InChI=1S/C18H13NO7/c20-11-4-1-9(2-5-11)7-14(18(25)26)19-15(21)12-6-3-10(17(23)24)8-13(12)16(19)22/h1-6,8,14,20H,7H2,(H,23,24)(H,25,26)/t14-/m1/s1