Phytochemical study of Tanacetum sonbolii aerial parts and the antiprotozoal activity of its components

The genus Tanacetum includes some popular endemic species of the flora of Iran, with important medicinal properties. In a project directed at structurally interesting bioactive metabolites from Iranian endemic species, we studied Tanacetum sonbolii Mozaff. Eight compounds comprising six phenolic and two terpenoidal compounds were isolated from the ethyl acetate extract of the aerial parts of the plant by normal and reverse phase chromatography. Their structures were established mainly by 1D and 2D NMR spectroscopic techniques, including 1H-1H COSY, HSQC and HMBC methods and confirmed by comparing their NMR data with those reported in the literature. The compounds namely: 2,4-dihydroxy-6-methoxyacetophenone (1), apigenin (2), 5-desmethylsinensetin (3), 5-desmethylnobiletin (4), 8-methoxycirsilineol (5), scopoletin (6), ursolic acid (7) and β-sitosterol (8). In vitro antiprotozoal activity of compounds 1, 3, and 5 were evaluated against Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani and Plasmodium falciparum parasites and also toxicity against rat myoblast (L6) cells. Compound 5 showed promising activity against T. b. rhodesiense.