Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Int J Mol Sci ; 18(11)2017 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-29084170

RESUMO

This review summarizes available data on argan fruit botany, geographical distribution, traditional uses, environmental interest, socioeconomic role, phytochemistry, as well as health beneficial effects and examination of future prospects. In particular, ethnomedical uses of argan fruits are carried out throughout Morocco where it has been used against various diseases. Different classes of bioactive compounds have been characterized including essential oils, fatty acids, triacylglycerols, flavonoids and their newly reported acylglycosyl derivatives, monophenols, phenolic acids, cinnamic acids, saponins, triterpenes, phytosterols, ubiquinone, melatonin, new aminophenols along with vitamin E among other secondary metabolites. The latter have already shown a wide spectrum of in vitro, and ex vivo biologicalactivities including antioxidant, anti-inflammatory, anti-diabetic, antihypertensive, anti-hypercholesterolemia, analgesic, antimicrobial, molluscicidal anti-nociceptive and anticancer potential. Argan flesh (pulp) contains a broad spectrum of polyphenolic compounds which may have utility for incorporation into nutraceuticals and cosmeceuticals relevant to the food, cosmetic and health industries. Further research is recommended, especially on the health beneficial effects of the aminophenols.


Assuntos
Frutas/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Sapotaceae/química , Frutas/metabolismo , Humanos , Metaboloma , Metabolômica/métodos , Marrocos , Fenóis/química , Óleos de Plantas/química , Sapotaceae/metabolismo
2.
Food Chem ; 455: 139879, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38824725

RESUMO

We used confocal microscopy and spectrofluorescence to characterize the emission spectra in hop flowers, to follow the isomerization processes in different hop preparations, and beers, to compare with HPLC extracted samples. Flowers of different hop cultivars produced in three regions of Brazil, were quantitated by HPLC and GC-MS. The fluorescence spectra showed two characteristic emission bands evaluated from different preparations. The isomerization process leads to a gradual decrease in fluorescence intensity as the reaction progresses. This demonstrates the valuable use of confocal microscopy and fluorescence spectroscopy for analysis of the correlation between bitter acid indices with fluorescence intensity and lifetime microscopy. Such techniques can be used directly in the flowers allowing rapid monitoring of the brewing process. Twenty-nine substances were characterized in the essential oils and some cultivars presented quantities of bitter acids and essential oil levels close to those expected for plants after more than three years of cultivation.


Assuntos
Cerveja , Flores , Humulus , Microscopia Confocal , Óleos Voláteis , Brasil , Flores/química , Flores/metabolismo , Humulus/química , Cromatografia Líquida de Alta Pressão , Cerveja/análise , Óleos Voláteis/química , Isomerismo , Espectrometria de Fluorescência/métodos , Cromatografia Gasosa-Espectrometria de Massas
3.
Food Chem ; 388: 132964, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35447586

RESUMO

We hypothesised that QuEChERS could be successfully applied to the extraction of bitter acids and xanthohumol from hops, which would be less time consuming, cheaper, and more eco-friendly by the severe reduction of solvent use. High performance liquid chromatography was used to separate the compounds after extraction and quantitation was evaluated against standard calibration curves for bitter acids prepared from an International calibration extract (ICE-4) and an authentic standard of xanthohumol. The standard QuEChERS method was compared to mini and micro-versions including clean-up and spiking procedures. The quantitative analyzes indicate the applicability of the QuEChERS method for the quantitation of bitter acids compared to Soxhlet extraction. The statistical data confirm reproducibility of the total alpha- and beta- acids measured by the standard method and the modified mini- and micro-QuEChERS procedures. Our hypothesis is supported by the data described and is consistent with other previous methods described in the literature.


Assuntos
Humulus , Propiofenonas , Ácidos/análise , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides , Humulus/química , Reprodutibilidade dos Testes
4.
J Integr Med ; 16(3): 185-191, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29631911

