RESUMO
Metal oxide (MOx) gas sensors have attracted considerable attention from both scientific and practical standpoints. Due to their promising characteristics for detecting toxic gases and volatile organic compounds (VOCs) compared with conventional techniques, these devices are expected to play a key role in home and public security, environmental monitoring, chemical quality control, and medicine in the near future. VOCs (e.g., acetone) are blood-borne and found in exhaled human breath as a result of certain diseases or metabolic disorders. Their measurement is considered a promising tool for noninvasive medical diagnosis, for example in diabetic patients. The conventional method for the detection of acetone vapors as a potential biomarker is based on spectrometry. However, the development of MOx-type sensors has made them increasingly attractive from a medical point of view. The objectives of this review are to assess the state of the art of the main MOx-type sensors in the detection of acetone vapors to propose future perspectives and directions that should be carried out to implement this type of sensor in the field of medicine.
Assuntos
Diabetes Mellitus , Compostos Orgânicos Voláteis , Humanos , Acetona/química , Gases/análise , Óxidos/química , Diabetes Mellitus/diagnóstico , Compostos Orgânicos Voláteis/análiseRESUMO
Garlic is a health promoter that has important bioactive compounds. The bioactive extraction is an important step in the analysis of constituents present in plant preparations. The purpose of this study is to optimize the extraction with the best proportion of solvents to obtain total phenolic compounds (TPC) and thiosulfinates (TS) from dried garlic powder, and evaluate the antioxidant activities of the optimized extracts. A statistical mixture simplex axial design was used to evaluate the effect of solvents (water, ethanol, and acetone), as well as mixtures of these solvents, after two ultrasound extraction cycles of 15 min. Results showed that solvent mixtures with a high portion of water and pure water were efficient for TPC and TS recovery through this extraction procedure. According to the regression model computed, the most significant solvent mixtures to obtain high TPC and TS recovery from dried garlic powder are, respectively, the binary mixture with 75% water and 25% acetone and pure water. These optimized extracts presented oxygen radical absorbance capacity. Pure water was better for total antioxidant capacity, and the binary mixture of water-acetone (75:25) was better for DPPH scavenging activity. These optimized extracts can be used for industrial and research applications.
Assuntos
Antioxidantes/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Alho/química , Polifenóis/isolamento & purificação , Acetona/química , Antioxidantes/farmacologia , Etanol/química , Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais/química , Polifenóis/farmacologia , Solventes/química , Água/químicaRESUMO
OBJECTIVE: This work aimed at evaluating the influence of organic solvents and stationary phases in the extraction with glass beads and chromatographic purification of carotenoids, especially torularhodin, from Sporobolomyces ruberrimus. RESULTS: The combinations of acetone:hexane (1:1 v/v) and acetone:ethyl ether (1:1 v/v) yielded 171.74 and 172.19 µg of total carotenoids.g of cells-1, respectively. The first blend resulted in the highest percent of cell lysis of 57.4%. Among different proportions of acetone:hexane, the 9:1 v/v mixture showed a significant difference (p < 0.05), resulting in a recovery of total carotenoids of 221.88 µg.g of cells-1. The purification of carotenoids was made by preparative chromatography and the yield of the silica-containing stationary phase was higher (24 µg torularhodin.g cells-1). The analyses of the purified fractions in thin layer chromatography and high performance liquid chromatography indicated that the purification of carotenoids, especially of torularhodin, was successfully performed. CONCLUSIONS: The combination of polar (acetone) and non-polar solvents (hexane) and the use of silica as stationary phase was efficient to recover and purify torularhodin from the intracellular pigments of Sporobolomyces ruberrimus.
Assuntos
Basidiomycota/química , Carotenoides/isolamento & purificação , Solventes/química , Acetona/química , Carotenoides/química , Cromatografia Líquida , Hexanos/químicaRESUMO
In this study, the novel bifunctional homochiral thiourea-L-prolinamides 1-4, tertiary amino-L-prolinamide 5, and bis-L-prolinamides 6 and 7 were prepared from enantiomerically pure (11R,12R)-11,12-diamino-9,10-dihydro-9,10-ethanoanthracene 8 and (11S,12S)-11,12-diamino-9,10-dihydro-9,10-ethanoanthracene ent-8. Highly enantioselective and diastereoselective aldolic intermolecular reactions (up to 95% enantiomeric excess, 93:7 anti/syn) between aliphatic ketones (20 equiv) and a range of aromatic aldehydes (1 equiv) were successfully carried out in the presence of water (10 equiv) and monochloroacetic acid (10 mol%), solvent-free conditions, at room temperature over 24 h using organocatalysts 1-7 (5 mol%). Stereoselective induction using density functional theory-based methods was consistent with the experimental data.
