Glabraquinone A and B, new anthraquinones from (Korth.) Valeton.

Two new anthraquinones, glabraquinone A and B (-) were isolated from the root of (Korth.) Valeton. In addition to the new glabraquinones, six known anthraquinones, that is, 1-hydroxy-2-methoxy-6-methylanthraquinone (), 1,2-dimethoxy-7-methylanthraquinone (), lucidin (), nordamnacanthal (), damnacanthal () and 2-carboxaldehyde-3-hydroxyanthraquinone ()) and an aromatic compound, that is, catechol diethyl ether () were isolated and characterized in this study. Compounds , and showed mild activity, reducing N2A cell viability to 77%, 82% and 77%, respectively, in anti-neuroblastoma assay.