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

Two new bis anthraquinones, glabraquinone A and B ( 1 - 2 ) were isolated from the root of Prismatomeris glabra (Korth.) Valeton. In addition to the new glabraquinones, six known anthraquinones, that is, 1-hydroxy-2-methoxy-6-methylanthraquinone ( 3 ), 1,2-dimethoxy-7-methylanthraquinone ( 4 ), lucidin ( 5 ), nordamnacanthal ( 6 ), damnacanthal ( 7 ) and 2-carboxaldehyde-3-hydroxyanthraquinone ( 8 )) and an aromatic compound, that is, catechol diethyl ether ( 9 ) were isolated and characterized in this study. Compounds 1 , 4 and 9 showed mild activity, reducing N2A cell viability to 77%, 82% and 77%, respectively, in anti-neuroblastoma assay.