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