RESUMO
Alcoholic extracts of leaves and stems of Vanilla fragrans were fractionated with ethyl acetate and aqueous butanol. All three fractions of ethyl acetate, butanol, and water were screened for toxic bioactivity against mosquito larvae. The results of these experiments showed that the fractions from the ethyl acetate and butanol phases were both active in the bioassay. Bioactivity of the ethyl acetate fraction was found to be much greater than that from the butanol fraction in mosquito larvae toxicity. The water phase appeared to contain no substances that impaired mosquito larval growth. Repeated column chromatography of the ethyl acetate fraction on silica gel led to the isolation of 4-ethoxymethylphenol (1), 4-butoxymethylphenol (2), vanillin (3), 4-hydroxy-2-methoxycinnamaldehyde (4), and 3,4-dihydroxyphenylacetic acid (5). Compounds 4 and 5 were isolated from Vanilla species for the first time and 2 has not been reported to have been found in a natural form. 4-Ethoxymethylphenol (1) was the predominant compound, but 4-butoxymethylphenol (2) showed the strongest toxicity to mosquito larvae. The structures of the compounds were determined on the basis of their mass spectra and (1)H or (13)C NMR data.
Assuntos
Inseticidas/isolamento & purificação , Orchidaceae/química , Animais , Culicidae/crescimento & desenvolvimento , Inseticidas/química , Larva , Espectroscopia de Ressonância Magnética , Extratos Vegetais/química , Folhas de Planta/química , Caules de Planta/química , Espectrometria de Massas por Ionização por Electrospray , VolatilizaçãoRESUMO
Four pyranocoumarins; dipetaline, alloxanthoxyletin, xanthoxyletin and xanthyletin; and two lignans; sesamin and asarinin were isolated from the northern prickly ash, Zanthoxylum americanum. To varying degrees, all inhibited the incorporation of tritiated thymidine into human leukaemia (HL-60) cells. Dipetaline was the most active with an IC(50) of 0.68 ppm, followed by alloxanthoxyletin (1.31 ppm), sesamin (2.71 ppm), asarinin (4.12 ppm), xanthoxyletin (3.48 ppm) and xanthylletin (3.84 ppm).
Assuntos
Antineoplásicos/farmacologia , Cumarínicos/farmacologia , Leucemia/prevenção & controle , Lignanas/farmacologia , Plantas Medicinais , Rosales , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Cumarínicos/química , Cumarínicos/uso terapêutico , Células HL-60/efeitos dos fármacos , Humanos , Lignanas/química , Lignanas/uso terapêutico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Caules de PlantaRESUMO
The intracellular localization of aryl acylamidase (aryl-acylamide amidohydrolase, EC 3.5.1.13) in rice (Oryza sativa L. var Starbonnet) leaves was investigated. The enzyme hydrolyzes and detoxifies the herbicide propanil (3,4-dichloropropionanilide) thereby accounting for immunity of the rice plant to herbicidal action. Fractionation of mesophyll protoplasts by differential centrifugation yielded the highest specific activity of amidase in the crude mitochondrial fraction. Further separation of density gradients of the silica sol Percoll also indicated that this enzyme was mitochondrial. By the use of biochemical markers, the purified mitochondrial fraction was shown to be substantially free of contamination from nuclei, chloroplasts, golgi, and plasma membranes. Subfractionation of the purified mitochondria suggests that this enzyme is located on the outer membrane.
RESUMO
The intracellular localization of aryl acylamidase (aryl-acylamide amidohydrolase, EC 3.5.1.13) in chicken kidney was investigated. By separation on density gradients of the silica sol Ludox AM, the enzyme was localized in the mitochondrial fraction. This mitochondrial fraction was shown to be substantially free of lysosomal contamination. Subfractionation of the purified mitochondria indicates that the enzyme is located on the outer membrane, can be solubilized, and may be a suitable marker enzyme for kidney mitochondria.