Assuntos
Aldeídos/química , Prolina/análogos & derivados , Acetona/química , Catálise , Técnicas de Química Sintética , Teoria da Densidade Funcional , Cetonas/química , Estrutura Molecular , Prolina/síntese química , Prolina/química , Solventes , Estereoisomerismo , Tioureia/químicaRESUMO
Triplet carbonyls generated by chemiexcitation are involved in typical photobiochemical processes in the absence of light. Due to their biradical nature, ultraweak light emission and long lifetime, electronically excited triplet species display typical radical reactions such as isomerization, fragmentation, cycloaddition and hydrogen abstraction. In this paper, we report chemical reactions in a set of amino acid residues induced by the isobutanal/horseradish peroxidase (IBAL/HRP) system, a well-known source of excited triplet acetone (Ac3* ). Accordingly, quenching of Ac3* by tryptophan (Trp) unveiled parallel enzyme damage and inactivation, likely explained by scavenging of IBAL tertiary radical reaction intermediate and Ac3* -derived 2-hydroxy-i-propyl radical. Quenching constants were calculated from Stern-Volmer plots, and the structure of radical adducts was revealed by mass spectrometry. As expected, a concurrent Schiff-type adduct was found to be one of the reaction by-products. These findings draw attention to potential structural and functional changes in enzymes involved in the electronic chemiexcitation of their products.
Assuntos
Acetona/análogos & derivados , Peroxidase do Rábano Silvestre/química , Triptofano/química , Acetona/química , Catálise , Eletroforese em Gel de Poliacrilamida , Cinética , OxirreduçãoRESUMO
Precipitation has been widely applied to purification and fractionation of biological macromolecules. Several physical-chemical factors contribute to the destabilization of those solutions, such as the nature of solvent employed, presence of salts, temperature, and concentration of the macromolecule. In the case of charged biopolymers, electrostatic forces are the major contributors to their stability in solution. However, the role of each variable and the exact mechanism of precipitation are not completely understood yet. The aim of this work was to study the precipitation of polyribosyl-ribitol-phosphate (PRP, a linear homogeneous anionic biopolymer) in presence of salts and non-solvents, in order to contribute to the elucidation of its precipitation mechanism. The solvents tested (acetone, ethanol, and isopropanol) presented distinct dielectric constants. The salts used (NH4Cl, NaCl, KCl, MgCl2, and CaCl2) differ by their cations. For each salt concentration, the solvent fraction that induces precipitation was identified and the dielectric constant of the bulk solution was calculated. Precipitation always occurred at well-defined combinations of solvents and salts. At low concentration of monovalent salts, there was a linear correlation between the logarithm of the salt concentration and the inverse of the medium dielectric constant at a defined precipitation point. This is a strong indication that the stability of the solution depends almost exclusively on the balance of electrostatic forces. This behavior is compatible with the DLVO modeling of colloidal systems. When divalent salts were used, low concentrations of the counterion were sufficient to induce precipitation, due to a phenomenon called ionic condensation. Apparently, PRP precipitates when around 90% of its charges are neutralized, value that is similar to charge neutralization for DNA precipitation.
Assuntos
Precipitação Química , Cloretos/química , Modelos Químicos , Polissacarídeos/química , Solventes/química , 2-Propanol/química , Acetona/química , Etanol/química , Concentração de Íons de Hidrogênio , Água/químicaRESUMO
An extraction method based on a multivariate analytical approach was developed for enhancement of the phenolic compounds in cashew nut extracts. The different extractor solvents (acetone, water, ethanol, and methanol) and their binary, ternary, and quaternary combinations were evaluated using a simplex-centroid design and surface response methodology. The special cubic model exhibits no lack of fit and explains 89.2% of the variance. The total phenolic measurements by the Folin-Ciocalteu method revealed the highest values for ethanol (5.93â¯mg GAE g-1) and acetone-methanol-ethanol ternary mixture (5.92â¯mg GAE g-1) extracts. ESI (-)-Q/TOFMS analyses combined with PCA and HCA revealed the presence of fatty acids, phospholipids, and sugars in the ternary mixture cashew extract, while for the ethanol extract only phenolic compounds, such as anacardic acids and derivatives, were found. The proposed approach was adequate to reach the optimal extractor which ethanol, a low-toxicity solvent, enabled the selective extraction of a high content of phenolic compounds from cashew nuts.
