RESUMEN
The rate of pH decline post - mortem and its interaction with temperature influences the final tenderness of meat, and therefore, the manipulation of the rate of pH decline is a strategy of interest in order to obtain consistent high quality meat. Ultrasound is a potential early post - mortem carcass intervention, which may alter the rate of glycolysis based on its ability to alter enzyme activity. In this study, homogenates (prepared from early post-mortem Longissimus thoracis et lumborum muscle) were subjected to different ultrasound intensities (0 %/60 %/100 % amp) and treatment durations (15/ 30 min). The effect of these treatments on the inherent activity of the glycolytic enzymes was investigated using an in vitro glycolytic buffer model system. It was found that ultrasound treatment intensity and duration had a significant interactive effect on the rate of pH decline, and on reducing sugars and lactic acid concentrations, specifically following the 100 % amp ultrasound for 30 min treatment and between 30 and 240 min incubation. No significant differences in pH or metabolites content were observed between treatments after 1440 min of incubation. No effect of ultrasound intensity or treatment duration was observed on the degradation of glycogen. Under the reported conditions of this trial, it can be concluded that the application of ultrasound has limited potential to have an impact on the glycolytic pathways in bovine muscle.
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Carne , Músculo Esquelético , Animales , Bovinos , Músculo Esquelético/química , Carne/análisis , Ácido Láctico/metabolismo , Glucólisis/fisiología , Mezclas Complejas/análisis , Mezclas Complejas/metabolismo , Concentración de Iones de HidrógenoRESUMEN
This study aimed to explore the antimicrobic potential of mucus samples collected from Cyprinus carpio and identify the specific antimicrobial peptides responsible for its activity. The crude extract was tested against various bacterial and fungal pathogens, and its protein content and profile were analyzed. Purification steps, including gel filtration chromatography, were employed to isolate the most active fraction (peak IV), which was further identified via liquid chromatography and mass spectroscopy. The results revealed varying degrees of antimicrobial activity of the crude extract against different bacterial and fungal strains, with Leclercia adecarboxylata, Candida glabrata, and Candida parapsilosis showing the highest susceptibility. SDS-PAGE analysis demonstrated the existence of multiple low molecular weight protein bands in the crude extract, while fraction IV obtained from gel filtration chromatography exhibited the strongest antimicrobial activity. Peak IV displayed a range of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC) values against the tested pathogens, spanning from 0.038 to 4.960 mg/mL. Further investigation identified the purified peptide derived from peak IV as G-type lysozyme 2, characterized by a molecular weight of 21 kDa. These findings shed light on the existence of a highly effective antimicrobial peptide, G-type lysozyme 2, within the mucus of Cyprinus carpio. This peptide demonstrates notable activity against diverse bacterial and fungal pathogens. The insights from this study enhance our understanding of the fish's antimicrobial defense mechanisms and hold promise for developing novel antimicrobial agents.
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Antiinfecciosos , Carpas , Animales , Muramidasa , Antiinfecciosos/farmacología , Bacterias , Péptidos/farmacología , Mezclas Complejas/análisis , Mezclas Complejas/farmacología , Moco , Pruebas de Sensibilidad MicrobianaRESUMEN
Workers in the waste-processing industry are potentially exposed to high concentrations of biological contaminants, leading to respiratory and digestive problems and skin irritations. However, few data on the exposure of waste collection truck (WCT) drivers are available. The goal was to document the microbial risk of the waste collection truck (WCT) workers while in the vehicle cab. Long-period sampling using the truck air filters (CAF) and short time ambient air sampling in the cab were used. The potential release of microbial particles from CAFs was also investigated since it could contribute to the microbial load of the cabin air. A combination of analytical methods also helped assess the complex mixture of the biological agents. Aspergillus sections Fumigati and Flavi, E. coli, Enterobacter spp. and Legionella spp. were detected in the CAF of trucks collecting three types of waste. The highest levels of bacteria and fungi were found in the CAF from organic WCT. The highest endotoxin concentrations in CAF were 300 EU/cm2. Most of the CAF showed cytotoxic effects on both lung cells and hepatocytes. Only one mycotoxin was detected in a CAF. The maximal concentrations in the ambient WCT air varied according to the type of waste collected. The highest proportion (84%) of the air samples without cytotoxic effects on the lungs cells was for the recyclable material WCTs. The results revealed the potential microbial risk to workers from a complex mixture of bio-contaminants in the cabs of vehicles collecting all types of waste. The sustained cytotoxic effect indicates the potential adverse health-related impact of mixed contaminants (biological and non-biological) for the workers. Overall, this study highlights the benefits of using complementary sampling strategy and combined analytical methods for a the assessment of the microbial risk in work environments and the need to implement protective measures for the workers.Implications: Exposure to microbial agents is a well-known occupational hazard in the waste management sector. No previous study had evaluated the cytotoxicity of ambient air and ventilation filters to document worker exposure to a combination of contaminants during waste collection. This research confirms the usefulness of ventilation filters for long-term characterization of exposure to infectious agents, azole-resistant fungi, coliform bacteria and mycotoxin. Overall, this study highlights the importance of using several sampling and analysis methods for a comprehensive assessment of microbial risk in work environments, as well as the need to implement appropriate protective measures for collection workers.
