Quassinoids, the bitter principles of the Simaroubaceae family, are a group of structurally complex and highly oxygenated degraded triterpenes. They are divided into five groups according to their basic skeleton, C-18, C-19, C-20, C-22 and C-25. In recent years, attention has been focused on quassinoids because several of them have shown promising biological activities. This paper features a review of some characteristics of these compounds, updating known information with discoveries from the last decade and covering chemical structures, basic skeletons, occurrence in genus and species, besides detailed studies of biological activities such as antitumor, antimalarial, phytotoxic, antifeedant, insecticidal, anti-inflammatory and antiulcer.

Antígenos solúveis de epimastigotas de Trypanosoma cruzi foram analisados por "imunoblot" a fim de verificar sua reatividade com soros de pacientes com doença de Chagas. Além disso, soro de pacientes com leishmaniose visceral (LVA) e tegumentar americana (LTA) foram também analisados com o objetivo de se identificar oa antígenos de reação cruzada com o Trypanosoma cruzi. Pelo menos 28 polipeptídeos, com pesos moleculares variando de 14 a 113 kDa foram identificados com soros de pacientes com doença de Chagas. Uma intensa reatividade cruzada foi observada quando foram utilizados soros de pacientes com leishmaniose visceral, enquanto que uma fraca reação cruzada foi observada com soros de pacientes portadores de leishmaniose tegumentar. Por outro lado, pelo menos 10 polipeptídeos puderam ser identificados apresentando reação específica com soros de pacientes chagásicos. Entre estes, os polipeptídeos de pesos moleculares de 46 kDa e 25 kDa que reagiram com todos esses soros e são potencialmente bons candidatos a antígenos específicos no diagnósticos sorológico da doença de Chagas.

Soluble antigens from epimastigotes of Trypanosoma cruzi were analyzed by western blot in terms of their reactivity with sera from patients with Chagas' disease. In addition, sera from patients with visceral (AVL) and tegumentar leishmaniasis (ATL) were also tested in order to identify cross-reactivities with Trypanosoma cruzy antigens. Twenty eight polypeptides with molecular weights ranging from 14 kDa to 113 kDa were identified with sera from Chagas' disease patients. An extensive cross-reactivity was observed when sera from human visceral leishmaniasis were used, while only a slight cross-reaction was observed with sera from tegumentar leishmaniasis. On the other hand, 10 polypeptidesspecifically reacting with sera from Chagas' disease patients were identified. Among them, the antigens with molecular weights of 46 kDa and 25 kDa reacted with all sera teste and may be good candidates for specific immunodiagnosis of Chagas' disease.

Um retrovírus foi isolado de um paciente brasileiro com "Síndrome de Imunodeficiência Adquirida" (SIDA/AIDS) e caracterizado em termos de sua reatividade com soros de indivíduos infectados com vírus da imunodeficiência humana dos tipos 1 e 2 (HIV-1 e HIV-2). A análise antigênica por "Western blot" revelou que o isolado brasileiro é bastante similar a uma cepa de HIV-1 bem caracterizada. A identificação do retrovírus como HIV-1 e não HIV-2 é reforçada pelo fato dos anticorpos do paciente do qual foi isolado o vírus não terem reagido com a glicoproteínas de envelope de 140 kDa, específica para HIV-2.

A retrovirus infecting a Brazilian AIDS patient was isolated and characterized in terms of its reactivity with sera from individuals infected with human immunodeficiency viruses 1 and 2 (HIV-1 and HIV-2). The Western blot analysis revealed that the Brazilian isolate is very similar to the well characterized HIV-1 strain. The serum of the patient from whom the virus was isolated did not react with the 140 kDa envelope glycoprotein specific for HIV-2.