5-Hydroxy-7-methoxy-2-phenyl-4H-1-benzopyran-4-one (Tectochrysin) and 2,5-Dihydroxy-7-methoxy-2-phenyl-2,3-dihydro-4H-1-benzopyran-4-one: Isolation From Uvaria rufas and X-Ray Structures

Abstract

5-Hydroxy-7-methoxy-2-phenyl-4H-1-benzopyran-4-one ( tectochrysin ) (1), 5-hydroxy-7,8-di-methoxy-2-phenyl-4H-1-benzopyran-4-one (7-0-methylwogonin) (2), 5-hydroxy-6,7-dimethoxy-2-phenyl-4H-1-benzopyran-4-one (6,7-O,O-dimethylbacaiein) (3) and 2,5-dihydroxy-7-methoxy-2-phenyl-4H-1-benzopyran-4-one (4) have been isolated from the roots of Uvaria rufas Blume. The crystal structures of (1) and (4) have been determined by X-ray diffraction methods from diffractometer data at 295 K and refined by full matrix least squares. Crystals of (1) are monoclinic P21/c, a 10.l28(3), b 15.289(5), c 8.215(4) �,β 92.39(3)� Z 4; R 0.045 for No 874 'observed' reflections; crystals of (4) are monoclinic P21/c, a 12.299(4), b 6.489(3), c 16.579(6) �, β 90.24(3)� Z 4; R 0.051 for No 1016.