Complementary sampling strategy and combined analytical methods are helpful in risk assessment.Air filter analysis (long-term sampling) assesses the presence of airborne biological contaminants over a long period.The type of waste collected influences the microbiological hazard of the workers.Waste collection workers are potentially exposed to infectious and mycotoxin-producing fungi.Cytotoxic assays revealed that waste collection workers are potentially.
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Contaminantes Ocupacionales del Aire , Micotoxinas , Exposición Profesional , Humanos , Contaminantes Ocupacionales del Aire/análisis , Exposición Profesional/análisis , Escherichia coli , Hongos , Micotoxinas/análisis , Pulmón , Vehículos a Motor , Mezclas Complejas/análisis , Microbiología del AireRESUMEN
A new amide tricholomine C was isolated from the dried fruiting bodies of Tricholoma bakamatsutake. Its structure was identified by a combination of nuclear magnetic resonance spectroscopic analysis and electronic circular dichroism (ECD) calculations. The ethyl alcohol crude extract and tricholomines A-C from T. bakamatsutake were evaluated for neuroprotective activities. Of these substances, the crude extract showed weak neurite outgrowth-promoting activity in rat pheochromocytoma (PC12) cells, as well as weak inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE).
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Acetilcolinesterasa , Butirilcolinesterasa , Ratas , Animales , Butirilcolinesterasa/análisis , Acetilcolinesterasa/análisis , Amidas/farmacología , Amidas/análisis , Cuerpos Fructíferos de los Hongos/química , Mezclas Complejas/análisisAsunto(s)
Carbono , Contaminantes Ambientales , Contaminación Ambiental , Sector de Atención de Salud , Contaminantes Atmosféricos/efectos adversos , Contaminantes Atmosféricos/análisis , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , Contaminación del Aire/prevención & control , Carbono/efectos adversos , Carbono/análisis , Mezclas Complejas/efectos adversos , Mezclas Complejas/análisis , Contaminantes Ambientales/efectos adversos , Contaminantes Ambientales/análisis , Contaminación Ambiental/efectos adversos , Contaminación Ambiental/análisis , Contaminación Ambiental/prevención & control , Sector de Atención de Salud/organización & administración , Sector de Atención de Salud/normas , Guías como AsuntoRESUMEN
A COVID-19 surgiu de forma repentina, acometendo milhões de pessoas e causando muitas mortes no mundo todo. Diante disso, torna-se necessário a busca de substâncias bioativas com propriedades antivirais. No Brasil, a espécie Tetradenia riparia foi inserida como planta ornamental exótica, com aroma intenso e agradável, sendo cultivada em parques, jardins, residenciais e hortos. O objetivo deste estudo foi identificar compostos presentes no extrato bruto das folhas de Tetradenia riparia com interesse antiviral. O extrato bruto das folhas secas foi obtido por maceração dinâmica por esgotamento do solvente e após, concentrado em evaporador rotativo. A composição química do extrato bruto foi analisada por cromatografia líquida de ultra eficiência acoplada à espectrometria de massas de alta resolução (UHPLC-ESI/qTOF). Foram identificados 31 compostos que foram investigados por meio de levantamento bibliográfico quanto ao seu potencial anti- SARS-CoV-2. Os compostos rosmanol, procianidina, cianidina, betulina, ácido betulínico e o ácido sagerínico, apresentaram potencial atividade antiviral sobre o SARS-CoV-2. Esta investigação é promissora, indicando possivelmente que no extrato bruto das folhas de T. ripária existem compostos que podem combater o SARS-CoV-2. Neste sentido, estudos de ancoramento molecular (docking) e análises in silico sobre a proteína Mpro do vírus devem ser realizadas corroborando desta forma a ação dos compostos identificados.
