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1.
J Chromatogr A ; 1608: 460421, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31405574

RESUMO

Liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) is used to analyze various types of samples, including foodstuffs, to determine their authenticity and trace their origin on the basis of their stable carbon isotope ratios (δ13C). However, multicomponent samples are difficult to analyze. For example, determining the δ13C values of the organic acids in honey is complicated by the presence of large amounts of carbohydrates. Herein, we present a heart-cutting two-dimensional LC/IRMS method for analysis of honey samples. In this method, the organic acids in the samples were first separated from the carbohydrates by a size-exclusion column, and then the organic acids were separated from each other by a reverse-phase column connected to the first column via a switching valve. By means of this method, the δ13C values for three organic acids in high-carbohydrate-content simulated honey samples could be determined with high accuracy and precision (≤0.3‰ and ≤0.1‰, respectively). In addition, the gluconic acid δ13C values for 25 honey samples were determined with high precision and found to range from -31.7 to -28.5‰ (mean: -30.0 ±â€¯0.7‰). These values shed some light on the mechanism of gluconic acid production. Taken together, our results suggest that this two-dimensional LC method has the potential to be more effective than one-dimensional LC for use in isotopic research.


Assuntos
Cromatografia Líquida/métodos , Gluconatos/análise , Mel/análise , Espectrometria de Massas/métodos , Isótopos de Carbono/análise
2.
J Appl Microbiol ; 127(4): 1101-1112, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31283860

RESUMO

AIMS: The formation of metabolically inactive and nongrowing cells is an inevitable by-product of intensive fermentation. This study investigated whether co-feeding can be used to resuscitate nongrowing Acetobacter senegalensis cells to enable them to produce gluconic acid in successive fermentation runs at 38°C. METHODS AND RESULTS: In the first fermentation cycle, 75 g l-1 of glucose were converted to gluconic acid. Subsequently, however, stationary-phase cells were unable to initiate a new fermentation cycle. The majority of stationary-phase cells (97%) were nonculturable on glucose at 38°C. In addition, 54 and 41% of cells contained non-active cellular dehydrogenases and a compromised cell envelope respectively. Co-feeding stationary-phase cells with a mixture of ethanol, glucose and acetic acid for 7 h enabled these cells to grow on 75 g l-1 of glucose and produce gluconic acid. Additionally, 74% of cells contained active forms of cellular dehydrogenases after 7 h of co-feeding. However, co-feeding did not improve cell envelope integrity. Quantification of cellular NAD content showed that stationary-phase cells contained moderately reduced levels of total NAD (NADt) as compared with exponential-phase cells. Interestingly, the analysis of stationary-phase cells showed that co-feeding resulted in higher levels of NADt and NADH, suggesting that the regeneration of NADH is one of the limiting factors of glucose consumption. Expression of catalase and superoxide dismutase was increased in stationary-phase cells, but analysis of protein carbonylation and lipid peroxidation did not confirm an extensive oxidative stress. CONCLUSIONS: Co-feeding with favourable nutrients may enable resuscitation of cells and utilization of less-favourable carbon sources in successive cycles. SIGNIFICANCE AND IMPACT OF THE STUDY: This study proposed a unique method for resuscitation of nongrowing cells during high-temperature fermentation. By applying this method, cells can be used for consecutive fermentation cycles.


Assuntos
Acetobacter , Fermentação/fisiologia , Gluconatos , Temperatura Alta , Acetobacter/metabolismo , Acetobacter/fisiologia , Biotecnologia , Meios de Cultura/química , Meios de Cultura/metabolismo , Gluconatos/análise , Gluconatos/metabolismo
3.
Food Chem ; 289: 49-55, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30955640

RESUMO

Stable carbon isotope ratios (δ13C) for glucose, fructose, disaccharides, trisaccharides, and organic acids in 116 commercial honey samples were measured by LC/IRMS. On the basis of EA/IRMS and LC/IRMS authenticity criteria, 39 of the samples were judged to have been adulterated. The δ13C values for organic acids from pure honey, reported here for the first time, ranged from -33.6 to -26.5‰. The mean Δδ13C (glucose-organic acids) value was +3.7 ±â€¯0.9‰. Glucose and organic acid δ13C values were strongly correlated (R = 0.71, P < 0.001). Gluconic acid, the predominant organic acid in honey, has been reported to be produced via decomposition of glucose by bee glucose-oxidase and certain Gluconobacter spp. This fact was confirmed by isotope analysis.


