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Chemical constituents and antibacterial activity of Annickia chlorantha (Oliv.) Setten & Maas (Annonaceae) and their chemophenetic significance


Raymond Ngansop Nono
Jean F. Zeutsop
Appolinaire Kene Dongmo
Jean R. Chouna
Pépin Nkeng-Efouet-Alango

Abstract

Background: Annickia chlorantha (Annonaceae) is an ornamental tree, which may grow up to 30 m high with dense foliage and spreading crown. It is used in traditional medicine for its anti-infective properties particularly in the treatment of fungal infections, malaria, hepatitis, jaundice and other bacterial infections. This study describes the chemical and antibacterial investigation of ethanol extract of the stem bark of A. chlorantha.


Methods: The compounds were obtained by separation using silica gel and Sephadex LH-20 CC. Their structures were elucidated through the analysis of their NMR and MS data. The antibacterial activities of the crude extract and isolated compounds were carried out using microdilution method against five sensitive bacterial strains


Results: The chemical investigation of the stem bark of A. chlorantha led to the isolation of ten known secondary metabolites classified into seven alkaloids (1-7), one triterpene (9), and two steroids (8a-8b, 10) including 1,2,3-trimethoxy-4,5-dioxo-6a,-dehydroaporphine A (1), cepharadione B (2), O-methyl-moschatoline (3), palmatine (4), jatrorrhizine (5), columbamine (6), pseudojatrorrhizine (7), the mixture of β-sistosterol (8a) and stigmasterol (8b), cyclofoetigenine A (9) and β-sitosterol-3-O-β-D-glucopyranoside (10). Their structures were elucidated through the analysis of their NMR and MS data. The crude extract exhibited weak antibacterial activity against Staphylococcus aureus (MIC = 1000 μg/mL). Compounds 2 and 4 exhibited moderate activity against Staphylococcus aureus (MIC = 125 μg/mL), while compound 5 displayed the same activity against Shigella flexneri. The chemophenetic significance of the isolated compounds was discussed.


Conclusion: The phytochemical and antibacterial investigation carried out on A. chlorantha showed that this plant contains some antibacterial compounds justifying its uses in traditional medicine for the treatment of bacterial infections.


Journal Identifiers


eISSN: 2617-0027
print ISSN: 2617-0019