LAUSR

Bioassay guided fractionation of the stem barks of Isolona cooperi led to the isolation of a new lactone, apoprunellelactone (APL, 1), and two known compounds, 5-[1-hydroxyhexyl]-2H-furan-2-one (2) and oleic acid (3). Their structures were elucidated by spectral analysis including MS, UV, IR, 1D and 2D-NMR spectroscopy. Evaluated for its antiprotozoal activities, APL (1) was found to be the most active on Leishmania donovani and L. major promastigotes with EC50 values of 16.3 and 8.2 µM, respectively. Against Trypanosoma brucei brucei trypomastigote forms, the activity of APL was moderated (MEC = 38.0 µM). Its hemisynthetic ester acetic derivative (1c) was 2-42 times more active than that of the APL and reference drugs, justifying further in vivo evaluation of the two compounds (1 and 1c) on Leishmania sp and Trypanosoma brucei brucei/mice models.