InChI=1S/C21H22O11/c1-28-13-6-4-10(7-14(13)29-2)3-5-11-8-12(9-15(22)30-11)31-21-18(25)16(23)17(24)19(32-21)20(26)27/h3-9,16-19,21,23-25H,1-2H3,(H,26,27)/b5-3+