Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Plants (Basel) ; 12(8)2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-37111804

RESUMO

Cafestol and kahweol are expressive furane-diterpenoids from the lipid fraction of coffee beans with relevant pharmacological properties for human health. Due to their thermolability, they suffer degradation during roasting, whose products are poorly studied regarding their identity and content in the roasted coffee beans and beverages. This article describes the extraction of these diterpenes, from the raw bean to coffee beverages, identifying them and understanding the kinetics of formation and degradation in roasting (light, medium and dark roasts) as the extraction rate for different beverages of coffee (filtered, Moka, French press, Turkish and boiled). Sixteen compounds were identified as degradation products, ten derived from kahweol and six from cafestol, produced by oxidation and inter and intramolecular elimination reactions, with the roasting degree (relationship between time and temperature) being the main factor for thermodegradation and the way of preparing the beverage responsible for the content of these substances in them.

2.
AoB Plants ; 14(5): plac041, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36267642

RESUMO

The division of labour hypothesis between stamens has explained the evolution of divergent functions between dimorphic stamens in the same flower. However, little is known about whether the distinct type of stamens differs in attractiveness to pollinators. Therefore, we investigate whether the two types of stamens commonly found in Swartzia have different visual and olfactory attractants. We performed observations of anthesis dynamics, registration and collection of floral visitors, measurements of reflectance of floral parts and chemical analysis of the volatile organic compounds of the floral parts of two species, S. flaemingii and S. simplex. Both species have two distinct sets of stamens: one with smaller and abundant stamens in the centre of the flower and the other with fewer but larger abaxial stamens. The sets differ in UV reflectance (only S. simplex) and exhibit a distinct chromatic contrast. Concerning olfactory attractiveness, aliphatic compounds make up most of the odour of the two species, both whole flowers and most of their floral organs. On the other hand, only S. simplex presented apocarotenoids (as ionones) and benzenoids. Furthermore, there are differences in the proportion of volatiles emitted by the stamen in both cases, as the high proportion of sesquiterpenes among the smaller stamens compared to the larger ones. In conclusion, the two types of stamens found in S. flaemingii and S. simplex show a distinct attractiveness. In addition, our data have demonstrated diverse ways of differential attractiveness both between distinct stamens set per flower and between the two species from the same pollen flowers genus.

3.
Nat Prod Res ; 36(20): 5342-5346, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33960255

RESUMO

Pepper is one of the most consumed spices in the world. Its main compound is capsaicin, a widely studied biomarker that has pharmacological activities due to its anti-inflammatory and analgesic capacity. Topical formulations such as patches based on capsaicin have been developed as an option in relieving pain and reducing swelling. In addition, capsaicin is used as an active ingredient in non-lethal weapon formulations such as pepper spray through the QuEChERS concept (Quick, Easy, Cheap, Effective, Robust, Safe) technique. Used for food analysis, it allows the direct analysis of the biomarker by TLC-ESI-MS, which are previously separated by HPTLC (High Performance Thin Layer Chromatography) using an internal standard for determination of Rf and confirmation of capsaicin in different matrices.[Formula: see text].


Assuntos
Capsicum , Piper nigrum , Capsaicina , Capsicum/química , Cromatografia em Camada Delgada , Especiarias
4.
Artigo em Inglês | MEDLINE | ID: mdl-34801941

RESUMO

Coffee is one of the most consumed beverages worldwide. Cafestol is an endogenous coffee diterpene present in raw coffee beans and also found in hot beverages, with several biological activities. However, there is still little information on this molecule after ingestion of coffee infusion. Zebrafish (Danio rerio) is a promising in vivo model for metabolic studies due to the annotation of mammalian orthologs to encode enzymes related to drug metabolism. Experiments using Zebrafish Water Tank (ZWT) model produce more significant number of metabolites for molecular investigation in a cleaner matrix than other classical models, such as purified hepatocytes. This work aimed to investigate the biotransformation of cafestol by the ZWT model using ultra-performance liquid chromatography coupled to hybrid quadrupole-orbitrap high-resolution mass spectrometry equipped with electrospray ionization (UPLC-HRMS) supported by in silico approach using SMARTCyp, Way2Drug and XenoSite Softwares. Twenty-five metabolites of cafestol were proposed by in silico analysis, in which 5 phase I metabolites were confirmed in the ZWT by UPLC and MS/HRMS investigation: 6-hydroxy-cafestol, 6,12-dihydroxy-cafestol, 2-oxo-cafestol, 6-oxo-cafestol and one isomer whose position in the carboxyl group was not determined. These metabolites were observed during 9 h of the experiment, whose contents were associated with the behavioral responses of the fish.