COVID-19 appeared suddenly, affecting millions of people and causing many deaths worldwide. Therefore, it is necessary to search for bioactive substances with antiviral properties. In Brazil, Tetradenia riparia was inserted as an exotic ornamental plant, with an intense and pleasant aroma, cultivated in parks, residential and vegetable gardens. This study aimed to identify compounds present in the crude extract of Tetradenia riparia leaves with antiviral interest. The crude extract of the dried leaves was obtained by dynamic maceration with solvent exhaustion and then concentrated in a rotary evaporator. The chemical composition of the crude extract was analyzed by ultra- performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC- ESI/qTOF). We identified 31 compounds investigated through a literature review for their anti- SARS-CoV-2 potential. The compounds rosmanol, procyanidin, cyanidin, betulin, betulinic acid, and sagerinic acid showed potential antiviral activity against SARS-CoV-2. Therefore, this investigation is promising, possibly indicating that in the crude extract of T. riparia leaves, there are compounds that can fight SARS-CoV-2. In this sense, molecular docking studies and in silico analyzes on the virus Mpro protein must be carried out, thus corroborating the action of the identified compounds.
SARS-CoV-19 ha aparecido repentinamente, afectando a millones de personas y causando muchas muertes en todo el mundo. Por ello, se hace necesaria la búsqueda de sustancias bioactivas con propiedades antivirales. En Brasil, la especie Tetradenia riparia ha sido introducida como planta ornamental exótica, con un aroma intenso y agradable, siendo cultivada en parques, jardines, residencias y centros de jardinería. El objetivo de este estudio fue identificar los compuestos presentes en el extracto crudo de las hojas de Tetradenia riparia con interés antiviral. El extracto crudo de las hojas secas se obtuvo por maceración dinámica por agotamiento del disolvente y después, se concentró en el evaporador rotatorio. La composición química del extracto crudo se analizó mediante cromatografía líquida de ultra rendimiento acoplada a espectrometría de masas de alto rendimiento (UHPLC-ESI/qTOF). Se identificaron 31 compuestos y se investigó su potencial anti-SARS-CoV-2 mediante un estudio bibliográfico. Los compuestos rosmanol, procianidina, cianidina, betulina, ácido betulínico y ácido sagerínico, mostraron una potencial actividad antiviral sobre el SARS-CoV-2. Esta investigación es prometedora, pues posiblemente indica que en el extracto crudo de las hojas de T. riparia hay compuestos que pueden combatir el SARS-CoV-2. En este sentido, deben realizarse estudios de docking y análisis in silico sobre la proteína Mpro del virus para corroborar la acción de los compuestos identificados.
