THE MUCILAGINOUS POLYSACCHARIDE MATERIAL ISOLATED FROM RUREDZO (DICEROCARYUM-ZANGUEBARIUM)

The mucilage isolated from ruredzo (Dicerocaryum zanguebarium) by precipitation with ethanol and fractionation with copper II acetate contained galactose, xylose, arabinose and mannose in the ratio 21:19:12:1. Samples were analysed by TLC on Whatman K5 plates impregnated with Na2HPO4 and developed with ethyl acetate: pyridine: water (10:4:3 v/v). Plates were sprayed with p-anisidine in methanol or diphenylamine/aniline/phosphoric acid reagent to visualize spots. R(f) values for sample spots corresponding to galactose, xylose, and arabinose were 0.62, 0.81 and 0.76. Mannose was not detectable during TLC. For GC the retention times for the alditol acetates of samples corresponding to galactose, xylose, arabinose and mannose were 18.2, 9.1, 6.4, and 16.2 min, respectively. The polymer, whose molecular weight was 500 000, released arabinose residues after hydrolysis with a 50 mM H2SO4 solution but not a 5 mM H2SO4 solution. Gel chromatography of acid hydrolysates on Sepharose 6B showed fragments of decreasing molecular weight with increased periods of hydrolysis. The mucilage has a specific optical rotation of +4.5-degrees, ash content of 7.6%, a protein content of 2.1% (Kjeldahl) and 1.8% (Lowry) and a uronic acid content of 8.1%.