Assuntos
Dissacarídeos/química , Frutose/química , Gluconatos/química , Glucose/química , Mel/análise , Animais , Abelhas , Isótopos de Carbono/química , Cromatografia Líquida de Alta Pressão , Dissacarídeos/análise , Frutose/análise , Gluconatos/análise , Glucose/análise , Marcação por Isótopo , Espectrometria de Massas
4.
Food Microbiol ; 73: 11-16, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29526195

RESUMO

Kombucha is a traditional beverage produced by tea fermentation, carried out by a symbiotic consortium of bacteria and yeasts. Acetic Acid Bacteria (AAB) usually dominate the bacterial community of Kombucha, driving the fermentative process. The consumption of this beverage was often associated to beneficial effects for the health, due to its antioxidant and detoxifying properties. We characterized bacterial populations of Kombucha tea fermented at 20 or 30 °C by using culture-dependent and -independent methods and monitored the concentration of gluconic and glucuronic acids, as well as of total polyphenols. We found significant differences in the microbiota at the two temperatures. Moreover, different species of Gluconacetobacter were selected, leading to a differential abundance of gluconic and glucuronic acids.


Assuntos
Ácido Acético/metabolismo , Bactérias/metabolismo , Chá de Kombucha/análise , Chá de Kombucha/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Fermentação , Gluconatos/análise , Gluconatos/metabolismo , Glucuronatos/análise , Glucuronatos/metabolismo , Microbiota , Filogenia , Polifenóis/análise , Polifenóis/metabolismo , Temperatura
5.
Talanta ; 175: 150-157, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28841972

RESUMO

A novel flowing liquid cathode glow discharge (LCGD) was developed as an excitation source of the atomic emission spectrometry (AES) for the determination of Ca and Zn in digested calcium and zinc gluconates oral solution and blood samples, in which the glow discharge is produced between the electrolyte (as cathode) overflowing from a quartz capillary and the needle-like Pt anode. The electron temperature and electron density of LCGD were calculated at different discharge voltages. The discharge stability and parameters affecting the LCGD were investigated in detail. In addition, the measured results of real samples using LCGD-AES were verified by ICP-AES. The results showed that the optimized analytical conditions are pH = 1 HNO3 as supporting electrolyte, 4.5mLmin-1 solution flow rate. The power consumption of LCGD is 43.5-66.0W. The R2 and the RSD ranged from 630 to 680V are 0.9942-0.9995 and 0.49%-2.43%, respectively. The limits of detections (LODs) for Zn and Ca are 0.014-0.033 and 0.011-0.097mgL-1, respectively, which are in good agreement with the closed-type electrolyte cathode atmospheric glow discharge (ELCAD). The obtained results of Ca and Zn in real samples by LCGD-AES are basically consistent with the ICP-AES and reference value. The results suggested that LCGD-AES can provide an alternative analytical method for the detection of metal elements in biological and medical samples.


Assuntos
Cálcio/análise , Gluconatos/análise , Espectrofotometria Atômica/instrumentação , Zinco/análise , Cálcio/sangue , Eletrodos , Desenho de Equipamento , Gluconatos/sangue , Humanos , Limite de Detecção , Soluções Farmacêuticas/análise , Espectrofotometria Atômica/métodos , Temperatura , Zinco/sangue
6.
Chem Biodivers ; 14(9)2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28686351

RESUMO

N-Acetyl-d-glucosamino-1,5-lactone 1 has been reported as a candidate component of the sex pheromone mixture of female blue crabs, Callinectes sapidus, since it is present in the urine of reproductive females and males detect it. Theoretically, 1 can convert to a 1,4-lactone isomer 2 or to the corresponding carboxylic acid, 2-acetamido-2-deoxygluconic acid 3 by hydrolysis in aqueous solution. In this study, we examined the biologically relevant state of equilibrium mixture of 1, 2, and 3 in crab urine using ESI-MS and NMR analyses. The ESI-MS analysis showed that the dominant form of solubilized synthetic 1 is lactone 1 and/or 2, immediately after solubilization in deuterated water, seawater, and phosphate buffer and gradually changing to carboxylic acid 3 which becomes most predominant in phosphate buffer. The NMR analysis showed that synthetic 1 converts to other forms in deuterated water and seawater, and reaches an equilibrium mixture of at least three forms within 24 h. In contrast, 1 converts to a single state of another form in deuterated water with 35 mm phosphate buffer pH 7.6 within 24 h, which is identical to the state in urine with or without phosphate buffer. Thus, we conclude that the molting biomarker sensed by male crabs is 3.


