RESUMO
Activity-guided fractionation of the n-butanol extract from the leaves of Artocarpus tonkinensis led to the isolation of the auronol glycosides maesopsin 4-O-glucoside (1), as well as the new alphitonin-4-O-glucoside (2). These structures were identified on the basis of MS and NMR spectroscopic data. The lymphocyte stimulation test showed both compounds having immunosuppressive activity.
Assuntos
Artocarpus/química , Benzofuranos/farmacologia , Glucosídeos/farmacologia , Glicosídeos/farmacologia , Imunossupressores/farmacologia , Benzofuranos/isolamento & purificação , Catequina/farmacologia , Ciclosporina/farmacologia , Glucosídeos/isolamento & purificação , Glicosídeos/isolamento & purificação , Humanos , Imunossupressores/isolamento & purificação , Técnicas In Vitro , Indicadores e Reagentes , Linfócitos/efeitos dos fármacos , Linfócitos/imunologia , Espectroscopia de Ressonância Magnética , Extratos Vegetais/química , Folhas de Planta/química , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
From the leaves of Xylopia vielana (Annonaceae) the three dimeric guaianes vielanin A-C were isolated and structurally elucidated by mass and NMR spectroscopy as 1-3. The structure of 1 contains a bridged ring system formed probably via a Diels-Alder reaction of two different guaiane monomers. Compounds 2 and 3 represent symmetric cyclobutanes formally generated from two equal guaiane moieties by [2 + 2] cycloaddition.
