Abstract: Objective: To analyze the contents of saccharides, the molecular weights of polysaccharides and monosaccharide composition of Abelmoschus manihot gum (AMG) from four different sources. Methods: The contents of reducing sugars, total saccharides and polysaccharides in four kinds of AMG samples were determined by 3,5-dinitros-alicylic acid (DNS) colorimetric method. Infrared spectra (IR) of AMG samples were also analyzed. The molecular weights of polysaccharides in purified AMG samples were characterized by gel permeation chromatography (GPC), and the monosaccharide composition of AMG samples were analyzed by gas chromatography (GC). Results: The contents of reducing sugars were 51.07%, 9.00%, 53.94% and 11.46%, respectively; the contents of total saccharides were 79.95%, 78.99%, 91.98% and 61.13%, respectively; and the contents of polysaccharides were 28.88%, 69.99%, 38.04% and 49.67%, respectivly, in four kinds of AMG samples. Infrared spectra indicated that AMG-1 and AMG-3 were mainly composed of α-D-glucopyranose, while AMG-2 and AMG-4 were mainly composed of mannose. The peak molecular weights of AMG polysaccharides were 3.91 × 103, 5.36 × 105, 3.87 × 103 and 5.12 × 105, respectivly. All four kinds of AMG samples contained mannose, glucose and galactose; and their molar ratios were 0.42:1.00:0.27, 1.00:0.15:0.54, 0.27:1.00:0.15 and 1.00:0.12:0.48, respectivly. Conclusion: The contents of reducing sugars, total saccharides and polysaccharides, the molecular weights of polysaccharides and monosaccharide composition apparently differ among AMG gums from different sources.

Key words: Abelmoschus manihot gum, saccharide, content, molecular weight, composition