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1.
Curr Pharm Biotechnol ; 22(2): 299-304, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32881665

RESUMO

BACKGROUND: The chicken eggshells and their subcrustal membranes are a valuable source of calcium, but they are not further processed but disposed of as waste from the food industry. Chicken eggshells have high content (>95%) of calcium carbonate. Some properties suggest that eggshells may be a promising alternative to the present calcium sources used in the pharmaceutical industry. METHODS: The effect of roasting chicken eggshells with a selected organic acid (citric or fumaric or lactic acid) on microbiological purity, including the presence of fungi and bacteria Salmonella spp., Staphylococcus aureus, Escherichia coli of obtained calcium salts, was investigated. In this study, chicken eggshells were subjected to chemical reactions with organic acids (citric, fumaric or lactic acid) at two different calcium-acid molar ratios (1:1 or 1:3) and the mixture was heat-treated for 1 or 3 hours at a temperature of 100°C or 120°C. RESULTS AND DISCUSSION: It was found that lactic acid was 100% effective against fungi, and the remaining citric and fumaric acids were -50% (regardless of the other examined conditions). The type of acid used has a significant effect on fungal growth inhibition (p<0.05). Fumaric acid and lactic acid will be nearly 100% effective against bacteria (100% fumaric acid and 97% lactic acid effectiveness), regardless of other factors. CONCLUSION: Lactic acid is the most effective against pathogenic flora - fungi and bacteria. The transformation of chicken eggshells into calcium lactate can provide us with sterile calcium salt, free of 100% fungi and 97% of all bacteria.


Assuntos
Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Compostos de Cálcio/síntese química , Ácido Cítrico/síntese química , Casca de Ovo/química , Fumaratos/síntese química , Ácido Láctico/síntese química , Animais , Cálcio , Compostos de Cálcio/isolamento & purificação , Compostos de Cálcio/farmacologia , Galinhas , Ácido Cítrico/isolamento & purificação , Ácido Cítrico/farmacologia , Fumaratos/isolamento & purificação , Fumaratos/farmacologia , Fungos/efeitos dos fármacos , Fungos/fisiologia , Ácido Láctico/isolamento & purificação , Ácido Láctico/farmacologia , Sais
2.
Nutrients ; 12(5)2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32392766

RESUMO

Mumefural is a bioactive compound derived from the processed fruit of Prunus mume Sieb. et Zucc., a traditional health food; however, its safety has not been evaluated. We investigated the toxicity of mumefural through single and repeated oral administration at doses of 1250, 2500, and 5000 mg/kg in Institute of Cancer Research (ICR) mice. The acute toxicity assessment was not associated with adverse effects or death. Similarly, the subacute (four weeks) toxicity assessment did not reveal any mumefural-associated mortality, abnormal organ damage, or altered clinical signs, body weight, food consumption, or hematological parameters. However, albumin/globulin ratio and chloride ion levels were significantly increased in male mice treated with mumefural at ≥ 2500 mg/kg. Female mice exhibited significantly higher levels of chloride, sodium, and potassium ions, at a dose of 5000 mg/kg. Furthermore, the administration of 2500 and 5000 mg/kg mumefural decreased the absolute weight of spleen in male mice. These findings indicated that the approximate lethal dose of mumefural in ICR mice was > 5000 mg/kg. No significant mumefural toxicity was observed at ≤ 5000 mg/kg. Our findings provide a basis for conducting future detailed studies to evaluate reproductive, neurological, genetic, and chronic toxicity of mumefural.


Assuntos
Ácido Cítrico/análogos & derivados , Alimento Funcional/análise , Furanos/isolamento & purificação , Furanos/toxicidade , Prunus/química , Administração Oral , Albuminas/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Cloretos/metabolismo , Ácido Cítrico/administração & dosagem , Ácido Cítrico/isolamento & purificação , Ácido Cítrico/toxicidade , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Análise de Alimentos , Furanos/administração & dosagem , Globulinas/metabolismo , Dose Letal Mediana , Masculino , Camundongos Endogâmicos ICR , Tamanho do Órgão/efeitos dos fármacos , Potássio/metabolismo , Caracteres Sexuais , Sódio/metabolismo , Baço/efeitos dos fármacos
3.
Molecules ; 25(10)2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32422967

