InChI=1S/C20H18O9/c21-11-3-1-2-9(6-11)13-7-10-4-5-12(8-14(10)28-13)27-20-17(24)15(22)16(23)18(29-20)19(25)26/h1-8,15-18,20-24H,(H,25,26)