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1.
Food Chem ; 305: 125463, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31520921

RESUMO

Protein conformation and the 3D water structure play important roles in the ability of bovine serum albumin (BSA) to form stable nanostructures with bioactive molecules. We studied the influence of BSA unfolding and those of two Hofmeister salts, sodium chloride (NaCl) as kosmotrope and sodium thiocyanate (NaSCN) as chaotrope, on BSA/lutein binding at pH 7.4 using fluorescence spectroscopy. The BSA/lutein complex formation was entropically driven and lutein was preferentially bound to site III of BSA. The binding constant (104 L mol-1), complex stoichiometry (1:1), and thermodynamic potential for BSA/lutein binding were independent of protein conformation and Hofmeister salts. However, the enthalpic and entropic components of BSA/lutein binding in the presence of NaSCN decreased as the temperature increased. The opposite was observed for BSA/lutein binding in the presence of NaCl and for denatured BSA/lutein binding. Therefore, the BSA conformation and 3D water structure directly affected the BSA/lutein binding thermodynamics.


Assuntos
Luteína/metabolismo , Sais/química , Soroalbumina Bovina/metabolismo , Animais , Sítios de Ligação , Bovinos , Luteína/química , Ligação Proteica , Conformação Proteica , Soroalbumina Bovina/química , Cloreto de Sódio/química , Espectrometria de Fluorescência , Temperatura Ambiente , Termodinâmica , Tiocianatos/química
2.
Food Microbiol ; 85: 103295, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31500701

RESUMO

Fermented red pepper (FRP) sauce has been eaten in worldwide for many years. The salt content and resident microbial community influences the quality of the FRP sauce and may confer health (e.g., probiotics) or harm (e.g., antibiotic resistance genes) to the consumers in some circumstances; however, the salt-mediated alteration of microbial community and antibiotic resistance genes are little known. In this study, a combination of whole genome sequencing and amplicon analysis was used to investigate the changes in microbial community and antimicrobial resistance genes in response to different salt content during red pepper fermentation. While the family Enterobacteriaceae dominated in high-salt (15-25%) samples, Lactobacillaceae quickly became the dominant population in place of Enterobacteriaceae after 24 days in 10% salt samples. Compared to 0.05 antibiotic resistance genes (ARGs) per cell number on average in 10% salt sample, 16.6 ARGs were present in high-salt samples, wherein the bacterial hosts were major assigned to Enterobacteriaceae including genera Enterobacter, Citrobacter, Escherichia, Salmonella and Klebsiella. Multidrug resistance genes were the predominant ARG type. Functional profiling showed that histidine kinase functions were of much higher abundance in high-salt samples and included several osmotic stress-related two-component systems that simultaneously encoded ARGs. These results give first metagenomic insights into the salt-mediated changes in microbial community composition and a broad view of associated antibiotic resistance genes in the process of food fermentation.


Assuntos
Capsicum/química , Farmacorresistência Bacteriana/genética , Enterobacteriaceae/genética , Lactobacillaceae/genética , Metagenoma , Microbiota , Cloreto de Sódio/química , Enterobacteriaceae/crescimento & desenvolvimento , Fermentação , Genes Bacterianos , Lactobacillaceae/crescimento & desenvolvimento , Metagenômica , Pressão Osmótica
3.
Chemosphere ; 238: 124691, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524626

RESUMO

In recent years, forward osmosis (FO) has represented numerous potential applications in safe water production. In this study, we improved the performance of FO thin film composite (TFC) membranes for the removal of trace organic compounds (TOrCs) by tuning the chemistry of its top active layer. The TFC membranes were synthesized by interfacial polymerization (IP) reaction between amine-containing monomers, e.g., meta-phenylene diamine (MPD) or para-phenylenediamine (PPD), and an acid chloride monomer, e.g., trimesoyl chloride (TMC). Owing to three free amine functionals over main core, melamine was used in the amine monomers solution to increase cross-linking among polyamide chains. Chemical and morphological characterization of the prepared membranes confirmed that melamine was successfully incorporated into the chemical structure of the top PA layer. Two agricultural toxic materials (atrazine and diazinon) were used to investigate the capability of the newly fabricated membranes in the removal of TOrCs. The obtained results showed that melamine-improved FO membranes provided higher atrazine and diazinon rejections in two different FO membrane configurations, including active layer facing feed solution (ALF) and active layer facing draw solution (ALD). The highest rejections of both diazinon (99.4%) and atrazine (97.3%) were achieved when the melamine modified MPD-based membrane served in ALF mode with 2 M NaCl as a draw solution.