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Antivirales/análisis , Hojas de la Planta , Lamiaceae/toxicidad , Mezclas Complejas/análisis , SARS-CoV-2/efectos de los fármacos , Cromatografía Liquida/instrumentación , Mezclas Complejas , Fitoquímicos/análisis , Ácido Betulínico/análisisRESUMEN
Ion mobility-mass spectrometry (IM-MS) is a combination of ion mobility separation and mass spectrometry technologies. In IM-MS, analytes are ionized by the ion source to form gas-phase ions, which are then rapidly separated using ion mobility based on their mobility difference, under the influence of both neutral buffer gas and an electric field, and then traversed and detected using mass spectrometry, which can separate ions based on mass-to-charge ratio. Furthermore, IM-MS could provide not only mass-to-charge ratio parameters like MS1 and MS2 spectra but also new structural information for component identification like collision cross-section values, drift time, arrival time, compensation voltage, and so on, which can be employed to resolve complex chemical components, especially indistinguishable isomers using mass spectrometry alone. In recent years, with the development of IM-MS technologies, IM-MS has become more widely employed in chemical analysis in traditional Chinese medicines (TCMs). Firstly, IM-MS was been successfully used in the separation of complex TCMs complex extract from interfering isobaric species. Secondly, IM-MS also offers new types of MS/MS fragmentation modes, and the combination of IM separation and fragmentation modes enables the acquisition of more specific and detailed fragment ion spectra. Thirdly, the collision cross-section is introduced by IM-MS, which is a unique physicochemical property of a component. Related data post-processing strategies based on experimentally derived collision cross-section values have been continuously developed in recent years to make full use of the collision cross-section values, these data post-processing strategies include collision cross-section database matching, theoretical collision cross-section values matching, machine-learning-based collision cross-section values prediction matching, mass-to-charge ratio versus collision cross-section correlation trend lines and so on. In doing so, these diverse strategies can greatly enhance the reliability and accuracy of the structural annotation of TCM compounds. This review primarily briefly introduces the major types and basic principles of IM-MS. The applications of IM-MS in TCM chemical analysis are highlighted in this study. The current applications of IM-MS in improving TCM chemical component separation are summarized, followed by a discussion of several strategies for enhancing separation selectivity. This review also offers some new fragmentation modes, novel data acquisition approaches, and collision cross-section data post-processing strategies applied in TCM qualitative analysis. Finally, the prospect of IM-MS applied in TCM chemical analysis is also discussed. This review provides approaches and ideas for future IM-MS research on TCM's chemical analysis.
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Mezclas Complejas , Espectrometría de Masas en Tándem , China , Mezclas Complejas/análisis , Cromatografía de Gases y Espectrometría de Masas , Iones/análisis , Iones/química , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/métodosRESUMEN
Chlorinated paraffins (CPs) are complex mixtures consisting of various C homologues (nC ≈ 10-30) and Cl homologues (nCl ≈ 2-20). Technical CP mixtures are produced on a large scale (>106 t/y) and are widely used such as plasticizers in plastic and coolants in metalwork. Since 2017, short-chain CPs (C10-C13) are classified as persistent organic pollutants (POPs) by the Stockholm Convention but longer-chain CPs are not regulated. Analysis of technical CP mixtures is challenging because they consist of hundreds of homologues and millions of constitutional isomers and stereoisomers. Furthermore, such mixtures can also contain byproducts and transformation products such as chlorinated olefins (COs). We applied a liquid-chromatography method coupled to an atmospheric pressure chemical ionization technique with a high-resolution mass detector (LC-APCI-Orbitrap-MS) to study CP and CO homologues in two plastic materials. Respective mass spectra can contain up to 23,000 signals from 1320 different C-Cl homologue classes. The R-based automated spectra evaluation routine (RASER) was developed to efficiently search for characteristic ions in these complex mass spectra. With it, the time needed to evaluate such spectra was reduced from weeks to hours, compared to manual data evaluation. Unique sets of homologue distributions could be obtained from the two plastic materials. CPs were found together with their transformation products, the chlorinated mono-olefins (COs), di-olefins (CdiOs), and tri-olefins (CtriOs) in both plastic materials. Based on these examples, it can be shown that RASER is an efficient and selective tool for evaluating high-resolution mass spectra of CP mixtures containing hundreds of homologues.
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Hidrocarburos Clorados , Parafina , Alquenos/análisis , China , Mezclas Complejas/análisis , Monitoreo del Ambiente/métodos , Hidrocarburos Clorados/análisis , Parafina/análisis , Parafina/química , Contaminantes Orgánicos Persistentes , Plastificantes/análisis , PlásticosRESUMEN
2D NMR is extensively used in many different fields, and its potential for the study of complex biochemical or chemical mixtures has been widely demonstrated. 2D NMR gives the ability to resolve peaks that overlap in 1D spectra, while providing both structural and quantitative information. However, complex mixtures are often analysed in situations where the data acquisition time is a crucial limitation, due to an ongoing chemical reaction or a moving sample from a hyphenated technique, or to the high-throughput requirement associated with large sample collections. Among the great diversity of available fast 2D methods, ultrafast (or single-scan) 2D NMR is probably the most general and versatile approach for complex mixture analysis. Indeed, ultrafast NMR has undergone an impressive number of methodological developments that have helped turn it into an efficient analytical tool, and numerous applications to the analysis of mixtures have been reported. This review first summarizes the main concepts, features and practical limitations of ultrafast 2D NMR, as well as the methodological developments that improved its analytical potential. Then, a detailed description of the main applications of ultrafast 2D NMR to mixture analysis is given. The two major application fields of ultrafast 2D NMR are first covered, i.e., reaction/process monitoring and metabolomics. Then, the potential of ultrafast 2D NMR for the analysis of hyperpolarized mixtures is described, as well as recent developments in oriented media. This review focuses on high-resolution liquid-state 2D experiments (including benchtop NMR) that include at least one spectroscopic dimension (i.e., 2D spectroscopy and DOSY) but does not cover in depth applications without spectral resolution and/or in inhomogeneous fields.