Assuntos
Ácidos Anacárdicos/análise , Anacardium/química , Nozes/química , Extração em Fase Sólida/métodos , Acetona/química , Ácidos Anacárdicos/isolamento & purificação , Análise por Conglomerados , Etanol/química , Metanol/química , Análise Multivariada , Análise de Componente Principal , Solventes/química , Espectrometria de Massas por Ionização por Electrospray/métodosRESUMO
We report for the first time the efficient use of accelerated solvent extraction (ASE) for extraction of ricin to analytical purposes, followed by the combined use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and MALDI-TOF MS/MS method. That has provided a fast and unambiguous method of ricin identification for in real cases of forensic investigation of suspected samples. Additionally, MALDI-TOF MS was applied to characterize the presence and the toxic activity of ricin in irradiated samples. Samples containing ricin were subjected to ASE, irradiated with different dosages of gamma radiation, and analyzed by MALDI-TOF MS/MS for verification of the intact protein signal. For identification purposes, samples were previously subjected to SDS-PAGE, for purification and separation of the chains, followed by digestion with trypsin, and analysis by MALDI-TOF MS/MS. The results were confirmed by verification of the amino acid sequences of some selected peptides by MALDI-TOF MS/MS. The samples residual toxic activity was evaluated through incubation with a DNA substrate, to simulate the attack by ricin, followed by MALDI-TOF MS/MS analyses.
Assuntos
Ricina/análise , Acetona/química , Sequência de Aminoácidos , Eletroforese em Gel de Poliacrilamida , Hexanos/química , Peptídeos/análise , Peptídeos/química , Ricina/química , Solventes/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em TandemRESUMO
Kainic acid (KA) has been used to study the neurotoxicity induced after status epilepticus (SE) due to activation of excitatory amino acids with neuronal damage. Medicinal plants can protect against damage caused by KA-induced SE; in particular, organic extracts of Heterotheca inuloides and its metabolite quercetin display antioxidant activity and act as hepatoprotective agents. However, it is unknown whether these properties can protect against the hyperexcitability underlying the damage caused by KA-induced SE. Our aim was to study the protective effects (with regard to behavior and antioxidant activity) of administration of natural products methanolic (ME) and acetonic (AE) extracts and quercetin (Q) from H. inuloides at doses of 30 mg/kg (ME30, AE30, and Q30 groups), 100 mg/kg (ME100, AE100, and Q100 groups), and 300 mg/kg (ME300, AE300, and Q300 groups) against damage in brain regions of male Wistar rats treated with KA. We found dose-dependent effects on behavioral and biochemical studies in the all-natural product groups vs. the control group, with decreases in seizure severity (Racine's scale) and increases in seizure latency (p < 0.05 in the ME100, AE100, Q100, and Q300 groups and p < 0.01 in the AE300 and ME300 groups); on lipid peroxidation and carbonylated proteins in all brain tissues (p < 0.0001); and on GPx, GR, CAT, and SOD activities with all the treatments vs. KA (p ≤ 0.001). In addition, there were strong negative correlations between carbonyl levels and latency in the group treated with KA and in the group treated with methanolic extract in the presence of KA (r = -0.9919, p = 0.0084). This evidence suggests that organic extracts and quercetin from H. inuloides exert anticonvulsant effects via direct scavenging of reactive oxygen species (ROS) and modulation of antioxidant enzyme activity.
