Ugandenial A, a New Drimane-type Sesquiterpenoid from Warburgia ugandensis

Min Xu,Marie-Thérèse Martin,John Kasenene,Françoise Guéritte,Vincent Dumontet,Marc Litaudon,Sabrina Krief,Bernard Kiremire

doi:10.3390/molecules14103844

Abstract

One new drimane-type sesquiterpenoid, named ugandenial A (1), was isolated from the ethyl acetate extract of the bark of Warburgia ugandensis (Canellaceae) together with eight known drimane-type sesquiterpenoids: 11α-hydroxycinnamosmolide (2), warburganal (3), polygodial (4), mukaadial (5), dendocarbin A (6), 9α-hydroxycinnamolide (7), dendocarbin L (8) and dendocarbin M (9). Their structures were established by detailed spectroscopic analysis. In addition a keto-enol equilibrium was demonstrated for compound 1 through a detailed NMR analysis run in CD2Cl2 at 190 K. Cytotoxicity of the isolated compounds against KB cells was evaluated.

Highlights

One new drimane-type sesquiterpenoid, named ugandenial A (1), was isolated from the ethyl acetate extract of the bark of Warburgia ugandensis (Canellaceae) together with eight known drimane-type sesquiterpenoids: 11α-hydroxycinnamosmolide (2), warburganal (3), polygodial (4), mukaadial (5), dendocarbin A (6), 9α-hydroxycinnamolide (7), dendocarbin L (8) and dendocarbin M (9)
In previous phytochemical investigations of W. ugandensis, a large number of drimane-type sesquiterpenoids have been isolated from the heart wood, like ugandensolide, ugandesidial, warburgin and warburgiadione [4] and from the stem bark [5,6,7], like muzigadiolide, deacetylugandensolide, cinnamolide, mukaadial, ugandensidial, muzigadial, waburganal and others, while flavonol glycosides
The chemical investigation of the EtOAc bark extract was undertaken since a strong cytotoxicity was found against KB cells

Summary

Introduction

One new drimane-type sesquiterpenoid, named ugandenial A (1), was isolated from the ethyl acetate extract of the bark of Warburgia ugandensis (Canellaceae) together with eight known drimane-type sesquiterpenoids: 11α-hydroxycinnamosmolide (2), warburganal (3), polygodial (4), mukaadial (5), dendocarbin A (6), 9α-hydroxycinnamolide (7), dendocarbin L (8) and dendocarbin M (9). The chemical investigation of the EtOAc bark extract was undertaken since a strong cytotoxicity was found against KB cells. HPLC and preparative TLC led to the isolation of one new compound 1, together with eight known drimane-type sesquiterpenes: 9α,11α-dihydroxy,6β-acetyl-cinnamolide (2), warburganal (3), polygodial (4), mukaadial (5), 9α-hydroxycinnamolide (7), and dendocarbins A, L and M (6, 8 and 9, respectively) reported for the first time in this species.

Results

Conclusion