Assuntos
Acetamidas/análise , Braquiúros/crescimento & desenvolvimento , Gluconatos/análise , Muda , Animais , Braquiúros/química , Feminino , Lactonas/análise , Espectroscopia de Ressonância Magnética , Masculino , Atrativos Sexuais/análise , Espectrometria de Massas por Ionização por Electrospray , Urina/química
7.
Food Chem ; 210: 660-70, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27211694

RESUMO

Due to the increase of sugar levels in wine grapes as one of the impacts of climate change, alcohol reduction in wines becomes a major focus of interest. This study combines the use of glucose oxidase and catalase activities with the aim of rapid conversion of glucose into non-fermentable gluconic acid. The H2O2 hydrolysing activity of purified catalase is necessary in order to stabilize glucose oxidase activity. After establishing the adequate enzyme ratio, the procedure was applied in large-scale trials (16L- and 220L-scale) of which one was conducted in a winery under industrial wine making conditions. Both enzyme activity and wine flavour were clearly influenced by the obligatory aeration in the different trials. With the enzyme treatment an alcohol reduction of 2%vol. was achieved after 30h of aeration. However the enzyme treated wines were significantly more acidic and less typical.


Assuntos
Catalase/metabolismo , Etanol/análise , Manipulação de Alimentos/métodos , Glucose Oxidase/metabolismo , Vitis , Vinho/análise , Mudança Climática , Frutas/química , Gluconatos/análise , Glucose/análise , Glucose/metabolismo , Peróxido de Hidrogênio/metabolismo , Paladar
8.
Food Chem ; 192: 268-73, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26304346

RESUMO

An accurate, simple and rapid liquid chromatography mass spectrometry method for the determination of organic acids in peach fruit has been developed. Direct injection and sample clean-up with a mixed-mode sorbent was compared. The best results for the determination of gluconic, oxalic, malic, citric and fumaric acids were obtained with only a simple dilution and filtration step, and nylon filters should be avoided since some organic acids are retained by them. It is the first time that gluconic acid has been determined in peach fruit. Different parameters involved in the separation and detection process have been optimized. Since matrix effects were observed in the peach commodity, organic acids were quantified by the standard addition method. All validation parameters of the method were found acceptable of all organic acids. Finally, the method was successfully applied to the analysis of samples of peach from two cultivars.


Assuntos
Cromatografia Líquida/métodos , Análise de Alimentos/métodos , Frutas/química , Gluconatos/análise , Ácido Oxálico/análise , Prunus persica/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Ácido Cítrico/análise
9.
Anal Bioanal Chem ; 408(3): 785-95, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26597916

RESUMO

An analytical procedure was proposed to estimate bioaccessibility of copper and zinc in Spirulina Pacifica tablets with respect to that of copper and zinc in gluconate complexes. Spirulina is the common name for diet supplements produced primarily from two species of cyanobacteria, namely Arthrospira platensis and Arthrospira maxima. Spirulina tablets are an excellent source of proteins, vitamins and minerals. To obtain information about the bioavailability of these elements, an in vitro bioaccessibility test was performed by application of a two-step protocol which simulated the gastric (pepsin) and intestinal (pancreatin) digestion. The species obtained were investigated by size exclusion chromatography on a chromatograph coupled to a mass spectrometer with inductively coupled plasma (SEC-ICP-MS) and an on-capillary liquid chromatograph coupled to an electrospray mass spectrometer (µ-HPLC-ESI-MS). Both copper and zinc were found to be highly bioaccessible in Spirulina tablets (90-111%) and those containing gluconate complexes (103% for Cu and 62% for Zn). In Spirulina tablets, copper was found to form two types of complex: (1) polar ones with glycine and aspartic acid and (2) more hydrophobic ones containing amino acids with cyclic hydrocarbons (phenylalanine, histidine, proline and tyrosine). Zinc and copper were also proved to form complexes during the digestion process with products of pepsin digestion, but the stability of these complexes is lower than that of the complexes formed in Spirulina. The results proving the involvement of proteins in the enhancement of copper and zinc bioaccessibility will be useful for the design of new copper and zinc supplements.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cobre/metabolismo , Suplementos Nutricionais/análise , Trato Gastrointestinal/metabolismo , Gluconatos/metabolismo , Spirulina/metabolismo , Zinco/metabolismo , Proteínas de Bactérias/análise , Disponibilidade Biológica , Cobre/análise , Digestão , Gluconatos/análise , Humanos , Modelos Biológicos , Espectrometria de Massas por Ionização por Electrospray , Spirulina/química , Zinco/análise
10.
Analyst ; 141(3): 823-6, 2016 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-26700062

