InChI=1S/C20H22O9/c1-4-20(2,3)11-7-9-5-6-10(8-12(9)28-18(11)26)27-19-15(23)13(21)14(22)16(29-19)17(24)25/h4-8,13-16,19,21-23H,1H2,2-3H3,(H,24,25)