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Mezclas Complejas , Imagen por Resonancia Magnética , Mezclas Complejas/análisis , Espectroscopía de Resonancia Magnética/métodos , Metabolómica , Manejo de EspecímenesRESUMEN
RATIONALE: Chlorinated paraffins (CPs) are a group of anthropogenic pollutants that consist of complex mixtures of polychlorinated n-alkanes of different chain lengths (~C10 to C30 ). Persistence, bioaccumulation, toxicity, and long-range transport of short-chain chlorinated paraffins (SCCPs, C10 - to C13 -CPs) have prompted their classification as persistent organic pollutants (POPs) by the Stockholm Convention in 2017. Due to the varying chain lengths and chlorination degrees, quantification of SCCPs and medium-chain chlorinated paraffins (MCCPs, C14 - to C17 ) using gas chromatography coupled with electron capture negative ion mass spectrometry in selected ion monitoring mode (GC/ECNI-MS-SIM) is not only challenging but also very time consuming. In particular, up to eight GC runs per sample are required for the comprehensive GC/ECNI-MS-SIM quantification of SCCPs and MCCPs. These efforts are high especially if the samples do not contain CPs above the limit of detection (LOD), subsequently. METHODS: We developed a semi-quantitative and sensitive method for the examination of SCCPs and MCCPs in one GC run. This GC/ECNI-MS-SIM screening method was based on the recording of Cl- (m/z 35 and 37), Cl2 - (m/z 70 and 72), and HCl2 - (m/z 71 and 73) isotope ions and evaluation of the ratios between them. RESULTS: Correctness of the results of the screening method was verified by analysis of edible oils with and without CPs, CP standards, as well as a technical CP mixture. Polychlorinated biphenyls (PCBs) and other polyhalogenated aromatic compounds, as well as brominated flame retardants, do not form all of the fragment ions analyzed by the screening method. CONCLUSIONS: After the screening, only CP-positive samples may need to be measured in detail. Measurement time will already be gained in the case of ~10% samples without CPs.
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Contaminantes Ambientales , Retardadores de Llama , Hidrocarburos Clorados , Bifenilos Policlorados , Alcanos/análisis , Mezclas Complejas/análisis , Electrones , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Retardadores de Llama/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Hidrocarburos Clorados/análisis , Hidrocarburos Clorados/química , Iones/análisis , Espectrometría de Masas , Aceites , Parafina/análisis , Parafina/química , Contaminantes Orgánicos Persistentes , Bifenilos Policlorados/análisisRESUMEN
This work studied the potential biotechnological applications of a naviculoid diatom (IMA053) and a green microalga (Tetraselmis marina IMA043) isolated from the North Adriatic Sea. Water, methanol, and dichloromethane (DCM) extracts were prepared from microalgae biomass and evaluated for total phenolic content (TPC) and in vitro antioxidant properties. Biomass was profiled for fatty acid methyl esters (FAME) composition. The DCM extracts had the highest levels of total phenolics, with values of 40.58 and 86.14 mg GAE/g dry weight (DW in IMA053 and IMA043, respectively). The DCM extracts had a higher radical scavenging activity (RSA) than the water and methanol ones, especially those from IMA043, with RSAs of 99.65% toward 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt (ABTS) at 10 mg/mL, and of 103.43% against 2,2-diphenyl-1-picrylhydrazyl (DPPH) at 5 mg/mL. The DCM extract of IMA053 displayed relevant copper chelating properties (67.48% at 10 mg/mL), while the highest iron chelating activity was observed in the water extract of the same species (92.05% at 10 mg/mL). Both strains presented a high proportion of saturated (SFA) and monounsaturated (MUFA) fatty acids. The results suggested that these microalgae could be further explored as sources of natural antioxidants for the pharmaceutical and food industry and as feedstock for biofuel production.
