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1.
Food Chem ; 366: 130561, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34284189

RESUMO

In this study, caseins and methylcellulose (MC) were selected as building materials to prepare a class of mixed gels by adding glucono-δ-lactone (GDL) to induce the gelation of composite MC/casein systems, where the casein concentration was fixed at 8.0% (w/v) and the MC concentration varied from 0 to 1.0% (w/v). It was found that with increasing amount of MC addition (0-0.4%), the mixed gels exhibited a structural conversion from a casein-dominant gel network to a "water-in-water emulsion structure", with the caseins as the continuous gelling phase and the MC as the dispersed phase; further MC addition (0.4-1.0%, w/v) caused a more significant phase separation phenomenon. The structural conversion was in consistent with the determination result of gel hardness. Furthermore, by a combination of confocal laser scanning microscope (CLSM) and rheological studies, the structural evolution process of the mixed gels was revealed to explore the underlying formation mechanism of the mixed gels.


Assuntos
Caseínas , Gluconatos , Géis , Concentração de Íons de Hidrogênio , Metilcelulose , Reologia
2.
J Dairy Sci ; 104(10): 10586-10593, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34304875

RESUMO

Paucilactobacillus wasatchensis, a nonstarter lactic acid bacteria, can cause late gas production and splits and cracks in aging cheese when it metabolizes 6-carbon substrates, particularly galactose, to a 5-carbon sugar, resulting in the release of CO2. Previous studies have not explained late gas production in aging cheese when no galactose is present. Based on the genome sequence of Pa. wasatchensis WDC04, genes for potential metabolic pathways were mapped using knowledgebase predictive biology software. This metabolic modeling predicted Pa. wasatchensis WDC04 could metabolize gluconate. Gluconate contains 6 carbons, and Pa. wasatchensis WDC04 contains genes to convert it to 6-P-gluconate and then to ribulose-5-P by using 6-phosphogluconate dehydrogenase in a decarboxylating step, producing CO2 during its metabolism. The goal of this study was to determine if sodium gluconate, often added to cheese to reduce calcium lactate crystal formation, could be metabolized by Pa. wasatchensis WDC04, resulting in gas production. Carbohydrate-restricted DeMan, Rogosa, and Sharpe broth was mixed with varying ratios of ribose, sodium gluconate, or d-galactose (total added substrate content of 1% wt/vol). Oxyrase (Oxyrase Inc.; 1.8% vol/vol) was also used to mimic the anaerobic environment of cheese aging in selected tubes. Tubes were inoculated with a 4-d culture of Pa. wasatchensis WDCO4, and results were recorded over 8 d. When inoculated into carbohydrate-restricted DeMan, Rogosa, and Sharpe broth containing only sodium gluconate as the added substrate, Pa. wasatchensis WDC04 grew, confirming gluconate utilization. Of the 10 ratios used, Pa. wasatchensis WDC04 produced gas in 6 scenarios, with the most gas production resulting from the ratio of 100% sodium gluconate with no added ribose or galactose. It was confirmed that obligately heterofermentative nonstarter lactobacilli such as Pa. wasatchensis WDC04 can utilize sodium gluconate to produce CO2 gas. Addition of sodium gluconate to cheese thus becomes another risk factor for unwanted gas production and formation of slits and cracks.


Assuntos
Queijo , Animais , Fermentação , Gluconatos , Lactobacillus
3.
Trials ; 22(1): 427, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34217337

