InChI=1S/C20H18O9/c1-8(22)29-3-2-9(7-21)15-14(25)6-12-17(19(15)27)20(28)16-11(18(12)26)4-10(23)5-13(16)24/h4-6,9,21,23-25,27H,2-3,7H2,1H3/p-1/t9-/m1/s1