InChI=1S/C21H26O11/c1-28-11-6-3-10(4-7-11)5-8-12-9-13(29-2)17(20(27)30-12)31-21-16(24)14(22)15(23)18(32-21)19(25)26/h3-8,12-18,21-24H,9H2,1-2H3,(H,25,26)/b8-5+