RESUMEN
Key odorants of red wine made from the hybrid grapes of Marselan (Vitis vinifera L.) were isolated by solid-phase extraction (SPE) and explored by gas chromatography-olfactometry (GC-O) analysis. Application of aroma extract dilution analysis (AEDA) revealed 43 odor-active compounds, and 31 odorants among them were detected with flavor dilution (FD) factors ranging from 9 to 2187. Comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry (GC × GC-TOF-MS) were exploited to quantitate the aroma-active compounds with FD ≥9. The identification indicated ß-damascenone as having the highest FD factors, followed by eugenol, 2,3-butanedione, citronellol, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, phenethyl acetate, guaiacol, and 2-methoxy-4-vinylphenol. A total of 21 compounds were found to have odor activity values (OAVs) >1.0. Aroma reconstitution validation experiments showed a good similarity of blackberry, green pepper, honey, raspberry, caramel, smoky, and cinnamon aroma attributes between the original Marselan wine and the reconstructed wine. In addition, omission tests were carried out to further determine the contribution of odorants to the overall aroma.
Asunto(s)
Odorantes/análisis , Olfato/fisiología , Vitis/química , Compuestos Orgánicos Volátiles/aislamiento & purificación , Vino/análisis , Monoterpenos Acíclicos/aislamiento & purificación , Diacetil/aislamiento & purificación , Eugenol/aislamiento & purificación , Femenino , Furanos/aislamiento & purificación , Cromatografía de Gases y Espectrometría de Masas , Guayacol/análogos & derivados , Guayacol/aislamiento & purificación , Humanos , Masculino , Norisoprenoides/aislamiento & purificación , Olfatometría/instrumentación , Olfatometría/métodos , Extracción en Fase Sólida/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Gusto/fisiología , Compuestos de Vinilo/aislamiento & purificación , Compuestos Orgánicos Volátiles/clasificaciónRESUMEN
BACKGROUND: Aroma-active compounds, together with sugars, amino acids, fat and nucleotides, are the main chemical species determining the characteristic aroma and taste of food. For selecting yeast extract pastes products with a less undesirable aroma, the aroma-active compounds that affect the overall consumer acceptance of yeast extract pastes products were analysed in this work. RESULTS: The aroma-active compounds of yeast extract pastes were extracted by using dynamic headspace extraction or simultaneous distillation extraction, and were detected by gas chromatography-olfactrometry-mass spectrometry in conjunction with dynamic headspace dilution analysis or aroma extract dilution analysis. Sensory results revealed that a meaty, roasted aroma was the dominant of overall aroma. The important aroma-active compounds referred in this work were mainly aldehydes, acids, ketones, furan derivatives, pyrazines, and sulfur-containing compounds. Of these, six volatile compounds such as 3-methylbutanal, 2,3-butanedione, 2,3,5-trimethyl-pyrazin, acetic acid ethenyl ester, 2-acetyl-1-pyrroline and (E,E)-2,4-decadienal had never been reported before as key aroma-active compounds of yeast extract pastes. CONCLUSIONS: The key aroma-active compounds were identified in basic and characteristic meaty flavour yeast extract pastes, and their characterisation was determined.
