Rose Lisieux R. Paiva Jácome

Plant-derived antimalarial agents: new leads and efficient phythomedicines. Part I. Alkaloids.

Malaria remains one of the most serious world health problem and the major cause of mortality and morbidity in the endemic regions. Brazil is among the 30 high-burden countries and most of the cases occur in the Legal Amazonian Region. New chemotherapeutical agents are needed for the treatment of malaria. Many plant species are used in traditional medicines of malarious countries and a relatively few number of these have been investigated for evaluation of their antimalarial effect. Still lower is the number of those that have had the active natural compounds isolated and the toxicity determined. This area is, then, of great research interest. discovery project of antimalarial natural products from plants traditionally used to treat malaria must include in vitro and in vivo assays as well as bioguided isolation of active compounds. The final products would be antimalarial chemical entities, potential new drugs or templates for new drugs development, and/or standardized antimalarial extracts which are required for pre-clinical and clinical studies when the aim is the development of effective and safe phythomedicines. This review discusses these two approaches, presents briefly the screening methodologies for evaluation of antimalarial activity and focuses the activity of alkaloids belonging to different structural classes as well as its importance as new antimalarial drugs or leads and chemical markers for phytomedicines.

ALCALÓIDES INDÓLICOS ISOLADOS DE ESPÉCIES DO GÊNERO Aspidosperma (APOCYNACEAE)

Species from genus Aspidosperma (Apocynaceae) are popularly employed to treat various diseases. This genus is characterized by the occurrence of indole alkaloids. Taking into account the various biological activities attributed to these alkaloids, the description of the chemical diversity in genus Aspidosperma is important. A review of simple carbolinic alkaloids isolated from species of various genera was published in 1979. In 1987, it was published another one dealing with the relationships between the chemical structures of the indole alkaloids and the evolution of Aspidosperma species. This work updates the information about the indole alkaloids isolated from Aspidosperma species.

Análise de naftoquinonas em extratos brutos de raízes de Zeyheria montana M. (bolsa-de-pastor)

Four naphthoquinones, lapachol, a-lapachone, dehydro-a-lapachone and 4-hydroxy-a-lapachone were isolated from the ethanol extract of Zeyheria montana M. roots (Bignoniaceae) and were identified by spectroscopic methods. These naphthoquinones, except 4-hydroxy-a-lapachone, were quantified by HPLC, in the crude ethanol extracts of Z. montana roots. The separation of lapachol, a-lapachone and dehydro-a-lapachone was achieved and these compounds were identified in the chromatograms by their retention times and by their on line UV-spectra. The quantification of the three naphthoquinones, in four different samples showed medium contents of 11,0 mg of lapachol, 6,1 mg of a-lapachone and 4,3 mg of dehydro-a-lapachone, in 100 mg of Z.montana roots.

Estudo químico e perfil cromatográfico das cascas de Aspidosperma parvifolium A. DC. ("pau-pereira")

Four known alkaloids, uleine, epiuleine, apparicine and desmethyluleine, besides the isoprenoids lupeol and stigmasterol were isolated from the stem bark of Aspidosperma parvifolium. Their identification was based on spectroscopic analysis (UV, IR, 1H-NMR, 13C-NMR, MS). The chromatographic profile of the ethanolic extract was obtained by HPLC and uleine, epiuleine and apparicine were identified in the extract.

Estudo morfoanatômico comparativo entre a poaia (Psychotria ipecacuanha (Brot.) Stokes - Rubiaceae) obtida da região Amazônica (habitat original) e proveniente de processo biotecnológico submetida a diferentes tratamentos de interceptação da radiação solar

A poaia ou ipeca (Psychotria ipecacuanha (Brot.) Stokes.-Rubiaceae) apesar de seu valor farmacologico e socio-economico e cada vez menos frequente no seu habitat. O objetivo deste trabalho foi realizar o estudo comparativo dos aspectos morfoanatomicos entre a especie originaria da Amazonia Brasileira e a obtida in vitro submetidas a diferentes tratamentos de interceptacao de radiacao solar, visando, desta forma, dar suporte a estudos com fins de preservacao, cultivo, validacao farmacognostica/farmacopeica e ampliar o conhecimento biotecnologico desta especie. A especie nativa foi obtida de fragmento de mata (fase vegetativa) e empregada para micropropagacao atraves do cultivo in vitro de fragmentos de segmentos internodais sobre meio de cultivo Murashige & Skoog com o regulador de crescimento BAP (2,0 mg/l de meio). Obtiveram-se plântulas que foram transferidas para casa de vegetacao por 2 anos sob dois tipos de ambiente e tres diferentes tratamentos de interceptacao da radiacao solar. Foi feito o estudo morfoanatomico, analisado estatisticamente. Verifica-se que as plantas originadas por processo biotecnologico e submetidas aos diferentes tratamentos apresentam morfologia semelhante a planta nativa, no entanto constatou-se um maior numero de raizes secundarias, nao ha diferenca significativa entre larguras e comprimentos de folhas, comprimento de raizes, estipulas, peso de raizes e rizomas. Mas, observou-se diferenca estatistica no comprimento do caule em relacao a nativa.

Estudo químico de Zeyheria montana M. (bolsa‑de‑pastor)

Zeyheria montana M. (Bignoniaceae) is a widespread species in the Cerrado area of Minas Gerais, Brazil, and is popularly known as bolsa‑de‑pastor. In the Brazilian tradicional medicine its roots are used for the treatment of skin diseases. Several species of Bignoniaceae contain naphthoquinones, and lapachol was previously reported in the stem wood of Z. digitalis. This paper describes the isolation of three naphtoquinones from Z. montana stem barks, namely α‑lapachone, dehydro‑α‑lapachone and 4‑hydroxy‑α‑lapachone, besides lapachol, stearic acid and β‑sitosterol. Furthermore, we report the HPLC fingerprint for the species, which allowed the identification of the isolated compounds, except β‑sitosterol. Since the in vitro antimicrobial activity of lapachol and α‑lapachone has been previously described, the presence of these naphthoquinones in the roots of Z. montana corroborates its popular use for the treatment of skin diseases.