1,3-Dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2-carbaldehyde

The title compound, C15H8O5, also known as nordamnacanthal, was isolated from the Malaysian Morinda citrifolia L. The 20 non-H atoms are coplanar. The structure is stabilized by intramolecular O—H⋯O hydrogen bonds and intermolecular O—H⋯O and C—H⋯O hydrogen bonds, forming bilayers of molecular tapes with alternating stacking directions along the a axis.