InChI=1S/C21H20O13/c22-8-5-11(25)13(9(23)3-1-7-2-4-10(24)15(27)14(7)26)12(6-8)33-21-18(30)16(28)17(29)19(34-21)20(31)32/h1-6,16-19,21-22,24-30H,(H,31,32)/b3-1+