RESUMO

BACKGROUND: Intravenous fluid therapy represents the most common intervention critically ill patients are exposed to. Hyperchloremia and metabolic acidosis associated with 0.9% sodium chloride have been observed to lead to worse outcomes, including mortality. Balanced solutions, such as Plasma-Lyte 148 and Compound Sodium Lactate, represent potential alternatives but the evidence on optimal fluid choices in critically ill children remains scarce. This study aims to demonstrate whether balanced solutions, when used as intravenous fluid therapy, are able to reduce the incidence of a rise in serum chloride level compared to 0.9% sodium chloride in critically ill children. METHODS: This is a single-centre, open-label randomized controlled trial with parallel 1:1:1 assignment into three groups: 0.9% sodium chloride, Plasma-Lyte 148, and Compound Sodium Lactate solutions for intravenous fluid therapy. The intervention includes both maintenance and bolus fluid therapy. Children aged < 16 years admitted to intensive care and receiving intravenous fluid therapy during the first 4 h of admission are eligible. The primary outcome measure is a ≥ 5mmol/L increase in serum chloride level within 48 h post-randomization. The enrolment target is 480 patients. The main analyses will be intention-to-treat. DISCUSSION: This study tests three types of intravenous fluid therapy in order to compare the risk of hyperchloremia associated with normal saline versus balanced solutions. This pragmatic study is thereby assessing the most common intervention in paediatric critical care. This is a single-centre open-label study with no blinding at the level of delivery of the intervention. Certain paediatric intensive care unit (PICU) patient groups such as those admitted with a cardiac condition or following a traumatic brain injury are excluded from this study. TRIAL REGISTRATION: The study has received ethical approval (HREC/19/QCHQ/53177: 06/06/2019). It is registered in the Australian New Zealand Clinical Trials Registry ( ACTRN12619001244190 ) from 9th September 2019. Recruitment commenced on 12th November 2019. The primary results manuscript will be published in a peer-reviewed journal.


Assuntos
Cloreto de Sódio , Lactato de Sódio , Austrália , Criança , Hidratação , Gluconatos , Humanos , Unidades de Terapia Intensiva Pediátrica , Cloreto de Magnésio , Cloreto de Potássio , Ensaios Clínicos Controlados Aleatórios como Assunto , Acetato de Sódio
4.
Sheng Wu Gong Cheng Xue Bao ; 37(6): 1827-1844, 2021 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-34227279

RESUMO

Vitamin C is an essential vitamin for human beings. It has a huge market in the fields of food and pharmaceuticals. 2-keto-L-gulonic acid is an important precursor to produce vitamin C by microbial fermentation in industrial. In microbial fermentations, the L-sorbose pathway and the D-gluconate pathway have been the focus of research because of high yield. This article aims at stating recent research progress in dehydrogenases related to biosynthesis of vitamin C in the L-sorbose pathway and the D-gluconate pathway. The properties of dehydrogenase in terms of localization, substrate specificity, cofactors, and electron transport carrier are elaborated. And then, the main problems and strategies are reviewed in the L-sorbose pathway and in the D-gluconate pathway. Finally, future research on the dehydrogenases in the biosynthesis of vitamin C through L-sorbose pathway and D-gluconate pathway is discussed.


Assuntos
Ácido Ascórbico/biossíntese , Oxirredutases , Fermentação , Gluconatos , Oxirredutases/metabolismo , Sorbose
6.
Nutrients ; 13(5)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064968

RESUMO

Increased potassium intake has been linked to improvements in cardiovascular and other health outcomes. We assessed increasing potassium intake through food or supplements as part of a controlled diet on blood pressure (BP), microcirculation (endothelial function), and potassium and sodium retention in thirty pre-hypertensive-to-hypertensive men and women. Participants were randomly assigned to a sequence of four 17 day dietary potassium treatments: a basal diet (control) of 60 mmol/d and three phases of 85 mmol/d added as potatoes, French fries, or a potassium gluconate supplement. Blood pressure was measured by manual auscultation, cutaneous microvascular and endothelial function by thermal hyperemia, utilizing laser Doppler flowmetry, and mineral retention by metabolic balance. There were no significant differences among treatments for end-of-treatment BP, change in BP over time, or endothelial function using a mixed-model ANOVA. However, there was a greater change in systolic blood pressure (SBP) over time by feeding baked/boiled potatoes compared with control (-6.0 mmHg vs. -2.6 mmHg; p = 0.011) using contrast analysis. Potassium retention was highest with supplements. Individuals with a higher cardiometabolic risk may benefit by increasing potassium intake. This trial was registered at ClinicalTrials.gov as NCT02697708.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Gluconatos , Hipertensão/tratamento farmacológico , Microcirculação , Potássio na Dieta/administração & dosagem , Potássio , Solanum tuberosum/química , Adulto , Fatores de Risco Cardiometabólico , Estudos Cross-Over , Dieta , Suplementos Nutricionais , Fezes/química , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Potássio/sangue , Sódio , Cloreto de Sódio na Dieta , Sódio na Dieta/administração & dosagem , Desequilíbrio Hidroeletrolítico , Adulto Jovem
7.
Int J Biol Macromol ; 185: 462-470, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34147525

