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1.
Molecules ; 25(21)2020 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-33114417

RESUMO

Volatile organic compounds (VOCs) from leaves of geranium (Pelargonium graveolens L' Herit) were extracted by dynamic headspace using Porapak Q (HSD-P) as adsorbent and peat, a novel adsorbent in the extraction of plant volatiles, analyzed by gas chromatography-mass spectrometry (GC/MS) and gas chromatography-flame ionization (GC/FID), and the results were compared with those obtained by hydrodistillation (HD). The yield volatiles changed with the extraction method. HD was more efficient for extracting linalool (11.19%) and citronellyl formate (9.41%). Citronellol (28.06%), geraniol (38.26%) and 6,9-guaiadiene (9.55%) and geranyl tiglate (8.21%) were the major components identified by dynamic headspace using peat (HSD-T), while citronellol (16.88%), geraniol (13.63%), 6,9-guaiadiene (16.98%) and citronellyl formate (6.95%) were identified by dynamic headspace using Porapak Q (HSD-P). Furthermore, this work showed, for the first time, that in natura peat is useful to extract VOCs from leaves of geranium.


Assuntos
Geranium/química , Óleos Voláteis/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Solo/química , Compostos Orgânicos Voláteis/isolamento & purificação , Monoterpenos Acíclicos/análise , Monoterpenos Acíclicos/isolamento & purificação , Adsorção , Crotonatos/análise , Crotonatos/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Hemiterpenos/análise , Hemiterpenos/isolamento & purificação , Monoterpenos/análise , Monoterpenos/isolamento & purificação , Extratos Vegetais/análise , Porosidade , Propriedades de Superfície , Compostos Orgânicos Voláteis/análise
2.
J Nat Prod ; 83(10): 2867-2876, 2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33052045

RESUMO

Two new hydroxylated ethacrylic acid derivatives (compounds 1 and 2) and 11 new hydroxylated tiglic acid derivatives (compounds 3-13), together with one known compound (compound 14), were isolated from the stems and branches of Enkianthus chinensis. Their structures were established by extensive spectroscopic analyses, while their absolute configurations were determined by X-ray crystallographic methods (compounds 1 and 2), Mo2(OAc)4-induced electronic circular dichroism experiments (compounds 3 and 4), and chemical methods (compounds 5-11). This study is the first investigation on the secondary metabolites of this species. The anti-inflammatory activities of all isolated compounds were evaluated in an LPS-induced mouse peritoneal macrophage model. Notably, compounds 3 and 12 both exerted potent inhibitory effects on NO production with IC50 values of 2.9 and 1.2 µM, respectively.


Assuntos
Anti-Inflamatórios/análise , Crotonatos/análise , Ericaceae/química , Hemiterpenos/análise , Animais , Anti-Inflamatórios/farmacologia , Crotonatos/farmacologia , Cristalografia por Raios X , Hemiterpenos/farmacologia , Hidroxilação , Camundongos , Estrutura Molecular
3.
Biomed Chromatogr ; 32(12): e4372, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30133709

RESUMO

Methotrexate (MTX) and teriflunomide (TEF) are the two most effective disease-modifying antirheumatic drugs used as combination therapy for rheumatoid arthritis and no robust high-performance liquid chromatography (HPLC) method is available for their simultaneous estimation to date. Therefore, we have developed and validated an isocratic reversed-phase HPLC method for simultaneous analysis of MTX and TEF spiked in the form of active pharmaceutical ingredients, tablets and nanoformulations. The best separation was achieved on a BDS, C18 , 4.6 × 250 mm, 5 µm analytical column (Thermo Hypersil) with methanol-ethylammonium formate-potassium dihydrogen phosphate buffer (55 mm, pH 3.5; 65:5:30, v/v) as mobile phase at a flow rate of 0.8 mL/min. All the samples were subjected to force degradation studies. Responses of MTX and TEF were found to be a linear function of concentration over the range 1-50 µg/mL (r2 = 0.9976 and 0.9982). The limits of detection and limit of quantification were 7.74 and 25.82 ng/mL and 10.74 and 35.80 ng/mL, respectively. Degradation products produced under the stress studies did not interfere with the detection of MTX and TEF and therefore the developed method can be regarded as stability indicating.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia de Fase Reversa/métodos , Crotonatos/análise , Metotrexato/análise , Nanopartículas/química , Toluidinas/análise , Crotonatos/química , Estabilidade de Medicamentos , Hidroxibutiratos , Limite de Detecção , Modelos Lineares , Metotrexato/química , Nitrilas , Reprodutibilidade dos Testes , Toluidinas/química
4.
Bioresour Technol ; 211: 267-72, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27023381