RESUMO

Hibiscus species (Malvaceae) have been long used as an antihypertensive folk remedy. The aim of our study was to specify the optimum solvent for extraction of the angiotensin-converting enzyme inhibiting (ACEI) constituents from Hibiscus sabdariffa L. The 80% methanol extract (H2) showed the highest ACEI activity, which exceeds that of the standard captopril (IC50 0.01255 ± 0.00343 and 0.210 ± 0.005 µg/mL, respectively). Additionally, in a comprehensive metabolomics approach, an ultra-performance liquid chromatography (UPLC) coupled to the high resolution tandem mass spectrometry (HRMS) method was used to trace the metabolites from each extraction method. Interestingly, our comprehensive analysis showed that the 80% methanol extract was predominated with secondary metabolites from all classes including flavonoids, anthocyanins, phenolic and organic acids. Among the detected metabolites, phenolic acids such as ferulic and chlorogenic acids, organic acids such as citrate derivatives and flavonoids such as kaempferol have been positively correlated to the antihypertensive potential. These results indicates that these compounds may significantly contribute synergistically to the ACE inhibitory activity of the 80% methanol extract.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Anti-Hipertensivos/química , Hibiscus/química , Extração Líquido-Líquido/métodos , Metanol/química , Peptidil Dipeptidase A/química , Solventes/química , Inibidores da Enzima Conversora de Angiotensina/isolamento & purificação , Anti-Hipertensivos/isolamento & purificação , Ácido Clorogênico/química , Ácido Clorogênico/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Ácido Cítrico/química , Ácido Cítrico/isolamento & purificação , Ácidos Cumáricos/química , Ácidos Cumáricos/isolamento & purificação , Ensaios Enzimáticos , Humanos , Quempferóis/química , Quempferóis/isolamento & purificação , Metaboloma , Peptidil Dipeptidase A/metabolismo , Extratos Vegetais/química , Ácido Quínico/análogos & derivados , Ácido Quínico/química , Ácido Quínico/isolamento & purificação , Metabolismo Secundário/fisiologia , Soluções , Relação Estrutura-Atividade , Espectrometria de Massas em Tandem
4.
Molecules ; 25(2)2020 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-31940896

RESUMO

The aim of this study is to combine advanced GC-MS and metabolite identification in a robust and repeatable technology platform to characterize the metabolome of buffalo milk and mozzarella cheese. The study utilized eleven dairies located in a protected designation of origin (PDO) region and nine dairies located in non-PDO region in Italy. Samples of raw milk (100 mL) and mozzarella cheese (100 g) were obtained from each dairy. A total of 185 metabolites were consistently detected in both milk and mozzarella cheese. The PLS-DA score plots clearly differentiated PDO and non-PDO milk and mozzarella samples. For milk samples, it was possible to divide metabolites into two classes according to region: those with lower concentrations in PDO samples (galactopyranoside, hydroxybuthyric acid, allose, citric acid) and those with lower concentrations in non-PDO samples (talopyranose, pantothenic acid, mannobiose, etc.,). The same was observed for mozzarella samples with the proportion of some metabolites (talopyranose, 2, 3-dihydroxypropyl icosanoate, etc.,) higher in PDO samples while others (tagatose, lactic acid dimer, ribitol, etc.,) higher in non-PDO samples. The findings establish the utility of GC-MS together with mass spectral libraries as a powerful technology platform to determine the authenticity, and create market protection, for "Mozzarella di Bufala Campana."


Assuntos
Queijo/análise , Análise de Alimentos/métodos , Metaboloma , Leite/química , Animais , Búfalos , Ácido Cítrico/isolamento & purificação , Feminino , Galactose/isolamento & purificação , Glucose/isolamento & purificação , Hexoses/isolamento & purificação , Hidroxibutiratos/isolamento & purificação , Itália , Mananas/isolamento & purificação , Ácido Pantotênico/isolamento & purificação
5.
Food Chem ; 277: 70-74, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30502206

RESUMO

The carbon stable isotopic composition (δ13C) is often analyzed to quantify the addition of acidulants to Japanese apricot liqueur, but little is known about the variation in the δ13C values of the main organic acids arising from differences in the ripeness of Japanese apricots. We show that in Japanese apricot liqueur prepared using fruits at different stages of ripeness, the δ13C values of citric acid and malic acid ranged from -25.1‰ to -23.7‰ and from -22.3‰ to -19.7‰, respectively, and the δ13C values decreased as the fruit ripened. The average δ13C value of citric acid from liqueurs was 0.7‰ higher than that from fresh fruits, whereas the δ13C values of malic acid showed no isotope discrimination. The variation in δ13C values of the main organic acids in Japanese apricot liqueurs will help detect acidulant addition and control authenticity.


