Research on African medicinal plants. III New alkaloids from Alstonia boonei

Two new alkaloids, N-formylechitamidine, 1, and N-formyl-12-methoxyechitamidine, 2, besides echitamidine, 3, have been isolated from the bark of Alstonia boonei. The 13C-NMR spectra of 1-3 and of 12-methoxyechitamidine, 4, are reported.