Asunto(s)
Aromatizantes/química , Saccharomyces cerevisiae/química , Aldehídos/análisis , Aldehídos/química , Aldehídos/aislamiento & purificación , Aldehídos/metabolismo , China , Diacetil/análisis , Diacetil/química , Diacetil/aislamiento & purificación , Diacetil/metabolismo , Femenino , Aromatizantes/análisis , Aromatizantes/aislamiento & purificación , Aromatizantes/metabolismo , Preferencias Alimentarias , Furanos/análisis , Furanos/química , Furanos/aislamiento & purificación , Furanos/metabolismo , Humanos , Cetonas/análisis , Cetonas/química , Cetonas/aislamiento & purificación , Cetonas/metabolismo , Masculino , Odorantes , Análisis de Componente Principal , Pirazinas/análisis , Pirazinas/química , Pirazinas/aislamiento & purificación , Pirazinas/metabolismo , Pirroles/análisis , Pirroles/química , Pirroles/aislamiento & purificación , Pirroles/metabolismo , Estereoisomerismo , Compuestos de Sulfhidrilo/análisis , Compuestos de Sulfhidrilo/química , Compuestos de Sulfhidrilo/aislamiento & purificación , Compuestos de Sulfhidrilo/metabolismo , Gusto , Compuestos de Vinilo/análisis , Compuestos de Vinilo/química , Compuestos de Vinilo/aislamiento & purificación , Compuestos de Vinilo/metabolismoRESUMEN
In the present work, a rapid, accurate and cost-effective method has been developed for the simultaneous quantification of phenolic compounds in oil using mixed-mode solid-phase extraction (SPE) coupled with chemical labeling UHPLC-MS/MS. Mix-mode SPE weak cation cartridges were selected to enrich and purify phenolic compounds in oil, and hydroxyl moiety was dansylation as stable-isotope internal standard. The major parameters that affected the extraction and chemical labeling efficiency were investigated, and the method was fully validated. The limit of quantifications and the limit of detections were 0.002 µg kg-1 ~ 0.10 µg kg-1 and 0.006 µg kg-1 ~ 0.30 µg kg-1, respectively. The recoveries were 61.2% ~ 129.3% with intra-day and inter-day precision less than 12%. The results for 38 rapeseed oils revealed that 14 phenolic compounds, including canolol, phenolic acids, phenolic alcohols, tyrosol and vanillin from trace levels to relatively high content.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Fenoles/análisis , Aceite de Brassica napus/química , Extracción en Fase Sólida/métodos , Espectrometría de Masas en Tándem/métodos , Marcaje Isotópico , Límite de Detección , Fenoles/aislamiento & purificación , Aceite de Brassica napus/análisis , Compuestos de Vinilo/análisis , Compuestos de Vinilo/aislamiento & purificaciónRESUMEN
Regarding hydrophilic interaction chromatography and normal phase liquid chromatography, RPLC is another choice used to separate polar compounds with the improvement of polar-modified C18 stationary phase. In this study, a method using conventional C18 column coupled with polar-copolymerized C18 column was successfully developed for the separation and purification of polar compounds from Radix isatidis, which is one of the most commonly used traditional Chinese medicines (TCMs). An XTerra MS C18 column was used to fractionate the extract of R. isatidis and a homemade polar-copolymerized C18 column was utilized for the final purification due to its good separation selectivity and high resolution for polar compounds. The established purification system demonstrated good orthogonality for the polar compounds. As a result, ten compounds were purified and three of them were identified as 3-methyl-5-vinyloxazolidin-2-one (compound A), 5-hydroxymethyl-2-furaldehyde (compound B) and 3-methylfuran-2-carboxylic acid (compound G) based on the MS, IR and extensive NMR data, respectively. It was demonstrated to be a feasible and powerful technique for the purification of polar compounds under RPLC mode and more chemical information of TCMs will be obtained to interpret the efficiency of TCMs.
Asunto(s)
Ácidos Carboxílicos/aislamiento & purificación , Cromatografía Liquida , Medicamentos Herbarios Chinos/química , Furaldehído/análogos & derivados , Compuestos de Vinilo/aislamiento & purificación , Cromatografía Liquida/instrumentación , Cromatografía Liquida/métodos , Furaldehído/aislamiento & purificación , Furanos/aislamiento & purificación , Medicina Tradicional China , Estructura Molecular , Raíces de Plantas/químicaRESUMEN
In a previous paper, the authors showed that a slight aeration of a methanogenic reactor treating wastewater from the manufacture of polymeric resins could improve its performance, by increasing or allowing the removal of some of its contaminants, including vinyl acetate (VA). This paper reports the isolation under aerobic conditions of a VA-biodegrading axenic culture (strain C1) retrieved from the sludge of a slightly aerated methanogenic reactor at 1 mg L(-1) d(-1) of dissolved oxygen (DO). The axenic culture obtained was phenotypically (morphology, biochemical properties, VA consumption kinetics) and phylogenetically characterized. It formed white colonies with a branched and flat morphology on solid medium. The cell morphology of the isolate was bacillus with round endings and flagellate. The cells could form chains and were stained Gram-negative. The isolate required simple nutritional elements and had a growth rate of 0.024 h(-1). The phylogenetical analysis showed that the aerobic bacterium was identified as Brevibacillus agri, with 99.3% similarity. The VA consumption kinetics in the methanogenic sludge were: volumetric consumption rate (rVA) of 1.74 +/- 0.2 mg L(-1) h(-1), maximum specific consumption rate (qVAmax) of 3.98 mg g(-1) volatile suspended solids (VSS) h(-1) and affinity constant (Ks) of 457.1 mg L(-1). The same parameters in the axenic culture were 1.69 +/- 0.04 mg L(-1) (h-1), 4.09 mg g(-1) dry weight h(-1) and 421.9 mg L(-1), respectively. These results show evidence that the aerobic isolated bacterium, identified as Brevibacillus agri, carried out the VA hydrolysis in the slightly aerated methanogenic sludge, which is the limiting step in the degradation of this compound.