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Antioxidantes/análisis , Chlorophyta/química , Diatomeas/química , Ésteres/análisis , Ácidos Grasos/análisis , Microalgas/química , Fenoles/análisis , Antioxidantes/química , Benzotiazoles/química , Compuestos de Bifenilo/química , Chlorophyta/genética , Mezclas Complejas/análisis , Mezclas Complejas/química , Cobre/química , Diatomeas/genética , Genoma , Hierro/química , Microalgas/genética , Océanos y Mares , Oxidación-Reducción , Fenoles/química , Filogenia , Picratos/química , Ácidos Sulfónicos/químicaRESUMEN
To elucidate the interactions between crude drugs in Kampo medicines (traditional Japanese medicines), it is important to determine the content of the constituents in a cost-effective and simple manner. In this study, we quantified the constituents in crude drug extracts using thin-layer chromatography (TLC), an inexpensive and simple analytical method, to elucidate the chemical interactions between crude drugs. We focused on five crude drugs, for which quantitative high-performance liquid chromatography (HPLC) methods are stipulated in the Japanese Pharmacopoeia XVIII (JP XVIII) and compared the analytical data of HPLC and TLC, confirming that the TLC results corresponded with the HPLC data and satisfied the criteria of JP XVIII. (Z)-ligustilide, a major constituent in Japanese Angelica Root, for which a method of quantification has not been stipulated in JP XVIII, was also quantitatively analyzed using HPLC and TLC. Furthermore, Japanese Angelica Root was combined with 26 crude drugs to observe the variation in the (Z)-ligustilide content from each combination by TLC. The results revealed that combinations with Phellodendron Bark, Citrus Unshiu Peel, Scutellaria Root, Coptis Rhizome, Gardenia Fruit, and Peony Root increased the (Z)-ligustilide content. Quantifying the constituents in crude drug extracts using the inexpensive and simple TLC method can contribute to elucidating interactions between crude drugs in Kampo medicines, as proposed by the herbal-pair theory.
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Cromatografía en Capa Delgada/métodos , Mezclas Complejas/análisis , Mezclas Complejas/metabolismo , Interacciones Farmacológicas , Medicamentos Herbarios Chinos/química , Medicina Kampo , Fitoquímicos/metabolismo , Extractos Vegetales/metabolismo , Fitoquímicos/análisis , Extractos Vegetales/análisis , Raíces de Plantas/químicaRESUMEN
The pomace of sea buckthorn berries is usually discarded when transforming into nonalcoholic or alcoholic beverages, jellies, jams, juices, candies and dairy products. Here, we established a promising approach for one step separation of five flavonoids from the waste pomace of sea buckthorn berries through counter-current chromatography. The crude extract of waste pomace of sea buckthorn berries after juicing was injected into counter-current chromatography with hexane/ethyl acetate/ethanol/water (v/v/v/v, 5:7:5:7) as the solvent system. As a result, five flavonoids, including quercetin, laricitrin, isorhamnetin-7-O-rhamnoside, kaempferol and isorhamnetin, were obtained in a single step separation. Our finding showed that ethanol is a good substitute for methanol to regulate the partition coefficient in hexane/ethyl acetate/ methanol/water system. This study provided a significant measure to utilize the waste pomace of Sea buckthorn berries.
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Hippophae , Cromatografía Líquida de Alta Presión/métodos , Mezclas Complejas/análisis , Distribución en Contracorriente , Etanol , Flavonoides/análisis , Frutas/química , Hexanos , Hippophae/química , Metanol , Agua/análisisRESUMEN
The Threshold of Toxicological Concern (TTC) has been applied to assess chemical safety for use, particularly in the food safety area. Although the TTC was developed for application to an individual chemical structure, more recently this concept has been suggested for the assessment of combined exposures to multiple chemicals. This study evaluated the potential for applying the TTC to a specific type of co-exposure, that of a complex substance of variable composition which contains multiple constituents, following the World Health Organization/International Programme on Chemical Safety framework for risk assessment of combined exposure to multiple chemicals. The results indicated that the TTC threshold was lower (i.e., more conservative) than regulatory thresholds derived for the same substance or even its most toxic constituent, providing assurance that the TTC could meet the requirements for a conservative screening process. This case study indicates that the TTC concept can be a useful tool to screen for potential risks from complex substances, with the consideration of additional aspects such as variability in chemical constituents and their relative proportions within the substance.