Assuntos
Ácido Cítrico/análise , Sucos de Frutas e Vegetais/análise , Malatos/análise , Prunus armeniaca/química , Isótopos de Carbono/química , Ácido Cítrico/isolamento & purificação , Frutas/química , Frutas/metabolismo , Marcação por Isótopo , Japão , Malatos/isolamento & purificação , Espectrometria de Massas , Prunus armeniaca/metabolismo , Extração em Fase Sólida
6.
J Sep Sci ; 41(12): 2623-2631, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29573150

RESUMO

A new method for the rapid determination of the metabolites oxalate and citrate in urine samples was based on capillary electrophoresis and capacitively coupled contactless conductivity detection coupled with solid-phase extraction. The detection cell for capacitively coupled contactless conductivity detection was improved with a smaller inner volume (1.5 nL), reduced noise (0.2∼0.5 mV) and better reproducibility and durability. Under optimal conditions, oxalate and citrate can achieve baseline separation within 4 min and the detection limits (S/N = 3) for oxalate and citrate are about 44 and 244 ng/mL, respectively. The overall recovery is between 80.0 and 89.2%. This method offers a better choice for quantitative analysis of strong anions such as oxalate and citrate in diagnostic testing associated with human diseases.


Assuntos
Ácido Cítrico/isolamento & purificação , Ácido Cítrico/urina , Eletroforese Capilar/métodos , Oxalatos/isolamento & purificação , Oxalatos/urina , Extração em Fase Sólida/métodos , Condutividade Elétrica , Eletroforese Capilar/instrumentação , Humanos , Limite de Detecção
7.
Molecules ; 23(2)2018 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-29438299

RESUMO

Plumeria rubra Linn of the family Apocynaceae is locally known in Malaysia as "Kemboja". It has been used by local traditional medicine practitioners for the treatment of arthritis-related disease. The LCMS/MS analysis of the methanol extract of flowers (PR-ME) showed that it contains 3-O-caffeyolquinic acid, 5-caffeoquinic acid, 1,3-dicaffeoquinic acid, chlorogenic acid, citric acid, 3,3-di-O-methylellagic acid, kaempferol-3-O-glucoside, kaempferol-3-rutinoside, kaempferol, quercetin 3-O-α-l-arabinopyranoside, quercetin, quinic acid and rutin. The flower PR-ME contained high amounts of phenol and flavonoid at 184.632 mg GAE/g and 203.2.2 mg QE/g, respectively. It also exhibited the highest DPPH, FRAP, metal chelating, hydrogen peroxide, nitric oxide superoxide radical scavenging activity. Similarly, the XO inhibitory activity in vitro assay possesses the highest inhibition effects at an IC50 = 23.91 µg/mL. There was no mortality or signs of toxicity in rats at a dose of 4 g/kg body weight. The administration of the flower PR-ME at doses of 400 mg/kg to the rats significantly reduced serum uric acid 43.77%. Similarly, the XO activity in the liver was significantly inhibited by flower PR-ME at doses of 400 mg/kg. These results confirm that the flower PR-ME of P. rubra contains active phytochemical compounds as detected in LCMS/MS that contribute to the inhibition of XO activity in vitro and in vivo in reducing acid uric level in serum and simultaneously scavenging the free radical to reduce the oxidative stress.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Apocynaceae/química , Hiperuricemia/tratamento farmacológico , Extratos Vegetais/farmacologia , Ácido Úrico/antagonistas & inibidores , Xantina Oxidase/antagonistas & inibidores , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Benzopiranos/química , Benzopiranos/isolamento & purificação , Compostos de Bifenilo/antagonistas & inibidores , Compostos de Bifenilo/química , Cinamatos/química , Cinamatos/isolamento & purificação , Ácido Cítrico/química , Ácido Cítrico/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Flores/química , Peróxido de Hidrogênio/antagonistas & inibidores , Peróxido de Hidrogênio/metabolismo , Hiperuricemia/sangue , Hiperuricemia/induzido quimicamente , Hiperuricemia/patologia , Quempferóis/química , Quempferóis/isolamento & purificação , Extração Líquido-Líquido/métodos , Masculino , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/metabolismo , Ácido Oxônico/administração & dosagem , Fenóis/química , Fenóis/isolamento & purificação , Picratos/antagonistas & inibidores , Picratos/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Ratos , Ratos Sprague-Dawley , Ácido Úrico/sangue , Xantina Oxidase/metabolismo
8.
Food Chem ; 217: 112-116, 2017 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-27664615