Assuntos
Antioxidantes/farmacologia , Asteraceae/química , Comportamento Animal/efeitos dos fármacos , Ácido Caínico/toxicidade , Extratos Vegetais/farmacologia , Quercetina/farmacologia , Estado Epiléptico/tratamento farmacológico , Acetona/química , Animais , Combinação de Medicamentos , Agonistas de Aminoácidos Excitatórios/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Metanol/química , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Estado Epiléptico/induzido quimicamente , Estado Epiléptico/metabolismo , Estado Epiléptico/patologiaRESUMO
The Venturi tube (VT) is an apparatus that produces turbulence which is taken advantage of to produce nanoparticles (NP) by solvent displacement. The objective of this study was to evaluate the potential of this device for preparing NP of poly-ε-caprolactone. Response Surface Methodology was used to determine the effect of the operating conditions and optimization. The NP produced by VT were characterized by Dynamic Light-Scattering to determine their particle size distribution (PS) and polydispersity index (PDI). Results showed that the Reynolds number (Re) has a strong effect on both PS and process yield (PY).The turbulence regime is key to the efficient formation of NP. The optimal conditions for obtaining NP were a polymer concentration of 1.6â¯w/v, a recirculation rate of 4.8â¯L/min, and a stabilizer concentration of 1.1â¯w/v. The predicted response of the PY was 99.7%, with a PS of 333â¯nm, and a PDI of 0.2. Maintaining the same preparation conditions will make it possible to obtain NP using other polymers with similar properties. Our results show that VT is a reproducible and versatile method for manufacturing NP, and so may be a feasible method for industrial-scale nanoprecipitation production.
Assuntos
Acetona/química , Nanopartículas , Poliésteres/química , Solventes/química , Tecnologia Farmacêutica/instrumentação , Composição de Medicamentos , Difusão Dinâmica da Luz , Equipamentos e Provisões , Excipientes/química , Nanotecnologia , Tamanho da Partícula , Tecnologia Farmacêutica/métodosRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: A recent ethnomedical survey on medicinal plants grown in Mexico revealed that Sechium edule (Jacq.) Sw. (Cucurbitaceae) is one of the most valued plant species to treat cardiovascular diseases, including hypertension. Fruits, young leaves, buds, stems, and tuberous roots of the plant are edible. Considering that endothelial dysfunction induced by Angiotensin II plays an important role in the pathogenesis of hypertension and is accompanied by a prooxidative condition, which in turn induces an inflammatory state, vascular remodeling, and tissue damage, and that S. edule has been reported to possess antioxidant, anti-inflammatory and antihypertensive activity, its capability to control endothelial dysfunction was also assessed. AIM OF THE STUDY: To assess in vivo the anti-endothelial dysfunction activity of the acetone fraction (rSe-ACE) of the hydroalcoholic extract from S. edule roots. MATERIALS AND METHODS: Endothelial dysfunction was induced in female C57BL/6â¯J mice by a daily intraperitoneal injection of angiotensin II for 10 weeks. Either rSe-ACE or losartan (as a control) were co-administered with angiotensin II for the same period. Blood pressure was measured at weeks 0, 5, and 10. Kidney extracts were prepared to determine IL1ß, IL4, IL6, IL10, IL17, IFNγ, TNFα, and TGFß levels by ELISA, along with the prooxidative status as assessed by the activity of antioxidant enzymes. The expression of ICAM-1 was evaluated by immunohistochemistry in kidney histological sections. Kidney and hepatic damage, as well as vascular tissue remodeling, were studied. RESULTS: The rSe-ACE fraction administered at a dose of 10â¯mg/kg was able to control hypertension, as well as the prooxidative and proinflammatory status in kidney as efficiently as losartan, returning mice to normotensive levels. Additionally, the fraction was more efficient than losartan to prevent liver and kidney damage. Phytochemical characterization identified cinnamic acid as a major compound, and linoleic, palmitic, and myristic acids as the most abundant non-polar components in the mixture, previously reported to aid in the control of hypertension, inflammation, and oxidative stress, three important components of endothelial dysfunction. IN CONCLUSION: this study demonstrated that rSe-ACE has anti-endothelial dysfunction activity in an experimental model and highlights the role of cinnamic acid and fatty acids in the observed effects.