RESUMO

Isolated polyhydroxyalkanoates (PHA) can be used to produce biobased bulk chemicals. However, isolation is complex and costly. To circumvent this, whole cells containing PHA may be used. Here, PHA containing 3-hydroxybutyrate and small amounts of 3-hydroxyvalerate was produced from wastewater and used in the conversion of the 3-hydroxybutyrate monomer to methyl crotonate. Due to the increased complexity of whole cell reaction mixtures compared to pure PHA, the effect of 3-hydroxyvalerate content, magnesium salts and water content was studied in order to evaluate the need for downstream processing. A water content up to 20% and the presence of 3-hydroxyvalerate have no influence on the conversion of the 3-hydroxybutyrate to methyl crotonate. The presence of Mg(2+)-ions resulted either in an increased yield or in byproduct formation depending on the counter ion. Overall, it is possible to bypass a major part of the downstream processing of PHA for the production of biobased chemicals.


Assuntos
Crotonatos , Poli-Hidroxialcanoatos , Águas Residuárias/química , Ácido 3-Hidroxibutírico/análise , Ácido 3-Hidroxibutírico/química , Crotonatos/análise , Crotonatos/química , Ácidos Pentanoicos/análise , Ácidos Pentanoicos/química , Poli-Hidroxialcanoatos/análise , Poli-Hidroxialcanoatos/química
5.
Magn Reson Chem ; 51(3): 168-75, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23348689

RESUMO

Ultrafast (UF) 2D NMR is a very promising methodology enabling the acquisition of 2D spectra in a single scan. In the last few years, the analytical performance of UF 2D NMR has been highly increased, consequently maximizing its range of applications. However, its implementation and use by non-specialists are far from being straightforward, because of the specific acquisition and processing procedures and parameters characterizing UF NMR. To make this methodology implementable and applicable by non-specialists, we developed a simple routine capable of translating conventional parameters (spectral widths and transmitter frequencies) into specific UF parameters (gradient and chirp pulse parameters). This macro was subsequently implemented in a Web page, which is available for external users. Although the algorithm was designed for two widely used 2D experiments, COSY and HSQC, it can easily be extended to any other pulse sequence. The robustness of this routine was verified successfully on a variety of small molecules. We believe that this tool will eliminate much of the technical difficulties related to UF 2D NMR and will make the technique accessible to a wider audience of organic and analytical chemists.


Assuntos
Deutério/química , Espectroscopia de Ressonância Magnética/métodos , Algoritmos , Crotonatos/análise , Glucose/análise , Ibuprofeno/análise
6.
J Pharm Biomed Anal ; 66: 399-401, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22521635

RESUMO

The aim of our study was to test an alternative principle of signal normalisation in LC-MS/MS. During analyses, post column infusion of the target analyte is done via a T-piece, generating an "area under the analyte peak" (AUP). The ratio of peak area to AUP is assessed as assay response. Acceptable analytical performance of this principle was found for an exemplary analyte. Post-column infusion may allow normalisation of ion suppression not requiring any additional standard compound. This approach can be useful in situations where no appropriate compound is available for classical internal standardisation.


Assuntos
Cromatografia Líquida/métodos , Crotonatos/análise , Espectrometria de Massas em Tandem/métodos , Toluidinas/análise , Pressão Atmosférica , Hidroxibutiratos , Imunossupressores/análise , Nitrilas , Reprodutibilidade dos Testes
7.
Analyst ; 137(1): 255-62, 2012 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-22081086

