InChI=1S/C21H22O11/c1-30-15-8-14(31-21-18(27)16(25)17(26)19(32-21)20(28)29)10(6-13(15)24)3-2-9-4-11(22)7-12(23)5-9/h2-8,16-19,21-27H,1H3,(H,28,29)/b3-2+