3.1.3 FT-IR analysis
The GP was analyzed by FT-IR spectra with recorded frequencies ranging
from 4,000 to 500 cm-1 (Fig. 1C). A wide absorption
peak at 3,446 cm-1 in the region of 3,500-3,200
cm−1 showed stretching vibrations of O-H and N-H,
indicating intramolecular hydrogen bonds. Two peaks in the 3,000-2,800
cm-1 region and the 1,400-1,200 cm-1region were angular vibrations of C-H, which indicated that the GP is a
polysaccharide compound. The peak at 1,633 cm-1indicates the stretching vibration of the C = O in the acetyl group. The
absorption peak at 789 cm-1 is the flat pyranose
α-type C-H bond in the sugar units.