Aporphine alkaloids with antitubercular activity isolated from Ocotea discolor Kunth (Lauraceae)

Tuberculosis disease causes thousands of deaths worldwide and, currently, the used drugs are either not enough or obsolete for its treatment. Therefore, new compounds that combat this disease are been seek. Thus, the antituberculosis activity of the alkaloids ocoxilonine (1), ocoteine (2), dicentrine (3) and 1,2-methylenedioxy-3,10,11-trimethoxyaporphine (4), isolated from Ocotea discolor wood was evaluated. Their structures were identified by analysis of nuclear magnetic resonance spectroscopic data (NMR 1D – 1H, 13C, 2D – COSY, HSQC and HMBC), mass spectra, and comparison with literature data. All the isolated compounds demonstrated antituberculosis activity, with ocoteine (2) being the most active compound, with a minimum inhibitory concentration value of 140 μM against the virulent strain Mycobacterium tuberculosis H37Rv. All the isolated compounds showed antituberculosis activity, with a variation range in the minimum inhibitory concentration between 140 to 310 μM, being ocoteine (2) the most active compound against the virulent strain Mycobacterium tuberculosis H37Rv.