InChI=1S/C20H21NO8/c1-8-12(27-2)7-11-13(9-5-3-4-6-10(9)21-11)17(8)28-20-16(24)14(22)15(23)18(29-20)19(25)26/h3-7,14-16,18,20-24H,1-2H3,(H,25,26)