Assuntos
Substâncias Húmicas/análise , Osmose/fisiologia , Purificação da Água/instrumentação , Purificação da Água/métodos , Atrazina/análise , Diazinon/análise , Membranas Artificiais , Nylons/química , Fenilenodiaminas/química , Polimerização , Cloreto de Sódio/química , Triazinas/química , Ácidos Tricarboxílicos/química , Água/química
4.
Pharm Res ; 36(12): 184, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31748894

RESUMO

PURPOSE: There is a plethora of studies on recombinant human bone morphogenetic protein-2 (rhBMP-2) application and delivery systems, but surprisingly few reports address the biophysical properties of the protein which are of crucial importance to develop effective delivery systems or to solve general problems related to rhBMP-2 production, purification, analysis and application. METHODS: The solubility, stability and bioactivity of rhBMP-2 obtained by renaturation of E. coli derived inclusion bodies was assessed at different pH and in different buffer systems using (dynamic) light scattering and thermal shift assays as well as intrinsic fluorescence measurements and luciferase based bioassays. RESULTS: rhBMP-2 is poorly soluble at physiological pH and higher. The presence of divalent anions further decreases the solubility even under acidic conditions. Thermal stability analyses revealed that rhBMP-2 precipitates are more stable compared to the soluble protein. Moreover, correctly folded rhBMP-2 is also bioactive as precipitated protein and precipitates readily dissolve under appropriate buffer conditions. Once properly formed rhBMP-2 also retains biological activity after temporary exposure to high concentrations of chaotropic denaturants. However, care should be taken to discriminate bioactive rhBMP-2 precipitates from misfolded rhBMP-2 aggregates, e.g. resolvability in MES buffer (pH 5) and a discrete peak in thermoshift experiments are mandatory for correctly folded rhBMP-2. CONCLUSIONS: Our analysis revealed that E. coli derived rhBMP-2 precipitates are not only bioactive but are also more stable compared to the soluble dimeric molecules. Knowledge about these unusual properties will be helpful to design improved delivery systems requiring lower amounts of rhBMP-2 in clinical applications.


Assuntos
Proteína Morfogenética Óssea 2/química , Escherichia coli/química , Fator de Crescimento Transformador beta/química , Heparina/química , Humanos , Concentração de Íons de Hidrogênio , Concentração Osmolar , Oxalatos/química , Tamanho da Partícula , Agregados Proteicos/efeitos dos fármacos , Conformação Proteica , Dobramento de Proteína/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Proteínas Recombinantes/química , Cloreto de Sódio/química , Solubilidade/efeitos dos fármacos , Temperatura Ambiente
5.
J Food Sci ; 84(11): 3213-3221, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31589344

