Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Z Naturforsch C J Biosci ; 67(9-10): 451-60, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23198402

RESUMO

An in-house strategy to dereplicate colchicinoid alkaloids was recently developed by our team. It aimed at quickly identifying Colchicum constituents using LC-MS (liquid chromatography-mass spectroscopy) and LC-UV/Vis PDA (liquid chromatography-ultraviolet/ visible photodiode array) techniques. In this project, our goal was to validate the developed method through analysing the alkaloid-rich fractions of three Colchicum species that had been previously studied phytochemically using the traditional bioactivity-guided fractionation methodology. The analysed species were Colchicum tauri Siehe ex Stefanoff, Colchicum stevenii Kunth, and Colchicum tunicatum Feinbr., all belonging to the family Colchicaceae. In addition to identifying the compounds previously isolated and characterized by the traditional methodology, the new strategy succeeded in tentatively identifying a set of known compounds, but new to the species.


Assuntos
Cromatografia Líquida/métodos , Colchicum/química , Espectrometria de Massas/métodos , Espectrofotometria Ultravioleta/métodos
2.
Environ Monit Assess ; 160(1-4): 425-9, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19083108

RESUMO

In this work, the atmospheric concentrations of selected heavy metals including lead (Pb), iron (Fe), cadmium (Cd), copper (Cu), nickel (Ni), manganese (Mn), and zinc (Zn) were measured for two different sampling sites (urban and rural) in the northern part of Jordan (Irbid city). Samples were collected according to a certain schedule for 1 year. High volume air samplers and glass fiber filters were used to collect the samples. Collected samples were digested using a mixture of analytical grade nitric acid and analytical grade hydrochloric acid, and analyzed to evaluate the levels of heavy metals by atomic absorption spectrophotometry. Six heavy metals (Pb, Fe, Cu, Ni, Mn, and Zn) were measured in all samples; the concentrations of Cd and Co were not detected in Irbid atmosphere by atomic absorption spectroscopy. The results were used to determine the levels of heavy metal pollutants in air, possible sources, and to compare the levels of selected heavy metals in the two studied sites. Aerosols from the rural site have lower concentrations for all the metals compared to those from the urban site. The daily and monthly variations of the elements were investigated. All heavy metals in urban and rural sites reached maximum concentrations in June, July, and August. This is consistent with the increased activities leading to particulate matter emission during the summer period. The enrichment factors with respect to earth crust and correlation coefficients of heavy metals were investigated to predict the possible sources of heavy metals in air.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Metais Pesados/análise , Ar/análise , Jordânia
3.
J Chromatogr Sci ; 47(2): 170-7, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19222926

RESUMO

A simple, rapid, reliable, and low cost one-step extraction method is developed and validated for the determination of nicotine and cotinine in human plasma and urine in smokers using reversed-phase high-performance liquid chromatography (RP-HPLC) and gas chromatography-mass spectrometry (GC-MS). The run times are 16 and 10 min for HPLC and GC-MS, respectively. The method is validated over a wide linear range of 1-5000 ng/mL with correlation coefficients being consistently greater than 0.9985. The criteria considered for validation are: limit of quantitation, linearity, accuracy, precision, recovery, specificity, and selectivity. This study is aimed to estimate the nicotine and cotinine in Jordanian smokers' blood and urine samples; to study the relationship between the concentration of nicotine in urine and plasma samples; and to investigate the effect of pH on the extraction of nicotine and cotinine in urine samples. In the presented study, one hundred blood and urine samples are collected from eighty smokers and twenty nonsmokers. Samples are taken from the same volunteer at the same time after each volunteer fills in a questionnaire. Results of nicotine concentrations in smokers' plasma are in the range of 181-3702 ng/mL with an average of 1263.1 ng/mL, whereas nicotine in urine samples is in the range of 1364-1972 ng/mL, with an average of 1618 ng/mL. Cotinine concentrations in smokers' plasma are in the range of 21-4420 ng/mL with an average of 379.4 ng/mL, whereas cotinine in urine is in the range of 6-3946 ng/mL with an average of 865 ng/mL. Statistical analysis indicates highly significant differences in nicotine and cotinine concentrations in smoker samples compared with nonsmoker samples (p<0.05).


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cotinina/sangue , Cotinina/urina , Cromatografia Gasosa-Espectrometria de Massas/métodos , Nicotina/sangue , Nicotina/urina , Fumar/sangue , Fumar/urina , Humanos , Concentração de Íons de Hidrogênio , Jordânia , Sensibilidade e Especificidade , Incerteza
4.
Biol Trace Elem Res ; 136(1): 40-7, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19777167

RESUMO

The aim of this study was to determine the levels of trace minerals Zn, Cu, and Se, the effect of dermatophytosis on the level of thiobarbituric acid reactive substances (TBARS) as an indicator of lipid peroxidation, the status of enzymatic and nonenzymatic antioxidants, and the relationship between the mentioned trace minerals and antioxidant defense system in calves with dermatophytosis. A total of 21 Holstein calves with clinically established diagnosis of dermatophytosis and an equal number of healthy ones were included in this study. Results showed that 81% of mycotic isolates were Trichophyton verrucosum, while 19% were Trichophyton mentagrophytes. The level of Zn, Cu, Se, and glutathione (GSH) and the activity of the antioxidant enzymes, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were significantly (P

Assuntos
Antioxidantes/análise , Tinha/veterinária , Oligoelementos/sangue , Animais , Cobre/sangue , Glutationa/sangue , Glutationa Peroxidase/sangue , Peroxidação de Lipídeos , Selênio/sangue , Superóxido Dismutase/sangue , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Tinha/sangue , Tinha/microbiologia , Trichophyton/isolamento & purificação , Zinco/sangue
5.
Nat Prod Res ; 24(2): 152-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20077308

RESUMO

A new colchicinoid from Colchicum crocifolium Boiss. (Colchicaceae) was isolated and identified as N,N-dimethyl-N-deacetyl-(-)-cornigerine (5), along with four known compounds, but new to the species: (-)-colchicine (1), (-)-demecolcine (2), (-)-N-methyl-(-)-demecolcine (3) and 3-demethyl-N-methyl-(-)-demecolcine (4). All isolated compounds showed potent cytotoxicity against a human cancer cell panel.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Colchicum/química , Extratos Vegetais/química , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Extratos Vegetais/farmacologia , Análise Espectral/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA