RESUMO
Five new triterpene saponins, arboreasides A-E (1-5), and two known saponins, ciwujianoside C(3) and 23-hydroxyursolic acid 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, were isolated from the bark of Cussonia arborea. The structures were established using extensive 1D and 2D NMR spectroscopic analyses and mass spectrometry.
Assuntos
Araliaceae/química , Saponinas/isolamento & purificação , Triterpenos/isolamento & purificação , Camarões , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Casca de Planta/química , Saponinas/química , Triterpenos/químicaRESUMO
Antimicrobial activity-directed fractionation of the seeds of Aframomum longifolius (Zingiberaceae) afforded two new labdane-type diterpenoids, 15-hydroxy-15-methoxylabda-8(17), 12( E)-dien-16-al (aframolin A) ( 1) and 8beta(17)-epoxy-15,15-dimethoxylabd-12( E)-en-16-al (aframolin B) ( 2), together with the known diterpenes labda-8(17),12( E)-diene-15,16-dial ( 3) and aframodial ( 4). Their structures were determined by spectroscopic methods. Compound 4 showed significant antimicrobial activity against Cryptococcus neoformans, Staphylococcus aureus and methicillin-resistant S. aureus (MRS) while 1, 2 and 3 were found to be inactive.
Assuntos
Anti-Infecciosos/farmacologia , Naftalenos/farmacologia , Compostos de Espiro/farmacologia , Zingiberaceae/química , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Candida albicans/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Diterpenos/química , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Resistência a Meticilina , Naftalenos/química , Preparações de Plantas/química , Preparações de Plantas/farmacologia , Compostos de Espiro/química , Staphylococcus aureus/efeitos dos fármacosRESUMO
The dichloromethane-methanol (1/1) extract of the stem bark of Turraeanthus africanus (Meliaceae) showed remarkable antimicrobial activity against Cryptococcus neoformans, Staphylococcus aureus and methicillin-resistant S. aureus. Phytochemical investigation of this extract afforded six new diterpenoid derivatives, (+)-16-acetoxy-12,15-epoxylabda-8(17),12,14-triene ( 3), [16( E),12 S,15 R]-16-acetoxy-12,15-epoxy-15-isopropoxy- ent-labda-8(17),13(16)-diene (turraeanin A, 4), [16( E),12 R,15 S]-16-acetoxy-12,15-epoxy-15-isopropoxy- ent-labda-8(17),13(16)-diene (turraeanin B, 5), [16( E),12 S,15 R]-16-acetoxy-12,15-epoxy-15-methoxy- ent-labda-8(17),13(16)-diene (turraeanin C, 6), [16( E),12 R,15 S]-16-acetoxy-12,15-epoxy-15-methoxy- ent-labda-8(17),13(16)-diene (turraeanin D, 7) and (12 S,13 S,15 R)-12,15-epoxy-15-methoxy- ent-labd-8(17)-en-16-al (turraeanin E, 9) together with the known compounds, 15,16-epoxy- ent-labda-8(17),13(16),14-triene ( 1), (+)-pumiloxide ( 2), ent-labda-8(17),12 ( E)-diene-15,16-dial ( 8) and 16-acetoxy-12( R),15-epoxy-15beta-hydroxylabda-8(17),13 (16)-diene ( 10). Compound 10 was obtained as its acetoxy derivative ( 10a) and compound 11 was the product of hydrolysis of 6. Antimicrobial activity of the isolates was assayed and compounds 8, 9, 10a and 11 exhibited significant activities.
Assuntos
Antibacterianos/farmacologia , Antivirais/farmacologia , Diterpenos/química , Diterpenos/farmacologia , Meliaceae/química , Antibacterianos/química , Antivirais/química , Candida albicans/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Resistência a Meticilina , Estrutura Molecular , Fitoterapia , Casca de Planta/química , Caules de Planta/química , Staphylococcus aureus/efeitos dos fármacosRESUMO
Two new triterpenoid saponins (1 and 2) were isolated from the stem bark of Cussonia bancoensis together with the known stigmasterol, ursolic acid, 23-hydroxyursolic acid (3), and 3beta-hydroxylup-20(29)-en-28-oic acid. On the basis of their spectroscopic data and on chemical transformations, the structures of the new saponins have been established as 3-O-(alpha-Ll-arabinopyranosyl)-23-hydroxyursolic acid (1) and 3-O-(beta-D-glucopyranosyl)-23-hydroxyursolic acid (2). In a nitric oxide (NO)-production bioassay, compound 3 exhibited significant NO inhibitory activity, while compounds 1 and 2 were less potent than 3.