RESUMO

Vitamin D3 was encapsulated in 10% wt soybean oil-in-water (O/W) Pickering emulsions stabilized by either nanofibrillated cellulose (NFC) or whey protein isolate (WPI) at 0.3%, 0.5%, and 0.7% w/w. The vitamin D3 -enriched emulsions were tested for their stability against temperature (30 °C to 90 °C), pH (2 to 8), and ionic strength (0 to 500 mM NaCl). The mean particle diameter (d32 ), ζ-potential, and creaming stability of the oil droplets in the emulsions were measured, as well as their vitamin D3 encapsulation efficiency (EE). After preparation, the oil droplet size (d32 ) of the emulsions stabilized by NFC increased with increasing emulsifier concentration, whereas the droplet size of emulsions stabilized by WPI decreased. NFC provided good stability to the emulsions through a combination of steric and electrostatic repulsion. The EE of vitamin D3 increased with increasing emulsifier concentration. Heating or ionic strength did not significantly (P < 0.05) affect the emulsions properties and EE. On the other hand, the NFC-stabilized emulsions were sensitive to highly acidic conditions (pH 2), with an increase in particle size and decrease in EE. The WPI-stabilized emulsions aggregated around the isoelectric point of the adsorbed proteins (pI ≈ 4.8). Increasing NFC or WPI concentration improved the stability and EE of the emulsions against environmental stresses. NFC-stabilized emulsions had good long-term stability. The results show that NFC can be used as an effective emulsifier for creating vitamin-enriched emulsions with good stability. PRACTICAL APPLICATION: This study can be used to develop more effective encapsulation technologies for fat-soluble vitamins in emulsion-based food products. Encapsulation using nanofibrillated cellulose effectively protected the encapsulated vitamins against environmental stresses which occur in industrial food production (such as pH changes, salt addition, and thermal processing). Moreover, nanofibrillated cellulose extracted from mangosteen rind is a nature-derived emulsifier that is environmental friendly.


Assuntos
Celulose/química , Colecalciferol/química , Composição de Medicamentos/métodos , Emulsões/química , Garcinia mangostana/química , Composição de Medicamentos/instrumentação , Estabilidade de Medicamentos , Emulsificantes/química , Concentração Osmolar , Tamanho da Partícula , Cloreto de Sódio/química , Eletricidade Estática , Temperatura Ambiente , Água/química
6.
J Photochem Photobiol B ; 200: 111655, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31655456

RESUMO

Textile effluent is often difficult to manage as it contains a high concentration of toxic and recalcitrant synthetic dyes. In this study, congo Red and textile effluent were treated by electrochemical oxidation using RuO2-IrO2 coated titanium electrode as an anode followed by biodecolorization using Pseudomonas stutzeri MN1 and Acinetobacter baumannii MN3. Effluent pre-treatment is often necessary to minimize the inhibitory effects of textile dyes on dye degrading bacterial during bio-treatment. The pre-treatment of Congo Red by electrochemical oxidation for 10 min resulted in a decolorization rate of 98% at a pH, NaCl concentration, and current density of 7, 2 g L-1, and 20 mA cm-2. Subsequent bio-treatment of the pretreated Congo Red enhanced the biodegradation to 93%. The COD removal efficiency in real textile effluent following electrochemical pretreatment and biological treatment using bacterial consortium were 3.8% and 93%, respectively. Therefore, integrating electrochemical oxidation and microbial consortia offers an effective and environmentally friendly approach for treating complex industrial effluents.


Assuntos
Biodegradação Ambiental , Vermelho Congo/química , Técnicas Eletroquímicas/métodos , Têxteis , Poluentes Químicos da Água/química , Acinetobacter/fisiologia , Compostos Azo/química , Vermelho Congo/metabolismo , Eletrodos , Concentração de Íons de Hidrogênio , Irídio/química , Oxirredução , Pseudomonas/fisiologia , Compostos de Rutênio/química , Cloreto de Sódio/química , Titânio/química , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/metabolismo
7.
Artigo em Inglês | MEDLINE | ID: mdl-31546576

