Naturally occurring quinones. Part XXV. Pterocarpenequinones (6H-benzofuro[3,2-c][1]benzopyranquinones) from Brya ebenus
Abstract
Bryaquinone, the principal purple pigment in the heartwood of Brya ebenus, is 4-hydroxy-3,7-dimethoxypterocarpene-9,10-quinone; the corresponding 4-deoxyquinone is also present. Bryebinal, a minor yellow component, is probably a 2-arylbenzofuran-3-carbaldehyde.