Asunto(s)
Reactores Biológicos/microbiología , Brevibacterium/metabolismo , Metano/metabolismo , Oxígeno/metabolismo , Compuestos de Vinilo/metabolismo , Contaminantes Químicos del Agua/metabolismo , Purificación del Agua/métodos , Biodegradación Ambiental , Brevibacterium/clasificación , Brevibacterium/aislamiento & purificación , Metano/química , Oxígeno/química , Compuestos de Vinilo/química , Compuestos de Vinilo/aislamiento & purificación , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificaciónRESUMEN
The baseline separation of divinylbenzene (DVB) and ethylvinylbenzene (EVB) isomers was achieved using HPLC with MIL-53(Fe) and MIL-100(Fe) packed columns respectively when hexane/dichloromethane (100:0) used as mobile phase, at flow rate of 0.5mLmin-1, room temperature, and monitored with a UV detector at 254nm. The two Fe-based MILs packed columns showed different separated performances, analytes had short retention time on MIL-100(Fe) compared to MIL-53(Fe), but selectivity of DVB isomers (m-DVB and p-DVB) was lower, which was mainly due to the differences of the pore size and structure of MILs. Moreover, the results of calculated thermodynamic parameters showed that the separation of DVB and EVB isomers was not only controlled by enthalpy change (ΔH), but also controlled by entropy change (ΔS). The head-to-tail stacking was the main reason for the separation according to the mechanism of the DVB and EVB isomers on Fe-based MILs packed columns.
Asunto(s)
Técnicas de Química Analítica/métodos , Cromatografía Líquida de Alta Presión , Compuestos Organometálicos/aislamiento & purificación , Estirenos/aislamiento & purificación , Compuestos de Vinilo/aislamiento & purificación , Técnicas de Química Analítica/instrumentación , Hexanos/química , Hierro/química , Isomerismo , Cloruro de Metileno/química , Compuestos Organometálicos/química , Estirenos/química , TermodinámicaRESUMEN
The chemical composition and antioxidant activities of the essential oil from Nandina domestica fruits were studied for the first time. Twenty-two compounds, representing 82.79% of the oil, were identified from the oil. The major compounds were 3-hexen-1-ol (12.9%), linalool (12.3%), 2-methoxy-4-vinylphenol (9.9%), oleic acid (8.0%), furfural (5.8%) and 2,6-di-tert-butyl-4-methylphenol (5.7%). The antioxidant activities of the oil were evaluated using reducing power, metal chelating ability and scavenging capacity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzthiazoline-6-sulfonate (ABTS) and superoxide anion free radical. The oil exhibited significant antioxidant activities.