RESUMO

Reductions in salt intake have the potential to markedly improve population health at low cost. Real life interventions that explore the feasibility and health effects of a gradual salt reduction lasting at least four weeks are required. The randomized controlled SalT Reduction InterVEntion (STRIVE) trial was developed to investigate the metabolic, behavioral and health effects of four months of consuming gradually salt reduced bread alone or in combination with dietary counselling. This paper describes the rationale and methods of STRIVE. Aiming at 120 healthy families, participants were recruited in February 2018 from the Danish Capital Region and randomly allocated into: (A) Salt reduced bread; (B) Salt reduced bread and dietary counseling; (C) Standard bread. Participants were examined before the intervention and at four months follow-up. Primary outcome is change in salt intake measured by 24 h urine. Secondary outcomes are change in urine measures of potassium and sodium/ potassium ratio, blood pressure, plasma lipids, the renin-angiotensin system, the sympathetic nervous response, dietary intake as well as salt taste sensitivity and preferences. The results will qualify mechanisms affected during a gradual reduction in salt intake in compliance with the current public health recommendations.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Pão/análise , Dieta , Hipertensão/etiologia , Hipertensão/prevenção & controle , Cloreto de Sódio na Dieta/administração & dosagem , Cloreto de Sódio/química , Feminino , Humanos , Cloreto de Sódio/administração & dosagem
8.
Environ Sci Pollut Res Int ; 26(29): 29660-29668, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31402436

RESUMO

Alkali metal chlorides emitted from sintering flue gas are easily adsorbed on the surface of activated carbon (AC) in the purification process. In this paper, NaCl particles adsorbing onto AC were simulated by impregnation method, and the size and morphology of NaCl particles were similar to those of NaCl-PM10 emitted from sintering flue gas. With the adsorption of NaCl particles, 2-10-µm pores of AC were filled, and the specific surface area of AC decreased. But NaCl led to the increase of acidic functional groups on the surface of AC. When 0.75 wt% NaCl was adsorbed, it was beneficial for AC catalytic denitration (de-NOx), because the chemical reaction was strengthened by acidic functional groups, so it showed a certain promotion of de-NOx efficiency. As 1.5 wt% NaCl and 3 wt% NaCl were adsorbed, NaCl had an inhibitory effect on AC de-NOx, which was because the specific surface area of AC decreased, and the prevention of physical adsorption played a major role. As a result, the de-NOx efficiency of AC adsorbed with 3 wt% NaCl decreased from 40.59 to 23.02% at 150 °C. Therefore, the absorption of NaCl fine particles on AC should not exceed 0.75 wt%.


Assuntos
Poluentes Atmosféricos/química , Carvão Vegetal/química , Gases/química , Cloreto de Sódio/química , Adsorção , Poluentes Atmosféricos/isolamento & purificação , Catálise , Resíduos Industriais , Óxido Nítrico/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
9.
Analyst ; 144(18): 5580-5588, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31418003

RESUMO

We previously reported that fully complementary DNA duplexes formed on gold nanoparticle (GNP) surfaces aggregate at high salt concentrations. We previously reported that DNA-functionalized gold nanoparticles (GNPs) aggregate by hybridization with fully complementary DNA at high salt concentrations. Although this behavior has been applied to some precise naked-eye colorimetric analyses of DNA-related molecules, the aggregation mechanism is still unclear and comprehensive studies are needed. In this paper, we reveal the key factors that influence GNP aggregation. The effects of temperature, electrolyte concentration, probe length, and particle size, which control the stabilities of double-stranded DNAs and GNPs, were investigated. Larger GNPs aggregated more easily, and GNP aggregates were easily formed with ∼15-mer-long probes, while longer probes prevented aggregation, perhaps by preventing the formation of rigid double-stranded DNA layers, compared to shorter probes. Furthermore, GNPs with purine bases at their 5' ends aggregated more easily than those with these bases at their 3' ends. This phenomenon is different from that based on the melting-temperature trend calculated using the nearest-neighbor method.