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Mezclas Complejas/análisis , Mezclas Complejas/toxicidad , Relación Dosis-Respuesta a Droga , Hexanos/análisis , Hexanos/toxicidad , Nivel sin Efectos Adversos Observados , Medición de RiesgoRESUMEN
Fast mixing of small volumes of solutions in microfluidic devices is essential for an accurate control and observation of the dynamics of a reaction in biological or chemical studies. It is often, however, a challenging task, as the Reynolds number (Re) in microscopic devices is typically < 100. In this report, we detail a novel mixer based on the "staggered herring bone" (SHB) pattern and "split-recombination" strategies with an optimized geometry, the periodic rotation of the flow structure can be controlled and recombined in a way that the vortices and phase shifts of the flow induce intertwined lamellar structures, thus increasing the contact surface and enhancing mixing. The optimization improves the mixing while using a low flow rate, hence a small volume for mixing and moderate pressure drops. The performances of the patterns were first simulated using COMSOL Multiphysics under different operating conditions. The simulation indicates that at very low flow rate (1-12 µL·min-1) and Re (3.3-40), as well as a very small working volume (~ 3 nL), a very good mixing (~ 98%) can be achieved in the ms time range (4.5-78 ms). The most promising design was then visualized experimentally, showing results that are consistent with the outcomes of the simulations. Importantly, the devices were fabricated using a classical soft-lithography method, as opposed to additive manufacturing often used to generate complex mixing structures. This new device minimizes the sample consumption and could therefore be applied for studies using precious samples.
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Mezclas Complejas/análisis , Simulación por Computador , Dispositivos Laboratorio en un Chip/normas , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas Analíticas Microfluídicas/métodos , Diseño de Equipo , HumanosRESUMEN
A dual-mode aptasensor using colorimetry and microfluidic chip (MC) together with stir bar sorptive extraction (SBSE) has been developed for firstly qualifying samples contaminated with Vibrio parahaemolyticus (V.P) and Salmonella typhimurium (S.T), then precisely determine both of them in positive samples. For this purpose, the aptamer-streptavidin encoded probes (Apt-SAEs) corresponding to different bacteria were prepared in advance. Then, a stir bar modified with 4-mercaptophenylboronic acid (MPBA) was made to extract bacteria together with Apt-SAE probes. The binding event of aptamer and target triggered the formation of two sandwich structures containing Apt-SAE, V.P or S.T. The concentration of bacteria could be enriched by 1000 times within 15 min to avoid long-time enrichment process. Finally, the stir bar was immersed in the 3,3',5,5'-Tetramethylbenzidine (TMB)-H2O2 solution for color development. The color could be observed by naked eyes to judge whether the analytes were present. The colorless samples were judged to be negative. For the positive samples, the adsorbed encoded probes corresponding to different bacteria would be eluted from the stir bar and rapidly analyzed by the MC. Under the optimized conditions, 100 CFU/mL of V.P or S.T or both of them could be observed by colorimetry and 35 CFU/mL of them could be detected (S/N = 3) by the MC. The assay has significant application value for on-site screening and multiple detection of food-borne pathogenic bacteria.
