A (1→3)-β-d-Glucan Isolated From Zea Shoot Cell Wall Preparations

A small quantity of (1-->3)-beta-d-glucan was extracted with a (1-->3),(1-->4)-beta-d-glucan by hot water after treatment of the insoluble fraction of a buffer homogenate of Zea shoots with 3 molar LiCl. An ammonium sulfate precipitation procedure effected a separation of the (1-->3)-beta-d-glucan from the more prevalent (1-->3),(1-->4)-beta-d-glucan. The minor component polysaccharide precipitated at a concentration of 20% ammonium sulfate (w/v) and was, as a consequence of precipitation, rendered insoluble in water. The insoluble products were dissolved in 1 normal NaOH followed by neutralization with CH(3)COOH. The purified polysaccharide accounted for approximately 0.3% of total hot water extract. It consisted mostly of glucose and its average mol wt was estimated to be about 7.0 x 10(4), based on elution from a calibrated Sepharose CL-4B column. Methylation analysis and enzymic hydrolysis or partial acid-hydrolysis of the polysaccharide followed by analysis of the hydrolysate showed that the polysaccharide consisted of (1-->3)-beta-linked glucose residues.