RESUMO

OBJECTIVE: Anabasis aretioides (Coss & Moq.), a Saharan plant belonging to Chenopodiaceae family, is widely distributed in semi-desert areas from the Tafilalet region of Morocco. This plant is extensively used by local population against diabetes and cardiovascular disorders. The purpose of the study was to investigate the effect of the aqueous A. aretioides extract on lipid metabolism in normal and streptozotocin (STZ)-induced diabetic rats and to identify the polyphenolic compounds present. In addition, the in vitro antioxidant activity of the aqueous A. aretioides extract was also evaluated. METHODS: The effect of an aerial part aqueous extract (APAE) of A. aretioides (5 mg/kg of lyophilized A. aretioides APAE) on plasma lipid profile was investigated in normal and STZ-induced diabetic rats (n = 6) after once daily oral administration for 15 days. The aqueous extract was tested for its 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. Polyphenolic compounds in the extracts were definitively characterized by high-performance liquid chromatography-diode array detection-electrospray ionization-mass spectrometry. RESULTS: In diabetic rats, oral administration of A. aretioides APAE provoked a significant decrease in both plasma cholesterol and triglyceride levels from the first to the second week (P < 0.01). A significant decrease on plasma triglyceride levels was also observed in normal rats (P < 0.01), where the reduction was 53%. In addition, the phytochemical analysis revealed the presence of 12 polyphenolic compounds. Moreover, according to the DPPH radical-scavenging activity, the aqueous extract showed an in vitro antioxidant activity. CONCLUSION: Aqueous A. aretioides APAE exhibits lipid-lowering and in vitro antioxidant activities. Many polyphenols were present in this extract and these phytoconstituents may be involved in the pharmacological activity of this plant.


Assuntos
Chenopodiaceae/química , Diabetes Mellitus Experimental/tratamento farmacológico , Hipolipemiantes/administração & dosagem , Hipolipemiantes/química , Compostos Fitoquímicos/administração & dosagem , Compostos Fitoquímicos/química , Polifenóis/administração & dosagem , Polifenóis/química , Animais , Antioxidantes/administração & dosagem , Colesterol/sangue , Cromatografia Líquida de Alta Pressão , Diabetes Mellitus Experimental/sangue , Humanos , Masculino , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Ratos , Ratos Wistar , Estreptozocina , Espectrometria de Massas em Tandem , Triglicerídeos/sangue
5.
Biomedicines ; 6(1)2018 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-29439506

RESUMO

Bryonolic acid (BrA) is a pentacyclic triterpene present in several plants used in African traditional medicine such as Anisophyllea dichostyla R. Br. Here we investigated the in vitro anticancer properties of BrA. We report that BrA inhibits acyl-coA: cholesterol acyl transferase (ACAT) activity in rat liver microsomes in a concentration-dependent manner, blocking the biosynthesis of the cholesterol fatty acid ester tumour promoter. We next demonstrated that BrA inhibits ACAT in intact cancer cells with an IC50 of 12.6 ± 2.4 µM. BrA inhibited both clonogenicity and invasiveness of several cancer cell lines, establishing that BrA displays specific anticancer properties. BrA appears to be more potent than the other pentacyclic triterpenes, betulinic acid and ursolic acid studied under similar conditions. The inhibitory effect of BrA was reversed by exogenous addition of cholesteryl oleate, showing that ACAT inhibition is responsible for the anticancer effect of BrA. This report reveals new anticancer properties for BrA.

6.
J Agric Food Chem ; 55(24): 9824-8, 2007 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-17979235

RESUMO

Varieties of kola nuts (Cola nitida alba, Cola nitida rubra A. Chev, and Cola acuminata Schott & Endl), a group of popular Nigerian and West African stimulants, were analyzed for their content of secondary plant metabolites. The three varieties of the kola nuts contained appreciable levels of (+)-catechin (27-37 g/kg), caffeine (18-24 g/kg), (-)-epicatechin (20-21 g/kg), procyanidin B 1 [epicatechin-(4beta-->8)-catechin] (15-19 g/kg), and procyanidin B2 [epicatechin-(4beta-->8)-epicatechin] (7-10 g/kg). Antioxidant capacity of the extracts and purified metabolites was assessed by two HPLC-based and two colorimetric in vitro assays. Extracts of all varieties exhibited antioxidant capacity with IC 50 values in the range 1.70-2.83 and 2.74-4.08 mg/mL in the hypoxanthine/xanthine oxidase and 2-deoxyguanosine HPLC-based assays, respectively. Utilization of HPLC-based assays designed to reflect in situ generation of free radicals (e.g., HO(*)), as opposed to general assays (DPPH, FRAP) in common use which do not, indicate that, of the major secondary plant metabolites present in kola nut extracts, caffeine is potentially the more effective cancer chemopreventive metabolite in terms of its antioxidant capacity.


