InChI=1S/C21H22O12/c1-29-11-7-10(31-13(23)8-11)5-3-9-4-6-12(22)18(30-2)17(9)32-21-16(26)14(24)15(25)19(33-21)20(27)28/h3-8,14-16,19,21-22,24-26H,1-2H3,(H,27,28)/b5-3+