The genus Haplopbyllum (Rutaceae) numbers some 70 species spread from the Mediterranean to eastern Siberia and is an abundant source of quinoline alkaloids belonging to various subgroups (e.g., 4-hydroxy-2-quinolones, 4-quinolones, furoquinolines, dihydropyrano-4-quinolones). Most previous studies on Haplopbyllum species were conducted in the Soviet Union, but Turkey also has no fewer than eight native species. Thus, an investigation of Haplopbyllum cappadocicum Spach. collected near Malatya in eastern Anatolia was initiated, resulting in the isolation and structural elucidation of the 4-quinolone alkaloid malatyamine (1) as its ethyl ester (2). Structural elucidation relied on: 200 MHz NMR (CDCl3) revealing an ethyl ester (triplet at δ 1.26, quartet at δ 4.15) and a 4-quinolone system (one-proton multiplet at δ 8.34, distinguishing it from 2-quinolones which show this signal near δ 7.95); IR (CHCl3) indicating a conjugated carbonyl (1635 cm-1) and aliphatic ester (1725 cm-1); UV (MeOH) absorption maxima at 212, 234, 315, 327 nm (log ε 4.40, 4.43, 4.01, 3.98) supporting a 4-quinolone structure; and mass spectrum of the ethyl ester with molecular ion m/z 287, fragments m/z 258 (loss of ethyl), m/z 242 (loss of ester moieties), and base peak m/z 159 (cation 3). Since ethyl esters are rare in natural products and EtOH was used in early extraction steps, the true alkaloid is likely the corresponding carboxylic acid 1, with 2 formed during isolation. Given the presence of the alkaloid hapovine (4) in Haplophyllum popovii, malatyamine (1) may be formed in vivo via oxidation of 4 or one of its analogs.