RESUMO

A method for detecting the undeclared addition of acidic ingredients is required to control the authenticity of Japanese apricot liqueur. We developed an analytical procedure that minimizes carbon isotope discrimination for measurement of the δ(13)C values of citric and malic acid isolated from Japanese apricot liqueur. Our results demonstrated that freeze-drying is preferable to nitrogen spray-drying, because it does not significantly affect the δ(13)C values of citric acid and results in smaller isotope discrimination for malic acid. Both 0.1% formic acid and 0.2% phosphoric acid are acceptable HPLC mobile phases for the isolation of citric and malic acid, although the δ(13)C values of malic acid exhibited relatively large variation compared with citric acid following isolation using either mobile phase. The developed procedure allows precise δ(13)C measurements of citric and malic acid isolated from Japanese apricot liqueur.


Assuntos
Bebidas Alcoólicas , Isótopos de Carbono/análise , Ácido Cítrico/isolamento & purificação , Malatos/isolamento & purificação , Prunus armeniaca , Cromatografia Líquida de Alta Pressão/métodos , Dessecação , Prunus armeniaca/química
9.
Metab Eng ; 38: 115-124, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27396355

RESUMO

Yarrowia lipolytica is a biotechnological chassis for the production of a range of products, such as microbial oils and organic acids. However, it is unable to consume xylose, the major pentose in lignocellulosic hydrolysates, which are considered a preferred carbon source for bioprocesses due to their low cost, wide abundance and high sugar content. Here, we engineered Y. lipolytica to metabolize xylose to produce lipids or citric acid. The overexpression of xylose reductase and xylitol dehydrogenase from Scheffersomyces stipitis were necessary but not sufficient to permit growth. The additional overexpression of the endogenous xylulokinase enabled identical growth as the wild type strain in glucose. This mutant was able to produce up to 80g/L of citric acid from xylose. Transferring these modifications to a lipid-overproducing strain boosted the production of lipids from xylose. This is the first step towards a consolidated bioprocess to produce chemicals and fuels from lignocellulosic materials.


Assuntos
Proteínas de Bactérias/metabolismo , Biocombustíveis/microbiologia , Ácido Cítrico/metabolismo , Lipídeos/biossíntese , Engenharia Metabólica/métodos , Xilose/metabolismo , Yarrowia/fisiologia , Proteínas de Bactérias/genética , Vias Biossintéticas/genética , Ácido Cítrico/isolamento & purificação , Melhoramento Genético/métodos , Redes e Vias Metabólicas/genética
10.
J Chromatogr A ; 1458: 63-9, 2016 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-27373374

RESUMO

Bio-based organic acids are promising renewable carbon sources for the chemical industry. However energy-consuming purification processes are used, like distillation or crystallization, to reach high purities required in some applications. That is why preparative chromatography was studied as an alternative separation technique. In a previous work dealing with the purification of lactic, succinic and citric acids, the Langmuir model was insufficient to explain the elution profiles obtained with a strong anionic resin. Consequently the Langmuir model was coupled with a usual ion-exchange model to take into account the retention of their conjugate bases (<2%), which are commonly neglected at low pH (<1.5). Elution simulations with both uptake mechanisms fitted very well with experimental pulse tests. Only two parameters were optimized (equilibrium constant of acid uptake and ion-exchange selectivity coefficient of conjugate base) and their value were coherent with experimental and resin suppliers' data. These results confirmed that the singular tailing and apparent delay observed with succinic and citric acids can be explained by the high affinity of succinate and citrate for resin cationic sites. The model was implemented in a preparative chromatography simulation program in order to optimize operating parameters of our pilot-scale ISMB unit (Improved Simulated Moving Bed). The comparison with experimental ISMB profiles was conclusive.


