InChI=1S/C20H20O7/c1-20(2)16(24)6-11-15(27-20)7-14(23)17-18(25)12(8-26-19(11)17)10-4-3-9(21)5-13(10)22/h3-5,7,12,16,21-24H,6,8H2,1-2H3