Two New Antiprotozoal Diterpenes From the Roots of Acacia nilotica

The powdered roots of the medicinal plant Acacia nilotica were extracted with hexane and ethyl acetate, extracts subjected to column chromatography for isolation potentially bioactive compounds their screening against kinetoplastid pathogens. NMR HREI mass spectrometric analyses identified two new diterpenes, characterized as 16, 19-dihydroxycassa-12-en-15-one (Sandynone, 1 ) (5S, 7R, 8R, 9R, 10S, 13Z, 17S)-7,8:7,17:16,17-triepoxy-7,8-seco-cassa-13-ene (niloticane B, 2 ). previously reported (5S,7R,8R,9R,10S) -(-)-7,8-seco-7, 8-oxacassa-13,15-diene-7,17-diol ( 3 ), 8-oxacassa-13,15-dien-7-ol-17-al 4 8-oxacassa-13,15-dien-7-ol 5 a, mixture stigmasterol 6a sitosterol 6b lupeol 7 also isolated. Several fractions displayed significant activity a panel Trypanosoma Leishmania spp., from most active fraction, compound was isolated high purity. activity, particularly T. brucei , evansi L. mexicana (0.88–11.7 µM) but only modest effect human embryonic kidney cells no cross-resistance commonly used melaminophenyl arsenical diamidine classes trypanocides. promastigotes irreversible after 5-h exposure, leading sterilization culture between 24 48 h.