Assuntos
Pareamento de Bases , DNA/química , Ouro/química , Nanopartículas Metálicas/química , Sequência de Bases , DNA/genética , Tamanho da Partícula , Polietilenoglicóis/química , Cloreto de Sódio/química
10.
Molecules ; 24(16)2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31426303

RESUMO

The aim of this work was to compare the composition and physicochemical properties (SEM, XRD, solubility, swelling power, paste clarity, retrogradation, freeze-thaw stability, thermal property, and pasting property) of three Chinese yam (Dioscorea opposita Thunb.) starches (CYYS-1, CYYS-2, and CYYS-3) in Yunlong town, Haikou, Hainan Province, China. Our results show that all the CYYS gave a typical C-type X-ray diffraction pattern. The swelling power of CYYS varied from 10.79% to 30.34%, whereas solubility index was in the range of 7.84-4.55%. The freeze-thaw stability of each CYYS showed a contrary tendency with its amylose content. In addition, CYYS-3 showed the highest To (81.1 °C), Tp (84.8 °C), Tc (91.2 °C), and ΔH (14.1 J/g). The pasting temperature of CYYS-1 increased significantly with sucrose addition. NaCl could inhibit the swelling power of CYYS. There were significant decreases in pasting temperature and pasting time of CYYS when pH decreased.


Assuntos
Dioscorea/química , Cloreto de Sódio/química , Amido/química , Sacarose/química , Tecnologia de Alimentos/métodos , Liofilização , Temperatura Alta , Humanos , Microscopia Eletrônica de Varredura , Solubilidade , Amido/isolamento & purificação , Amido/ultraestrutura , Molhabilidade
11.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1126-1127: 121744, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31437774

RESUMO

Viral particle purification is a challenge due to the complexity of the broth, the particle size, and the need to maintain virus activity. Aqueous two-phase systems (ATPSs) are a viable alternative for the currently used and expensive downstream processes. This work investigated the purification of two non-enveloped viruses, porcine parvovirus (PPV), and human rhinovirus (HRV) at various ATPS tie lines. A polyethylene glycol (PEG) 12 kDa-citrate system at pH 7 was used to study the behavior of the partitioning on three different thermodynamic tie line lengths (TLLs). It was experimentally determined that increasing the TLL, and therefore increasing the hydrophobic and electrostatic driving forces within the ATPS, facilitated higher virus recoveries in the PEG-rich phase. A maximum of 79% recovery of infectious PPV was found at TLL 36 w/w% and tie line (TL) ratio 0.1. Increased loading of PPV was studied to observe the change in the partitioning behavior and similar trends were observed for all the TLs. Most contaminants remained in the citrate-rich phase at all the chosen TLLs, demonstrating purification of the virus from protein contaminants. Moderate DNA removal was also measured. Net neutral charged HRV was studied to demonstrate the effects of driving forces on neutrally charged viruses. HRV recovery trends remained similar to PPV on each TLL studied, but the values were lower than PPV. Recovery of viral particles in the PEG-rich phase of the PEG-citrate system utilized the difference in the surface hydrophobicity between virus and proteins and showed a direct dependence on the surface charge of each studied virus. The preferential partitioning of the relatively hydrophobic viral particles in the PEG-rich phase supports the hypothesis that both hydrophobic and electrostatic forces govern the purification of viruses in ATPS.


Assuntos
Extração Líquido-Líquido/métodos , Parvovirus Suíno/isolamento & purificação , Rhinovirus/isolamento & purificação , Vírion/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Parvovirus Suíno/química , Polietilenoglicóis/química , Rhinovirus/química , Cloreto de Sódio/química , Eletricidade Estática , Termodinâmica , Vírion/química
12.
Int J Pharm ; 569: 118608, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31415881

RESUMO

With respect to all biopharmaceuticals marketed to date, monoclonal antibodies represent the largest fraction with more than 48% market share (2012). However, the development of biopharmaceutical formulations is a challenging task, and time-consuming and cost-intensive high-throughput screenings are still state-of-the-art in formulation design. These screening techniques are almost exclusively based on heuristic decisions thus the benefit in terms of mechanistic understanding is often unclear. It requires novel, physical-sound methods to enhance/optimize future formulation development, ideally by understanding molecular interactions in these complex solutions. A suitable and evaluated measure-of-choice to characterize protein-protein interactions in aqueous protein solutions is the second osmotic virial coefficient B22 which can be measured using static light scattering techniques. Furthermore B22 can be modeled/predicted via the extended mxDLVO model for protein-protein interactions in the presence of single excipients and excipient-mixtures. Building up on this approach, giving an additional insight into water-water and water-excipient interactions, the thermodynamic equation-of-state ePC-SAFT is used to calculate water activity coefficients in the presence of excipient-mixtures. Immunoglobulin G (IgG) was chosen as a model protein to predict B22-values for IgG in the presence of model excipient-mixtures (trehalose-NaCl, l-histidine-trehalose, l-histidine-NaCl). The combination of water activity coefficients and B22 allows to quickly identify a first guess on suitable formulation conditions that then can be further evaluated with existing methods/knowledge.