Assuntos
Resinas de Troca Aniônica/química , Cromatografia por Troca Iônica/métodos , Ácido Cítrico/isolamento & purificação , Ácido Succínico/isolamento & purificação , Ânions/química , Cátions/química , Ácido Cítrico/química , Concentração de Íons de Hidrogênio , Troca Iônica , Modelos Químicos , Ácido Succínico/química
11.
Mar Biotechnol (NY) ; 18(1): 1-14, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26470708

RESUMO

In this study, a pyruvate carboxylase gene (PYC1) from a marine fungus Penicillium rubens I607 was cloned and characterized. ORF of the gene (accession number: KM397349.1) had 3534 bp encoding 1177 amino acids with a molecular weight of 127.531 kDa and a PI of 6.20. The promoter of the gene was located at -1200 bp and contained a TATAA box, several CAAT boxes and a sequence 5'-SYGGRG-3'. The PYC1 deduced from the gene had no signal peptide, was a homotetramer (α4), and had the four functional domains. After expression of the PYC1 gene from the marine fungus in the marine-derived yeast Yarrowia lipolytica SWJ-1b, the transformant PR32 obtained had much higher specific pyruvate carboxylase activity (0.53 U/mg) than Y. lipolytica SWJ-1b (0.07 U/mg), and the PYC1 gene expression (133.8%) and citric acid production (70.2 g/l) by the transformant PR32 were also greatly enhanced compared to those (100 % and 27.3 g/l) by Y. lipolytica SWJ-1b. When glucose concentration in the medium was 60.0 g/l, citric acid (CA) concentration formed by the transformant PR32 was 36.1 g/l, leading to conversion of 62.1% of glucose into CA. During a 10-l fed-batch fermentation, the final concentration of CA was 111.1 ± 1.3 g/l, the yield was 0.93 g/g, the productivity was 0.46 g/l/h, and only 1.72 g/l reducing sugar was left in the fermented medium within 240 h. HPLC analysis showed that most of the fermentation products were CA. However, minor malic acid and other unknown products also existed in the culture.


Assuntos
Ácido Cítrico/metabolismo , Penicillium/enzimologia , Piruvato Carboxilase/química , Piruvato Carboxilase/metabolismo , Yarrowia/genética , Yarrowia/metabolismo , Sequência de Aminoácidos , Ácido Cítrico/isolamento & purificação , Clonagem Molecular/métodos , Melhoramento Genético/métodos , Dados de Sequência Molecular , Penicillium/genética , Piruvato Carboxilase/genética , Proteínas Recombinantes/metabolismo , Regulação para Cima/genética
12.
J Chromatogr Sci ; 53(7): 1217-21, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25713106

RESUMO

Electromembrane extraction (EME) coupled with high-performance liquid chromatography was developed for determination of organic compounds including citric, tartaric and oxalic acid in biological samples. Organic compounds moved from aqueous samples, through a thin layer of 1-octanol immobilized in the pores of a porous hand-made polypropylene tube, and into a basic aqueous acceptor solution present inside the lumen of the tube. This new set-up for EME has a future potential such as simple, cheap and fast sample preparation technique for extraction of organic compounds in various complicated matrices. The pH of acceptor phase, extraction time, voltage, ionic strength, temperature and stirring speed were studied and optimized. Optimum conditions were: the pH of acceptor phase, 7; extraction time, 30 min; voltage, 30 V and stirring speed, 500 rpm. At the optimum conditions, the preconcentration factors of 175-200, the limits of detection of 1.9-3.1 µg L(-1) were obtained for the analytes. The developed procedure was then applied to the extraction and determination of organic acid compounds from biological samples.


