RESUMO
Five new stemoninine-type alkaloids, bisdehydrostemoninine (1), isobisdehydrostemoninine (2), bisdehydroneostemoninine (3), and bisdehydrostemoninines A (4) and B (5), were isolated from the crude-alkaloid extract of the roots of Stemona tuberosa. Their structures were elucidated on the basis of one- and two-dimensional NMR and other spectroscopic studies. The relative configuration of 4 was determined by X-ray diffraction. Alkaloid 1 displayed significant antitussive activity in the citric acid-induced guinea pig cough model.
Assuntos
Alcaloides/isolamento & purificação , Antitussígenos/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Lactonas/isolamento & purificação , Plantas Medicinais/química , Pirrolidinas/isolamento & purificação , Stemonaceae/química , Alcaloides/química , Alcaloides/farmacologia , Animais , Antitussígenos/química , Antitussígenos/farmacologia , Cristalografia por Raios X , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Cobaias , Lactonas/química , Lactonas/farmacologia , Modelos Animais , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Raízes de Plantas/química , Pirrolidinas/química , Pirrolidinas/farmacologiaRESUMO
Several novel bioactive components isolated from Chinese medicinal plants will be presented. These include novel maytansinoid tumor, inhibitors, some new ent-kaurane and rosane diterpenoids from Mallotus anomalus Meer et Chun (Euphorbiaceae), as well asnovel insecticide, stemona alkaloids from Stemona parviflora C. H. Wright (Stemonaceae). Both are native plants of Hainan island, Chine. 2D NMR techniques such as mono and hetero-COSY, NOESY, COLOC as well as H-NMR line broadening effect were utilized for structure elucidation. The separation techniques, struture elucidations and bioassay results will be reported.
