(2Z)-2-(3,4-dihydroxybenzylidene)-4,5,6-trimethoxy-1-benzofuran-3(2H)-one 3(2H)-benzofuranone, 2-[(3,4-dihydroxyphenyl)methylene]-4,5,6-trimethoxy-, (2Z)- InChI=1/C18H16O7/c1-22-14-8-12-15(18(24-3)17(14)23-2)16(21)13(25-12)7-9-4-5-10(19)11(20)6-9/h4-8,19-20H,1-3H3/b13-7