RESUMO
Four hexaglycosides of methyl 3S,12S-dihydroxyhexadecanoate (1-4) were provided after treatment of the crude convolvulin fraction from Rhizoma Jalapae Braziliensis (the root of Ipomoea operculata (GOMES) MART., Convolvulaceae) with indium(III) chloride in methanol. The structures of 1-4 were elucidated on the basis of spectroscopic and chemical methods. Their sugar moieties were partially acylated with organic acids including (3S,9R)-3,6:6,9-diepoxydecanoic (exogonic) acid, (E)-2-methylbut-2-enoic (tiglic) acid, and isovaleric acid.
Assuntos
Ácidos/síntese química , Glicosídeos/síntese química , Índio/química , Metanol/química , Éteres Metílicos/síntese química , Resinas Vegetais/química , Ácidos/química , Acilação , Convolvulaceae/química , Glicosídeos/química , Éteres Metílicos/química , Estrutura Molecular , Raízes de Plantas/químicaRESUMO
Calophyllum brasiliense and Mammea americana (Clusiaceae) are two trees from the tropical rain forests of the American continent. A previous screening showed high trypanocidal activity in the extracts of these species. Several mammea-type coumarins, triterpenoids and biflavonoids were isolated from the leaves of C. brasiliense. Mammea A/AA was obtained from the fruit peels of M. americana. These compounds were tested in vitro against epimastigotes and trypomastigotes of Trypanosoma cruzi, the etiologic agent of Chagas disease. The most potent compounds were mammea A/BA, A/BB, A/AA, A/BD and B/BA, with MC100 values in the range of 15 to 90 microg/ml. Coumarins with a cyclized gamma,gamma-dimethylallyl substituent on C-6, such as mammea B/BA, cyclo F + B/BB cyclo F, and isomammeigin, showed MC100 values > 200 microg/ml. Several active coumarins were also tested against normal human lymphocytes in vitro, which showed that mammea A/AA and A/BA were not toxic. Other compounds from C. brasiliense, such as the triterpenoids, friedelin, canophyllol, the biflavonoid amentoflavone, and protocatechuic and shikimic acids, were inactive against the epimastigotes. The isopropylidenedioxy derivative of shikimic acid was inactive, and its structure was confirmed by X-ray diffraction. Our results suggest that mammea-type coumarins could be a valuable source of trypanocidal compounds.
Assuntos
Biflavonoides/farmacologia , Cumarínicos/farmacologia , Mammea/química , Triterpenos/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Adulto , Animais , Biflavonoides/química , Biflavonoides/isolamento & purificação , Cumarínicos/química , Cumarínicos/isolamento & purificação , Dimetil Sulfóxido/farmacologia , Humanos , Dose Letal Mediana , Linfócitos/efeitos dos fármacos , Masculino , Extratos Vegetais/farmacologia , Triterpenos/química , Triterpenos/isolamento & purificação , Tripanossomicidas/química , Tripanossomicidas/isolamento & purificaçãoRESUMO
Calophyllum brasiliense and Mammea americana (Clusiaceae) are two trees from the tropical rain forests of the American continent. A previous screening showed high trypanocidal activity in the extracts of these species. Several mammea-type coumarins, triterpenoids and biflavonoids were isolated from the leaves of C. brasiliense. Mammea A/AA was obtained from the fruit peels of M. americana. These compounds were tested in vitro against epimastigotes and trypomastigotes of Trypanosoma cruzi, the etiologic agent of Chagas disease. The most potent compounds were mammea A/BA, A/BB, A/AA, A/BD and B/BA, with MC100 values in the range of 15 to 90 g/ml. Coumarins with a cyclized ,-dimethylallyl substituent on C-6, such as mammea B/BA, cyclo F + B/BB cyclo F, and isomammeigin, showed MC100 values > 200 g/ml. Several active coumarins were also tested against normal human lymphocytes in vitro, which showed that mammea A/AA and A/BA were not toxic. Other compounds from C. brasiliense, such as the triterpenoids, friedelin, canophyllol, the biflavonoid amentoflavone, and protocatechuic and shikimic acids, were inactive against the epimastigotes. The isopropylidenedioxy derivative of shikimic acid was inactive, and its structure was confirmed by X-ray diffraction. Our results suggest that mammea-type coumarins could be a valuable source of trypanocidal compounds.
Assuntos
Adulto , Animais , Humanos , Masculino , Biflavonoides/farmacologia , Cumarínicos/farmacologia , Mammea/química , Triterpenos/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Biflavonoides/química , Biflavonoides/isolamento & purificação , Cumarínicos/química , Cumarínicos/isolamento & purificação , Dimetil Sulfóxido/farmacologia , Linfócitos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Triterpenos/química , Triterpenos/isolamento & purificação , Tripanossomicidas/química , Tripanossomicidas/isolamento & purificaçãoRESUMO
Crude extracts of Mexican medicinal plants were screened for trypanocidal activity against Trypanosoma cruzi, which is the etiological agent for Chagas' disease, one of the most serious protozoan diseases in Latin America. There were 71 kinds of methanolic and other organic extracts from 65 plants, which were newly examined by a preliminary screening test to observe immobilization of epimastigotes and trypomastigotes of T. cruzi in vitro. The MeOH extract of seeds of Persea americana (avocado) showed moderate activity against epimastigotes. In order to identify the principal compounds for the activity, the MeOH extract was subjected to bioassay-guided fractionation. From the active fractions, six 1,2,4-trihydroxyheptadecane derivatives and two 1,2,4-trihydroxynonadecane derivatives including a new one were isolated. These compounds showed moderate activity against epimastigotes and trypomastigotes.