Assuntos
Diterpenos/química , Diterpenos/metabolismo , Peixe-Zebra/metabolismo , Animais , Biotransformação , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Café/química , Café/metabolismo , Simulação por Computador , Espectrometria de Massas , Modelos Animais , Estrutura Molecular
5.
Molecules ; 26(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34206998

RESUMO

BACKGROUND: N-octadecanoyl-5-hydroxytryptamide (C18-5HT) is an amide that can be obtained by the coupling of serotonin and octadecanoic acid. This study aims to characterize the in vivo and in vitro anti-inflammatory activity of C18-5HT. METHODS: A subcutaneous air pouch model (SAP) was used. The exudates were collected from SAP after carrageenan injection to assess cell migration and inflammatory mediators production. RAW 264.7 cells were used for in vitro assays. RESULTS: C18-5HT significantly inhibited leukocyte migration into the SAP as well as nitric oxide (NO) and cytokines production and protein extravasation. We also observed an reduction in some cytokines and an increase in IL-10 production. Assays conducted with RAW 264.7 cells indicated that C18-5HT inhibited NO and cytokine produced. CONCLUSIONS: Taken together, our data suggest that C18-5HT presents a significant effect in different cell types (leukocytes collected from exudate, mainly polumorphonuclear leukocytes and cell culture macrophages) and is a promising compound for further studies for the development of a new anti-inflammatory drug.


Assuntos
Anti-Inflamatórios/farmacologia , Inflamação/tratamento farmacológico , Serotonina/farmacologia , Animais , Carragenina/farmacologia , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Citocinas/metabolismo , Modelos Animais de Doenças , Inflamação/induzido quimicamente , Inflamação/metabolismo , Mediadores da Inflamação/metabolismo , Interleucina-10/metabolismo , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Óxido Nítrico/metabolismo , Células RAW 264.7
6.
Biomedicines ; 9(5)2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922159

RESUMO

In this work, we describe a new route for the synthesis and the antinociceptive effects of two new ßN-alkanoyl-5-hydroxytryptamides (named C20:0-5HT and C22:0-5HT). The antinociceptive activities were evaluated using well-known models of thermal-induced (reaction to a heated plate, the hot plate model) or chemical-induced (licking response to paw injection of formalin, capsaicin, or glutamate) nociception. The mechanism of action for C20:0-5HT and C22:0-5HT was evaluated using naloxone (opioid receptor antagonist, 1 mg/kg), atropine (muscarinic receptor antagonist, 1 mg/kg), AM251 (cannabinoid CB1 receptor antagonist, 1 mg/kg), or ondansetron (5-HT3 serotoninergic receptor antagonist, 0.5 mg/kg) 30 min prior to C20:0-5HT or C22:0-5HT. The substances both presented significant effects by reducing licking behavior induced by formalin, capsaicin, and glutamate and increasing the latency time in the hot plate model. Opioidergic, muscarinic, cannabinoid, and serotoninergic pathways seem to be involved in the antinociceptive activity since their antagonists reversed the observed effect. Opioid receptors are partially involved due to tolerant mice demonstrating less antinociception when treated with both compounds. Our data showed a quicker and simpler route for the synthesis of the new ßN-alkanoyl-5-hydroxytryptamides. Both compounds demonstrated significant antinociceptive effects. These new compounds could be used as a scaffold for the synthesis of analogues with promising antinociceptive effects.

