InChI=1S/C21H17N3O4/c25-19(26)17-9-13-11-5-1-4-8-16(11)23-18(13)21(28,20(27)24-17)14-10-22-15-7-3-2-6-12(14)15/h1-8,10,17,22-23,28H,9H2,(H,24,27)(H,25,26)/t17-,21-/m0/s1