Chitooligosaccharides are used in medicines, cosmetics and foods due to their bioactivity and non-toxicity in the human body. Because they are frequently present as complex mixtures, with various degrees of polymerization, degrees of acetylation and isobars that have a number of sequences, simultaneous analysis can be a challenging task. Here, we report on a method for the simultaneous sequencing of chitooligosaccharides by the UHPLC-tandem MS analysis. Chitooligosaccharides that were produced by digestion with chitinase were labeled with 2-aminopyridine to label the reducing end. After the purification by preparative-SEC, we identified the sequence of chitooligosaccharides (DP 1–5) from MS/MS spectra by the UHPLC-tandemMS analysis. In this method, the MS
n analysis, the decrease in the sensitivity of MS spectra is not important, because the chitooligosaccharides are first separated by chromatography. This sequencing method can be used in the characterization of deacetylase and structural studies of other bioactive chitooligosaccharides.
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