Dunaliine A (1), a new amino diketone, has been isolated from the leaves of Desmos dunalii together with four known dihydrochalcones: 2′,4-dihydroxy- 4′,6′-dimethoxy-3′,5′-dimethyldihydrochalcone (2), 2′,4-dihydroxy-4′,6′-dimethoxydihydrochalcone (3), 2′,4-dihydroxy-4′,5′,6′-trimethoxydihydrochalcone (4) and 2′,4-dihydroxy-5′-methyl-4′,6′- dimethoxydihydrochalcone (5). The structures of these compounds were established notably by spectral analysis (1D- and 2D- 1H, 13C NMR), UV, IR and HRMS. © 2009 Taylor & Francis.