7.
ACS Omega ; 5(40): 25712-25722, 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33073097

RESUMO

This work investigates batch and continuous-flow heterogeneous catalytic hydrogenation of a mixture of cafestol and kahweol (C&K) to obtain pure cafestol. These diterpenes were extracted from green coffee beans, and hydrogenation was performed using well-established palladium catalysts (Pd/C, Pd/CaCO3, Pd/BaSO4, and Pd/Al2O3) and a carbon black-supported Pd catalyst coated by a covalently tethered SiO2 shell with mesoporous texture (Pd/CB@SiO2), all partially deactivated with quinoline. Pd/C 10% poisoned with 1 wt % quinoline gave the best result for batch reaction, producing cafestol from kahweol with high selectivity (>99%) after 10 min. Excellent selectivity was also obtained with the catalyst Pd/CB@SiO2 with only 1% Pd. In addition, Pd/C-quinoline adapted for continuous-flow experiments exhibited the best catalytic activity, also providing cafestol with excellent selectivity (>99%) after 9.8 s.

8.
Food Res Int ; 119: 349-358, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30884665

RESUMO

A novel dynamic approach is described to profile volatile organic compound (VOC) and semi-VOC (SVOC) emission during coffee roasting aimed at analysing components present in the roasting plume, and to monitor their evolution during the process. Two sorbents - coconut shell charcoal (CSC) and styrene-divinylbenzene resin (XAD-2) - were evaluated while collecting substances in four sequential time intervals (0-3, 3-6, 6-9 and 9-12 min). Extracted VOCs (<200 Da) and SVOCs were analysed by gas chromatography (GC), and comprehensive two-dimensional gas chromatography (GC × GC) with flame ionisation (FID) and time-of-flight mass spectrometry (TOFMS) detection. Results showed CSC extraction presented poor recovery of VOCs and SVOCs released during roasting. However, XAD-2 was able to collect both groups, including SVOCs of >400 Da. GC × GC resolved many co-eluting compounds observed in 1D GC and allowed chemical group type cluster analysis, revealing that many non-polar VOCs are observed within the 0-3 min interval, and that the release of polar and higher molar mass SVOCs were mostly found within the 3-6 min interval. These group-type cluster analyses offer a broad spectrum chemical profile of the released substances. It may also reveal detailed insights into the roast process evolution over time.


Assuntos
Café/química , Sementes/química , Compostos Orgânicos Voláteis/análise , Brasil , Ácidos Graxos/análise , Ionização de Chama , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Massas , Extratos Vegetais/química , Esteróis/química , Fatores de Tempo
9.
Sci Rep ; 8(1): 10027, 2018 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-29968799

RESUMO

The present study examined the potential antinociceptive activity of C18 5-HT (ßN-octadecanoyl-5-hydroxytryptamide) using chemical and thermal nociception models in mice. Orally administered C18 5-HT (0.1, 1 and 10 mg/kg) produced significant dose-dependent antinociceptive effects in formalin-, capsaicin- and glutamate-induced licking models. This compound also induced a significant increase in the response to thermal stimuli in the hot plate test, and its antinociceptive effect was not related to muscle relaxant or sedative actions. In a thermal hyperalgesia model, C18 5-HT presented an anti-hyperalgesic profile as evidenced by the increase in the response time of the animals. Furthermore, intraperitoneal (i.p) pretreatment with naloxone (a non-selective opioid receptor antagonist, 1 mg/kg), ondansetron (serotoninergic receptor antagonist (5-HT3 subtype), 0.5 mg/kg) or AM241 (CB1 cannabinoid receptor antagonist, 1 mg/kg) reversed the antinociceptive effects of C18 5-HT in the hot plate model. In the formalin-induced licking model, pretreatment with naloxone reversed the antinociceptive effects of C18 5-HT, as demonstrated by an increase in the paw licking response when compared with the C18 5-HT-treated group. These findings suggest that C18 5-HT has peripheral and central antinociceptive effects and that its mechanism of action involves, ate least in part, opioid, serotoninergic and cannabinoid pathways.


