The experiments described in this report were aimed at determining whether L-arginine (L-arg)-derived nitrogen oxidation products (nitric oxide, nitrous acid, nitrites) are involved in the intracellular killing of Leishmania parasites by activated murine macrophages in vitro. Peritoneal or bone marrow-derived macrophages were infected with L. enriettii or L. major, then activated by exposure to...

Quassinoids neosergeolide and isobrucein B, obtained from Picrolemma sprucei, have proven in vitro antitumor, antimalarial, anthelminthic, cytotoxic, insecticide and leishmanicidal activities. There is interest in the in vivo pharmacological study of these natural compounds and their semi-synthetic derivatives, however, the quantities obtained in previous extraction processes have been shown to...

Epoxidation of argentilactone (1) with m-chloroperbenzoic acid gave a diasteromeric mixture of 2 and 3 in a ratio 1.8 : 1, with total yield 60%. The configuration of 7,8-oxirane ring for both diasteromers was determined by NMR analysis. Reaction of 1 with urea hydrogen peroxide gave the 3,4-epoxide (4) in 65% yield. The in vitro activity of 2, 3, 4 and argentilactone against Leishmania amazonen...

The dichloromethane extract of Calea uniflora afforded a mixture of two novel chromanones, uniflorol-A (1) and uniflorol-B (2), and one known chromanone, 2,2-dimethyl-6-(1-hydroxyethyl)-chroman-4-one (3). The structures of these compounds were determined by spectroscopic methods. Biological activity of the compounds against Leishmania major promastigotes was evaluated. Mixture of the novel chro...

Due to the limited availability of effective pharmaceutical products and serious side effects of the available therapy for leishmaniasis, search for useful medicinal plants is necessary. Previous studies reported preventative effect of Echinacea against Leishmania infections through immunologic stimulation. Here we tested concentrated ethanolic extract of the root of Echinacea purpurea prepared...

Leishmaniasis is considered one of the most untreated tropical diseases in world. In this study, we investigated vitro leishmanicidal activity and cytotoxicity various isolated lichen substances, including atranorin (1), usnic acid (2), gyrophoric (3), salazinic (4), galbinic (5), parietin (6), some semi-synthetic imine derivatives (7, 8, 9) (10, 11, 12, 13). Imine condensation reactions with h...