InChI=1S/C21H18O9/c22-13-9-14(10-4-2-1-3-5-10)29-15-8-11(6-7-12(13)15)28-21-18(25)16(23)17(24)19(30-21)20(26)27/h1-9,16-19,21,23-25H,(H,26,27)