Assuntos
Analgésicos/farmacologia , Hiperalgesia/tratamento farmacológico , Dor/tratamento farmacológico , Serotonina/análogos & derivados , Serotonina/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Capsaicina/toxicidade , Café/química , Modelos Animais de Doenças , Feminino , Formaldeído/toxicidade , Ácido Glutâmico/toxicidade , Temperatura Alta , Masculino , Camundongos , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Ondansetron/farmacologia , Medição da Dor , Piperidinas/farmacologia , Pirazóis/farmacologia
10.
Food Chem ; 259: 226-233, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29680048

RESUMO

Cafestol and kahweol (C&K), two coffee diterpene alcohols with structural similarity which exhibit anticarcinogenic effects, were isolated from green coffee Arabica beans, followed by their lipase-catalysed esterification and purification by preparative high-performance liquid chromatography (HPLC). The isolation and enzymatic synthesis parameters of C&K esters were studied, with the latter optimised by a Central Composite Design; both procedures were monitored by gas chromatography. Scale up and improved isolation conditions resulted in 1.29 g of C&K, with 98% purity from 300 g of green Arabica beans. The highest C&K ester yields were observed using an alcohol:fatty acid molar ratio of 1:5, 73.3 mg mL-1 of CAL-B enzyme, 70 °C and 240 rpm for 3 days in toluene, leading to 85-88% conversion among a variety of tested C&K esters, including n-C14:0-C20:0, C18:1, C18:2 and C18:3.


Assuntos
Diterpenos/metabolismo , Ésteres/metabolismo , Lipase/metabolismo , Biocatálise , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Café/química , Café/metabolismo , Diterpenos/química , Ésteres/análise
11.
J Chromatogr A ; 1536: 75-81, 2018 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-28890267

RESUMO

Comprehensive two-dimensional gas chromatography (GC×GC) approaches with cryogenic modulation were developed for the qualitative analysis of selected low volatility compounds in raw coffee bean extracts, without derivatisation. The approaches employed short first (1D) and second (2D) dimension columns, specifically a 1D 65% phenyl methyl siloxane column (11m) and a 2D 5% phenyl methyl siloxane column (1m), which allowed elution of high molar mass compounds (e.g.>600Da). Solutes included hydrocarbons, fatty acids, diterpenes, tocopherols, sterols, diterpene esters, and di- and triacylglycerides. An oven temperature program up to 370°C was employed. The effects of experimental conditions were investigated, revealing that the GC×GC results strongly depended on the cryogenic trap T, and oven T program. An appropriate condition was selected and further applied for group type analysis of low volatility compounds in green Arabica coffee beans. Retention indices were compiled for 1D GC analysis and were similar for the composite column data in GC×GC. The elution of some compounds was confirmed by use of authentic standards. The approach allowed direct analysis of coffee extract in ethyl acetate solution, with improved analyte peak capacity (approximately 200 compounds were detected) without prior fractionation or pre-treatment of the sample. This avoided potential hydrolysis of high molar mass conjugate esters as well as degradation of thermally labile compounds such as the derivatives of the diterpenes cafestol and kahweol.


Assuntos
Técnicas de Química Analítica/instrumentação , Técnicas de Química Analítica/métodos , Cromatografia Gasosa/instrumentação , Café/química , Temperatura , Volatilização
12.
Rapid Commun Mass Spectrom ; 30(1): 61-8, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26661971

RESUMO

RATIONALE: The study of natural products by electrospray ionization tandem mass spectrometry (ESI-MS/MS) is an important strategy for the characterization of the major fragmentation reactions which can then help to determine the composition of complex mixtures. Application of ESI-MS/MS to a series of isopimarane diterpenes from Velloziaceae allowed the rationalization of their fragmentation mechanisms. METHODS: Velloziaceae diterpenes were isolated by silica gel column chromatography and investigated by ESI-MS/MS analysis. The fragmentation studies were performed on a quadrupole-time-of-flight instrument using N2 as the collision gas. To help rationalize the fragmentation pathways observed, the geometry and sites of reactivity of the diterpenes were obtained by theoretical calculations using the B3LYP/6-31 + G(d,p) model. Fragmentation mechanisms were proposed on the basis of the calculated protonation sites and product ions energies using density functional theory (DFT) methods. RESULTS: The presence of hydroxyl and carbonyl groups on the terpene core influences the protonation site observed. One compound showed a radical cation as the base peak. MS/MS spectra exhibit water elimination as the major fragmentation pathway (via two ways), either when protonation takes place on the oxygen atom, or through elimination after activation from hydrogen migration. After the elimination of water, the formation of an endocyclic double bond induces a sequential retro-Diels-Alder (RDA) reaction as the major fragmentation step. CONCLUSIONS: A thorough rational analysis of the fragmentation mechanisms of protonated Velloziaceae diterpenes was used to propose the dissociation mechanisms in ESI-MS/MS. The presence of esters in the side chain also influenced the intensity or occurrence of the observed protonated or cationized molecules in ESI-MS. These results will aid the identification of analogues in sample extracts in future metabolomics studies.