Assuntos
Excipientes/química , Imunoglobulina G/química , Água/química , Composição de Medicamentos , Histidina/química , Cloreto de Sódio/química , Trealose/química
13.
Biochem Med (Zagreb) ; 29(3): 031001, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31379463

RESUMO

Introduction: Phlebotomy is an error-prone process in which mistakes are difficult to reveal. This case report describes the effect on laboratory results originating from a blood sample collected in close proximity to an intravenous catheter. Materials and methods: A 69-year-old male patient was referred to the Emergency department where pneumonia was suspected. Phlebotomy was performed to collect blood samples to assess electrolytes, renal function, liver function, infection and haematological parameters. Results: The laboratory analysis showed reduced potassium and calcium concentrations. To prevent life-threatening cardiac failure the clinician decided to correct those electrolytes. Remarkably, the electrocardiogram showed no abnormalities corresponding to hypokalaemia and hypocalcaemia. This observation, in combination with an overall increase in laboratory parameters with the exception of sodium and chloride, led to the suspicion of a preanalytical error. Retrospectively, an intravenous catheter was inserted in close proximity of the puncture place but no continuous infusion was started prior to phlebotomy. However, the intravenous catheter was flushed with sodium chloride. Since potential other causes were excluded, the flushing of the intravenous catheter with sodium chloride prior to phlebotomy was the most probable cause for the deviating laboratory results and subsequently for the unnecessary potassium and calcium suppletion. Conclusion: This case underlines the importance of caution in the interpretation of laboratory results obtained from specimens that are collected in the proximity of an intravenous catheter, even in the absence of continuous infusion.


Assuntos
Cateteres , Flebotomia/métodos , Idoso , Cálcio/sangue , Eletrocardiografia , Serviço Hospitalar de Emergência , Insuficiência Cardíaca/diagnóstico , Humanos , Masculino , Potássio/sangue , Fase Pré-Analítica , Cloreto de Sódio/química
14.
J Chem Theory Comput ; 15(10): 5404-5416, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31461277

RESUMO

Based on induced solvent charges, a new model of solvent screening is developed in the framework of the fragment molecular orbital combined with the polarizable continuum model. The developed model is applied to analyze interactions in a prototypical zwitterionic system, sodium chloride in water, and it is shown that the large underestimation of the interaction in the original solvent screening based on local charges is successfully corrected. The model is also applied to a complex of the Trp-cage (PDB: 1L2Y ) miniprotein with an anionic ligand, and the physical factors determined protein-ligand binding in solution are unraveled.


Assuntos
Teoria Quântica , Solventes/química , Ligantes , Cloreto de Sódio/química , Água/química
15.
J Food Sci ; 84(9): 2499-2506, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31393020

