Some new decussine-type alkaloids from Strychnos decussata, Strychnos dale and Strychnos elaecocarpa

From the stem bark of Strychnos decussata (Pappe) Gilg (Loganiaceae), four tertiary indole alkaloids have been isolated: bisnordihydrotoxiferine and three new alkaloids. The structures of two of the new alkaloids, 3,14-dihydrodecussine (III) and 10-hydroxy-3,14-dihydrodecussine (IV), have been ascribed on the basis of their spectral data. The muscle-relaxant activity of these new compounds is discussed. Further studies of the alkaloids present in the stem bark of Strychnos dale and Strychnos elaeocarpa revealed the presence of decussine (V) and dihydrodecussine in S. dale and decussine, dihydrodecussine, and bisnordihydrotoxiferine in S. elaeocarpa.