The content of total sugar and uronic acid of the polysaccharides
was determined by the phenol-sulfuric acid method [23] and the
sulfuric carbazole method [24], respectively.
The infared spectra were measured with a Nicolet Magna 760
instrument with KBr pellets, while 1H NMR spectra recorded with
a Bruker AVANCE III 500 M NMR instrument with D2O used assolvent. GC–MS was performed with an Agilent 6890GC/5973MS
instrument.