RESUMO

This study evaluated the differences in the physicochemical, digestion and microstructure of soy protein gels acidified with Lactobacillus casei (L. casei), glucono-δ-lactone (GDL) and citric acid. The maximum acidification rate was as follows: citric acid > GDL > L. casei. The gelation points of L. casei-induced gel (LC gel) and GDL-induced gel (GDL gel) occurred at 74 min and 55 min; however, gelation point of citric acid-induced gel (CA gel) was not detected because acidification was too fast. LC gel showed the high gel hardness (20.40 ± 2.23 g) and water holding capacity (84.58 ± 0.59%). At the end of intestinal digestion, the average particle size of the LC gel was the largest, but there was no significant difference between GDL gel and CA gel. The microstructure of the GDL gel was found to be the densest. Acidification rate was the "key step" of acid-induced gels, while both the proteolytic and exopolysaccharide (EPS) production capacity were involved in LC gel.


Assuntos
Ácido Cítrico/química , Gluconatos/química , Lactobacillus casei/química , Lactonas/química , Proteínas de Soja/química , Fenômenos Químicos , Manipulação de Alimentos , Géis , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Reologia
8.
Molecules ; 26(9)2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-34066480

RESUMO

This paper investigates the potential of the enzymatic management of high pH in white juice and wine using a combination of enzymes-glucose oxidase coupled with catalase. Catazyme® 25 L, a commercially available blend of the two enzymes, was added at different doses (0.2 g/L, 0.6 g/L, and 1g/L) to white grape juice and various parameters (glucose, gluconic acid, pH) were monitored over 24 h of treatment. Treated wines were fermented to dryness without any difficulty and the wines were chemically and sensorially evaluated. At the highest dose (1 g/L), pH was reduced from 3.9 to 3.2, with 20.5 g of gluconic acid produced, while at the lowest dose (0.2 g/L), pH decreased from 4.0 to 3.5 and 8.8 g of gluconic acid was produced. Flash profiling indicated that treated wines were lighter in color than the control and were described using terms such as floral, fruit, citrus, and sour while the control wine was described as being fermented, medicinal, pungent, and oxidized. In conclusion, glucose oxidase coupled with catalase was shown to be effective at significantly reducing juice and wine pH in a short amount of time and with a positive impact on the organoleptic profiles of the treated wines.


Assuntos
Enzimas/química , Análise de Alimentos/métodos , Tecnologia de Alimentos/métodos , Vitis/química , Vinho/análise , Catalase/química , Clima , Fermentação , Frutas/química , Gluconatos/química , Glucose/química , Glucose Oxidase/química , Concentração de Íons de Hidrogênio
9.
Mol Biochem Parasitol ; 244: 111383, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34048823

RESUMO

Giardia lamblia, due to the habitat in which it develops, requires a continuous supply of intermediate compounds that allow it to survive in the host. The pentose phosphate pathway (PPP) provides essential molecules such as NADPH and ribulose-5-phosphate during the oxidative phase of the pathway. One of the key enzymes during this stage is 6-phosphogluconate dehydrogenase (6 PGDH) for generating NADPH. Given the relevance of the enzyme, in the present work, the 6pgdh gene from G. lamblia was amplified and cloned to produce the recombinant protein (Gl-6 PGDH) and characterize it functionally and structurally after the purification of Gl-6 PGDH by affinity chromatography. The results of the characterization showed that the protein has a molecular mass of 54 kDa, with an optimal pH of 7.0 and a temperature of 36-42 °C. The kinetic parameters of Gl-6 PGDH were Km = 49.2 and 139.9 µM (for NADP+ and 6-PG, respectively), Vmax =26.27 µmol*min-1*mg-1, and Kcat = 24.0 s-1. Finally, computational modeling studies were performed to obtain a structural visualization of the Gl-6 PGDH protein. The generation of the model and the characterization assays will allow us to expand our knowledge for future studies of the function of the protein in the metabolism of the parasite.


