InChI=1S/C21H20O11/c1-2-3-4-5-6-12-7-9-21(32-12)13(8-10-29-21)30-14(22)11-28-20-17(25)15(23)16(24)18(31-20)19(26)27/h6-10,13,15-18,20,23-25H,11H2,1H3,(H,26,27)/b12-6+