[Potential anticancer and antiparasitic indole alkaloids].

Many drugs are derived from active molecules isolated from plants or micro-organisms. Nevertheless, a lot of species have not yet been studied; they constitute an important source of new structures that could possess interesting pharmacological activities and/or original modes of action, for example in the field of anticancer or antiparasitic drugs (taxol, artemisinin, swainsonine, camptothecin,...). Among all the bioactive natural products, we studied more particularly indole alkaloids extracted from different tropical Strychnos species. Several new alkaloids have been isolated from cytotoxic crude extracts. Some of them possess interesting cytotoxic, antitumor or antiparasitic properties. We also realised molecular modelling studies in order to explain the activity of usambarensine.