Adducts of nitroimidazole derivatives with rhodium(II) carboxylates: syntheses, characterization, and evaluation of antichagasic activities.

Adducts of several rhodium(II) carboxylates with two antiparasitic nitroimidazole ligands were prepared and characterized by elemental microanalysis, thermogravimetry, spectrophotometry (IR, UV, and visible), and proton magnetic resonance. Results of elemental and thermogravimetric analyses were consistent with the general formula Rh2(RCOO)4. 2L (R = aliphatic or aromatic carboxylic groups; L = metronidazole or benznidazole). The reddish-brown color of the adducts as well as their visible spectra suggest axial coordination of the nitroimidazole ligands through nitrogen atoms. NMR spectra indicate N3 as the coordinating atoms. Screening tests performed on cultures of T. cruzi indicate that aliphatic complexes--particularly propionate and acetate adducts--were more active than their aromatic counterparts, the same being observed with benznidazole adducts in relation to their metronidazole analogues. Evaluated for their usefulness as transfusion prophylactic agents against Chagas' disease, propionate derivatives failed to sterilize T. cruzi infected blood. An oral toxicity assay in mice showed mild toxic effects with daily doses of 5 mg/kg for 20 days.

Estudo comparativo entre a eficiencia de hemoculturas e xenodiagnosticos seriados efetuados em gambas do genero Didelphis, naturalmente infectados pelo Trypanosoma Cruzi. / Comparative study the efficiency of hemocultures and serial xenodiagosis performed in opossums of the genus Didelphis, naturally infected by Trypanosoma cruzi

Em ecotopos naturais de varios municipios dos Estados de Sao Paulo e Minas Gerais foram capturados gambas do genero Didelphis, naturalmente infectados, dos quais foram selecionados 25 exemplares de cada subespecie, D. albiventris e D. aurita.Nestes animais foram feitos 4 hemoculturas (5 tubos de cada vez) e 4 xenodiagnosticos seriados (5 insetos de cada especie), sendo utilizado o meio de Warren e as especies de triatomineos Panstrongylus megistus Triatoma sordida e Rhodnius neglectus, com intervalo de uma semana entre cada repeticao. Os resultados foram submetidos a analise de varianca e ao teste de Duncan, o qual demonstrou que houve um aumento de eficiencia dos dois metodos, a medida em que sao repetidos os exames e que os xenodiagnosticos sempre foram superiores as hemoculturas