RESUMO

Silylation is usually carried out on γ-hydroxybutyrate (GHB) for its analysis by Gas Chromatography/Mass Spectrometry (GCMS) and requires potentially long incubation times before injection during which the derivatisation reagent and derivatives (such as trimethyl-silyl compounds) can hydrolyse. Moreover, alternative internal standards (IS) are often useful depending on sample matrices, extraction/purification procedures, commercial availability and price. This study evaluated the possibility of silylating GHB with an injection port derivatisation procedure using N-methyl-N-[tert-butyldimethyl-silyl]trifluoroacetimide (MTBSTFA) with 1% tert-butyldimethylchlorosilane (TBCS) as the derivatisation reagent, producing di-tert-butyldimethyl-silyl derivatives as a novel means of analyzing GHB. In parallel, trans-hydroxycrotonic acid (t-HCA) was investigated as a potential IS for GHB quantification. Analyses were carried out with a temperature programmable injector and the GHB(t-BDMS)(2) and t-HCA(t-BDMS)(2) derivatives were successfully produced, characterised and derivatisation conditions optimised. t-HCA behaved very similarly to GHB through the derivatisation processes and was used as the IS for the determination of urinary endogenous GHB concentrations in human subjects where the method showed a limit of detection of 0.049 µg mL(-1), a limit of quantification of 0.162 µg mL(-1), and a limit of confirmation of 1.33 µg mL(-1), suitable for toxicological GHB concentration determination.


Assuntos
Crotonatos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos de Organossilício/química , Silício/química , Oxibato de Sódio/análise , Adulto , Crotonatos/química , Feminino , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Cromatografia Gasosa-Espectrometria de Massas/normas , Humanos , Limite de Detecção , Masculino , Valores de Referência , Oxibato de Sódio/química , Oxibato de Sódio/urina , Temperatura , Adulto Jovem
8.
Am J Clin Pathol ; 133(3): 454-7, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20154284

RESUMO

Leflunomide (Arava), a drug with immunosuppressive and antiviral effects, is being used in renal transplant recipients, primarily for its action against BK polyomavirus (BKV), which affects 1% to 10% of renal transplant recipients and often causes failure of grafted kidneys. Leflunomide effects are solely due to an active metabolite, teriflunomide (formerly A77 1726). Trough blood concentrations of teriflunomide exceeding 40 microg/mL (148 micromol/L) are associated with progressive clearance of BKV. Toxic effects become increasingly apparent at higher concentrations. We have developed a rapid, simple, and robust high-performance liquid chromatography (HPLC) method for therapeutic monitoring of teriflunomide in renal transplant recipients. Sample preparation is rapid, and each HPLC separation takes about 7 minutes. Intraday and interday coefficients of variation were 1.5% or less and 5.6% or less, respectively. The method was linear to 200 microg/mL (740 micromol/L), which is well above teriflunomide concentrations that are likely to be observed.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Crotonatos/análise , Monitoramento de Medicamentos/métodos , Isoxazóis/uso terapêutico , Toluidinas/análise , Vírus BK , Humanos , Hidroxibutiratos , Imunossupressores/uso terapêutico , Transplante de Rim , Leflunomida , Espectrometria de Massas , Nitrilas , Infecções por Polyomavirus/tratamento farmacológico , Análise de Regressão
9.
Phytochemistry ; 70(17-18): 2058-63, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19815244

RESUMO

The Floridian marine cyanobacterium Lyngbya confervoides afforded cyclodepsipeptides, termed tiglicamides A-C (1-3), along with their previously reported analogues largamides A-C (4-6), all of which possess an unusual tiglic acid moiety. Their structures were deduced by one- and two-dimensional NMR combined with mass spectrometry and the absolute configurations established by chiral HPLC and Marfey's analysis of the degradation products. Compounds 1-3 moderately inhibited porcine pancreatic elastase in vitro with IC(50) values from 2.14 to 7.28 microM. Compounds 1-6 differ from each other by one amino acid residue within the cyclic core structure, suggesting an unusually relaxed substrate specificity of the nonribosomal peptide synthetase that is the putative biosynthetic enzyme responsible for the corresponding amino acid incorporation.


Assuntos
Cianobactérias/química , Depsipeptídeos/isolamento & purificação , Inibidores Enzimáticos/isolamento & purificação , Elastase Pancreática/antagonistas & inibidores , Aminoácidos/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Crotonatos/análise , Depsipeptídeos/química , Depsipeptídeos/farmacologia , Inibidores Enzimáticos/farmacologia , Hemiterpenos , Concentração Inibidora 50 , Estrutura Molecular , Peptídeo Sintases/metabolismo , Especificidade por Substrato , Suínos
10.
Planta Med ; 75(5): 528-33, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19214948

RESUMO

Three unusual tiglic acid-containing cyclodepsipeptides, possessing the revised regioisomeric structures for largamides A-C (1-3), have been isolated from the marine cyanobacterium Lyngbya confervoides collected from southeastern Florida. The two-dimensional structures were determined by NMR spectroscopy and the absolute configurations by chiral HPLC analysis of degradation products. Compounds 1-3 are moderate inhibitors of mammalian elastase activity in vitro with IC(50) values ranging from 0.53 to 1.41 microM.


