Studies on the Constituents of Polygonaceous Plants. III

Dried root of Polygonum cuspidatum was consecutively extracted with ethanol and ether, transited to the alkaline solution, and submitted to liquid chromatography by which hydroxyanthraquinones were isolated. By repeated purification through vacuum sublimation and recrystallization, each was identified by zinc distillation, acetylation, or one-dimentional paper chromatography. Besides hydroxyanthraquinones, such as emodin, emodin monomethyl ether, and chrysophanic acid, some reddish brown amorphous powder of m.p. 280° (decomp.) was obtained and glucose and rhamnose were identified as their osazones. The total amount of hydroxyanthraquinoes was 0.1-0.5% of the dried root.