Polysaccharides of soy-beans. Part II. Fractionation of hull cell-wall polysaccharides and the structure of a xylan

Abstract

Successive extractions of water-extracted soy-bean hulls with aqueous solutions of ammonium oxalate, ethylenediaminetetra-acetic acid disodium salt, potassium hydroxide, and sodium hydroxide–sodium borate afford a series of acidic polysaccharide fractions of the pectic acid type, a xylan, and a mannan containing a small proportion of galactose residues, and leave a cellulosic residue. Structural studies have shown that the xylan contains essentially linear chains of 1,4-linked β-D-xylopyranose residues which carry 3–4% of D-glucopyranosyluronic acid residues as single-unit side-chains joined by 1,2-linkages.