InChI=1S/C20H18O9/c1-7-5-10(25-3)9-6-27-20-13-12(19(24)29-20)14(21)8(2)15(22)17(13)28-16(9)11(7)18(23)26-4/h5,20-22H,6H2,1-4H3/t20-/m0/s1