Assuntos
Giardia lamblia/enzimologia , Gluconatos/química , NADP/química , Fosfogluconato Desidrogenase/química , Proteínas de Protozoários/química , Ribulosefosfatos/química , Motivos de Aminoácidos , Sítios de Ligação , Clonagem Molecular/métodos , Expressão Gênica , Geobacillus stearothermophilus/química , Geobacillus stearothermophilus/enzimologia , Giardia lamblia/genética , Gluconatos/metabolismo , Humanos , Cinética , Modelos Moleculares , NADP/metabolismo , Via de Pentose Fosfato/genética , Fosfogluconato Desidrogenase/genética , Fosfogluconato Desidrogenase/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ribulosefosfatos/metabolismo , Homologia Estrutural de Proteína , Especificidade por Substrato , Termodinâmica
10.
Chemosphere ; 279: 130541, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33873070

RESUMO

Carboxylic acid leaching has been established eco-friendly pre-treatment method for producing biogenic silica (BSi) from rice husk. The most urgent issue is for carboxylic acid to promote new readily biodegradable acids and enhance carboxylic acid sustainability in BSi preparation. This research investigates gluconic acid (GA) applicability for biogenic silica preparation from rice husk compared with citric acid (CA). The results demonstrated that GA was preferable to CA on BSi recovery with 89.91% efficiency. Although GA leaching promoted slightly higher silica loss, the primary metal alkali impurities, such as K2O, Na2O, and Al2O3, were effectively removed at 92-93%, 89-93%, 95-97%, respectively. The combination effect of silica loss and high removal impurities resulted in lower rice husk thermal decomposition activation energy. The characteristics of BSi prepared by GA leaching were comparable with CA leaching, mainly mesoporous with 114.06 m2/g of specific surface area and 0.23 cm3/g of the pore volume. In addition, GA leaching was environmentally better than CA leaching, indicated by minor contribution to all environmental impact indices. The findings suggested that GA could be a potential replacement for prevalent carboxylic acids in BSi preparation.


Assuntos
Oryza , Dióxido de Silício , Ácido Cítrico , Gluconatos
11.
Chem Commun (Camb) ; 57(33): 4051-4054, 2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33885674

RESUMO

Exploiting suitable oxidation catalysts is of great importance in the development of sugar-based fuel cells (SFCs). Herein, a novel room-temperature glucose/O2 fuel cell (GFC), which employs 4-acetamido-2,2,6,6-tetramethylpiperidin-1-oxyl (ACT) as an anodic electrocatalyst and air-breathing Pt-C as a cathode, is demonstrated. Under room temperature operation, the as-assembled GFCs are capable of delivering a maximum power density of 100 µW cm-2 in the presence of 50 mM glucose. Bulk electrolysis products of glucose identified by mass spectrum and Fourier transform infrared spectroscopy include gluconic acid and glucaric acid, suggesting that the aldehyde and primary hydroxy groups of glucose can be deeply oxidized into carboxyl groups through a 6e- pathway. The deep glucose oxidation capability makes ACT a promising anodic electrocatalyst for SFCs.


Assuntos
Óxidos N-Cíclicos/química , Glucose/química , Aldeídos/química , Fontes de Energia Bioelétrica , Catálise , Técnicas Eletroquímicas , Eletrodos , Eletrólise , Ácido Glucárico/química , Gluconatos/química , Oxirredução , Oxigênio/química , Propriedades de Superfície , Temperatura
12.
J Hazard Mater ; 414: 125564, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-33684819

RESUMO

Gluconate is known to mediate metal leaching. However, during bioleaching by e.g., Gluconobacter oxydans, gluconate can be oxidized to 2-ketogluconate and 5-ketogluconate. The impact of bio-oxidation of gluconate on metal leaching has not been investigated. Therefore, the aim of this study was to investigate leaching of rare earth elements (REEs) and base metals from spent nickel-metal-hydride (NiMH) batteries using gluconate, 2-ketogluconate and 5-ketogluconate. Batch leaching assays were conducted under controlled and uncontrolled pH conditions for 14 days using 60 mM of either the individual leaching agents or their various combinations. At target pH of 6.0 ± 0.1 and 9.0 ± 0.1 and without pH control, complexolysis was the dominating leaching mechanism and higher REE leaching efficiency was obtained with gluconate, while 5-ketogluconate enabled more efficient base metal leaching. At target pH of 3.0 ± 0.1, acidolysis dominated, and the base metal and REE leaching yields with all the tested leaching agents were higher than under the other studied pH conditions. The highest base metal and REE leaching yields (%) were obtained using gluconate at target pH of 3.0 ± 0.1 being 100.0 Mn, 90.3 Fe, 89.5 Co, 58.5 Ni, 24.0 Cu, 29.3 Zn and 56.1 total REEs. The obtained results are useful in optimization of heterotrophic bioleaching.


