InChI=1S/C20H20O7/c1-20-8-11(10-6-5-9(21)7-14(10)24)15(19(25)26)17(18(20)27-20)16-12(22)3-2-4-13(16)23/h2-7,11,15,17-18,21-24H,8H2,1H3,(H,25,26)