InChI=1S/C21H20O10/c1-8(22)19-17(27)18(28)21(31-19)29-11-6-12(24)14-13(7-11)30-20(16(26)15(14)25)9-2-4-10(23)5-3-9/h2-8,17-19,21-24,26-28H,1H3