Chemical Study of Cassane-type Diterpenoid Isomers from the Root Bark of Erythrophleum ivorense A. Chev. (Fabaceae)
Akoubet-Ouayogode Aminata
Département de Chimie Analytique, Minérale et Générale, Technologie Alimentaire, UFR Sciences Pharmaceutiques et Biologiques, Université Félix HOUPHOUËT-BOIGNY, 06 BP 2256 Abidjan 06, Côte d’Ivoire.
Konan Dibi Jacques
Laboratoire de Chimie Bio-Organique et de Substances Naturelles (LCBOSN), UFR-SFA, Université Nangui ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire.
Kablan Richmond Jean-François
Département de Mathématiques-Physique-Chimie, UPR de Chimie organique, UFR des Sciences Biologiques, Université Peleforo GON COULIBALY, BP 1328 Korhogo, Côte d’Ivoire.
Kablan Ahmont Landry Claude *
Département de Mathématiques-Physique-Chimie, UPR de Chimie organique, UFR des Sciences Biologiques, Université Peleforo GON COULIBALY, BP 1328 Korhogo, Côte d’Ivoire.
Kabran Aka Faustin
Laboratoire de Constitution et Réaction de la Matière, UFR Sciences des Structures de la Matière et Technologie, Université Félix HOUPHOUËT-BOIGNY, 22 BP 582 Abidjan 22, Côte d’Ivoire.
Attioua Koffi Barthelemy
Laboratoire de Constitution et Réaction de la Matière, UFR Sciences des Structures de la Matière et Technologie, Université Félix HOUPHOUËT-BOIGNY, 22 BP 582 Abidjan 22, Côte d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
Cassane-type diterpenoid alkaloids are among the major secondary metabolites reported in the genus Erythrophleum and are known for their important biological activities. In the present study, the methanolic extract of the root bark of Erythrophleum ivorense was investigated in order to isolate and characterize cassane-type diterpenoid isomers. Successive chromatographic separations of the ethyl acetate extract led to the isolation of two diterpenoid alkaloid isomers. Their structures were elucidated by combining IR, HR-ESI-MS, 1D and 2D NMR analyses. The two compounds exhibited the same molecular formula, C25H39NO7, and were identified as N,N-dimethyl-3β,6α-dihydroxy-nor-cassane and N,N-dimethyl-3β,7α-dihydroxy-nor-cassane. These compounds had previously been reported in the genus Erythrophleum, but this work constitutes their first isolation from the root bark of Erythrophleum ivorense. This study contributes to the phytochemical knowledge of the species and confirms the richness of its root bark in cassane-type diterpenoid alkaloids.
Keywords: Erythrophleum, IR, HR-ESI-MS, NMR, diterpenoid alkaloids, isolation