Asunto(s)
Antioxidantes/química , Antioxidantes/farmacología , Berberidaceae/química , Aceites Volátiles/química , Aceites Volátiles/farmacología , Monoterpenos Acíclicos , Compuestos de Bifenilo/química , Evaluación Preclínica de Medicamentos/métodos , Frutas/química , Guayacol/análogos & derivados , Guayacol/aislamiento & purificación , Hexanoles/aislamiento & purificación , Concentración 50 Inhibidora , Monoterpenos/aislamiento & purificación , Picratos/química , Superóxidos/química , Compuestos de Vinilo/aislamiento & purificaciónRESUMEN
Hierochloë odorata (L.) P. Beauv. (Poaceae), commonly known as sweetgrass, has documented use as an insect repellent by the Flatheads of Montana and Blackfoot of Alberta. Both the Flatheads of Montana and Blackfoot of Alberta would use braided plant material in a sachet in clothing or burn them from one end as incense, air/clothing freshener, and insect repellent. This study evaluated the insect-repellent properties of this plant using an in vitro mosquito Aedes aegypti feeding bioassay-directed approach to identify the compound(s) responsible for the observed activities. Evaluation of crude extracts produced from H. odorata revealed that the hydrodistillate had the highest level of mosquito biting deterrence. Fractionation of this extract, followed by re-evaluation for mosquito biting deterrence, produced many active fractions, which were evaluated by spectroscopic techniques and determined to contain phytol, coumarin, and 2-methoxy-4-vinylphenol. Phytol and coumarin were both determined to be responsible for the Ae. aegypti biting deterrency. Scientific evidence reported here validates its traditional use as a biting-insect deterrent.
Asunto(s)
Aedes/efectos de los fármacos , Repelentes de Insectos/aislamiento & purificación , Repelentes de Insectos/farmacología , Poaceae/química , Animales , Cumarinas/aislamiento & purificación , Cumarinas/farmacología , Evaluación Preclínica de Medicamentos/métodos , Etnobotánica , Femenino , Guayacol/análogos & derivados , Guayacol/aislamiento & purificación , Guayacol/farmacología , Humanos , Indígenas Norteamericanos , Aceites Volátiles/análisis , Aceites Volátiles/química , Fitol/aislamiento & purificación , Fitol/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Compuestos de Vinilo/aislamiento & purificación , Compuestos de Vinilo/farmacologíaRESUMEN
Background Antioxidant and antihistamine agents from Barleria noctiflora L.f. as natural source due to the existing modern medicine give various adverse effects to overcome these problems with natural products. MethodsB. noctiflora leaves extract was fractionated with column chromatography; the homogenized fractions were monitored with thin layer chromatography (TLC) and characterized by using UV-visible, FT-IR, 1H NMR, 13C NMR and mass spectrometry spectral studies. The volatile phytoconstituents of B. noctiflora extract were analysed by gas chromatography-mass spectrometry. Phytoconstituents from B. noctiflora leaves extract were screened for their antioxidant and antihistamine potential in vitro (2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, 2,2'-azinobis-3-ethylbenzothiozoline-6-sulfonic acid radical decolouration assay, nitric oxide radical scavenging activity, superoxide radical scavenging activity and hydrogen peroxide radical scavenging activity) and in silico (molecular docking), respectively. Results Antioxidant and antihistamine barlerinoside has been isolated and characterized from the leaves of B. noctiflora L.f. Barlerinoside revealed their free-radical scavenging ability on OH-, OHâ¢, NO-, O2- and H2O2 radicals and found high percentage inhibition against OH- radical at the IC50 value of 50.45±2.52â µg. The methanol (MeOH) extract of B. noctiflora leaves contains cyclotene; N,N-dimethylglycine; tetrahydrocyclopenta [1,3] dioxin-4-one; phenol, 2-methoxy-; benzofuran, 2-methyl-; 1,4:3,6-dianhydro-α-d-glucopyranose; 2-methoxy-4-vinylphenol; 1,3;2,5-dimethylene-l-rhamnitol; levoglucosan and bicyclo[2.2.2]oct-7-ene-2,5-dione as being the major compounds. Among phytoconstituents present in the extract, the hexestrol; 1,2-benzenedicarboxylic acid, bis(2-methylpropyl) ester; 1-(3,6,6-trimethyl-1,6,7,7a-tetrahydrocyclopenta[c]pyran-1-yl) ethanone; megastigmatrienone; furan interacted with histamine H1 receptor and bind at GLU-177 and ASP-178 with high binding energy score -13.95, -13.41, -12.56, -12.03, and -11.72âkcal/mol, respectively, and the expected hydrolysed products of compound-1a and compound-1b from barlerinoside showed -8.91 and -8.68âkcal/mol binding energy against the histamine H1 receptor. This showed that the active ligands exactly bind with active binding site of the protein. ConclusionsWe can conclude that isolated barlerinoside from B. noctflora L.f. has potent antioxidant activity against synthetic free radicals and antihistamine activity against histamine H1 receptor.