Assuntos
Cianobactérias/química , Depsipeptídeos/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Inibidores de Proteases/isolamento & purificação , Animais , Bovinos , Crotonatos/análise , Depsipeptídeos/química , Depsipeptídeos/farmacologia , Hemiterpenos , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Suínos
11.
Anal Chim Acta ; 606(2): 217-22, 2008 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-18082653

RESUMO

Stimulants are banned by the World Anti-Doping Agency (WADA) if used "in competition". Being the analysis of stimulants presently carried out on urine samples only, it might be useful, for a better interpretation of analytical data, to discriminate between an early intake of the substance and an administration specifically aimed to improve the sport performance. The purpose of the study was to investigate the differences, in terms of excretion/disappearance of drugs, between urine and oral fluid, a sample that can reflect plasmatic concentrations. Oral fluid and urine samples were collected following oral administration of the following stimulants: modafinil (100 mg), selegiline (10 mg), crotetamide/cropropamide (50 mg each), pentetrazol (100 mg), ephedrine (12 mg), sibutramine (10 mg), mate de coca (a dose containing about 3mg of cocaine); analysis of drugs/metabolites was carried out by gas chromatography/mass spectrometry (GC/MS) in both body fluids. Our results show that both the absolute concentrations and their variation as a function of time, in urine and in oral fluid, are generally markedly different, being the drugs eliminated from urine much more slowly than from oral fluid. Our results also suggest that the analysis of oral fluid could be used to successfully complement the data obtained from urine for "in competition" anti-doping tests; in all those cases in which the metabolite(s) concentration of a substance in urine is very low and the parent compound is not detected, it is indeed impossible, relying on urinary data only, to discriminate between recent administrations of small doses and remote administrations of higher doses.


Assuntos
Estimulantes do Sistema Nervoso Central/urina , Dopagem Esportivo , Saliva/química , Detecção do Abuso de Substâncias/métodos , Adulto , Aminobutiratos/análise , Aminobutiratos/farmacocinética , Aminobutiratos/urina , Compostos Benzidrílicos/análise , Compostos Benzidrílicos/farmacocinética , Compostos Benzidrílicos/urina , Calibragem , Estimulantes do Sistema Nervoso Central/análise , Estimulantes do Sistema Nervoso Central/farmacocinética , Cocaína/análise , Cocaína/farmacocinética , Cocaína/urina , Crotonatos/análise , Crotonatos/farmacocinética , Crotonatos/urina , Efedrina/análise , Efedrina/farmacocinética , Efedrina/urina , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Modafinila , Selegilina/análise , Selegilina/farmacocinética , Selegilina/urina , Fatores de Tempo
12.
J Chem Ecol ; 30(3): 577-88, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15139309

RESUMO

Analyses of pygidial gland contents of two species of a previously uninvestigated family of beetles (Trachypachidae) by Gas Chromatography-Mass Spectrometry (GC-MS) revealed that their chemistry is similar to that reported from many members of the family Carabidae. Nevertheless, the composition of defensive gland fluids of the two species Trachypachus slevini and T. gibbsii differs sufficiently to distinguish between the two species solely on the basis of their defensive chemistry. The major components of T. slevini glandular fluid are methacrylic, tiglic, and octanoic (= caprylic) acids, together with the hydrocarbon (Z)-9-pentacosene. In contrast, the glandular contents of T. gibbsii contain a rather unique mixture of polar and nonpolar compounds, the principal constituents of which are methacrylic and ethacrylic acids (= 2-ethylacrylic acid), together with 2-phenylethanol, 2-phenylethyl methacrylate, 2-phenylethyl ethacrylate, and (Z)-9-pentacosene.