Assuntos
Ácido Cítrico/isolamento & purificação , Técnicas Eletroquímicas/instrumentação , Microextração em Fase Líquida/instrumentação , Ácido Oxálico/isolamento & purificação , Tartaratos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Ácido Cítrico/sangue , Ácido Cítrico/urina , Desenho de Equipamento , Humanos , Limite de Detecção , Membranas Artificiais , Compostos Orgânicos , Ácido Oxálico/sangue , Ácido Oxálico/urina , Tartaratos/sangue , Tartaratos/urina
13.
J Zhejiang Univ Sci B ; 15(11): 1006-10, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25367793

RESUMO

The properties of the screened mutants for hyper-production of citric acid induced by carbon ((12)C(6+)) ion beams and X-ray irradiation were investigated in our current study. Among these mutants, mutant H4002 screened from (12)C(6+) ion irradiation had a higher yield of citric acid production than the parental strain in a 250-ml shaking flash. These expanded submerged experiments in a bioreactor were also carried out for mutant H4002. The results showed that (177.7-196.0) g/L citric acid was accumulated by H4002 through exploiting corn meal hydrolysate (containing initial 200.0-235.7 g/L sugar) with the productivity of (2.96-3.27) g/(L∙h). This was especially true when the initial sugar concentration was 210 g/L, and the best economical citric acid production reached (187.5±0.7) g/L with a productivity of 3.13 g/(L∙h). It was observed that mutant H4002 can utilize low-cost corn meal as a feedstock to efficiently produce citric acid. These results imply that the H4002 strain has the industrial production potentiality for citric acid and offers strong competition for the citric acid industry.


Assuntos
Aspergillus niger/genética , Aspergillus niger/metabolismo , Reatores Biológicos/microbiologia , Ácido Cítrico/metabolismo , Melhoramento Genético/métodos , Zea mays/microbiologia , Aspergillus niger/efeitos da radiação , Metabolismo dos Carboidratos/fisiologia , Ácido Cítrico/isolamento & purificação , Hidrólise , Mutação/genética
14.
Appl Biochem Biotechnol ; 174(3): 1032-42, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24869744

RESUMO

In this study, a very thin film of biocompatible gelatin B (GB) fabricated onto indium tin oxide (ITO)-coated glass substrate for electrochemical catalytic activity towards different metabolites has been investigated. The optical and electrochemical properties of bare GB/ITO electrode and with different metabolites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and electrochemical techniques. The optical properties clearly indicate the structural and surface morphological changes on electrode surface. FTIR spectra showed displacement of the IR peaks towards smaller wave numbers, indicating possible existence of hydrogen bonding between the GB and metabolites. The catalytic behaviour of GB/ITO electrode towards ascorbic acid (AA), citric acid (CA), oxalic acid (OA), glucose (Glu), sucrose (Suc), lactose (Lac) and fructose (Fru) has been investigated by cyclic voltammetry (CV). The electrochemical response studies of GB/ITO electrode have been monitored with different metabolites in the range of 10-500 mg/dl. The sensitivity of GB/ITO electrode for AA and OA was found as 0.156 and 0.108 µA/(mg/dl cm(-2)) respectively. The results indicate that the GB/ITO electrode has higher specificity towards the AA and OA. The attractive properties of GB/ITO electrode provide the potential applications in the simultaneous detection of AA and OA. The excellent electrocatalytic behaviour of GB/ITO electrode may be useful towards the construction of electrochemical biosensors.


Assuntos
Técnicas Biossensoriais , Eletrodos , Gelatina/química , Ácido Ascórbico/isolamento & purificação , Ácido Ascórbico/metabolismo , Ácido Cítrico/isolamento & purificação , Ácido Cítrico/metabolismo , Frutose/isolamento & purificação , Frutose/metabolismo , Glucose/isolamento & purificação , Glucose/metabolismo , Lactose/isolamento & purificação , Lactose/metabolismo , Microscopia Eletrônica de Varredura , Ácido Oxálico/isolamento & purificação , Ácido Oxálico/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Sacarose/isolamento & purificação , Sacarose/metabolismo , Compostos de Estanho/química
15.
Int J Biol Macromol ; 58: 253-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23603074

