Abstract:

Purpose: To refine α-1,3-glucan and acquire a series of α-1,3-gluco-oligosaccharides. Methods: Crude polysaccharides
from Lentinula edodes fruit bodies was extracted sequentially with 0.9% NaCl, water, and 5% NaOH/0.05% NaBH4, and then
fractional preciptitation was conducted by adjustment of the pH to neutrality with 1 mol/L acetic acid . Five fractions were acquired
as LFⅠ, LFⅡ, LFⅣ, PⅢ and PⅣ. The structural identification of PⅣ was carried out using HPLC, IR and NMR methods,
and then PⅣ was hydrolyzed with 10 mmol/L TFA and separated with FPLC using Bio-Gel P4 column for obtaining a series
of oligosaccharides. Each fraction of PⅣ was characterized by matrix-assisted laser desorption/ionization mass spectrometry
(MALDI-MS) and electrospray ionization mass spectrometry (ESI-MS). Results: PⅣ was a linear α-1,3-glucan, and 12 kinds of
α-1,3-gluco-oligosaccharides were acquired. Conclusion: A library of α-1,3-gluco-oligosaccharides had been established.

Key words: α-1,3-glucan, structural identification, nuclear magnetic resonance (NMR), α-1,3-gluco-oligosaccharide, matrix assisted laser desorption ionization mass spectrometry (MALDI-MS)