RESUMO

The influx of exogenous substrates into cellular reaction cascades on the seconds time scale is directly observable by NMR spectroscopy when using nuclear spin polarization enhancement. Conventional NMR assignment spectra for the identification of reaction intermediates are not applicable in these experiments due to the non-equilibrium nature of the nuclear spin polarization enhancement. We show that ambiguities in the intracellular identification of transient reaction intermediates can be resolved by experimental schemes using site-specific isotope labelling, optimised referencing and response to external perturbations.


Assuntos
Espectroscopia de Ressonância Magnética Nuclear de Carbono-13/métodos , Glucose/química , Radioisótopos de Carbono , Deutério , Gluconatos/análise , Ácidos Glicéricos/análise , Concentração de Íons de Hidrogênio , Saccharomyces cerevisiae/química
11.
Appl Spectrosc ; 69(1): 52-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25506686

RESUMO

A series of metal gluconates (Na(+), K(+), Mg(2+), Ca(2+), Fe(2+), Cu(2+), and Zn(2+)) were investigated by terahertz (THz) time-domain spectroscopy. The absorption coefficients and refractive indices of the samples were obtained in the frequency range of 0.5-2.6 THz. The gluconates showed distinct THz characteristic fingerprints, and the dissimilarities reflect their different structures, hydrogen-bond networks, and molecular interactions. In addition, some common features were observed among these gluconates, and the similarities probably come from the similar carbohydrate anion group. The X-ray powder diffraction measurements of these metal gluconates were performed, and the copper(II) gluconate was found to be amorphous, corresponding to the monotonic increase feature in the THz absorption spectrum. The results suggest that THz spectroscopy is sensitive to molecular structure and physical form. Binary and ternary mixtures of different gluconates were quantitatively analyzed based on the Beer-Lambert law. A chemical map of a tablet containing calcium D-gluconate monohydrate and α-lactose in the polyethylene host was obtained by THz imaging. The study shows that THz technology is a useful tool in pharmaceutical research and quality control applications.


Assuntos
Gluconatos/análise , Gluconatos/química , Espectroscopia Terahertz/métodos
12.
Meat Sci ; 98(2): 158-63, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24954554

RESUMO

This study investigated the effects of binders and glucono-δ-lactone (GdL) on characteristics of pressure-induced (450MPA for 3min) cold-set restructured pork. Isolated soy protein (SP), wheat flour (WF), and κ-carrageenan (CG) were adopted as binders. The addition of binders improved water-binding properties of restructured pork, and the binders diminished the decrease in water binding properties caused by GdL-induced acidification. Pressure-induced restructured pork prepared with binders showed less harder and more cohesive texture than those of the thermal-treated control (TC). The results indicate that pressure-induced cold-set meat restructuring could be achieved when binders and GdL were used in the formulation.