Assuntos
Abietanos/análise , Abietanos/química , Magnoliopsida/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Modelos Moleculares
13.
Rev. bras. farmacogn ; 25(6): 612-618, Nov.-Dec. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-769936

RESUMO

Abstract The gorgonian Phyllogorgia dilatata Esper is an octocoral known to be source of biologically active terpenes. In this study, odoriferous compounds present in P. dilatata tissues were investigated, due to their exotic olfactory notes. The search of volatile compounds was performed in a dichloromethane/methanol extract submitted to a silica gel vacuum chromatography and HPLC, yielding the isomers (Z,E) and (E,E)-germacrones, identified by GC/MS, 1 and 2D NMR. The stereochemistry of (E,E)-germacrone, as well as its preferred conformation, was confirmed by NOESY. Sensory analysis of the two isomers revealed a fragrant, citrus, woody and weak marine odor, similar to the odor of the natural gorgonian, and (E,E)-germacrone has a three times more intense aroma than the (Z,E) isomer.

14.
Talanta ; 139: 159-66, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25882422

RESUMO

A new gas chromatography method using pulsed split injector (PS-GC) was validated to quantify thermolabile diterpenes cafestol, kahweol and isokahweol in methanolysed Arabica coffee oils. Linearity was 0.99 from 8 to 69mgmL(-1), recovery ranged from 99% to 101% and precision of less than 4% was obtained. Besides, Soxhlet extraction time was evaluated and Tukey׳s test indicated that the mass of diterpenes obtained in 4h is equivalent to a 16h period, which represents a space-time yield four times higher. The microwave assisted methanolysis proved to be efficient to quantitatively convert the natural diterpene esters in their respective alcohols and fatty acid methyl esters, accompanied by PS-GC. Also, the intact diterpene esters were analyzed by GC for the first time by the comparison between cold on-column (COC) and PS injection techniques. In all these stages, the molecular integrity of the thermolabile furokaurane diterpenes was maintained. The methanolysed oils from 13 samples of green Brazilian Arabica coffees were analyzed by PS-GC and the diterpenes composition varied from 8 to 12% w/w in oil and 0.7-1% in coffee beans. The ratio between cafestol and kahweol was successfully used to predict the quality of coffee even before the roasting and brewing processes.


Assuntos
Cromatografia Gasosa/métodos , Café/química , Diterpenos/análise , Óleos de Plantas/análise , Controle de Qualidade , Cromatografia Líquida de Alta Pressão/métodos , Diterpenos/isolamento & purificação , Micro-Ondas , Óleos de Plantas/isolamento & purificação
15.
Molecules ; 19(1): 514-24, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24451247

RESUMO

Tetradenia riparia (Hochstetter) Codd belongs to the Lamiaceae family and it was introduced in Brazil as an exotic ornamental plant. A previous study showed its antimicrobial, acaricidal and analgesic activities. Two compounds were isolated from essential oil of T. riparia leaves and identified as 9ß,13ß-epoxy-7-abietene (1), a new one, and 6,7-dehydroroyleanone (2), already reported for another plant. The structure of these compounds was determined by spectroscopic analysis and by comparison with literature data. The cytotoxic activities of the essential oil and compounds 1 and 2 were determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, and by tumor cells MDA-MB-435 (human breast carcinoma), HCT-8 (human colon), SF-295 (human nervous system) and HL-60 (human promyelocytic leukemia). The essential oil and compound 1 showed high cytotoxic potential of the cell lines SF-295 (78.06% and 94.80%, respectively), HCT-8 (85.00% and 86.54%, respectively) and MDA-MB-435 (59.48% and 45.43%, respectively). Compound 2 had no cytotoxic activity. The antioxidant activity was determined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), ß-carotene-linoleic acid system and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The inhibitory concentration (IC50 in µg mL-1) for essential oil and compound 2 was, respectively 15.63 and 0.01 for DPPH; 130.1 and 109.6 for ß-carotene-linoleic acid and 1524 and 1024 for ABTS. Compound 1 had no antioxidant activity. By fractioning the oil, it was possible to identify two unpublished compounds: 1 with high cytotoxic potential and 2 with high antioxidant potential.


