Structural studies of a new acidic polysaccharide of apricot seeds

This article reports the isolation and structural investigation of an acidic polysaccharide of the seeds of Prunus armeniaca (apricot) - a plant of commercial importance. The polysaccharide is composed of three sugars - mannose (50%), glucose (37.5%) and glucuronic acid (12.5%). The results of methylation analysis, partial depolymerisation, Smith degradation and NMR spectroscopic studies indicate a branched structure consisting of a straight chain of mainly alpha-(1 --> 3)mannan, which is interspersed with 4-O-(beta-D-mannopyranosyl)glucuronic acid residues. The side chain is bound to the alpha-mannan chain in the form of a trisaccharide of the glucose.