InChI=1S/C20H20O9/c21-13(10-5-2-1-3-6-10)14(22)11-7-4-8-12(9-11)28-20-17(25)15(23)16(24)18(29-20)19(26)27/h1-9,13,15-18,20-21,23-25H,(H,26,27)