2-[(2-oxo-1,2-Dihydro-quinoline-4-carbonyl)-amino]-succinic acid 4-n-butyl ester 3-[(2-Oxo-1,2-Dihydro-quinoline-4-carbonyl)-amino]-propionic acid butyl ester 4-butoxy-4-oxo-2-{[(2-oxo-1,2-dihydroquinolin-4-yl)carbonyl]amino}butanoic acid (non-preferred name) InChI=1/C18H20N2O6/c1-2-3-8-26-16(22)10-14(18(24)25)20-17(23)12-9-15(21)19-13-7-5-4-6-11(12)13/h4-7,9,14H,2-3,8,10H2,1H3,(H,19,21)(H,20,23)(H,24,25 Sterculinine I aspartic acid, N-[(1,2-dihydro-2-oxo-4-quinolinyl)carbonyl]-, 4-butyl ester