Assuntos
Cucurbitaceae/química , Endotélio Vascular/efeitos dos fármacos , Extratos Vegetais/farmacologia , Doenças Vasculares/prevenção & controle , Acetona/química , Angiotensina II/administração & dosagem , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Animais , Antioxidantes/metabolismo , Cinamatos/isolamento & purificação , Cinamatos/farmacologia , Modelos Animais de Doenças , Endotélio Vascular/patologia , Ácidos Graxos/isolamento & purificação , Ácidos Graxos/farmacologia , Feminino , Losartan/farmacologia , México , Camundongos , Camundongos Endogâmicos C57BL , Raízes de Plantas , Doenças Vasculares/patologiaRESUMO
This study explored the variation in susceptibility to acetone:water plant extracts between infective larvae (L3) of ten Haemonchus contortus isolates from different geographical origin. The L3 of 10 different isolates were exposed either to the acetone:water extract of a temperate plant (Onobrychis viciifolia) or a tropical plant (Acacia pennatula) and were evaluated with the larval exsheathment inhibition assay (LEIA). The L3 of each isolate were incubated with different concentrations of each extract (0, 25, 50, 100, 200, 400, 600, 800, 1000 and 1200µg/mL of phosphate buffered saline (PBS)). After incubation, the exsheathment process of L3 was induced using a solution with sodium hypochlorite (2%) and sodium chloride (16.5%). The proportion of exsheathed L3 was determined for each concentration at 0, 20, 40 and 60min. Effective concentrations 50% (EC50) and the corresponding 95% confidence intervals (95% CI) were calculated for every isolate with both extracts. Moreover, a resistance ratio (RR) was calculated for each extract to compare isolates, using the most susceptible isolate as the respective reference for each extract. To determine the role of polyphenols on the reported effect, a second set of incubations was made for each isolate and each extract, using the extracts at a concentration of 1200µg/mL PBS with or without polyvinylpolypyrrolidone (PVPP), a polyphenol blocking agent, and controls without extract. The ten different H. contortus isolates showed variation in susceptibility for each of the 2 extracts tested (P<0.05). The EC50 values for A. pennatula extract ranged from 36 to 501µg/mL (RR: 2.11-13.68). Meanwhile, the EC50 values for O. viciifolia extract ranged from 128 to 1003µg/mL (RR: 1.25-7.82). The use of PVPP revealed that polyphenols were responsible for the anthelmintic activity recorded for both extracts. However, tested H. contortus isolates suggested that susceptibility to one polyphenol-rich extract did not determine the susceptibility to the other polyphenol rich extract. The latter result indicated that the different H. contortus isolates varied in their susceptibility to the polyphenols present in each extract evaluated.
Assuntos
Anti-Helmínticos/farmacologia , Haemonchus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Acetona/química , Animais , Anti-Helmínticos/química , Doenças das Cabras/tratamento farmacológico , Doenças das Cabras/parasitologia , Cabras , Hemoncose/tratamento farmacológico , Hemoncose/veterinária , Larva/efeitos dos fármacos , Extratos Vegetais/química , Polifenóis/química , Água/químicaRESUMO
Crassulacean acid metabolism plants have some morphological features, such as succulent and reduced leaves, thick cuticles, and sunken stomata that help them prevent excessive water loss and irradiation. As molecular constituents of these morphological adaptations to xeric environments, succulent plants produce a set of specific compounds such as complex polysaccharides, pigments, waxes, and terpenoids, to name a few, in addition to uncharacterized proteases. Since all these compounds interfere with the analysis of proteins by electrophoretic techniques, preparation of high quality samples from these sources represents a real challenge. The absence of adequate protocols for protein extraction has restrained the study of this class of plants at the molecular level. Here, we present a rapid and reliable protocol that could be accomplished in 1 h and applied to a broad range of plants with reproducible results. We were able to obtain well-resolved SDS/PAGE protein patterns in extracts from different members of the subfamilies Agavoideae (Agave, Yucca, Manfreda, and Furcraea), Nolinoideae (Dasylirion and Beucarnea), and the Cactaceae family. This method is based on the differential solubility of contaminants and proteins in the presence of acetone and pH-altered solutions. We speculate about the role of saponins and high molecular weight carbohydrates to produce electrophoretic-compatible samples. A modification of the basic protocol allowed the analysis of samples by bidimensional electrophoresis (2DE) for proteomic analysis. Furostanol glycoside 26-O-ß-glucosidase (an enzyme involved in steroid saponin synthesis) was successfully identified by mass spectrometry analysis and de novo sequencing of a 2DE spot from an Agave attenuata sample.