RESUMO

As many of the maternal and child health complications result from folic acid, iron, and iodine deficiencies; it makes sense to combat these simultaneously. We have developed cost-effective technology to deliver these three micronutrients simultaneously through salt. Our goal was to retain at least 70% of the micronutrients during 6 months of storage. The fortified salt was formulated by spraying a solution that contained 2% iodine and 0.5% or 1% folic acid onto salt and adding encapsulated ferrous fumarate. The formulated triple fortified salt contained 1,000 ppm iron, 50 ppm iodine, and 12.5 or 25 ppm folic acid. The spray solution and the salt were stored for 2 and 6 months respectively at 25, 35, and 45 °C 60 to 70% relative humidity. Even at 45 °C, over 70% of both iodine and folic acid were retained in the salt. The best formulation based on the color of the salt and stability of iodine and folic acid contained 12.5 ppm folic acid, 50 ppm iodine, and 1,000 ppm iron. These results indicate that iron, iodine, and folic acid can be simultaneously delivered to a vulnerable population through salt using the technology described. Also, the quality control of the process can be developed around pteroic acid that was detected as a primary degradation product of folic acid. PRACTICAL APPLICATION: The technology developed is already transferred to India for industrial scale up. When fully operational, the technology will simultaneously solve iron, iodine, and folic acid deficiencies in vulnerable populations at a very low cost.


Assuntos
Composição de Medicamentos/métodos , Compostos Ferrosos/química , Ácido Fólico/química , Iodo/química , Cloreto de Sódio/química , Composição de Medicamentos/economia , Estabilidade de Medicamentos , Alimentos Fortificados/análise , Alimentos Fortificados/economia , Índia , Micronutrientes/química
16.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1126-1127: 121760, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31445214

RESUMO

Separation of molecules in aqueous two-phase systems (ATPS) depends on many factors, e.g. salt concentration, pH, polyethylene glycol (PEG) concentration and molecular weight. The aim of the study was to analyze partition of model proteins (lysozyme, bovine serum albumin and hemoglobin) depending on the magnetic field action and the factors mentioned above in PEG/MgSO4 ATPS. Partition of these proteins studied always depended on PEG molecular weight, while salt concentration influenced only BSA and HGB separation. Two of the proteins tested, i.e. lysozyme and BSA showed high affinity to the PEG-rich-phase. The magnetic field significantly forced distribution of BSA and lysozyme to the phase rich in MgSO4. Hemoglobin, which presented a tendency to accumulation in salt phase was not affected by the magnetic field. Thus, the influence of the magnetic field on protein partition in ATPS is a consequence of the properties of separated molecules, and rearranges of water dipoles and hydrogen bonds reshape.


Assuntos
Extração Líquido-Líquido/métodos , Sulfato de Magnésio/química , Campos Magnéticos , Polietilenoglicóis/química , Proteínas , Concentração de Íons de Hidrogênio , Peso Molecular , Proteínas/análise , Proteínas/química , Proteínas/isolamento & purificação , Cloreto de Sódio/química
17.
J Chromatogr A ; 1607: 460403, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31378523

RESUMO

MOF-1210(Zr/Cu) is a new heterometallic cluster-based metal-organic framework material as well as a promising solid phase extraction coating material with ordered spatial structure, permanent high porosity and large specific surface area. In this work, a novel MOF-1210(Zr/Cu) modified magnetic nanoparticles (MNPs) was successfully prepared for magnetic solid phase extraction (MSPE) of benzophenones, including 2,4-dihydroxybenzophenone (BP-1), 2-hydroxy-4-methoxybenzophenone (BP-3) and 2,2',4,4'-tetrehydroxybenzophenone (BP-6). The MOF-1210(Zr/Cu)-MNPs were synthesized in one step by a simple solvothermal method and showed high extraction efficiency towards analytes (with enrichment factors of 91-122). The extraction mechanism studies showed that the hydrogen bond interaction and coordination interaction between MOF-1210(Zr/Cu) and BPs played important roles during the extraction process. By coupling with HPLC, the MOF-1210(Zr/Cu)-MNPs-based MSPE-HPLC method showed wide linear range (0.1-300.0 ng·mL-1), good linearity (R ≥ 0.9982), excellent reproducibility (RSD ≤ 3.60%) and remarkable sensitivity (LODs in the range of 0.01-0.02 ng·mL-1). This method was also successfully applied to the extraction and detection of benzophenones in soil samples. Good recoveries were obtained (87.6%-113.8%) with RSDs less than 11.12%, which demonstrated the practicality of the proposed method.


