Patent ID: 6998262

Claim:
A process for preparing a polysaccharide extract of Dioscorea sp. capable of improving immunological activities in a subject consisting essentially of the steps of: (1) extracting a tuber of Dioscorea sp. using a 40% methanol solution in the presence of 1% acetic acid, followed by separation, so as to obtain an insoluble solid portion; (2) subjecting the insoluble solid portion obtained in step (1) to an aqueous solvent in the presence of a starch hydrolyzing enzyme to obtain an aqueous solution; and (3) treating the aqueous solution obtained in step (2) with a 75% alcohol based solvent to obtain a precipitated solid portion; and (4) treating the precipitated solid portion obtained in step (3) with a deproteinizing agent to remove proteinaceous substances therefrom.