Assuntos
Qualidade dos Alimentos , Gluconatos/análise , Lactonas/análise , Carne/análise , Pressão , Animais , Carragenina/análise , Temperatura Baixa , Cor , Farinha/análise , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Proteínas de Soja/análise , Suínos , Triticum/química , Água/análise
13.
Sensors (Basel) ; 14(6): 11097-109, 2014 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-24960084

RESUMO

In winemaking gluconic acid is an important marker for quantitative evaluation of grape infection by Botrytis cinerea. A screen-printed amperometric bienzymatic sensor for the determination of gluconic acid based on gluconate kinase (GK) and 6-phospho-D-gluconate dehydrogenase (6PGDH) coimmobilized onto polyaniline/poly (2-acrylamido-2-methyl-1-propanesulfonic acid; PANI-PAAMPSA) is reported in this study. The conductive polymer electrodeposed on the working electrode surface allowed the detection of NADH at low potential (0.1 V) with a linear range from 4 × 10(-3) to 1 mM (R2 = 0.99) and a sensitivity of 419.44 nA∙mM(-1). The bienzymatic sensor has been optimized with regard to GK/6PGDH enzymatic unit ratio and ATP/NADP+ molar ratio which resulted equal to 0.33 and 1.2, respectively. Under these conditions a sensitivity of 255.2 nA∙mM(-1), a limit of detection of 5 µM and a Relative Standard Deviation (RSD) of 4.2% (n = 5) have been observed. Finally, the biosensor has been applied for gluconic acid measurements in must grape samples and the matrix effect has been taken into consideration. The results have been compared with those obtained on the same samples with a commercial kit based on a spectrophotometric enzyme assay and were in good agreement, showing the capability of the bienzymatic PANI-PAAMPSA biosensor for gluconic acid measurements and thus for the evaluation of Botrytis cinerea infection in grapes.


Assuntos
Compostos de Anilina/química , Botrytis/metabolismo , Condutometria/instrumentação , Contaminação de Alimentos/análise , Gluconatos/análise , Vitis/química , Vitis/microbiologia , Técnicas Biossensoriais/instrumentação , Botrytis/isolamento & purificação , Desenho de Equipamento , Análise de Falha de Equipamento , Análise de Alimentos/instrumentação
14.
Anal Chim Acta ; 811: 76-80, 2014 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-24456597

RESUMO

The gold nanostar@silica core-shell nanoparticles conjugated with glucose oxidase (GOx) enzyme molecules have been developed as the surface-enhanced Raman scattering (SERS) biosensor for label-free detection of glucose. The surface-immobilized GOx enzyme catalyzes the oxidation of glucose, producing hydrogen peroxide. Under laser excitation, the produced H2O2 molecules near the Au nanostar@silica nanoparticles generate a strong SERS signal, which is used to measure the glucose concentration. The SERS signal of nanostar@silica∼GOx nanoparticle-based sensing assay shows the dynamic response to the glucose concentration range from 25 µM to 25 mM in the aqueous solution with the limit of detection of 16 µM. The sensing assay does not show any interference when glucose co-exists with both ascorbic acid and uric acid. The sensor can be applied to a saliva sample.


Assuntos
Técnicas Biossensoriais , Técnicas de Química Analítica/instrumentação , Glucose/análise , Ouro/química , Nanopartículas Metálicas/química , Dióxido de Silício/química , Análise Espectral Raman , Ácido Ascórbico/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Gluconatos/análise , Glucose Oxidase/química , Glucose Oxidase/metabolismo , Peróxido de Hidrogênio/análise , Oxirredução , Ácido Úrico/química
15.
Talanta ; 113: 113-7, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23708631

RESUMO

A simple ion chromatographic (IC) method for simultaneous determination of glucose, D-gluconic acid (DGA), 2-keto-D-gluconic acid (2-KDG) and 5-keto D-gluconic acid (5-KDG) was proposed, with pulsed amperometric detection (PAD) and column-switching technique. Using this technique, the four compounds were detected simultaneously in a short time with strongly retained compounds (2-KDG and 5-KDG) eluted out prior to weakly retained compounds (glucose and DGA). Under the optimized conditions, the method showed good linearity in the range of 0.01-20 mg L(-1) with determination coefficients (R(2))≥ 99.84%. Low detection limits (LODs) in the range of 0.87-2.59 µg L(-1) and good repeatability (RSD<3%, n=6) were obtained. The proposed method has been successfully applied to the analysis of the four compounds in the fermentation broth, in which Gluconobacter oxydans was used to produce gluconic acids from glucose.


