RESUMO
A potent antioxidant, resveratrol (3,4',5-trihydroxystilbene), was extracted using 80% methanol from peanut roots (Arachis hypogaea L.), isolated with a solid-phase extraction column, purified by a semipreparative HPLC, and identified with 1H NMR and MS. The highest and lowest resveratrol contents in the peanut roots of 2000 fall and 2001 spring crops were 1.330 and 0.130 mg/g and 0.063 and 0.015 mg/g, respectively. When the dehydrated peanut root powders of spring and fall crops were combined and cooked with pork-fat patties (1%, w/w) and the separated oils were stored at 60 degrees C for conjugated diene hydroperoxide (CDHP) determination, CDHP contents of the control oils increased after 3 days of storage, whereas the contents in the peanut root-treated oils of spring and fall crops did not increase after 9 and 15 days of storage, respectively. It is of merit to find that peanut roots, usually left in the field as agricultural waste, contain resveratrol and bear potent antioxidative activity.
Assuntos
Arachis/química , Raízes de Plantas/química , Estilbenos/análise , Antioxidantes/análise , Cromatografia Líquida de Alta Pressão , Peróxido de Hidrogênio , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Óleo de Amendoim , Óleos de Plantas/química , Resveratrol , Estações do Ano , Estilbenos/isolamento & purificaçãoRESUMO
Five new constituents including a flavonoid, artemisidin A (1), and four coumarins, artemicapins A (2), B (3), C (4) and D (5), together with 70 known compounds (6-75), have been isolated and characterized from the aerial part of Artemisia capillaris. The structures of these compounds were determined from spectral analyses and/or chemical evidence. Among them, 15 compounds (3, 6, 10, 18. 30-32, 38-41, 44, 45, 51, and 55) showed antiplatelet aggregation activity and three compounds (10, 17, and 51) demonstrated significant activity against HIV replication in H9 lymphocytic cells.
Assuntos
Acetileno/análogos & derivados , Fármacos Anti-HIV/isolamento & purificação , Artemisia/química , Plantas Medicinais , Inibidores da Agregação Plaquetária/isolamento & purificação , Acetileno/farmacologia , Animais , Plaquetas/efeitos dos fármacos , Ácidos Cafeicos/farmacologia , Cumarínicos/farmacologia , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Inibidores da Agregação Plaquetária/farmacologia , Coelhos , EspectrofotometriaRESUMO
One new biphenyl ether, aristogin C (1), and two new porphyrins, aristophylls A (2) and B (3), as well as 11 known compounds, were isolated from the leaves of Aristolochia elegans. Their structures were elucidated according to the spectroscopic (NMR and MS) analyses or by comparison with literature values.
Assuntos
Éteres Fenílicos/química , Plantas Medicinais/química , Porfirinas/química , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Éteres Fenílicos/isolamento & purificação , Folhas de Planta/química , Porfirinas/isolamento & purificação , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
Reinvestigation of the root of Rhinacanthus nasutus afforded, in addition to rhinacanthin-A to -D reported previously, two new dimethyldihydropyranonaphthoquinone esters (5, 6) and eight new 2-hydroxy-1,4-naphthoquinone esters (7-14) were isolated. The stereochemistry of rhinacanthin-A was determined as the R configuration. Compounds rhinacanthin-G to -N, belong to a class of 2-hydroxy-3-(3-hydroxy-2,2-dimethylpropyl)-1,4-naphthoquinone esters, and so far have been isolated only in this plant. Their biosynthesis is also discussed.
Assuntos
Antivirais/isolamento & purificação , Ésteres/isolamento & purificação , Naftoquinonas/isolamento & purificação , Plantas Medicinais/química , Anti-Hipertensivos/química , Anti-Hipertensivos/isolamento & purificação , Antivirais/química , Ésteres/química , Espectroscopia de Ressonância Magnética , Naftoquinonas/químicaRESUMO
The continuing investigation of the root of Rhinacanthus nasutus afforded a 1,4-naphthoquinone ester, rhinacanthin-Q, accompanied by twenty-four known compounds. The structure was elucidated on the basis of spectroscopic analyses. The cytotoxicity and antiplatelet effect of this compound was also discussed.
Assuntos
Naftoquinonas/isolamento & purificação , Naftoquinonas/farmacologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Humanos , Células KB/efeitos dos fármacos , Naftoquinonas/química , Ressonância Magnética Nuclear Biomolecular , Extratos Vegetais/química , Raízes de Plantas/química , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologiaRESUMO
Five new carbazole alkaloids, clausines B, E, H, I and K, as well as 22 known compounds, were isolated from the stem bark of Clausena excavata. The structures were established from spectral data and chemical transformation. These compounds showed significant inhibition of rabbit platelet aggregation and caused vasocontraction. The crude methanol extract, partitioned layers and chromatographic fractions revealed the presence of promotive and inhibitive constituents, simultaneously. These results might explain the philosophy of use in Chinese medicine, in that the dose and content variation in a prescription produced different, promotive or inhibitive, effects on therapy.