InChI=1S/C20H18O6/c1-20(2)17(23)7-12-15(26-20)9-16-18(19(12)24)13(22)8-14(25-16)10-3-5-11(21)6-4-10/h3-6,8-9,17,21,23-24H,7H2,1-2H3