To obtain a new compound having a lipid metabolism-accelerating activity and peroxylipid-formation inhibiting activity and useful for the prevention of obesity, and the prevention and treatment of hyperlipemia, arteriosclerosis, cardiomyopathy, and used as a raw material of a health food.

This new soybean saponin is 3-O-[β-D-glucopyranosyl(1→2)-β-D- glucuronopyranosyl]-sophoradiol of the formula, derived from a soybean (Glycine max(L.) Merrill). The compound of the formula is obtained by a method, etc., of de-fating the soybean which is the seed of the soybean as a Dicotyledones plant belonging to the genus Glycine max Merrill of Leguminosae, extracting by using an aliphatic alcohol (an aqueous solution), then distilling off the solvent under a reduced pressure, filtering the precipitated material as necessary, concentrating the filtrate, partitioning it by using water and n-butanol, concentrating the n-butanol layer under a reduced pressure to obtain a concentrated residue consisting of crude saponins and purifying the residue.