Assuntos
Abietanos/química , Abietanos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Lamiaceae/química , Óleos Voláteis/química , Abietanos/toxicidade , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Extratos Vegetais/química
16.
Ciênc. rural ; 43(8): 1516-1521, ago. 2013. ilus, tab
Artigo em Português | LILACS | ID: lil-680684

RESUMO

O objetivo do presente trabalho foi determinar os compostos voláteis em frutos de caqui Mikado adstringentes e destanizados, em dois períodos de armazenamento, utilizando microextração em fase sólida (MEFS, fibra DVB/CAR/PDMS) por cromatografia gasosa acoplada à espectrometria de massas (CG-EM). A partir dos resultados foi possível observar diferenças na composição volátil em frutos adstringentes e destanizados de caqui Mikado, com perdas em ambas as amostras. A remoção da adstringência com exposição ao álcool promoveu aumento dos voláteis no 1o dia após a destanização. Os compostos voláteis de caqui Mikado são representados, majoritariamente, por hidrocarbonetos terpênicos, seguidos de ésteres de cadeia linear.


The objective of this study was to determine the volatile compounds in persimmon (Diospyros kaki) Mikado variety, astringent and astringency removal in two periods of storage, using solid phase microextraction (SPME, fiber DVB/CAR/PDMS) by gas chromatography mass spectrometry (GC-MS). The results showed differences in the volatile composition of astringent and astringency removal, with losses in both analyses. The removal of astringency with alcohol exposure increased the volatiles on day 1 after astringency removal. The volatiles from persimmon Mikado are mainly represented by terpene hydrocarbons, followed by straight-chain esters.

17.
Curr Drug Metab ; 13(9): 1244-50, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22519371

RESUMO

In the recent years the way of thinking about human health necessarily passes by human food. Recent discoveries are not only concerned about valuable biomolecules but also contaminants. Thus, the screening of substances in animal and vegetable matrices by analytical techniques is focused on the presence and absence of target substance. In both cases, the majority of these substances are present as traces or in very low levels. Contaminants could be naturally present in the food, inserted on it or even developed on it as a consequence of food processing or cooking. Pesticides, mycotoxins, dioxins, acrylamide, Sudan red, melamine and now 4(5)-methylimidazole can be, at present, be listed as some of the world big problems related to food contaminants and adulterants. With the development of liquid chromatography coupled to mass spectrometry (LC-MS-MS), in the last few decades, analysis of some food contaminants in trace levels trace become less laborious, more accurate and precise. The multiple approach of those techniques make possible to obtain many results in one single run. On the other hand, European Union (2002/657/EC) established regulations for analytical methods regarding mass spectrometry as detection tool, showing the importance of this technique in food quality control. The EU criteria uses identification points (IPs) that could be achieved basically with four product ions (including molecular ion) or reduced with the use of high resolution equipments. This kind of mass spectrometers made the IPs criteria more accessible, as the exact mass information is a differential tool. In view of this the aim of this review is to present the actual scenario for mass spectrometry analysis in a complex vegetable food matrix such as roasted coffee, with emphasis on needs and challenges regarding the LC-MS technique in order to meet and contribute to food safety standards in this complex matrix.


