ARTICLE IN PRESS
D.B. Dom ´ı nguez-Carmona et al. / Phytomedicine 17 (2010) 379–382
381
Fig. 1. Betulinic acid and derivatives.
produce 3), resulted in a significant increase of leishmanicidal
activity against L. amazonensis (Table 1). Alternatively, the
modifications on the C-28 carboxyl group did not show a clear
effect since while betulinic acid (1) and betulin (5) lack
leishmanicidal activity, betulinic acid methyl ester (4) showed
an improved activity against L. braziliensis (Table 1). On the other
hand, the evaluation of the trypanocidal activity of the various
terpenoids showed that any modification on the betulinic acid
skeleton resulted in a lower activity (Table 1). Finally, and
although our results showing betulinic acid (1) as an adequate
antiplasmodial agent are in agreement with those reported in the
literature (Ziegler et al. 2004; Duker-Eshun et al. 2004), testing of
the various derivatives showed that only the esterification of the
C-3 hydroxyl group (to produce 2) results in an improved activity
Program CYTED (Projects X.5 and RIBIOFAR) and Project FOMIX-
Yucat aꢀ n (66262).
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The authors wish to thank Paulino Sim aꢀ for the identi-
fication of the plant material. This work was supported by