Assuntos
Gluconatos/análise , Glucose/análise , Cromatografia/métodos , Fermentação , Gluconobacter oxydans , Reprodutibilidade dos Testes
16.
J Appl Microbiol ; 114(3): 762-70, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23163324

RESUMO

AIMS: To investigate the interactions between Botrytis cinerea and other moulds during grape withering and postharvest infection to obtain noble-rotten grapes. METHODS AND RESULTS: Strains of Botrytis cinerea, Penicillium expansum, Penicillium crustosum, Aspergillus niger, Fusarium verticilloides and Alternaria alternata, isolated from naturally withered grapes and identified by molecular tools, were used to infect Garganega and Corvina grapes. Individually sterilized berries were infected by a single inoculation of each strain or a simultaneous inoculation of B. cinerea together with one of each of the other moulds. Withering kinetics, glycerol, gluconic acid, total polyphenols, total anthocyanins and laccase activity greatly varied among each strain and also in respect to untreated berries. Successful noble rot settlement was ascertained by an additional infection assay carried out on nonsterilized berries. CONCLUSIONS: The suitability of inducing noble rot infection during grape withering and the improvement of the health of noble-rotten grapes have been demonstrated. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides insights on the effects of mould interactions on withered grape quality. Implementing noble rot induction by postharvest infection in winery drying fruit rooms to standardize the level of grape botrytization is encouraged.


Assuntos
Botrytis/fisiologia , Microbiologia de Alimentos , Fungos/fisiologia , Vitis/microbiologia , Antocianinas/análise , Botrytis/genética , Fungos/isolamento & purificação , Genótipo , Gluconatos/análise , Glicerol/análise , Lacase/metabolismo , Vinho/microbiologia
17.
Planta ; 236(4): 959-73, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22526504

RESUMO

Plants are routinely subjected to multiple environmental stresses that constrain growth. Zinc (Zn) deficiency and high bicarbonate are two examples that co-occur in many soils used for rice production. Here, the utility of metabolomics in diagnosing the effect of each stress alone and in combination on rice root function is demonstrated, with potential stress tolerance indicators identified through the use of contrasting genotypes. Responses to the dual stress of combined Zn deficiency and bicarbonate excess included greater root solute leakage, reduced dry matter production, lower monosaccharide accumulation and increased concentrations of hydrogen peroxide, phenolics, peroxidase and N-rich metabolites in roots. Both hydrogen peroxide concentration and root solute leakage were correlated with higher levels of citrate, allantoin and stigmasterol. Zn stress resulted in lower levels of the tricarboxylic acid (TCA) cycle intermediate succinate and the aromatic amino acid tyrosine. Bicarbonate stress reduced shoot iron (Fe) concentrations, which was reflected by lower Fe-dependent ascorbate peroxidase activity. Bicarbonate stress also favoured the accumulation of the TCA cycle intermediates malate, fumarate and succinate, along with the non-polar amino acid tyrosine. Genotypic differentiation revealed constitutively higher levels of D-gluconate, 2-oxoglutarate and two unidentified compounds in the Zn-efficient line RIL46 than the Zn-inefficient cultivar IR74, suggesting a possible role for these metabolites in overcoming oxidative stress or improving metal re-distribution.


Assuntos
Bicarbonatos/farmacologia , Metaboloma/efeitos dos fármacos , Oryza/metabolismo , Raízes de Plantas/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Zinco/deficiência , Antioxidantes/análise , Antioxidantes/metabolismo , Biomassa , Genótipo , Gluconatos/análise , Gluconatos/metabolismo , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/metabolismo , Ferro/análise , Ferro/metabolismo , Metabolômica , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Oryza/fisiologia , Estresse Oxidativo , Fenótipo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Zinco/análise , Zinco/metabolismo
18.
J Nutr ; 142(2): 233-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22223567