Assuntos
Extração Líquido-Líquido/métodos , Folhas de Planta/química , Proteínas de Plantas/isolamento & purificação , Proteômica/métodos , beta-Glucosidase/isolamento & purificação , Acetona/química , Agave/química , Asparagaceae/química , Cactaceae/química , Eletroforese em Gel Bidimensional , Espectrometria de Massas , Solventes/química , Yucca/químicaRESUMO
Background: Jatropha curcas is a wide-spreading latex-rich biodiesel plant with high oil content in seeds that have always been under intense studies. However, studies are lacking on the latex component that is considered rich in proteins with potentially important physiological functions and secondary metabolites that are a promising source for new drugs. The proteomic analysis, which would be the first step to study these substances, was hampered by the presence of interfering components. Phenol extraction and Trichloroacetic acid (TCA)/ acetone extraction, two major plant proteomic isolation methods, were used and compared in this study. Results: We identified 459 proteins from the J. curcas latex proteome using the combination of the two extraction techniques. Although more number of latex proteins were identified by the phenol extraction (401 proteins vs. 123 proteins by the TCA/acetone extraction), only 65 proteins were commonly isolated by both methods. Analysis of the biochemical properties revealed that relatively more number of lower isoelectric point (pI) proteins were isolated by the TCA/acetone method (pI mode: 4.79, 6.51 for phenol). Moreover, GO, COG, and KEGG analyses showed that certain classes/categories/pathways annotated more number of proteins than others, and most of them had proportionally comparable protein counts by both the methods, however, with exemplified exceptions. Conclusions: A large number of proteins were found and exclusively identified by either method, indicating that a better proteome coverage of plant samples in a similar context needs the combined use of multiple isolation methods. In addition, the core biological function of the latex may be uncovered by certain GO, COG, and KEGG classes/categories/pathways that annotate more proteins.
Assuntos
Proteínas de Plantas/análise , Caules de Planta/química , Jatropha , Proteômica/métodos , Látex/química , Acetona/química , Proteínas de Plantas/isolamento & purificação , Cromatografia Líquida , Fenol/química , Espectrometria de Massas por Ionização por Electrospray , Eletroforese em Gel de Poliacrilamida , Espectrometria de Massas em TandemRESUMO
Analysis of pesticide residues in irrigated rice grains is important for food security. In this study, we analyzed accelerated solvent extraction (ASE) conditions for the extraction of thiamethoxam and chlorantraniliprole insecticides from rice hulls, rice bran, and polished rice grains. Several variables, including extraction solvent, extraction temperature, extraction pressure, cell size, static extraction time, and sample concentration, were investigated. The average recoveries of the three matrixes were between 89.7 and 109.7% at the fortification level of 0.75 mg/kg. The optimum ASE operating conditions were acetonitrile (100%) as extraction solvent, extraction temperature of 75°C for rice hulls and 100°C for rice bran and polished rice grains, extraction cell pressure of 10.3 MPa, 22 mL cell size, and two extraction cycles. The total extraction time was approximately 25 min. The extracted volume was evaporated to dryness and the residues were redissolved in 2 mL acetonitrile after 1 min of vortex-shaking. Thiamethoxam and chlorantraniliprole were analyzed by ultra-HPLC with tandem MS. In conclusion, ASE in rice hulls, rice bran, and polished rice grains offers the possibility of a fast and simple method for obtaining a quantitative extraction of the studied pesticides.
Assuntos
Inseticidas/análise , Nitrocompostos/análise , Oryza/química , Oxazinas/análise , Tiazóis/análise , ortoaminobenzoatos/análise , Acetona/química , Acetonitrilas/química , Pressão do Ar , Fracionamento Químico , Cromatografia Líquida de Alta Pressão , Hexanos/química , Limite de Detecção , Metanol/química , Neonicotinoides , Solventes , Espectrometria de Massas em Tandem , Temperatura , TiametoxamRESUMO
A suitable analytical method is required to study the behaviour of florfenicol (FF) and its metabolite florfenicol amine (FFA) in broiler's feathers. An LC-MS/MS method was developed, assessed and intra-laboratory-validated for FF and FFA analyses. We chose cloramphenicol-d5 as an internal standard, acetone as a solvent for the extraction of the analytes and dichloromethane for the clean-up. Through LC-MS/MS analysis, we established a detection limit of 20 µg kg-1, as well as calculated quantification limits of 24.4 and 24.5 µg kg-1 for FF and FFA, respectively. Validation parameters such as linearity, recovery and precision were calculated following Commission Decision 2002/657/EC. For linearity, all standard curves showed a standard coefficient greater than 0.99. Recoveries ranged from 99% to 102% for all studied concentrations. The results show that this analytical method is precise and reliable. For the depletion study, 64 Ross 308 broilers were treated with a therapeutic dosage of 10% FF during 5 consecutive days and their feathers were then analysed. Samples were drawn on days 5, 10, 15, 20, 25, 30, 35 and 40 post-treatments. As for the control group, 16 broiler chickens were raised under the same regime. Throughout the whole study, the detected concentrations of FF and FFA in feather samples were above 100 µg kg-1. In fact, even on day 30 post-treatment we detected concentrations of 221.8 and 28.8 µg kg-1 for FF and FFA, respectively. Based on these results, we conclude that these analytes will persist for a long time and will deplete slowly in feathers of treated broiler chickens.
