InChI=1S/C22H20O11/c1-30-19-12(32-22-17(27)15(25)16(26)20(33-22)21(28)29)6-5-11-14(24)13(31-18(11)19)8-9-3-2-4-10(23)7-9/h2-8,15-17,20,22-23,25-27H,1H3,(H,28,29)/b13-8+