InChI=1S/C20H14O9/c1-26-13-3-8(4-14(27-2)18(13)23)19-17(22)10-7-15(20(24)25)28-11-5-9(21)6-12(29-19)16(10)11/h3-7H,1-2H3,(H3-,21,22,23,24,25)/p+1