Assuntos
Metais Terras Raras , Níquel , Fontes de Energia Elétrica , Gluconatos , Metais
13.
Biochem Biophys Res Commun ; 551: 161-167, 2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33740623

RESUMO

Physiological oxygen concentration (physioxia) ranges from 1 to 8% in human tissues while many researchers cultivate mammalian cells under an atmospheric concentration of 21% (hyperoxia). Oxygen is one of the significant gases which functions in human cells including energy production in mitochondria, metabolism in peroxidase, and transcription of various genes in company with HIF (Hypoxia-inducible factors) in the nucleus. Thus, mammalian cell culture should be deliberated on the oxygen concentration to mimic in vivo physiology. Here, we studied if the cultivation of human skin cells under physiological conditions could affect skin significant genes in barrier functions and dermal matrix formation. We further examined that some representative active ingredients in dermatology such as glycolic acid, gluconolactone, and salicylic acid work in different ways depending on the oxygen concentration. Taken together, we present the importance of oxygen concentration in skin cell culture for proper screening of novel ingredients as well as the mechanistic study of skin cell regulation.


Assuntos
Hidroxiácidos/farmacologia , Oxigênio/farmacologia , Pele , Linhagem Celular , Colágeno Tipo I/genética , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Gluconatos/metabolismo , Glicolatos/metabolismo , Humanos , Queratina-1/genética , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Lactonas/metabolismo , Metaloproteinase 1 da Matriz/genética , Oxigênio/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/genética , Proteínas S100/genética , Ácido Salicílico/metabolismo , Pele/citologia , Pele/efeitos dos fármacos , Pele/metabolismo
14.
Biochem Biophys Res Commun ; 554: 33-40, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-33774277

RESUMO

Glucocorticoid-induced osteoporosis (GIOP) has emerged as a challenge after long-term glucocorticoid administration during the clinical therapy of diverse diseases. Although some candidates for GIOP treatment have been explored, there is still a lack of reliable drugs for GIOP prevention. In this study, rat bone marrow stem cells (rBMSCs) were utilized to investigate the feasibility of applying strontium gluconate (GluSr), which displays mild activity, easy absorption and good biocompatibility, for GIOP prevention. Thirty-two SD rats were divided into 4 groups to explore the effects of GluSr on osteoporosis rescue in vivo. Our results suggested that GluSr markedly alleviated dexamethasone (DEX)-induced apoptosis of osteoblast precursor cells and rBMSCs and enhanced rBMSC osteogenesis differentiation in vitro. GluSr also effectively promoted osteoblast survival, inhibited osteoclast differentiation and restored bone formation in GIOP rat models. Microarray analysis of the femora from GIOP rats treated with GluSr revealed that the signalling pathways of the glucocorticoid receptor (GR), oestrogen receptor gene (ESR) and vitamin D receptor (VDR) were involved in bone restoration by GluSr. In summary, our study proved that GluSr enhanced osteoblast differentiation and suppressed osteoclast activity both in vitro and in vivo. GluSr might function as a novel strontium reagent for GIOP prevention.


Assuntos
Glucocorticoides/efeitos adversos , Gluconatos/farmacologia , Osteoblastos/efeitos dos fármacos , Osteoporose/tratamento farmacológico , Células-Tronco/efeitos dos fármacos , Estrôncio/farmacologia , Animais , Medula Óssea/metabolismo , Células Cultivadas , Dexametasona/efeitos adversos , Modelos Animais de Doenças , Masculino , Camundongos , Osteoblastos/metabolismo , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteogênese/efeitos dos fármacos , Osteoporose/induzido quimicamente , Osteoporose/metabolismo , Osteoporose/patologia , Ratos , Ratos Sprague-Dawley , Células-Tronco/citologia , Células-Tronco/metabolismo
15.
Int J Biol Macromol ; 174: 330-338, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33529626