Asunto(s)
Mezclas Complejas/análisis , Oro/química , Nanopartículas del Metal/química , Salmonella typhimurium/química , Vibrio parahaemolyticus/química , Adsorción , Bencidinas/química , Técnicas Biosensibles , Ácidos Borónicos/química , Colorimetría , Peróxido de Hidrógeno/química , Límite de Detección , Microfluídica , Compuestos de Sulfhidrilo/químicaRESUMEN
We intended to reformulate an existing platelet-derived wound healing formula to target each phase of the healing wound with the appropriate phase-specific molecules. A decreased perfusion of the skin, often associated with conditions such as thalassemia, sickle cell disease, diabetes mellitus, and chronic vascular disease, is the most common etiology of cutaneous ulcers and chronic wounds. We had previously shown that a PDWHF topically applied to a chronic nonhealing ulcer of a ß-thalassemia homozygote stimulated and accelerated closure of the wound. The PDWHF was prepared from a pooled platelet concentrate of a matching blood group, consisting of a combination of platelet α-granule-derived factors. Processing of the apheresis-pooled platelets yielded various amounts of proteins (3.36 g/mL ± 0.25 (SD) (N = 10)) by the better lysis buffer method. Immunoglobulin G was found to be the most abundant α-granule-secreted protein. Equally broad quantities of the IgG (10.76 ± 12.66% (SD) (N = 10)) and IgG/albumin ratios (0.6 ± 0.4 (SD) (N = 10)) were quantified. We have developed a method using a reformulated lysis buffer followed by size exclusion chromatography and affinity chromatography to extract, identify, quantify, and purify IgG from activated platelets. IgG purification was confirmed by Western blot and flow cytometry. It was thought unlikely that the platelet IgG could be accounted for by adsorption of plasma protein, though the variable quantities could account for diversity in wound healing rates. The IgG could protect the wound even from subclinical infections and functionally advance healing. It may be useful in the management of skin ulcers in the early phase of wound healing.
Asunto(s)
Mezclas Complejas/análisis , Mezclas Complejas/química , Inmunoglobulina G/química , Inmunoglobulina G/aislamiento & purificación , Cicatrización de Heridas , Plaquetas/química , Cromatografía de Afinidad , HumanosRESUMEN
In this review of assays of Na+/K+-ATPase (NKA), we explore the choices made by researchers assaying the enzyme to investigate its role in physiological regulation. We survey NKA structure and function in the context of how it is typically assayed, and how technical choices influence what can be said about the enzyme. In comparing different methods for extraction and assay of NKA, we identified a series of common pitfalls that compromise the veracity of results. We include experimental work to directly demonstrate how choices in detergents, salts and substrates influence NKA activities measured in crude homogenates. Our review of assay approaches integrates what is known from enzymology, biomedical physiology, cell biology and evolutionary biology, offering a more robust method for assaying the enzyme in meaningful ways, identifying caveats and future directions to explore its structure and function. The goal is to provide the sort of background on the enzyme that should be considered in exploring the function of the enzyme in comparative physiology.
Asunto(s)
Mezclas Complejas/análisis , ATPasa Intercambiadora de Sodio-Potasio/análisis , Animales , HumanosRESUMEN
The Rhipicephalus (Boophilus) microplus tick is a major concern for the livestock market worldwide, as it causes serious economic damage. Plant-derived acaricides are an attractive alternative to control this ectoparasite and limit the development of resistance. Therefore, the aim of this study was to evaluate the acaricidal activity of Furcraea foetida leaf extract against engorged female R. (B.) microplus ticks. Our in vitro bioassays showed that the crude extract of leaves from F. foetida caused hemorrhagic swelling and skin lesions in the ticks, and three days of treatment caused 100% mortality. Dose-response assay indicated that this toxicity effect was dose-dependent. Similar effects were observed when the crude extract from F. foetida leaves was denatured by boiling at 100°C. These results suggest that the toxicity of the leaf extract might be associated with thermostable biomolecules. Together, our results show for the first time that the crude extract of F. foetida leaves has acaricidal activity against engorged female R. (B.) microplus ticks and it acts in a dose-dependent manner.
Asunto(s)
Mezclas Complejas/análisis , Mezclas Complejas/toxicidad , Rhipicephalus/efectos de los fármacos , AcaricidasRESUMEN
Multiomic studies are increasingly performed to gain a deeper understanding of molecular processes occurring in a biological system, such as the complex microbial communities (i.e., microbiota) that reside the distal gut. While a combination of metabolomics and proteomics is more commonly used, multiomics studies including peptidomcis characterization are less frequently undertaken. Here, we investigated three different extraction methods, chosen for their previous use in extracting metabolites, peptides, and proteins, and compared their ability to perform metabolomic, peptidomic, and proteomic analysis of mouse cecum content. The methanol/chloroform/water extraction performed the best for metabolomic and peptidomic analysis as it detected the largest number of small molecules and identified the largest number of peptides, but the acidified methanol extraction performed best for proteomics analysis as it had the highest number of protein identifications. The methanol/chloroform/water extraction was further analyzed by identifying metabolites with tandem mass spectrometry (MS/MS) analysis and by gene ontology analysis for the peptide and protein results to provide a multiomics analysis of the gut microbiota.