InChI=1S/C18H19BrN4O4/c1-4-27-18-11(9-20)13(21)8-16(23-18)22-17(24)6-10-5-15(26-3)12(19)7-14(10)25-2/h5,7-8H,4,6H2,1-3H3,(H3,21,22,23,24)