Assuntos
Antioxidantes , Estimulantes do Sistema Nervoso Central/isolamento & purificação , Cola/química , Flavonoides/isolamento & purificação , Flavonoides/metabolismo , Fenóis/isolamento & purificação , Fenóis/metabolismo , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Biflavonoides/isolamento & purificação , Biflavonoides/metabolismo , Cafeína/isolamento & purificação , Cafeína/metabolismo , Catequina/isolamento & purificação , Catequina/metabolismo , Estimulantes do Sistema Nervoso Central/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Colorimetria , Relação Dose-Resposta a Droga , Humanos , Concentração Inibidora 50 , Nigéria , Polifenóis , Proantocianidinas/isolamento & purificação , Proantocianidinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo
7.
J Chromatogr A ; 1512: 98-106, 2017 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-28720218

RESUMO

An analytical method using a quick, easy, cheap, effective, rugged and safe (QuEChERS) procedure for multi-residue determination of 52 pesticides in coffee leaf extractshas been developed and validated according to SANTE/11945/2015 guidelines. Different sorbent combinations for dispersive solid phase extraction (d-SPE) clean-up as well as dispersive liquid-liquid microextraction (DLLME) were tested. The relative standard deviations (RSDs) for the recovery of 87-94% of pesticides added to coffee leaf extracts,was ≤20% for samples spiked at concentrations up to 50ng*g-1 depending on the clean-up procedures. However, samples spiked with a 100ng*g-1 pesticide mixture gave RSDs>20% for most pesticides when d-SPE was carried out adding Supelclean ENVI-Carb 120/400. To explain this fact,the secondary metabolic profile was analyzed in all the extraction and clean-up procedures. Only in the clean-up procedure with the addition of Supel QuE Z-Sep+, does caffeine show a constant adsorption between blank and spiked samples. In other clean-up procedures, the amount of caffeine was higher in those samples spiked with pesticides. This indicates competition between caffeine and pesticides for adsorption to the sorbent. Addition of Supel QuE Z-Sep+ to the procedure revealed only a 32% matrix effect, whereas using PSA+ C18 the matrix effect was close to 97%. The process efficiency is up to 54% with the addition of Supel QuE Z-Sep+ and just up to 7% for the other clean-up procedures. The method was successfully tested in coffee leaves from different types of cultivars. Pesticides were not detected in organic coffee leaf extracts, but thiametoxan was clearly detected in 50% of coffee leaf extracts harvested from coffee trees grown under traditional conditions as determined by UHPLC-TOFMSLC/QqTOF-MS/MS.


Assuntos
Coffea/química , Café/química , Contaminação de Alimentos/análise , Resíduos de Praguicidas/isolamento & purificação , Folhas de Planta/química , Extração em Fase Sólida/métodos , Adsorção , Cromatografia Líquida/métodos , Resíduos de Praguicidas/química , Espectrometria de Massas em Tandem/métodos
8.
J Agric Food Chem ; 54(12): 4378-82, 2006 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-16756370

RESUMO

The antioxidant capacity of essential oils obtained by steam hydrodistillation from five species of the genus Ocimum, namely Ocimum basilicum var. purpurascens, Ocimum basilicum, Ocimum gratissimum, Ocimum micranthum, and Ocimum tenuiflorum (syn. O. sanctum), were evaluated using a high-performance liquid chromatography-based hypoxanthine/xanthine oxidase and the DPPH assays. The yield of oils from the leaves of the five species was variable with the greater amount obtained from Ocimum gratissimum (3.5%) and the least from Ocimum basilicum var. purpurascens (0.5%). In the hypoxanthine/xanthine oxidase assay, strong antioxidant capacity was evident in all the oils but the greater was shown by that obtained from Ocimum tenuiflorum (syn. O. sanctum) (IC50 = 0.46 microL/mL) compared to Ocimum basilicum var. purpurascens (IC50 = 1.84 microL/mL). Antioxidant capacity was positively correlated (r = 0.92, p < 0.05) with a high proportion of compounds possessing a phenolic ring such as eugenol, while a strong negative correlation (r = -0.77, p > 0.1) with other major volatiles was observed. These correlations were confirmed to a large extent in the DPPH assay. The results of a 24 h experiment with Ocimum tenuiflorum (syn. O. sanctum) shows that the antioxidant capacity factor (amount of essential oil obtained x free radical scavenging capacity; mg x %/100) reaches a threshold between 10 and 12.00 h, corresponding to maximum sunlight intensity in Brasil and furthermore exhibits a clear diurnal variation. The data generated with Ocimum species indicates that essential oils obtained from various herbs and spices may have an important role to play in cancer chemoprevention, functional foods, and in the preservation of pharmacologic products.