RESUMO

Optimized conditions were obtained by one-factor-at-a-time test (OFAT) and ternary quadratic regression orthogonal composite design (TQROCD) respectively. By pulse electric fields (PEF) technology, the process of eggshell calcium citrate malate (ESCCM), eggshell calcium citrate (ESCC) and eggshells calcium malate (ESCM) were comprehensive compared. The levels of tartrate-resistant acid phosphatase (TRAP) and the bioavailability on mice fed with eggshell calcium citrate malate (ESCCM) treated by pulsed electric field (PEF) were evaluated. Results showed that the rates of calcium dissolution of the different acids studied can be arranged as ESCCM (7.90 mg/mL)>ESCC (7.12 mg/mL)>ESCM (7.08 mg/mL) from highest to lowest rate of dissolution. At the same dose 133.0 mg kg(-1) d(-1), the levels of TRAP in the ESCCM treatment groups were significantly lower than those in ESCM and ESCC (P<0.05). Bone calcium content in the mice fed with ESCCM was generally higher than fed with ESCM and ESCC.


Assuntos
Fosfatase Ácida/metabolismo , Cálcio/administração & dosagem , Ácido Cítrico/administração & dosagem , Isoenzimas/metabolismo , Malatos/administração & dosagem , Absorção , Animais , Disponibilidade Biológica , Cálcio/isolamento & purificação , Cálcio/farmacocinética , Ácido Cítrico/isolamento & purificação , Ácido Cítrico/farmacocinética , Ovos , Eletrólise , Fêmur/metabolismo , Malatos/isolamento & purificação , Malatos/farmacocinética , Masculino , Camundongos , Osteoclastos/enzimologia , Fosfatase Ácida Resistente a Tartarato
16.
Exp Toxicol Pathol ; 65(1-2): 49-53, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21703836

RESUMO

The potential of oral exposure to calcium and magnesium citrate, a natural product obtained from dolomite, to initiate teratogenesis was analyzed in Wistar rats. Animals received calcium and magnesium citrate oral doses of 250, 500 and 1000 mg/kg during the period of gestation from day 6 to 17 post conception. Maternal, embryo and fetal toxicity was evaluated. Calcium and magnesium citrate exposure did not produce maternal toxicity assessed by clinical observations, body weight gain, food intake, hematology, biochemical parameters and necropsy finding. Signs of embryo-fetal toxicity were not observed. Skeletal and visceral malformations were seen occasionally in all drug-treated and control groups. Skeletal and visceral variations were similar in control and drug-treated groups except for incomplete ossification rib. These finding was spontaneous and unrelated to the drug. In conclusion, in this study we found that the oral exposure to rats of up to 1000 mg/kg of calcium and magnesium citrate during organogenesis did not induce significant maternal and embryo-fetal toxicity. The experimentally derived NOAEL for developmental toxicity was 1000 mg/kg.


Assuntos
Citrato de Cálcio/toxicidade , Ácido Cítrico/toxicidade , Exposição Materna/efeitos adversos , Organogênese/efeitos dos fármacos , Compostos Organometálicos/toxicidade , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Animais , Carbonato de Cálcio/química , Citrato de Cálcio/isolamento & purificação , Ácido Cítrico/isolamento & purificação , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Desenvolvimento Embrionário/efeitos dos fármacos , Determinação de Ponto Final , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Magnésio/química , Anormalidades Musculoesqueléticas/induzido quimicamente , Anormalidades Musculoesqueléticas/embriologia , Nível de Efeito Adverso não Observado , Compostos Organometálicos/isolamento & purificação , Gravidez , Ratos , Ratos Wistar , Costelas/anormalidades , Costelas/efeitos dos fármacos , Costelas/embriologia
17.
Nat Prod Res ; 26(21): 2013-9, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22117164

RESUMO

From an endophytic strain of Gliocladium sp. isolated from the Amazonian plant Strychnos cf. toxifera, we obtained the diketopiperazine alkaloid cyclo-(glycyl-L-tyrosyl)-4,4-dimethylallyl ether (1), the steroids ergosterol (2), ergosterol peroxide (3), cerevisterol (4) and the citric acid (5). The AcOEt extract of the fermented broth by Gliocladium sp. showed potent activity against the cancer cell lines MDA-MB435 (human breast cancer cells), HCT-8 (human colorectal cancer cells) and SF-295 (human glioblastoma cancer cells). Compound 1 exhibited a strong antimicrobial activity against Micrococcus luteus at a concentration of 43.4 µM.