Assuntos
Antibacterianos/análise , Cromatografia Líquida/normas , Resíduos de Drogas/análise , Plumas/química , Espectrometria de Massas em Tandem/normas , Tianfenicol/análogos & derivados , Acetona/química , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacocinética , Galinhas , Cloranfenicol/análise , Resíduos de Drogas/farmacocinética , Guias como Assunto , Limite de Detecção , Cloreto de Metileno/química , Padrões de Referência , Solventes/química , Tianfenicol/administração & dosagem , Tianfenicol/análise , Tianfenicol/farmacocinéticaRESUMO
The aim of the study was to examine the variation in the in vitro susceptibility of ten Haemonchus contortus isolates from different geographical origins using respective egg hatch assays (EHA) with acetone:water extracts of two tannin containing plants, chimay (Acacia pennatula) and sainfoin (Onobrychis viciifolia). Fresh eggs were incubated in PBS with different concentrations of each extract (0, 600, 1200, 2400, 3600, 5000 and 8000 µg/ml PBS). Additional concentrations were tested for O. viciifolia (75, 100, 200 and 400 µg/ml PBS). Effective concentrations 50% (EC50), with the corresponding 95% confidence interval (95% CI), were calculated for every isolate with both extracts. Moreover, a resistance ratio (RR) was calculated to compare the isolates, using the most susceptible isolate for each extract as the respective reference. A second set of incubations were made using polyvinylpolypyrrolidone (PVPP) (0, 5000 µg/ml, 5000 µg/ml+PVPP) to determine the influence of polyphenols on the AH effect. The proportion of morulated eggs, eggs with L1 larvae failing eclosion (%LFE), and emerged larvae were estimated at different extract concentrations. Data of each isolate was used to calculate the effective concentration 50% (EC50) for each extract. The EC50 of each isolate was used to determine resistance ratio (RR) for the different isolates. For the 2 extracts, a susceptibility variation in egg hatching was observed for the different H. contortus isolates. The EC50 values for A. pennatula ranged from 2203 to 14106 µg (RR from 2.01 to 6.40). The O. viciifolia extract showed higher variability with EC50 values ranging from 104 to 4783 µg (RR from 3.66 to 45.74). The main AH effects of the two extracts tested on the ten isolates consisted in blocking the emergence of L1 larvae (higher% LFE). Additional observations on emerged larvae showed that extract exposure caused alterations in the internal structure, separating the cuticle from the pharynx, bulb and intestinal cells. The use of PVPP revealed that (a) condensed tannins were not the sole plant secondary metabolites responsible for the AH effects, and (b) different H. contortus isolates showed variability in the role of tannins either on the ovicidal effect or the %LFE.
