InChI=1S/C21H22O15/c1-8(22)33-16(19(30)31)17(34-11(24)7-4-9-2-5-10(23)6-3-9)20(32)36-21-14(27)12(25)13(26)15(35-21)18(28)29/h2-7,12-17,21,23,25-27H,1H3,(H,28,29)(H,30,31)/b7-4+