InChI=1S/C18H22O9/c1-8(6-7-11-9-4-2-3-5-10(9)17(24)26-11)25-18-14(21)12(19)13(20)15(27-18)16(22)23/h3,5,7-8,12-15,18-21H,2,4,6H2,1H3,(H,22,23)/b11-7+