Assuntos
Acacia/química , Fabaceae/química , Haemonchus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Acetona/química , Animais , Antinematódeos/farmacologia , Concentração Inibidora 50 , Óvulo/efeitos dos fármacos , Povidona/análogos & derivados , Povidona/farmacologia , Especificidade da Espécie , Taninos/farmacologia , Água/químicaRESUMO
OBJECTIVE: To evaluate the effect of organic gel solvents (70% acetone and 90% ethanol) and ultrasound in the removal of metallic brackets. MATERIALS AND METHODS: Metallic brackets were bonded with light-cured orthodontic composite (Transbond XT) in 120 human bicuspids and divided into 6 groups for the enamel etch-and-rinse adhesive system (XT) and 6 groups to self-etching system (SEPT) according to pretreatment to removal test: control, 70% acetone, 90% ethanol, ultrasound, 70% acetone+ultrasound, and 90% ethanol+ultrasound. The brackets were subjected to removal by shear testing and Adhesive Remnant Index (ARI) evaluation. Some specimens were prepared and its adhesive interface and etching ability observed by scanning electron microscopy (SEM). RESULTS: Only the factor 'ultrasound' and its interaction with 'adhesive' were detected as a source of variance, with the SEPT/ultrasound showing the lowest shear strength than the other groups. Regardless the factor 'ultrasound', XT showed a higher ARI than SEPT; however, when the solvents were used, no differences were detected between XT and SEPT. CONCLUSION: The organic solvents were not effective in reducing shear bond strength. The etch-and-rinse adhesive system showed a higher and more favorable ARI score than the self-etching primer. The behavior of the organic solvents on ARI showed to be better when associated with the self-etching primer. The ultrasound was effective in reducing the shear bond strength of the self-etching adhesive system but not in affecting the ARI of the adhesive systems.
Assuntos
Cimentos Dentários/química , Descolagem Dentária/métodos , Braquetes Ortodônticos , Solventes/química , Ultrassonografia de Intervenção/métodos , Acetona/química , Adesividade , Dente Pré-Molar , Pesquisa Comparativa da Efetividade , Esmalte Dentário/lesões , Etanol/química , Humanos , Teste de Materiais , Cimentos de Resina/química , Resistência ao CisalhamentoRESUMO
The rose-hip oil holds skin regenerating properties with applications in the dermatological and cosmetic area. Its nanoencapsulation might favor the oil stability and its incorporation into hydrophilic formulations, besides increasing the contact with the skin and prolonging its effect. The aim of the present investigation was to develop suitable rose-hip-oil-loaded nanocapsules, to verify the nanocapsule effect on the UV-induced oxidation of the oil and to obtain topical formulations by the incorporation of the nanocapsules into chitosan gel and film. The rose-hip oil (500 or 600 µL), polymer (Eudragit RS100®, 100 or 200 mg), and acetone (50 or 100 mL) contents were separately varied aiming to obtain an adequate size distribution. The results led to a combination of the factors acetone and oil. The developed formulation showed average diameter of 158 ± 6 nm with low polydispersity, pH of 5.8 ± 0.9, zeta potential of +9.8 ± 1.5 mV, rose-hip oil content of 54 ± 1 µL/mL and tendency to reversible creaming. No differences were observed in the nanocapsules properties after storage. The nanoencapsulation of rose-hip oil decreased the UVA and UVC oxidation of the oil. The chitosan gel and film containing rose-hip-oil-loaded nanocapsules showed suitable properties for cutaneous use. In conclusion, it was possible to successfully obtain rose-hip-oil-loaded nanocapsules and to confirm the nanocapsules effect in protecting the oil from the UV rays. The chitosan gel and film were considered interesting alternatives for incorporating the nanoencapsulated rose-hip oil, combining the advantages of the nanoparticles to the advantages of chitosan.
Assuntos
Hidrogéis/química , Nanocápsulas/química , Nanopartículas/química , Óleos de Plantas/química , Rosa/química , Acetona/química , Resinas Acrílicas/química , Administração Tópica , Química Farmacêutica/métodos , Quitosana/química , Tamanho da Partícula , Polímeros/química , Raios Ultravioleta/efeitos adversosRESUMO
Two sulfonated resorcinarenes were synthesized by reacting C-tetra(butyl) resorcinarene or C-tetra(2-(methylthio)ethyl)resorcinarene with formaldehyde in the presence of sodium sulfite. Their structures were determined via FT-IR, 1H-NMR, 13C-NMR and mass spectrometry. Thermal gravimetric analyses of the derivatives were also carried out and revealed the presence of water molecules in the solid state. The sulfonated product of C-tetra(butyl)resorcinarene was characterized by an X-ray crystal structure determination. The asymmetric unit contains eight molecules of water and two of acetone, and analysis indicated that sulfonated resorcinarene prefers a cone configuration (rccc conformation) in the solid state. In the crystal array, classical hydrogen bond interactions O-H···O and intermolecular contacts were observed. In the crystal packing, a linear array of capsules of sulfonated resorcinarenes was generated for a chain of sodium atoms and sulfonate groups.