InChI=1S/C20H26O9/c1-2-3-8-28-19(26)20(27)10-15(23)18(25)16(11-20)29-17(24)7-5-12-4-6-13(21)14(22)9-12/h4-7,9,15-16,18,21-23,25,27H,2-3,8,10-11H2,1H3/b7-5-