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BackgroundWell known as teak, Tectona grandis is widely used in African folk medicine for its pharmacological relevance. In Cameroon, this species is a reputed laxative in the Northern Region while in the Western Region, it is used in the treatment of skin diseases and diarrhoea.Materials and methodsSeparation and isolation of compounds were performed using different chromatographic methods while their structures were elucidated by spectroscopic techniques including MS and NMR, and by comparison of data with those reported in the literature. Isolated compounds as well as crude ethanol extract were tested for their antibacterial activities using broth micro-dilution method against four Gram negative bacteria strains Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (PA 01), Klebsiella pneumonia (ATCC 11296) and Escherichia aerogenes (ATCC 13048).ResultsThree known compounds were isolated, including two quinones and one triterpene. They were identified as tectograndone (1), 6-methyl-1,4-dihydroxyanthraquinone (2), and 2β-hydroxyursolic acid (3) respectively. Crude ethanol extract showed good activity against the bacteria strains tested with MIC of 64–256 μg/mL. Among the isolated metabolites, 6-methyl-1,4-dihydroxyanthraquinone exhibited a strong activity against Escherichia aerogenes with MIC of 16 μg/mL, while tectograndone showed a moderate activity against Escherichia coli with MIC of 32 μg/mL. The antibacterial screening of the fruits of this plant as well as that of compounds 1 and 2 is reported herein for the first time.ConclusionThe research work presented here shows that Tectona grandis fruits possess compounds which could be developed in the treatment of bacterial diseases.

Mots cl es : Vitex thyrsiflora Verbenaceae Triterp enes St eroïdes Activit e antiplasmodiale Cameroun r é s u m é L' etude phytochimique de l'extrait au dichlorom ethane des ecorces du tronc Vitex thyrsiflora Baker (Verbenaceae) a permis d'isoler six compos es identifi es a l'acide 20(R),24(E)-3-oxo-9blanosta-7,24-di en-26-oïque (1), a-amyrine (2), b-amyrine (3), friedeline (4), au palmitate de bsitost erol (5) et au glucoside de b'-sitost erol (6). Tous ces compos es ont et e isol es pour la premi ere fois de cette plante. Leurs structures ont et e elucid ees sur la base de leurs donn ees spectroscopiques et par comparaison avec celles de la litt erature. Le compos e 5 a pr esent e une activit e antiplasmodiale significative avec des CI 50 de 3,09 et 8,98 mg/mL, contre les souches multi-r esistantes Dd2 et K1 de P. falciparum, tandis que celle des compos es 1 et 4 etait moder ee. Toutes les mol ecules test ees ont et e non cytotoxiques sur la souche de cellule epith eliale de singe (LLC-MK2). Les r esultats obtenus peuvent justifier l'utilisation traditionnelle des ecorces du tronc de Vitex thyrsiflora dans le traitement du paludisme.