This paper describes the synthesis and in vitro biological activities of imidazolidine and hexahydropyrimidine derivatives against bacteria (Escherichia coli, Staphylococcus aureus and Mycobacterium tuberculosis) and Leishmania protozoa. Out of sixteen heterocyclic derivatives tested, none were cytotoxic against mammalian cells. The compounds showed significant bacterial effects and leishmanicidal activity. Compounds 4a and 4c were active against S. aureus and E. coli, respectively. Compounds 3a-3f, 4h and 4i presented promising results against M. tuberculosis, with MIC values ranging from 12.5 to 25.0 μg/mL, comparable to the "first and second line" drugs used to treat tuberculosis. Compounds 4a, 4c and 4e were active against L major. Three of them were structurally characterized by single-crystal X-ray diffraction.

This paper describes the preparation of N,N'-disubstituted ethylenediamine and imidazolidine derivatives and their in vitro biological activities against Leishmania species. Of the nine synthesized compounds, five displayed a good activity in both L. amazonensis and L. major promastigotes. The compounds 1,2-Bis(p-methoxybenzyl)ethylenediamine (4) and 1,3-Bis(p-methoxybenzyl)imidazolidines (5) showed the best activity on intracellular amastigotes, with IC50 values of 2.0 and 9.4 μ/mL, respectively. In addition, none of compounds were cytotoxic against mammalian cells. The leishmanicidal activity can be related with inhibition of polyamine synthesis and cellular penetration within biological membranes.

Stilbenes are compounds found in numerous medicinal plants and food products with some known biological and even antileishmanial activity. This paper describes the preparation of Aza-stilbene derivatives and their in vitro biological activities against Leishmania species. Most of the compounds with hydroxyl groups (2a, 2b, 2d, 2e and 2f) showed interesting results against three Leishmania species tested. Compound 2f showed the best activity against intracellular forms of L. amazonensis, with IC50 of 7.48 μM, very similar when compared to reference drug Miltefosine. It not possible associate NO production with leishmanicidal activity for all aza-stilbene derivatives. It is noteworthy that none of compounds tested showed cytotoxicity against macrophages.