RESUMO
Two new withanolide glycosides, (20R,22R)-O-(3)-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl-1 alpha,12 beta-diacetoxy-20-hydroxywitha-5,24-dienolide (3) and (20R,22R)-O-(3)-beta-D-xylopyranosyl(1-->3)-[beta-D-xylopyranosyl(1-->4)]-beta-D-glucopyranosyl-1 alpha-acetoxy-12 beta,20-dihydroxywitha-5,24-dienolide (4), were isolated from the leaves and root of Dunalia brachyacantha. Their aglycones, (20R,22R)-1 alpha,12 beta-diacetoxy-3 beta,20-dihydroxywitha-5,24-dienolide (or 1 alpha,12 beta-diacetyldunawithagenine) and (20R,22R)-1 alpha-acetoxy-3 beta,12 beta,20-trihydroxywitha-5,24-dienolide (or 1 alpha-acetyl-12 beta-hydroxydunawithagenine), are novel. The known 18-acetoxywithanolide D (1) and 18-acetoxy-5,6-deoxy-5-withenolide D (2) were also isolated from the leaves. These last two compounds were shown to be responsible for the trypanocidal, leishmanicidal, and bactericidal activities manifested by the crude ethanolic extract. The structures were deduced from spectroscopic data and on the basis of chemical evidence.
Assuntos
Dissacarídeos/isolamento & purificação , Ergosterol/análogos & derivados , Lactonas/isolamento & purificação , Plantas Medicinais/química , Solanaceae/química , Trissacarídeos/isolamento & purificação , Tripanossomicidas/isolamento & purificação , Tripanossomicidas/farmacologia , Animais , Bactérias/efeitos dos fármacos , Bolívia , Dissacarídeos/química , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Lactonas/química , Leishmania/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Folhas de Planta/química , Raízes de Plantas/química , Espectrofotometria Infravermelho , Trissacarídeos/química , Trypanosoma cruzi/efeitos dos fármacos , VitanolídeosRESUMO
Quercitol, five saponins and 3-O-(6'-O-palmitoyl) beta-D-glucopyranosyl stigmasterol were isolated from the stem bark of Myrisine pellucida. These compounds are described for the first time in this plant and their structures were determined using a combination of 1H and 13C NMR, and mass spectroscopy. The two saponins are new compounds, 3-O-(alpha-L-rhamnopyranosyl (1-->2) beta-D-glucopyranosyl (1-->4) alpha-L-arabinopyranosyl) cyclamiretin A and 3-O-(beta-D-xylopyranosyl) (1-->2) beta-D-glucopyranosyl (1-->4) [beta-D-glucopyranosyl (1-->2)] alpha-L-arabinopyranosyl) cyclamiretin D.