RESUMO

Homologs of PtxS are ubiquitous transcriptional regulators controlling the expression of the glucose dehydrogenase and kgu operon to globally regulate the 2-ketogluconic acid (2KGA) metabolism in Pseudomonas. In the present study, a PtxS from a 2KGA industrial producer Pseudomonas plecoglossicida JUIM01 (PpPtxS) was heterologously expressed in E. coli BL21(DE3), then structurally and functionally characterized. The obtained results showed that PpPtxS was a 36.65-kDa LacI-family transcriptional regulator. 2KGA was the sole effector of PpPtxS. Glucose negatively affected the molecular binding of PpPtxS and 2KGA, and gluconic acid inhibited the PpPtxS-2KGA binding reaction. PpPtxS in water solution mainly existed as a dimer and bound to two molecules of 2KGA. The effector 2KGA mainly bound to the region close to the C-terminal of PpPtxS by interacting with the 299th to the 301st amino acids (Ala, Gln, Pro, Thr, Glu and Arg). PpPtxS specifically recognized and bound to a 14-bp palindrome sequence (5'-TGAAACCGGTTTCA-3') due to its conserved HTH motif at the N-terminal. The characterization of PpPtxS in this study would provide a theoretical guidance for the industrial production of 2KGA.


Assuntos
Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/crescimento & desenvolvimento , Gluconatos/metabolismo , Pseudomonas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Calorimetria , Dicroísmo Circular , Clonagem Molecular , Proteínas de Ligação a DNA/genética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Simulação de Acoplamento Molecular , Óperon , Conformação Proteica , Pseudomonas/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
JAMA Netw Open ; 4(2): e210369, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33576820

RESUMO

Importance: There is limited evidence regarding early treatment of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection to mitigate symptom progression. Objective: To examine whether high-dose zinc and/or high-dose ascorbic acid reduce the severity or duration of symptoms compared with usual care among ambulatory patients with SARS-CoV-2 infection. Design, Setting, and Participants: This multicenter, single health system randomized clinical factorial open-label trial enrolled 214 adult patients with a diagnosis of SARS-CoV-2 infection confirmed with a polymerase chain reaction assay who received outpatient care in sites in Ohio and Florida. The trial was conducted from April 27, 2020, to October 14, 2020. Intervention: Patients were randomized in a 1:1:1:1 allocation ratio to receive either 10 days of zinc gluconate (50 mg), ascorbic acid (8000 mg), both agents, or standard of care. Outcomes: The primary end point was the number of days required to reach a 50% reduction in symptoms, including severity of fever, cough, shortness of breath, and fatigue (rated on a 4-point scale for each symptom). Secondary end points included days required to reach a total symptom severity score of 0, cumulative severity score at day 5, hospitalizations, deaths, adjunctive prescribed medications, and adverse effects of the study supplements. Results: A total of 214 patients were randomized, with a mean (SD) age of 45.2 (14.6) years and 132 (61.7%) women. The study was stopped for a low conditional power for benefit with no significant difference among the 4 groups for the primary end point. Patients who received usual care without supplementation achieved a 50% reduction in symptoms at a mean (SD) of 6.7 (4.4) days compared with 5.5 (3.7) days for the ascorbic acid group, 5.9 (4.9) days for the zinc gluconate group, and 5.5 (3.4) days for the group receiving both (overall P = .45). There was no significant difference in secondary outcomes among the treatment groups. Conclusions and Relevance: In this randomized clinical trial of ambulatory patients diagnosed with SARS-CoV-2 infection, treatment with high-dose zinc gluconate, ascorbic acid, or a combination of the 2 supplements did not significantly decrease the duration of symptoms compared with standard of care. Trial Registration: ClinicalTrials.gov Identifier: NCT04342728.


Assuntos
Ácido Ascórbico/uso terapêutico , COVID-19/tratamento farmacológico , Suplementos Nutricionais , Zinco/uso terapêutico , Adulto , Assistência Ambulatorial , Antioxidantes/uso terapêutico , COVID-19/complicações , Tosse/tratamento farmacológico , Tosse/etiologia , Dispneia/tratamento farmacológico , Dispneia/etiologia , Fadiga/tratamento farmacológico , Fadiga/etiologia , Feminino , Febre/tratamento farmacológico , Febre/etiologia , Gluconatos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , SARS-CoV-2 , Índice de Gravidade de Doença , Padrão de Cuidado , Oligoelementos/uso terapêutico , Resultado do Tratamento
17.
J Sci Food Agric ; 101(11): 4662-4671, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-33491224

