InChI=1S/C20H21NO8/c1-27-13-7-9(6-11-10-4-2-3-5-12(10)21-14(11)13)8-28-20-17(24)15(22)16(23)18(29-20)19(25)26/h2-7,15-18,20-24H,8H2,1H3,(H,25,26)