Antiparasitic Constituents of Beilschmiedia louisii and Beilschmiedia obscura and Some Semisynthetic Derivatives (Lauraceae).

Christine C Waleguele,Jean J K Bankeu,Angelbert F Awantu,Rui W M Krause,Brice M Mba’Ning,Yannick S F Fongang,Augustin S Ngouela,Norbert Sewald,Bruno N Lenta,Etienne Tsamo

doi:10.3390/molecules25122862

Abstract

The MeOH/CH2Cl2 (1:1) extracts of the roots and leaves of Beilschmiedia louisii and B. obscura showed potent antitrypanosomal activity during preliminary screening on Trypanosoma brucei brucei. Phytochemical investigation of these extracts led to the isolation of a mixture of two new endiandric acid derivatives beilschmiedol B (1) and beilschmiedol C (2), and one new phenylalkene obscurene A (3) together with twelve known compounds (4–15). In addition, four new derivatives (11a–11d) were synthesized from compound 11. Their structures were elucidated based on their NMR and MS data. Compounds 5, 6, and 7 were isolated for the first time from the Beilschmiedia genus. Additionally, the NMR data of compound 4 are given here for the first time. The isolates were evaluated for their antitrypanosomal and antimalarial activities against Tb brucei and the Plasmodium falciparum chloroquine-resistant strain Pf3D7 in vitro, respectively. From the tested compounds, the mixture of new compounds 1 and 2 exhibited the most potent antitrypanosomal activity in vitro with IC50 value of 4.91 μM.

Highlights

The genus Beilschmiedia is one of the most widespread genera of the Lauraceae family
The neutral fraction of the MeOH/CH2Cl2 (1:1) extract of stem bark of B. obscura was subjected to column chromatography (CC) over silica gel to afford beilschmiedol B (1), beilschmiedol C (2), and obscurene A (3)
The organic solvents used for the extraction of plant material and for column chromatography (CC) were of technical and laboratory grade, while those use in reactions were of analytical grade

Summary

Introduction

The genus Beilschmiedia is one of the most widespread genera of the Lauraceae family. It is commonly distributed in tropical Asia and Africa and comprises of about 250 species. Forty-one of these species can be found in Cameroon, principally, in the South Western, Center; Eastern, Littoral, and Western regions [1,2]. The bark and leaves of some Beilschmiedia species have been reported to be used in traditional medicine for the treatment of uterine tumors, Molecules 2020, 25, 2862; doi:10.3390/molecules25122862 www.mdpi.com/journal/molecules. In Cameroon, the decoction of the bark of B. obscura is used in the center region for the treatment of microbial and parasitic infections [4].

Objectives

Methods

Results

Conclusion