[Analysis of mannoligosaccharides by liquid chromatography-electrospray ionization mass spectrometry]

Oligosaccharide characterization has been of utmost interest in various areas such as medicine, biochemistry, and food chemistry. These biologically relevant molecules are ideally suited for mass spectrometric investigation, because of the capability of this technique in offering structure and relative molecular mass information. Therefore, liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) was applied to characterize the acetolysis of mannan from Saccharomyces cerevisiae. The electrospray using Na+ as adducts proved to be superior to the LC-MS for the determination of mannoligosaccharides. LC separation was accomplished by the use of NH2 column and the elution by acetonitrile-water (70:30, volume ratio). The results showed that mannoligosaccharides side chain consisted of mannose, mannobiose, mannotriose and mannotetraose. The method developed is accurate, fast and convenient and can be used to characterize the relative molecular mass of the oligosaccharides.