Assuntos
Antioxidantes/análise , Ocimum/química , Óleos Voláteis/química , Óleos de Plantas/química , Antioxidantes/farmacologia , Compostos de Bifenilo , Cromatografia Líquida de Alta Pressão , Eugenol/análise , Eugenol/farmacologia , Hipoxantina , Ocimum basilicum/química , Óleos Voláteis/farmacologia , Picratos , Folhas de Planta/química , Óleos de Plantas/farmacologia , Volatilização , Xantina Oxidase
9.
Rapid Commun Mass Spectrom ; 21(14): 2245-54, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17569095

RESUMO

A gas chromatography/mass spectrometry (GC/MS) method for the simultaneous quantitation of ten estrogen metabolites in human urine was optimized. The method consists of initial enzymatic hydrolysis of the estrogen conjugates using beta-glucuronidase followed by solid-phase extraction (SPE) on Sep-pak C18 columns and further sample purification by ion-exchange chromatography on QAE-Sephadex cartridges in the acetate form. QAE-Sephadex cartridges in the borate form were used to separate estrogens into two fractions: one fraction containing estrogens lacking vicinal cis-hydroxyls (Fr 1) and another containing estrogens possessing vicinal cis-hydroxyls (catecholestrogens; Fr 2). Finally, following O-trimethylsilyl ether derivatization, the estrogens were analyzed by GC/MS in the selected ion monitoring mode. Estrogens were quantitated using deuterated internal standards, which were added to the samples at the initiation of the work-up procedures. After addition to estrogen-low male human samples the standards showed good chromatographic linear response and reproducibility. A reduction in the number of steps and improvements in the robustness of the work-up procedures were achieved. The modified method described is less complex, amenable to use with commercially available SPE columns and fulfils all the reliability criteria, resulting in highly specific and accurate results.


Assuntos
Estrogênios/urina , Cromatografia Gasosa-Espectrometria de Massas/métodos , Urinálise/métodos , Marcação por Isótopo/métodos , Técnica de Diluição de Radioisótopos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
Rapid Commun Mass Spectrom ; 20(20): 3119-29, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16986210

RESUMO

Very few relevant methods have been described for the detection and quantitation of phenolic compounds in faecal matrix. Extraction with conventional organic solvents such as chloroform/methanol (2:1, Folch reagent), methanol and ethanol (72%) showed high extraction efficiency for lipids and also gave good recovery of the major phenolic compounds present in the matrix. However, in comparison with a newly developed phosphate buffer method, the yield of minor phenolics was negligible when detected by these conventional methods. Conventional methods also lead to contamination of the ion source of the mass spectrometer and rapid deterioration of column performance mostly due to the high concentration of lipids. However, if the faecal matrix is initially extracted with phosphate buffer, and the extract acidified and re-extracted with diethyl ether, the range and yield of phenolic compounds are enhanced and the problem of lipid contamination is substantially alleviated. Following pilot studies and optimisation of the procedure, individual phenolic compounds (n = 29) were identified by nano-electrospray ionisation mass spectrometry (nano-ESI-MS), nano-ESI-tandem mass spectrometry (MS/MS) and gas chromatography/mass spectrometry (GC/EI-MS) and quantitated (n = 27) by GC/MS in subsets (n = 5) of faecal samples, collected during the European Agency for Cancer Prevention calcium/fibre intervention study from four European countries (Italy, Germany, Spain and Denmark). A range of phenolic compounds (mainly acids) was detected, dominated by phenylacetic, benzoic, phenylpropionic and m-hydroxyphenylpropionic acids, representing on average 9.91 (93%), 8.25 (92%), 9.45 (95%) and 11.05 (98%) mM in the Italian, German, Spanish and Danish samples, respectively. The new method should enable large epidemiologic, case-control and intervention studies on the relevance of phenolic antioxidants in the aetiology of colorectal cancer to be conducted in the future.


Assuntos
Eletrocromatografia Capilar/métodos , Fezes/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Nanotecnologia/métodos , Fenol/análise , Fenol/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Humanos , Microquímica/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA