naghibione; a novel sesquiterpenoid with antiplasmodial effect from dorema hyrcanum koso-pol. root, a plant used in traditional medicine

some dorema species are used in persian traditional medicine. in the present study the total extract from the roots of dorema hyrcanum koso-pol. was investigated for its in vitro (pldh assay) and in vivo (peters’ 4-days suppressive test) antiplasmodial effects and assessed for cytotoxicity against the normal cell line mdbk (mtt test). the ic50 values for a chloroquine- sensitive (3d7) and a chloroquine- resistance (k1) strain of plasmodium falciparum were 28.64 and 9.79 µg/ml, respectively. the inhibition percentage of the rodent parasite, plasmodium berghei, on day 4 in mice was 77.9% and ic50 value on madin–darby bovine kidney cells (mdbk cells) was 59.84µg/ml. the total extract was subjected to a bioassay-guided fractionation protocol based on the in vivo model which resulted in the isolation of an acetophenon (compound 1), one new sesquiterpenoid, 1(2-hydroxy-4-methoxy)- 3,7,11- trimethyl-3-vinyl-6(e), 10 dodecadiene- 1- dione (compound 2) and two known sesquiterpenoid derivatives (compounds 3, 4). their structures were elucidated by spectroscopic analysis, including 1d and 2d nmr experiments and esi-ms. all compounds were evaluated for in vivo antiplasmodial effect and the results revealed that compound 2 showed good suppression activity, inhibiting 68.1 % of the parasite growth.