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