RESUMEN
Andrographolide was subjected to degradation under acidic and basic conditions. Three degradation products including two novel compounds, 8,9-didehydroandrographolide (AG-A) and 15-seco-andrographolide (AG-B2), and a known product, 14-deoxy-11,12-didehydroandrographolide (AG-B1), were isolated by chromatography and identified on the basis of their NMR and MS data. The degradation product, AG-A, may result from the isomerization of andrographolide under acidic conditions whereas the base degradation products, AG-B1 and AG-B2, were formed most likely due to the dehydration of allyl alcohol and the hydrolysis of andrographolide at the lactone ring, respectively.
Asunto(s)
Diterpenos/química , Diterpenos/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Ácido Clorhídrico/química , Hidrólisis , Espectrometría de Masas , Hidróxido de Sodio/químicaRESUMEN
Chloroform and ethyl acetate extracts of Aspergillus fischeri TISTR 3272 showed good growth inhibitory activity on Mimosa pigra and Echinochloa crus-galli. Bioassay-directed fractionation of the active extracts led to the isolation of five known compounds, (+)-terrein (1), (-)-6-hydroxymellein (2), two diketopiperazines (cyclo-(S-Pro-S-Leu) (3) and cyclo-(S-Pro-S-Val) (4)) and butyrolactone I (5). Compounds 2-5 were reported for the first time in this fungus. Their structural determinations were based on analyses of spectroscopic data and their weed growth inhibitory effects were assessed.
Asunto(s)
Aspergillus/química , Echinochloa/efectos de los fármacos , Herbicidas/farmacología , Mimosa/efectos de los fármacos , 4-Butirolactona/análogos & derivados , 4-Butirolactona/química , 4-Butirolactona/aislamiento & purificación , 4-Butirolactona/farmacología , Ciclopentanos/química , Ciclopentanos/aislamiento & purificación , Ciclopentanos/farmacología , Dicetopiperazinas/química , Dicetopiperazinas/aislamiento & purificación , Dicetopiperazinas/farmacología , Echinochloa/crecimiento & desarrollo , Herbicidas/química , Herbicidas/aislamiento & purificación , Isocumarinas/química , Isocumarinas/aislamiento & purificación , Isocumarinas/farmacología , Mimosa/crecimiento & desarrollo , Estructura Molecular , Ocratoxinas/química , Ocratoxinas/aislamiento & purificación , Ocratoxinas/farmacología , Péptidos Cíclicos/química , Péptidos Cíclicos/aislamiento & purificación , Péptidos Cíclicos/farmacologíaRESUMEN
A new ursane-type triterpene, glyptopetolide, was isolated along with two known triterpenoids, isoarborinol and cangoronine, from the stem bark of Glyptopetalum sclerocarpum LAWS. (Celastraceae). The structure of glyptopetolide was elucidated as 3,4-seco-14alpha,27-cyclo-urs-4(23)-en-3,11alpha-ol ide by spectroscopic analysis.
Asunto(s)
Plantas Medicinales/química , Triterpenos/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Conformación Molecular , Epidermis de la Planta/química , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Triterpenos/químicaRESUMEN
Quinone-methide triterpenes of the tingenone series were evaluated for their antimicrobial activity. These compounds were effective against Bacillus cereus, B. subtilis, Sarcina lutea, Staphylococcus aureus, Microsporum gypseum and a Gram-negative bacterium, Klebsiella pneumoniae. Under acidic conditions, the quinone-methide part of these compounds rearranged into the divinyl-phenolic system, and the antimicrobial activity was thus lost.
Asunto(s)
Antiinfecciosos/farmacología , Bacterias Grampositivas/efectos de los fármacos , Klebsiella pneumoniae/efectos de los fármacos , Triterpenos/farmacología , Antibacterianos , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Bacillus cereus/efectos de los fármacos , Bacillus subtilis/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Microsporum/efectos de los fármacos , Estructura Molecular , Sarcina/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Relación Estructura-Actividad , Triterpenos/química , Triterpenos/aislamiento & purificaciónRESUMEN
Sclerocarpic acid, a new sesquiterpene with a novel carbon skeleton, was isolated from the stem bark of Glyptopetalum sclerocarpum Laws. (Celastraceae). The compound exhibited antiviral activity against herpes simplex virus types 1 and 2, and antimicrobial activity against Gram-positive bacteria and a fungus.