Synthesis and in vitro evaluation of leishmanicidal activity of 7-hydroxy-4-phenylcoumarin derivatives

Eight coumarin derivatives (2–8) were synthesized from 7-hydroxy-4-phenylcoumarin 1 and were evaluated for their in vitro leishmanicidal activity against promastigote and amastigote forms of Leishmania amazonensis, as well their toxicity in murine macrophages. Compounds 4 and 7 showed the most significant results against promastigote forms of L. amazonensis. They were at least three-fold more active than 1 and Compound 4 was as effective as Amphotericin B. Compound 4, a 7-O-prenylated derivative, and 7, a tetra- O -acetyl-β- D -glucopyranosyl derivative, presented IC50 values of 21.35 and 10.03 µM against promastigote and IC50 values of 58.10 and 34.93 µM, respectively against amastigote forms. Furthermore, they do not cause toxicity in mammalian or Leishmania cells in vitro. This study shows that these coumarin derivatives are potential prototypes for the development of novel drugs with leishmanicidal activity.