Assuntos
Besouros/fisiologia , Glândulas Exócrinas/química , Glândulas Exócrinas/fisiologia , Animais , Caprilatos/análise , Crotonatos/análise , Cromatografia Gasosa-Espectrometria de Massas , Hemiterpenos , Hidrocarbonetos/análise , Metacrilatos/análise , Peso Molecular , Padrões de Referência , Especificidade da Espécie , Volatilização
13.
Arch Microbiol ; 179(4): 242-9, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12605290

RESUMO

An anaerobic, mesophilic, syntrophic benzoate-degrading bacterium, designated strain FB(T), was isolated from methanogenic sludge which had been used to treat wastewater from the manufacture of terephthalic acid. Cells were non-motile gram-positive rods that formed spores. The optimum temperature for growth was 35-40 degrees C, and the optimum pH was 7.0-7.2. A co-culture with the hydrogenotrophic methanogen Methanospirillum hungatei converted benzoate to acetate, carbon dioxide, and methane. Butyrate transiently accumulated at a high concentration of 2.5 mM during degradation. Besides benzoate, no other compound tested supported growth of the co-culture. Crotonate supported growth of strain FB(T) in pure culture. Furthermore, the strain degraded benzoate in pure culture with crotonate as co-substrate to produce acetate and butyrate. The strain was not able to utilize sulfate, sulfite, thiosulfate, nitrate, fumarate, or Fe(III) as electron acceptor. The G+C content of the DNA was 46.8 mol%. Strain FB(T) contained MK-7 as the major quinone and C(16:1) as the major fatty acid. 16S rDNA sequence analysis revealed that the strain was a member of the genus Sporotomaculum, even though it exhibited significant differences, such as the capacity for syntrophic growth, to the known member of the genus. Hence, we propose the name Sporotomaculum syntrophicum sp. nov. for strain FB(T). The type strain is strain FB(T) (DSM 14795, JCM 11475).


Assuntos
Bactérias Anaeróbias/metabolismo , Benzoatos/metabolismo , Microbiologia Ambiental , Ácidos Ftálicos/síntese química , Bactérias Anaeróbias/crescimento & desenvolvimento , Bactérias Anaeróbias/isolamento & purificação , Benzoatos/análise , Biodegradação Ambiental , Crotonatos/análise , Crotonatos/metabolismo , Deltaproteobacteria/metabolismo , Concentração de Íons de Hidrogênio , Resíduos Industriais/análise , Methanospirillum/crescimento & desenvolvimento , Methanospirillum/metabolismo , Dados de Sequência Molecular , Filogenia , Esgotos/microbiologia , Especificidade por Substrato , Temperatura
14.
Zhongguo Zhong Yao Za Zhi ; 28(7): 627-9, 2003 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-15139106

RESUMO

OBJECTIVE: To provide the foundation for reasonable utilization by analyzing the essential oils of Ligularia virgaurea. METHOD: The essential oils were extracted by using steam distillation and separated with GC capillary columns. The components were quantitatively determined with normalization method, and were identified with GC-MS. RESULT: 41 components were identified, which took up 72.73% of the essential oils. CONCLUSION: The main components of essential oils were 4-methyl-1-(1-methylethyl)-3-cyclohexen-1-ol(14.369%), crotonic acid, 2,2-dimethyl-butanoic acid, 1-methyl-3-(1-methylethyl)-benzene, (1s-endo)-1,7,7-trimethyl-bicyclo[2,2,1]heptan-2-ol, trans-1-methyl-4-(1-methylethyl)-2-cyclohexen-1-ol, alpha-cadinol and alpha,alpha,4-trimethyl-3-cyclohexene-1-methanol.


Assuntos
Asteraceae/química , Óleos Voláteis/química , Plantas Medicinais/química , Butiratos/análise , Crotonatos/análise , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis/isolamento & purificação , Óleos de Plantas/química , Óleos de Plantas/isolamento & purificação , Terpenos/análise
17.
Hokkaido Igaku Zasshi ; 51(5): 439-44, 1976 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1034615

RESUMO

Short-chain fatty acids and organic acids in aqueous solution were separated quantitatively by using a liquid chromatography. JLC-2A, which posseses a thermodetector with ion-exchange resin. A peak height of thermogram showing a thermal difference caused by adsorption and desorption of substance was proportional to the concentration. Each sample was detectable at least between approximately 10(-5) and 2 X 10(-3) moles. The "inter-day" coefficient of variation obtained from two peak heights of acetic and n-butyric acids was 1.9 and 2.3%, respectively.


Assuntos
Cromatografia Líquida/métodos , Ácidos Graxos Voláteis/análise , Ácido Mevalônico/análise , Acetatos/análise , Adsorção , Butiratos/análise , Crotonatos/análise , Temperatura Alta , Malonatos/análise
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