InChI=1S/C20H16O6/c1-9(2)15-6-12-16(26-15)7-17-18(19(12)23)20(24)13(8-25-17)11-4-3-10(21)5-14(11)22/h3-5,7-8,15,21-23H,1,6H2,2H3