RESUMO
In a survey of plants from Ecuador with antiprotozoal activity, Cupania cinerea was found to show significant in vitro activity against the Plasmodium falciparum K1 strain and Trypanosoma brucei rhodesiense. Subsequently, activity-guided isolation of the n-hexane and dichloromethane extracts from the bark of C. cinerea afforded two diterpene glycosides (1 and 2), named cupacinoside and 6'-de-O-acetylcupacinoside, and a lactonized triterpene bearing an oxepin moiety named cupacinoxepin (3), together with the known compounds scopoletin (4), caryophyllene oxide (5), two bisabolane sesquiterpenes (6 and 7), lichexanthone (8), gustastatin (9), lupenone (10), betulone (11), 17ß,21ß-epoxyhopan-3-one (12), taraxerol (13), and taraxerone (14). For compound 3, X-ray crystallography was employed to elucidate the relative configuration. For cupacinosides (1) and (2) and cupacinoxepin (3), in vitro activities against the P. falciparum K1 strain (IC(50)1, 1.3; 2, 1.8; and 3, 8.7 µM) and T. b. rhodesiense (IC(50)1, 4.5; 2, 15.8; and 3, 71.6 µM) were found. Cytotoxicity toward L-6 cells is discussed for all the compounds isolated.
Assuntos
Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Sapindaceae/química , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Trypanosoma brucei rhodesiense/efeitos dos fármacos , Animais , Antiprotozoários/química , Células Cultivadas , Cristalografia por Raios X , Diterpenos/química , Equador , Glicosídeos/química , Hexanos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Sesquiterpenos Policíclicos , Ratos , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Triterpenos/químicaRESUMO
In a survey of plants from Ecuador with antiprotozoal activity, Jacaranda glabra was found to show promising activity against the Plasmodium falciparum K1 strain. Subsequently, activity-guided isolation of the dichloromethane extract from the leaves of J. glabra afforded four new phenylethanoid glucosides containing jacaranone-type moieties (1-4), named jacaglabrosides A-D. Their chemical structures were identified using NMR spectroscopy and MS techniques. The compounds were found to be active in vitro against the P. falciparum K1 strain (IC(50) 1, 1.02; 2, 0.56; 3, 0.56; and 4, 0.55 microg/mL) and generally possessed a low cytotoxicity toward L-6 cells, with the exception of compound 1 (IC(50) 1, 8.3; 2, >90; 3, 87; and 4, 85 microg/mL).