of Stevia rebaudiana (Bert.) Bertoni

“…Particularly significant was the analysis of FOS or inulin from some plants, using MALDI-MS (Wang, Sporn, & Low, 1999;Štikarovská & Chmelík, 2004;Lasytovicková & Chmelík, 2006;Arrizon, Morel, Gschaedler, & Monsan, 2010). We therefore applied this technique for determination of the DPs of fractions RFOS and LFOS.…”

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for the period 2005–2006

“…Although addition of salts is usually detrimental to signal strength in positive ion mode, the authors of this work report that the ionization efficiency for the production of [M þ Cl] À ions increases in the presence of an excess of ammonium chloride. Laštovicková and Chmelík (2006) have obtained negative ion spectra of carbohydrates such as inulin (6) directly from the five matrices DHB, THAP, CHCA, 3-aminoquinoline (3-AQ, 1/24) and HABA. Of these, THAP was by far the best.…”