5,3 '-Dihydroxy-3,6,7,4 '-tetramethoxyflavone

Abstract

The title compound [systematic name: 5-hydroxy-2-(3-hydroxy-4-methoxyphenyl)-3,6,7- trimethoxychromen-4-one (casticin)], C19H18O8, was isolated from the seeds of Vitex agnus-castus L. The fused chromene ring system and the benzene ring bonded to it are close to coplanar, with a dihedral angle between their respective mean planes of 8.30 ( 12)degrees. The two hydroxy H atoms are involved in intramolecular O - (HO)-O-... hydrogen bonding. Intermolecular O - (HO)-O-... and C - (HO)-O-... hydrogen bonds and pi-pi interactions help to stabilize the crystal structure.