Asunto(s)
Acanthaceae/química , Antioxidantes/farmacología , Ácidos Cafeicos/farmacología , Antagonistas de los Receptores Histamínicos/farmacología , Oligosacáridos/farmacología , Extractos Vegetales/farmacología , Antioxidantes/aislamiento & purificación , Compuestos de Bifenilo/metabolismo , Ácidos Cafeicos/aislamiento & purificación , Ácidos Cafeicos/metabolismo , Guayacol/análogos & derivados , Guayacol/aislamiento & purificación , Guayacol/farmacología , Antagonistas de los Receptores Histamínicos/aislamiento & purificación , Radical Hidroxilo/metabolismo , Oligosacáridos/aislamiento & purificación , Oligosacáridos/metabolismo , Picratos/metabolismo , Extractos Vegetales/química , Hojas de la Planta/química , Receptores Histamínicos H1/metabolismo , Compuestos de Vinilo/aislamiento & purificación , Compuestos de Vinilo/farmacologíaRESUMEN
A potent antioxidative compound in crude canola oil, canolol, was recently identified, and reported herein are studies of its scavenging capacity against the endogenous mutagen peroxynitrite (ONOO(-)). ONOO(-) is generated by the reaction between superoxide anion radical and nitric oxide, both of which are produced by inflammatory leukocytes. Among various antioxidative substances of natural or synthetic origin, canolol was one of the most potent antimutagenic compounds when Salmonella typhimurium TA102 was used in the modified Ames test. Its potency was higher than that of flavonoids (e.g., rutin) and alpha-tocopherol and was equivalent to that of ebselen. Canolol suppressed ONOO(-)-induced bactericidal action. It also reduced intracellular oxidative stress and apoptosis in human cancer SW480 cells when used at a concentration below 20 microM under H(2)O(2)-induced oxidative stress. In addition, canolol suppressed plasmid DNA (pUC19) strand breakage induced by ONOO(-), as revealed by agarose gel electrophoresis.
Asunto(s)
Antimutagênicos/farmacología , Antioxidantes/farmacología , Ácidos Grasos Monoinsaturados/química , Fenoles/aislamiento & purificación , Fenoles/farmacología , Compuestos de Vinilo/aislamiento & purificación , Compuestos de Vinilo/farmacología , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Neoplasias del Colon , Daño del ADN/efectos de los fármacos , Humanos , Pruebas de Mutagenicidad , Estrés Oxidativo/efectos de los fármacos , Ácido Peroxinitroso/antagonistas & inhibidores , Aceite de Brassica napus , Células Tumorales CultivadasRESUMEN
Three species of brown algae, Laminaria sinclairii, L. saccharina and L. setchellii, have been investigated for the presence of oxylipins. From one, L. sinclairii, three new divinyl ether fatty acids have been characterized as methyl ester derivatives (methyl 12-[1'(Z),3'(Z)-hexadienyloxy]-6(Z), 9(Z),11(E)-dodecatrienoate, methyl 12-[1'(Z),3'(Z)-hexadienyloxy]-9(Z), 11(E)-dodecadienoate, and methyl 14-[1'(Z),3'(Z)-hexadienyloxy]- 5(Z),8(Z),11(Z),13(E)-tetradecatetraenoate) by a variety of spectroscopic methods. In addition, one new [13(S)-hydroxy-6(Z),9(Z),11(E),15(Z)-octadecatetraenoic acid] and four known monohydroxy polyunsaturated fatty acids have been isolated from all three species as their methyl ester derivatives. The occurrence of these compounds in brown algae strongly suggests that these organisms possess an active lipoxygenase(s) with omega 6 specificity.
