InChI=1S/C20H18O8/c21-7-12(23)20(28)5-4-8-10(6-20)18(26)14-15(16(8)24)19(27)13-9(17(14)25)2-1-3-11(13)22/h1-3,12,21-24,26,28H,4-7H2/t12?,20-/m1/s1