RESUMO

Liver cells respond to copper loading upregulating protective mechanisms. However, to date, except for liver content, there are no good indicators that identify individuals with excess liver copper. We hypothesized that administering high doses of copper to young (5.5 mg Cu · kg⁻¹ . d⁻¹) and adult (7.5 mg Cu · kg⁻¹ . d⁻¹) capuchin monkeys would induce detectable liver damage. Study groups included adult monkeys (2 females, 2 males) 3-3.5 y old at enrollment treated with copper for 36 mo (ACu); age-matched controls (1 female, 3 males) that did not receive additional copper (AC); young monkeys (2 female, 2 males) treated from birth with copper for 36 mo (YCu); and young age-matched controls (2 female, 2 males) that did not receive additional copper (YC). We periodically assessed clinical, blood biochemical, and liver histological indicators and at 36 mo the hepatic mRNA abundance of MT2a, APP, DMT1, CTR1, HGF, TGFß, and NFκΒ only in adult monkeys. After 36 mo, the liver copper concentration was 4-5 times greater in treated monkeys relative to controls. All monkeys remained healthy with normal routine serum biochemical indices and there was no evidence of liver tissue damage. Relative mRNA abundance of HGF, TGFß and NFκB was significantly greater in ACu than in AC monkeys. In conclusion, capuchin monkeys exposed to copper at doses up to 50 times the current upper level enhanced expression of genes related to inflammation and injury without clinical, blood biochemical, or histological evidence of liver damage.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/patologia , Gluconatos/administração & dosagem , Gluconatos/toxicidade , Fígado/metabolismo , Transcrição Genética/fisiologia , Administração Oral , Envelhecimento , Animais , Biomarcadores/metabolismo , Cebus , Relação Dose-Resposta a Droga , Feminino , Gluconatos/análise , Cabelo/química , Fígado/citologia , Fígado/efeitos dos fármacos , Testes de Função Hepática , Masculino , Modelos Animais , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Genética/efeitos dos fármacos
19.
Acta Pol Pharm ; 68(6): 845-51, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22125948

RESUMO

The content of pyridoxine hydrochloride in two-component pharmaceutical preparations containing various magnesium compounds was examined. The UV differentiation spectrophotometry was devised and compared with the reference method of high performance liquid chromatography (HPLC). The analysis of the absorbance spectra (A) and its first (D1) and second (D2) derivatives made it possible to establish the appropriate analytical wavelengths (A: 290 nm; D1: 302 nm; D2: 308 nm). It was proved that spectrum differentiation significantly corrects errors resulting from overlapping background especially when the magnesium hydroaspartate, lactate or magnesium lactogluconate is present together with vitamin B6.


Assuntos
Compostos de Magnésio/análise , Preparações Farmacêuticas/análise , Piridoxina/análise , Espectrofotometria Ultravioleta , Tecnologia Farmacêutica/métodos , Vitamina B 6/análise , Ácido Aspártico/análise , Calibragem , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Gluconatos/análise , Padrões de Referência , Espectrofotometria Ultravioleta/normas , Tecnologia Farmacêutica/normas
20.
Macromol Biosci ; 11(12): 1653-61, 2011 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-22052691

RESUMO

Man-made artificial organic polymers are among the more recent sources of materials used by humans. In medicine, they contribute to applications in surgery, dentistry and pharmacology. Nowadays, innovations in the field of therapeutic polymers rely on novel polymers for specific applications such as guided tissue regeneration, tissue engineering, drug delivery systems, gene transfection, etc. Introducing reactive chemical functions within or along polymer backbones is an attractive route to generate functional polymers for medicine. However, any candidate to effective application must fulfil a number of requirements, grouped under the terms biocompatibility and biofunctionality, to be of real interest and have a future for effective application. Whenever the application requires a therapeutic aid for a limited period of time to help natural healing, bioresorbability is to be taken into account on top of biocompatibility and biofunctionality. This contribution presents the case of "artificial biopolymers" and discusses the potential of some members of the family with respect to temporary therapeutic applications that require functional polymers.


Assuntos
Materiais Biocompatíveis/metabolismo , Biopolímeros/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Regeneração Tecidual Guiada/métodos , Engenharia Tecidual/métodos , Aminoácidos/análise , Aminoácidos/química , Aminoácidos/metabolismo , Materiais Biocompatíveis/análise , Materiais Biocompatíveis/síntese química , Biodegradação Ambiental , Biopolímeros/análise , Biopolímeros/química , Técnicas de Transferência de Genes , Gluconatos/análise , Gluconatos/química , Gluconatos/metabolismo , Humanos , Malatos/análise , Malatos/síntese química , Malatos/metabolismo , Poliaminas/análise , Poliaminas/síntese química , Poliaminas/metabolismo , Polilisina/análogos & derivados , Polilisina/análise , Polilisina/síntese química , Polilisina/metabolismo , Polimerização , Polímeros/análise , Polímeros/síntese química , Polímeros/metabolismo
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