Assuntos
Benzofenonas/análise , Cobre/química , Nanopartículas de Magnetita/química , Estruturas Metalorgânicas/química , Solo/química , Extração em Fase Sólida/métodos , Zircônio/química , Acetonitrilos/química , Ácidos/química , Adsorção , Concentração de Íons de Hidrogênio , Limite de Detecção , Reprodutibilidade dos Testes , Cloreto de Sódio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo
18.
Food Chem ; 299: 125133, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31323441

RESUMO

The aim of this study was to investigate the effect of NaCl on the formation, structure and property of samples formed from wheat starch (WS) and the fatty acids (lauric acid (LA), myristic acid (MA), palmitic acid (PA) and stearic acid (SA)). Results from RVA, DSC, XRD and Raman analyses showed that LA, and to a lesser extent MA, formed complexes with WS. Under the experimental conditions used, only minor amounts of WS-PA and WS-SA complexes formed. The low solubility of PA and SA, and to some extent MA, in water caused these fatty acids to mostly self-aggregate. The presence of NaCl promoted the formation of WS-LA complexes and, to a lesser extent complexes with MA, but had little effect on the formation of WS-PA and WS-SA complexes. Solubility of fatty acids in aqueous medium was proposed to be a major factor for the formation of starch-fatty acid complexes.


Assuntos
Ácidos Graxos/química , Lipídeos/química , Cloreto de Sódio/química , Amido/química , Triticum/química , Varredura Diferencial de Calorimetria , Solubilidade , Análise Espectral Raman , Viscosidade , Difração de Raios X
19.
Comput Biol Chem ; 83: 107091, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31349122

RESUMO

Human α -defensin 5 (HD5) is a 32-residue cysteine-rich host-defense peptide that exhibits broad-spectrum antimicrobial activity and plays an essential role in innate immunity in the human gut and other organ systems. Although its antimicrobial mechanism of action remains unclear, the high salt concentration seems to attenuate the antimicrobial function of HD5 via an unknown mechanism. In this work, we employ Molecular Dynamics (MD) simulations to analyse the oligomerization behaviour of HD5 when exposed to different salt concentration. We demonstrate that the presence of salt, such as sodium chloride (NaCl), promotes HD5 to form higher-order oligomers (up to heptamers) in our simulations. In addition, we also analyse the electrostatic interactions between the two Glu residues (E14 and E21) and their neighbouring residues. Our data confirm that the E14 residue is essential for the structural integrity, whereas the E21 residue contributes to the dimerization of HD5, suggesting that these Glu residues are important for the antimicrobial function of this peptide.


Assuntos
Simulação de Dinâmica Molecular , alfa-Defensinas/química , Humanos , Cloreto de Sódio/química , Soluções , Eletricidade Estática , alfa-Defensinas/síntese química
20.
Chem Commun (Camb) ; 55(62): 9188-9191, 2019 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-31305808

RESUMO

The metal salts ubiquitously present in biological samples cause serious ion suppression, capillary clogging and signal fluctuation in ESI/nESI. Herein, a current-limited high voltage polarity reversing approach was applied for the online separation of intrinsic metal ions in biological samples, resulting in the generation of protonated analytes at the nESI tip for mass analysis without interference from salt cations. Stable and durable signals (∼30-60 s) were observed for protonated proteins, peptides and metabolites in complex biological samples, including liquids, solids and viscous samples, even with very high salt concentration (100 mM NaCl), allowing comprehensive tandem MS analysis with on average ca. 5-times higher analyte signal intensities compared to the conventional nESI analysis. Therefore this approach offers improved performance of nESI/ESI for the sensitive molecular analysis of untreated biological samples, opening new possibilities in various disciplines, including biology, medicine, chemistry, life sciences, etc.


Assuntos
Peptídeos/análise , Proteínas/análise , Cloreto de Sódio/química , Íons/análise , Peptídeos/metabolismo , Proteínas/metabolismo , Prótons , Espectrometria de Massas por Ionização por Electrospray/instrumentação
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