N-butyl-1-methyl-4-{[(1-methyl-4-{[(1-methyl-4-{[(3-methyl-6-nitro-2,4-dioxo-3,4-dihydropyrimido[4,5-b]quinolin-10(2H)-yl)acetyl]amino}-1H-pyrrol-2-yl)carbonyl]amino}-1H-pyrrol-2-yl)carbonyl]amino}-1H-pyrrole-2-carboxamide