New cassane diterpenoids from the root bark of Erythrophleum suaveolens

Phytochemical investigation of the methanol extract from the root barks of Erythrophleum suaveolens (Guill. et Perr.) Brenan led to the isolation of four cassane diterpenoid amides and five cassane diterpenoid amines. Among these compounds, two were considered as new structures: 3β-hydroxy-3-methylbutanoyloxy-6α-hydroxy-nor-cassamine (1) and 3β-hydroxy-3-methylbutanoyloxy-erythrosuamine (2). Compounds 3 (3β-acetoxy-nor-erythrosuamine), 4 (nor-cassamine), 5 (6α-hydroxy-nor-cassamine), 6 (3β-hydroxy-erythrosuamide), 7 (6α-hydroxy-nor-erythrophlamide), 8 (nor-cassaidide) and 9 (nor-cassamidide) were known. Their structures were established by spectral analysis including MS, IR, 1D and 2D-NMR spectroscopy. The originality of this study lies in the fact that two new natural molecules were identified and all the isolated compounds (1-9) were reported for the first time from the root barks of E. suaveolens.