Chemical investigations on the gum exudate from sajna (Moringa oleifera)

The purified, whole-gum exudate from the drum-stick plant (Moringa oleifera) was found to contain l-arabinose, d-galactose, d-glucuronic acid, l-rhamnose, d-mannose, and d-xylose in the molar ratios of ～ 14.5:11.3:3:2:1:1. A homogeneous, degraded-gum polysaccharide consisting of d-galactose, d-glucuronic acid, and d-mannose in the molar ratios of ～ 11.7:3.9:1, was obtained on mild hydrolysis of the whole gum with acid. Permethylation studies were conducted on the whole gum, the degraded gum, and their carboxyl-reduced products, and the results were in good agreement with those obtained from periodate oxidation followed by Smith degradation. Also, isolation and characterization of the oligosaccharides obtained from the mother liquor during preparation of the degraded gum, and by graded hydrolysis of the degraded gum, were achieved. On the basis of the results obtained from these studies, a tentative structure was assigned to the average repeating-unit of the gum.