Assuntos
Alcaloides/química , Alcaloides/farmacologia , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Dicetopiperazinas/química , Gliocladium/química , Strychnos/microbiologia , Alcaloides/isolamento & purificação , Antineoplásicos/farmacologia , Linhagem Celular Tumoral/efeitos dos fármacos , Ácido Cítrico/isolamento & purificação , Dicetopiperazinas/isolamento & purificação , Relação Dose-Resposta a Droga , Endófitos/química , Ergosterol/análogos & derivados , Ergosterol/isolamento & purificação , Gliocladium/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Micrococcus luteus/efeitos dos fármacos , Estrutura Molecular , Peptídeos Cíclicos/química , Peptídeos Cíclicos/isolamento & purificação , Fitosteróis/isolamento & purificação
18.
J Colloid Interface Sci ; 354(2): 739-48, 2011 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21167495

RESUMO

Unadsorbed emulsifiers affect the physical and chemical behaviour of oil-in-water (O/W) emulsions. A simple methodology to quantify unadsorbed emulsifiers in the aqueous phase of O/W emulsions has been developed. Emulsions were centrifuged and filtered to separate the aqueous phase from the oil droplets and the concentration of unadsorbed emulsifiers in the aqueous phase determined. The quantification of unadsorbed surfactants based on the direct transesterification of their fatty acids was validated for Tween 20, Tween 80, citric acid ester (Citrem), Span 20 and monolauroyl glycerol. To determine unadsorbed proteins, results obtained with Folin-Ciocalteu reagent or UV-spectrophotometry were compared on emulsions stabilized by ß-lactoglobulin (BLG), ß-casein (BCN) or bovine serum albumin (BSA). The first method gave more accurate results especially during aging of emulsions in oxidative conditions. The whole methodology was applied to emulsions stabilized with single or mixed emulsifiers. This approach enables optimization of emulsion formulations and could be useful to follow changes in the levels of unadsorbed emulsifiers during physical or chemical aging processes.


Assuntos
Emulsificantes/isolamento & purificação , Emulsões/química , Óleos/química , Proteínas/isolamento & purificação , Tensoativos/isolamento & purificação , Água/química , Adsorção , Animais , Caseínas/isolamento & purificação , Bovinos , Ácido Cítrico/isolamento & purificação , Lactoglobulinas/isolamento & purificação , Polissorbatos/isolamento & purificação , Soroalbumina Bovina/isolamento & purificação
19.
Biosci Biotechnol Biochem ; 74(3): 573-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20208347

RESUMO

To evaluate the protective effects of fruit juices against D-galactosamine (GalN)-induced liver injury, lyophilized fruit juices (total 12 kinds) were fed to rats for 7 d, and then we evoked liver injury by injecting GalN. The juice of camu-camu (Myrciaria dubia) significantly suppressed GalN-induced liver injury when the magnitude of liver injury was assessed by plasma alanine aminotransferase and aspartate aminotransferase activities, although some other juices (acerola, dragon fruit, shekwasha, and star fruit) also tended to have suppressive effects. An active compound was isolated from camu-camu juice by solvent fractionation and silica gel column chromatography. The structure was determined to be 1-methylmalate. On the other hand, malate, 1,4-dimethylmalate, citrate, and tartrate had no significant effect on GalN-induced liver injury. It is suggested that 1-methylmalate might be a rather specific compound among organic acids and their derivatives in fruit juices in suppressing GalN-induced liver injury.


Assuntos
Bebidas , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Frutas/química , Malatos/uso terapêutico , Myrtaceae/química , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Ácido Cítrico/isolamento & purificação , Galactosamina/toxicidade , Malatos/isolamento & purificação , Masculino , Ratos , Ratos Wistar , Tartaratos/isolamento & purificação
20.
J Environ Sci (China) ; 21(1): 35-40, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19402397

RESUMO

Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes (Fe2+/H2O2, UV/Fe2+/H2O2, and electrolysis/ Fe2+/H2O2) in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light (photo-Fenton) or electron current (electro-Fenton) was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.


Assuntos
Ácido Cítrico/química , Ácido Cítrico/isolamento & purificação , Peróxido de Hidrogênio/química , Ferro/química , Fosfitos/química , Fosfitos/isolamento & purificação , Processos Fotoquímicos , Eletroquímica , Concentração de Íons de Hidrogênio , Oxirredução
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