The Pectic Substances of Plants. Part II. A Preliminary Investigation of the Chemistry of the Cell-walls of Plants

Effect of Acid and Alkaline Hydrolysis on the Estimation of Hemicellulose and Associated Groups in Young Apple Wood

“…Either the 4 per cent. NaOH destroys some of the carbohydrate material, or its action upon the tissue is less drastic.…”

“…H2SO, for a period of 2 hours. The other residue was extracted with 4 per cent. NaOH at room temperature in a shaking machine.…”

The Hemicelluloses. I. The Hemicellulose of Wheat Flour

“…The distribution appears to be a very wide one. In some lignified tissues they exist in relatively large quantities ("wood-gums"), and the product isolated many years ago from barley by O'Sullivan and called by him "amylan" also apparently belongs to this class.The first investigations were carried out on leguminous seeds from which a " hemicellulose " and also " cytopectic acid " [see Clayson, Norris and Schryver, 1921] were isolated and in extending the work to cereals wheat flour was chosen as the chief material for research. By means of the process described in detail below, a product giving a blue coloration with iodine like starch, but differing in many essential properties from this substance, was isolated.…”

“…The first investigations were carried out on leguminous seeds from which a " hemicellulose " and also " cytopectic acid " [see Clayson, Norris and Schryver, 1921] were isolated and in extending the work to cereals wheat flour was chosen as the chief material for research. By means of the process described in detail below, a product giving a blue coloration with iodine like starch, but differing in many essential properties from this substance, was isolated.…”

“…During the course of some researches on the constituents of the cell-wall substances of plants by Clayson, Norris and Schryver [1921], it was found that, by means of N sodium hydroxide solution, substances could be extracted from all the materials investigated, which were soluble in the more concentrated alkaline solutions, but not in very weak alkali; they could be precipitated from the alkaline solutions on addition of acids, and as they yielded reducing sugars on hydrolysis with acids, they were assumed to belong to the class of products termed by Schulze the "bemicelluloses." Most of the products isolated gave on hydrolysis relatively large amounts of pentoses, and all of them gave a blue coloration with iodine.…”