In vitro antiplasmodial activity of the isolated compounds from the stem bark of Vitex thyrsiflora

Phytochemical study of Vitex thyrsiflora (Verbenaceae), a medicinal plant commonly used in traditional medicine to treat malaria, have allowed to isolate six compounds identified 20(R),24(E)-3-Oxo-9β-lanosta-7,24-dien-26-oic acid (1), α-amyrin (2), β-amyrin (3), friedelin (4), β-sitosterol palmitate (5) and a sterol glucoside (6). All these compounds were isolated for the first time in this plant. Their structures were determined on the basis of their physical and spectroscopic data (IR, MS, UV, NMR) and by comparison of these data with those reported in the literature. Compound 5 showed significant antiplasmodial activity with IC50 of 3,09 and 8,98 μg/mL against multi-resistant strains Dd2 and K1 of P. falciparum. All these constituents were isolated from this plant for the first time. The tested compounds were non-cytotoxic on the LLC-MK2 monkey kidney epithelial cells. The results obtained can justify the use of Vitex thyrsiflora stem bark in traditional medicine for the treatment of malaria.