RESUMO
Two new unusual 6-furanoflavones, hoslunfuranine (5) and 5-O-methylhoslunfuranine (6), were isolated from the leaves of Hoslundia opposita Vahl.. Four known methylpyranoflavonic analogues [hosloppin (1), hoslundin (2), 5-O-methylhoslundin (3), oppositin (4)], all specific of the species, were also obtained. Their structures were established on the basis of their spectroscopic data. In vitro cytotoxic, trypanocidal, and leishmanicidal activities of compounds 1 and 3 to 6 were evaluated. Compounds 4 and 6 exhibited leishmanicidal potential in the micromolar range.
Assuntos
Flavonas/farmacologia , Lamiaceae/química , Folhas de Planta/química , Pironas/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Flavonas/química , Flavonas/isolamento & purificação , Humanos , Células KB , Leishmania donovani/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Parasitária , Pironas/química , Pironas/isolamento & purificação , Trypanosoma brucei brucei/efeitos dos fármacosRESUMO
The essential oil from the rhizomes of Aframomum sceptrum (Zingiberaceae) was analyzed by GC/MS, and its major constituents were found to be ß-pinene (12.7%), caryophyllene oxide (10.0%), and cyperene (6.0%). The oil was also evaluated for antimicrobial activities, in comparison with ß-pinene, caryophyllene oxide, and the leaf essential oil of Melaleuca alternifolia (Myrtaceae). The A. sceptrum essential oil exhibited bacteriostatic activity against the Gram-positive bacteria Bacillus subtilis, Staphylococcus epidermidis, and S. aureus, but not against Gram-negative bacteria. Moreover, it showed mild fungicidal activity against Candida albicans and Aspergillus fumigates, and remarkable antiprotozoal activity against Trypanosoma brucei brucei (MLC of 1.51â µl/ml) and Trichomonas vaginalis (IC(50) of 0.12±0.02 and MLC of 1.72â µl/ml).