Two new anthraquinones from the roots of Rubia cordifolia Linn.

Two new anthraquinones, named cordifoliol and cordifodiol, have been isolated from the roots of Rubia cordifolia. Their structures have been established as 1-hydroxy-3-ethyl-9,10-anthraquinone (1) and 1,8-dihydroxy-11, 20 (15-pentyl-naphthaquinonyl) phenanthrene (2) on the basis of spectral data analyses and chemical reactions.