RESUMO
Investigation of the constituents of the whole plant of Hyptis suaveolens led to the isolation of three new abietane diterpenes, isosuaveolic acid (1), 8α,9α-epoxysuaveolic acid (2), and 14-O-methylsuaveolic acid (3), together with eleven known compounds. The structures of 1-3 were established by spectroscopic methods and chemical correlations. Some isolates were tested for their antimycobacterial and cytotoxic activities.
Assuntos
Abietanos/química , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Hyptis/química , Abietanos/farmacologia , Antibacterianos/química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Neoplasias/tratamento farmacológico , Preparações de Plantas/química , Preparações de Plantas/farmacologiaRESUMO
Unique electrical and surface-to-volume properties of carbon nanotubes have made these conductive molecules highly attractive in many applications. In this work, the influence of multi-walled carbon nanotubes into a zinc oxide active layer of dye-sensitized zinc oxide solar cell has been investigated. With this method, a significant improvement in the performance of the solar cell has been achieved. Compared to the typical zinc oxide photoelectrochemical cells, the photocurrent-voltage characteristics of the fabricated cell containing 0.05 percent by weight of carbon nanotubes in the metal oxide film displayed a higher short-circuit photocurrent, consequently caused an increase of the solar-to-electricity conversion efficiency by a factor of approximately 1.4. Further increase of the conductive carbon material resulted in a decrease of the energy conversion of the photovoltaic cell. The enhancement of the energy conversion at this optimum carbon nanotube loading may be attributed to the dye-adsorption ability and the electrochemical activity of the composite photoanodes. The fabricated photovoltaic cells with the highest efficiency exhibited the maximum dye adsorption intensity and the minimum charge transfer resistance, as measured by ultraviolet-visible spectroscopy and electrochemical impedance spectroscopy, respectively.
RESUMO
Three new diarylheptanoids, a 1:2 mixture of (3S)- and (3R)-1-(4-methoxyphenyl)-7-phenyl-(6E)-6-hepten-3-ol (13a and 13b) and 1-(4-hydroxyphenyl)-7-phenyl-(6E)-6-hepten-3-one (15), together with two synthetically known diarylheptanoids 1,7-diphenyl-(1E,3E,5E)-1,3,5-triene (9) and 1-(4-hydroxyphenyl)-7-phenyl-(4E,6E)-4,6-heptadien-3-one (16), and nine known diarylheptanoids, 2, 8, 10-12, 14, a 3:1 mixture of 17a and 17b, and 18, were isolated from the rhizomes of Curcuma comosa Roxb. The absolute stereochemistry of the isolated compounds has also been determined using the modified Mosher's method. The isolated compounds and the chemically modified analogues were evaluated for their estrogenic-like transcriptional activity using RT-PCR in HeLa cell line. Some of the isolated diarylheptanoids and their modified analogues exhibited estrogenic activity comparable to or higher than that of the phytoestrogen genistein. Based on the transcriptional activation of both estrogenic targets, Bcl-xL and ERbeta gene expression, the structural features for a diarylheptanoid to exhibit high estrogenic activity are the presence of an olefinic function conjugated with the aromatic ring at the 7-position, a keto group at the 3-position, and a phenolic hydroxyl group at the p-position of the aromatic ring attached to the 1-position of the heptyl chain.
Assuntos
Curcuma/química , Diarileptanoides/farmacologia , Fitoestrógenos/farmacologia , Rizoma/química , Diarileptanoides/isolamento & purificação , Receptor beta de Estrogênio/genética , Estrogênios/química , Estrogênios/farmacologia , Células HeLa , Humanos , Fitoestrógenos/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Relação Estrutura-Atividade , Transcrição Gênica/efeitos dos fármacos , Proteína bcl-X/genéticaRESUMO
One new dihydrochalcone, dihydromonospermoside (7), was isolated from the flowers of Butea monosperma together with three known chalcones, butein (2), monospermoside (4) and isoliquiritigenin (8), one flavone, 7,3',4'-trihydroxyflavone (6), four flavanones, (-)-butin (1a), (-)-butrin (3a), (+)-isomonospermoside (5b) and (-)-liquiritigenin (9a), and three isoflavones, formononetin (10), afrormosin (11) and formononetin-7-O-beta-D-glucopyranoside (12). The structure of the new compound was elucidated by spectroscopic techniques whereas those of the known compounds were identified by comparisons of spectroscopic and some physical data with those of reported compounds. The absolute configurations at the 2-position of the flavanones 1a, 3a, 5b and 9a were established to be 2S, 2S, 2R and 2S, respectively, by circular dichroism spectral measurements and were confirmed by comparison of the optical rotations with those of reported values and by enzymic hydrolysis of the glucosides to the corresponding aglycones. The isolated flavonoids exhibited varying antimycobacterial activity with the chalcone 2 being the most active compound (MIC 12.5 microg/ml).