InChI=1S/C17H20O9/c1-2-24-11(18)8-5-9-3-6-10(7-4-9)25-17-14(21)12(19)13(20)15(26-17)16(22)23/h3-8,12-15,17,19-21H,2H2,1H3,(H,22,23)/b8-5+