InChI=1S/C20H21NO9/c1-28-12-6-8(7-22)5-9-13-10(21-14(9)12)3-2-4-11(13)29-20-17(25)15(23)16(24)18(30-20)19(26)27/h2-6,15-18,20-25H,7H2,1H3,(H,26,27)