RESUMO
Four new steroidal saponins (1-4) were isolated from the stem and bark of two species of Dracaena: deistelianosides A and B (1 and 2) from D. deisteliana and arboreasaponins A and B (3 and 4) from D. arborea. Six known saponins and one known sapogenin were also isolated. The structures of 1-4 were established as diosgenin 3-O-[3-O-sulfate-alpha-l-rhamnopyranosyl-(1-->4)]-beta-d-glucopyranoside (1), 1-O-beta-d-xylopyranosyl-(1-->2)-[alpha-l-rhamnopyranosyl-(1-->3)]-beta-d-fucopyranosyl(23S,24S)-spirosta-5,25(27)-diene-1beta,3beta,23alpha,24alpha-tetrol 24-O-alpha-l-arabinopyranoside (2), pennogenin-3-O-alpha-l-rhamnopyranosyl-(1-->2)-[alpha-l-rhamnopyranosyl-(1-->3)]-[6-O-acetyl]-beta-d-glucopyranoside (3), and 24alpha-hydroxypennogenin 3-O-alpha-l-rhamnopyranosyl-(1-->2)-[alpha-l-rhamnopyranosyl-(1-->3)]-beta-d-glucopyranoside (4) using extensive 1D and 2D NMR spectroscopic analyses and mass spectrometry. Cytotoxic activity of several of these compounds was evaluated against the HT-29 and HCT 116 human colon cancer cell lines.
Assuntos
Dracaena/química , Plantas Medicinais/química , Saponinas/isolamento & purificação , Esteroides/isolamento & purificação , Camarões , Células HCT116 , Células HT29 , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Casca de Planta/química , Caules de Planta , Saponinas/química , Saponinas/farmacologia , Estereoisomerismo , Esteroides/química , Esteroides/farmacologiaRESUMO
In a chemical investigation on the stem bark of Ouratea flava, two biflavonoids: 1-[3-(2,4-dihydroxy-benzoyl)-4,5,6-trihydroxy-2-(4-hydroxy-phenyl)-benzofuran-7-yl] -3-(4-hydroxy-phenyl) -propenone (flavumone A) and 3-(2,4-dihydroxy-benzoyl)-4-hydroxy-2,7-bis-(4-hydroxy-phenyl) -7,8- dihydro-furo[2,3-f]chromen-9-on (flavumone B) were isolated along with five known flavonoids. Their structures were established by various analyses including 2D-NMR spectroscopy.
Assuntos
Flavonoides/isolamento & purificação , Rosales/química , Flavonoides/química , Ressonância Magnética Nuclear Biomolecular , Casca de Planta/química , Caules de Planta/química , Plantas Medicinais/químicaRESUMO
Fractionation of the methanolic extract of Ochna afzelii stem bark has resulted in the isolation of two biflavonoids afzelones A and B along with five known flavonoids, calodenins A and B, afzelone C, 4',5-dimethoxy-6,7-methylenedioxyisoflavone, 4',5,7-trimethoxyisoflavone and the glucoside lanceoloside A. Their structures were determined using spectroscopic and chemical methods.
Assuntos
Acanthaceae/química , Flavonoides/isolamento & purificação , Flavonoides/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Casca de Planta/química , Caules de Planta/química , Plantas Medicinais/químicaRESUMO
The leaves of the Cameroonian medicinal plant Lophira alata afforded two new biflavonoids, lophirone L (1) and lophirone M (2), and the known luteolin and lithospermoside. Both biflavonoids were obtained in small quantities, and their structures show some new and unusual biflavonoid diversity.