The mucilage from the tubers ofAsparagus filicinus, when subjected to partial hydrolysis by heating with 4 per cent. sulphuric acid at 80° for 3 hours, breaks into an aldobionic acid and a polysaccharide. The aldobionic acid is composed of mannose and glucuronic acid, while the polysaccharide is constituted from two molecules of fructose, eight molecules of glucose and nine of mannose.

The polysaccharide does not melt or decompose below 250° and has a specific rotation of −14·45°. It undergoes easy acetylation when treated with acetic anhydride and anhydrous sodium acetate. The acetyl derivative decomposes at about 180° and has a specific rotation of −15·0° in chloroform solution.