Asunto(s)
Ácidos Grasos/aislamiento & purificación , Laminaria/química , Compuestos de Vinilo/aislamiento & purificación , Hidroxilación , Espectroscopía de Resonancia Magnética , Extractos Vegetales/químicaRESUMEN
[1-14C]Linolenic acid was incubated with a homogenate of leaves of Clematis vitalba, a plant belonging to the Ranunculaceae family. Analysis of the reaction product by reversed-phase high-performance liquid radiochromatography demonstrated the presence of the following labeled oxylipins: 12-oxo-10, 15(Z)-phytodienoic acid, 9(S)-hydroxy-10(E), 12(Z), 15(Z)-octadecatrienoic acid, omega5(Z)-etherolenic acid, and 9-[1'(E), 3'(Z),6'(Z)-nonatrienyloxy]-8(Z)-nonenoic acid [8(Z)-colnelenic acid]. The last compound was a new divinyl ether FA, and an analogous compound, i.e., 9-[1'(E),3'(Z)-nonadienyloxy]-8(Z)-nonenoic acid [8(Z)-colneleic acid], was obtained following incubation of linoleic acid with the Clematis homogenate. Structures of the two divinyl ethers were assigned by spectral and chromatographic comparison with authentic compounds prepared synthetically using previously described methodology. Separate incubation of the 9- and 13-hydroperoxides of linolenic acid demonstrated that the first hydroperoxide served as the precursor of 8(Z)-colnelenic acid and indicated the presence in C. vitalba of a new divinyl ether synthase acting on 9-lipoxygenase-generated hydroperoxides. A close structural relationship between this enzyme and the well-studied divinyl ether synthase in the potato and tomato seems likely.
Asunto(s)
Clematis/química , Ácidos Grasos/aislamiento & purificación , Compuestos de Vinilo/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Sistema Enzimático del Citocromo P-450 , Peróxido de Hidrógeno/metabolismo , Lipooxigenasa/metabolismo , Oxidorreductasas , Hojas de la Planta/química , Proteínas de PlantasRESUMEN
Roasting of high erucic mustard (HEM) seed has been reported to give a typical flavor and increase the oxidative stability of the extracted oil. A potent radical scavenging compound was successfully isolated from roasted HEM seed oil in a single-step chromatographic separation using an amino solid-phase extraction column. Nuclear magnetic resonance and mass spectrometry spectra revealed the compound as 2,6-dimethoxy-4-vinylphenol (generally known as canolol), and its identity was fully confirmed by chemical synthesis. The formation of canolol during roasting was compared among HEM varieties (Brassica juncea, B. juncea var. oriental, Brassica nigra, and Sinapis alba) together with a low erucic rapeseed variety. HEM varieties were shown to produce less than one-third of canolol compared to rapeseed at similar roasting conditions. This observation was linked to a lower free sinapic acid content together with a lower loss of sinapic acid derivatives in the HEM varieties compared to rapeseed. Around 50% of the canolol formed in the roasted seed was shown to be extracted in the oil. Roasting of HEM seed before oil extraction was found to be a beneficial step to obtain canolol-enriched oil, which could improve the oxidative stability.
Asunto(s)
Manipulación de Alimentos/métodos , Depuradores de Radicales Libres/aislamiento & purificación , Planta de la Mostaza/química , Fenoles/aislamiento & purificación , Aceites de Plantas/química , Semillas/química , Compuestos de Vinilo/aislamiento & purificación , Brassica rapa , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Aromatizantes/análisis , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Nepal , Especias/análisisRESUMEN
Although size exclusion chromatography (SEC) has been used successfully to determine the molecular weight distribution (MWD) of statistical poly[(N-vinyl pyrrolidone)-co-(vinyl acetate)]s [PVPVAs], SEC cannot separate the copolymers according to their chemical composition. In this article, the separation of commercial PVPVAs with varying chemical compositions is reported, by aqueous reversed-phase gradient liquid chromatography (RPLC) using polystyrene-divinylbenzene-based wide pore columns. RPLC-SEC cross-fractionation indicates the presence of molar mass dependant effects during RPLC separation due to broad MWD for the copolymer studied; therefore the width of the RPLC peak could not be associated entirely with chemical composition distribution of the copolymer. Coupling of RPLC with online FTIR spectroscopy reveals the increase of VA content with increasing THF gradient, an indication of interaction mechanism between VA repeating units and the stationary phase for water soluble PVPVAs. Separation of water insoluble PVPVAs and PVAs by the RPLC are possibly based on both interaction and precipitation/redissolution mechanisms.
