(3,8'-Bi-4H-1-benzopyran)-4,4'-dione, 2,2',3,3'-tetrahydro-3',5,5',7,7'-pentahydroxy-2'-(3-hydroxy-4-methoxyphenyl)-2-(4-hydroxyphenyl)-, (2S,2'R,3R,3'R)- 68705-66-8