Assuntos
Café/química , Contaminação de Alimentos/análise , Espectrometria de Massas/métodos , Cromatografia Líquida/métodos , Poluentes Ambientais/análise , Temperatura Alta , Espectrometria de Massas/instrumentação
18.
J Nat Med ; 66(2): 367-72, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21915628

RESUMO

Two flavonoids 3,5,7,3',4'-pentahydroxy-6-prenylflavonol (1) and 3,5,7,3',4'-pentahydroxy-8-methyl-6-prenylflavonol (2) were isolated from the ethyl acetate extract of sheaths of Vellozia kolbekii Alves (Velloziaceae). This is the first time that compound 2 has been described. The crude extract and flavonoids were found to be active as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavengers and were able to the increase tolerance of the eukaryotic microorganism Saccharomyces cerevisiae to oxidative stress generated by H(2)O(2). The protective effect was correlated with a reduction in the oxidation of proteins and lipids. In addition, flavonoids isolated from Velloziaceae showed an inhibitory effect on mutations in p53, which is mutated and nonfunctional in more than 50% of cases of human cancer.


Assuntos
Flavonoides/farmacologia , Peróxido de Hidrogênio/toxicidade , Magnoliopsida/química , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Antioxidantes/química , Antioxidantes/farmacologia , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Extratos Vegetais/química , Carbonilação Proteica/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo
19.
Exp Parasitol ; 129(2): 175-8, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21762693

RESUMO

Tetradenia riparia (Lamiaceae) is a well-known herbal medicine with a variety of useful properties, including its acaricidal effect. This experiment was carried out to study the bioacaricidal activity of T. riparia essential oil (EO) against engorged females of Rhipicephalus (Boophilus) microplus (Acari; Ixodidae). For this purpose, nine serial concentrations (12.50%, 6.25%, 3.75%, 1.80%, 0.90%, 0.45%, 0.22%, 0.11%, and 0.056% w/v) of T. riparia were used for the adult immersion test (AIT). For the larval packet test (LPT), we used 14 serial concentrations (100.00%, 50.00%, 25.00%, 12.50%, 6.25%, 3.65%, 1.82%, 0.91%, 0.45%, 0.228%, 0.114%, 0.057%, 0.028%, and 0.014% w/v). The results for AIT showed 100.00% and 2.05% mortality, 19.00 and 90.20% for the total number of eggs, egg-laying inhibition of 0.00% and 90.20%, hatchability inhibition of 0.00% and 70.23%, and product effectiveness of 100.00% and 2.89%, respectively. The AIT indicated that the LC(50) and LC(99.9), calculated using the Probit test, were for mortality (%) 0.534g/mL (0.436-0.632) and 1.552g/mL (1.183-1.92); for total number of eggs were 0.449g/mL (0.339-0.558) and 1.76g/mL (1.27-2.248); and for hatchability inhibition were 0.114g/mL (0.0-0.31) and 2.462g/mL (1.501-3.422), respectively. Larvae between 14 and 21days old were fasted and placed in each envelope. Bioassays were performed at 27°±1°C, RH⩾80%. Larval mortality was observed 24h after treatment and showed 10.60-100% mortality in the LPT bioassay. The LPT showed that the LC(50) and LC(99.9) were 1.222g/mL (0.655-1.788) and 11.382g/mL (7.84-14.91), respectively. A positive correlation between T. riparia EO concentration and tick control, was observed by the strong acaricidal effects against R. (B.) microplus, and the mortality rate of ticks was dose-dependent. Our results showed that T. riparia is a promising candidate as an acaricide against resistant strains of R. (B.) microplus.


Assuntos
Acaricidas/farmacologia , Lamiaceae/química , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Rhipicephalus/efeitos dos fármacos , Animais , Bioensaio , Bovinos , Doenças dos Bovinos/parasitologia , Feminino , Larva/efeitos dos fármacos , Oviposição/efeitos dos fármacos , Folhas de Planta/química , Distribuição Aleatória , Rhipicephalus/fisiologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária
20.
Nat Prod Commun ; 5(8): 1167-70, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20839610

RESUMO

The CH2Cl2 crude extract and a fraction enriched with halogenated monoterpenes of the Brazilian red alga Plocamium brasiliense were evaluated for cytotoxicity and against the virus HSV-1. The extract showed low cytotoxicity compared with the fraction containing monoterpenes. The crude extract showed, in vitro, a high reduction of infectivity of the virus HSV-1.


Assuntos
Antivirais/farmacologia , Herpesvirus Humano 1/efeitos dos fármacos , Monoterpenos/farmacologia , Plocamium/química , Brasil
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...