Asunto(s)
Cromatografía de Fase Inversa/métodos , Pirrolidinas/aislamiento & purificación , Compuestos de Vinilo/aislamiento & purificación , Cromatografía en Gel , Modelos Químicos , Peso Molecular , Pirrolidinas/química , Espectroscopía Infrarroja por Transformada de Fourier , Compuestos de Vinilo/químicaRESUMEN
Knowledge on the solubility behaviour and dissolution rate of speciality and commodity polymers is very important for the use of such materials in high-tech applications. We have developed methods for the quantification and characterization of dissolved copolymers of N-vinyl-2-pyrrolidone (VP) and vinyl acetate (VA) during dissolution in water. The methods are based on pyrolysis (Py) performed in a programmed-temperature vaporization injector with subsequent identification and quantification of the components in the pyrolysate using capillary gas chromatography-mass spectrometry (GC-MS). By injecting large volumes and applying cryo-focussing at the top of the column, low detection limits could be achieved. The monomer ratio was found to have the greatest effect on the dissolution rate of the PVP-co-VA copolymers. The material with the highest amount of VA (50%) dissolves significantly slower than the other grades. Size-exclusion chromatography (SEC) and Py-GC-MS were used to measure molecular weights and average chemical compositions, respectively. Combined off-line SEC//Py-GC-MS was used to determine the copolymer composition (VP/VA ratio), as a function of the molecular weight for the pure polymers. In the dissolution experiments, a constant VP/VA ratio across the dissolution curve was observed for all copolymers analysed. This suggests a random distribution of the two monomers over the molecules.
Asunto(s)
Cromatografía de Gases y Espectrometría de Masas/métodos , Pirrolidinas/química , Compuestos de Vinilo/química , Cromatografía en Gel , Cinética , Peso Molecular , Pirrolidinas/aislamiento & purificación , Temperatura , Compuestos de Vinilo/aislamiento & purificación , Agua/químicaRESUMEN
Although inflammation acts as host defense mechanism against infection or injury and is primarily a self limiting process, inadequate resolution of inflammatory responses leads to various chronic disorders. This work aimed to elucidate the anti-inflammatory effects of 2-methoxy-4-vinylphenol (2M4VP) isolated from pine needles in LPS-stimulated RAW264.7 cells. Some key pro-inflammatory mediators including nitric oxide (NO), prostaglandins (PGE(2)), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2) were studied by sandwich ELISA and western blot. In addition, suppression of NF-κB and MAPK activation, and histone acetylation was studied by western blot analysis and immunostaining. 2M4VP dosedependently inhibited NO and PGE(2) production and also blocked LPS-induced iNOS and COX-2 expression. In addition, 2M4VP potently inhibited the translocation of NF-κB p65 into the nucleus by IκB degradation following IκB-α phosphorylation and the phosphorylation of MAPKs such as p38, ERK1/2, and JNK. Also, 2M4VP inhibited hyper-acetylation of histone H3 (Lys9/Lys14) induced by LPS. Taken together, our results suggest that 2M4VP, a naturally occurring phenolic compound, exert potent anti-inflammatory effects by inhibiting LPS-induced NO, PGE(2), iNOS, and COX-2 in RAW264.7 cells. These effects are mediated by suppression of NF-κB and MAPK activation and histone acetylation.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Guayacol/análogos & derivados , Histonas/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , FN-kappa B/antagonistas & inhibidores , Extractos Vegetales/farmacología , Compuestos de Vinilo/farmacología , Acetilación , Animales , Antiinflamatorios no Esteroideos/aislamiento & purificación , Línea Celular , Activación Enzimática/efectos de los fármacos , Guayacol/aislamiento & purificación , Guayacol/farmacología , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Pinus/química , Compuestos de Vinilo/aislamiento & purificaciónRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Asplenium trichomanes was used as an expectorant, anti-cough remedy, laxative, emmenagogue, abortifacient and for irregular menses. AIM OF THE STUDY: To investigate the in vitro estrogenic activity of Asplenium trichomanes extracts and isolated compounds and their ability to activate ERalpha and ERbeta. MATERIALS AND METHODS: Leaves infusion (IF), decoction (DC) and methanol extract (ME) were prepared. MCF7/EREluc cell line which expresses endogenous ERalpha, and SK-NBE cells transiently transfected with the estrogen receptors (ERalpha and ERbeta) were used for the estrogenic activity assays. Phytochemical investigations were performed (CC, HPLC, etc.) and structure of isolated compounds were achieved on the basis of 1D and 2D NMR techniques and HR-MS spectrometry. RESULTS: IF and ME were active in our MCF7 model; selectivity for the ERbeta receptor was observed in the SK-NBE test. Two new phenol derivatives, 4-vinyl-phenol-1-O-[alpha-L-rhamno(1-->6)-beta-d-glucopyranosyde] (1) and kaempferol-3-O-alpha-[2'acetyl]-arabinofuranosyl-7-O-alpha-L-rhamnopyranoside (2) were isolated with six known compounds (3-8). Compounds 2-4, 7 and 8 showed selectivity for the activation of the ERbeta receptor although with a moderate activity compared with 17-beta-estradiol. CONCLUSION: Further investigations about the estrogenic effects of this plant are needed but our data can, at least in part, explain some of its traditional use as emmeagogue.
Asunto(s)
Disacáridos/farmacología , Receptor alfa de Estrógeno/efectos de los fármacos , Receptor beta de Estrógeno/efectos de los fármacos , Helechos/química , Quempferoles/farmacología , Fitoestrógenos/farmacología , Extractos Vegetales/farmacología , Compuestos de Vinilo/farmacología , Disacáridos/química , Disacáridos/aislamiento & purificación , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Humanos , Quempferoles/química , Quempferoles/aislamiento & purificación , Fitoestrógenos/aislamiento & purificación , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta , Compuestos de Vinilo/química , Compuestos de Vinilo/aislamiento & purificaciónRESUMEN
Alkylhydroperoxides in oxidized oil are undesirable components because they become alkylperoxyl radicals (ROO*) in the presence of heme, hemoglobin, or myoglobin in red meat. ROO* are biochemically reactive and damage nucleic acids and proteins, thereby harming living cells. We isolated a component, a highly potent ROO* scavenger, from crude canola oil (rapeseed), which we designated canolol, and identified its chemical structure, 4-vinyl-2,6-dimethoxyphenol. The canolol content of crude canola oil greatly increased after the seed was roasted as compared with that from unroasted seed, but it decreased in highly purified oil. This anti-ROO* activity was highest in crude oil, deceased after each refining step, and was lowest in highly purified refined oil. Canolol was thus generated during roasting. As shown previously, canolol is one of the most potent anti-ROO* components in crude canola oil and its potency is much greater than that of well-known antioxidants, including alpha-tocopherol, vitamin C, beta-carotene, rutin, and quercetin.
Asunto(s)
Depuradores de Radicales Libres/aislamiento & purificación , Peróxidos/química , Fenoles/aislamiento & purificación , Compuestos de Vinilo/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Depuradores de Radicales Libres/química , Depuradores de Radicales Libres/farmacología , Espectroscopía de Resonancia Magnética , Estructura Molecular , Fenoles/química , Fenoles/farmacología , Compuestos de Vinilo/química , Compuestos de Vinilo/farmacologíaRESUMEN
NMR studies have shown that seven new sesquiterpenoids, 3, 4, 5a, and 7-10, isolated from dried samples of the New Zealand liverwort Lepidolaena hodgsoniae have the same substituted cyclopentapyran ring system as the previously described insecticidal sesquiterpene diene hodgsonox (1), which has been reported only from this plant. In all but one compound, 10, the 1,1-disubstituted double bond of hodgsonox has migrated into an endocyclic position, but only two, 5a and 9, have the double bonds in conjugation. These seven new compounds represent a variety of different oxidation levels. Two of the new derivatives, 9 and 10, were isolated only from an aged sample and are presumably artifacts. The only other terpenoid isolated in significant quantity was (7R,10R)-calamenene (2).