RESUMO

BACKGROUND: The environmental risk of the application of synthetic chelates has furthered the implementation of biodegradable complexes to correct manganese (Mn)-deficient plants. This study used the biodegradable ligands of heptagluconate (G7) and gluconate (G6) to test the influence of the Mn2+ :ligand ratio on their fertilizers' capacity to provide Mn to plants. The efficacy of these complexes to correct Mn-deficient soybean was evaluated in hydroponics and calcareous soil conditions and compared with the synthetic chelate EDTA (ethylenediaminetetraacetic acid). RESULTS: This study demonstrated that G7 was a biodegradable alternative to EDTA for supplying Mn, maintaining an adequate nutritional balance compared with G6, which reduced iron (Fe) uptake by the plants. The efficacy of the Mn complexes depended on both the ligand and the Mn:ligand ratio, with the 1:1 and 1:2 molar ratios of Mn2+ :G7 being the most effective complexes in the short term on the basis of their chemical structure and stability. CONCLUSION: The Mn2+ :G7 (1:1 and 1:2) complexes were found to be effective Mn sources for plant nutrition due to their chemical structures providing adequate stability in alkaline solution and their fast-action effect. © 2021 Society of Chemical Industry.


Assuntos
Gluconatos/metabolismo , Ferro/metabolismo , Manganês/metabolismo , Soja/metabolismo , Ácido Edético/química , Ácido Edético/metabolismo , Fertilizantes/análise , Hidroponia , Ferro/química , Quelantes de Ferro/química , Quelantes de Ferro/metabolismo , Ligantes
18.
PLoS One ; 16(1): e0241325, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33471829

RESUMO

Monolignol glucosides are storage forms of monolignols, which are polymerized to lignin to strengthen plant cell walls. The conversion of monolignol glucosides to monolignols is catalyzed by monolignol ß-glucosidases. Rice Os4BGlu18 ß-glucosidase catalyzes hydrolysis of the monolignol glucosides, coniferin, syringin, and p-coumaryl alcohol glucoside more efficiently than other natural substrates. To understand more clearly the basis for substrate specificity of a monolignol ß-glucosidase, the structure of Os4BGlu18 was determined by X-ray crystallography. Crystals of Os4BGlu18 and its complex with δ-gluconolactone diffracted to 1.7 and 2.1 Å resolution, respectively. Two protein molecules were found in the asymmetric unit of the P212121 space group of their isomorphous crystals. The Os4BGlu18 structure exhibited the typical (ß/α)8 TIM barrel of glycoside hydrolase family 1 (GH1), but the four variable loops and two disulfide bonds appeared significantly different from other known structures of GH1 ß-glucosidases. Molecular docking studies of the Os4BGlu18 structure with monolignol substrate ligands placed the glycone in a similar position to the δ-gluconolactone in the complex structure and revealed the interactions between protein and ligands. Molecular docking, multiple sequence alignment, and homology modeling identified amino acid residues at the aglycone-binding site involved in substrate specificity for monolignol ß-glucosides. Thus, the structural basis of substrate recognition and hydrolysis by monolignol ß-glucosidases was elucidated.


Assuntos
Oryza/genética , beta-Glucosidase/genética , beta-Glucosidase/ultraestrutura , Sequência de Aminoácidos , Sítios de Ligação , Gluconatos/metabolismo , Hidrólise , Lactonas/metabolismo , Lignina/genética , Lignina/metabolismo , Simulação de Acoplamento Molecular , Oryza/metabolismo , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , beta-Glucosidase/metabolismo
19.
Eur J Med Chem ; 213: 113182, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33486198

RESUMO

In this paper, two new Cu(II) complexes, [Cu(Gluc)(HPB)(H2O)]Gluc (CuG1) and [Cu(Gluc)(HPBC)(H2O)]Gluc (CuG2) (where HPB = 2-(2'-pyridyl)benzimidazole, HPBC = 5-chloro-2-(2'-pyridyl)benzimidazole, Gluc = d-Gluconic acid), with good water solubility were synthesized and characterized. These complexes exhibited a five-coordinated tetragonal pyramidal geometry. The DNA binding and cleavage properties of the complexes were investigated using multi-spectroscopy, viscosity measurement, molecular docking and gel electrophoresis analysis methods. The results showed that the complexes could interact with DNA by insertion and groove binding, and cleave CT-DNA through a singlet oxygen-dependent pathway in the presence of ascorbic acid. The studies on antibacterial and anticancer activities in vitro demonstrated that both complexes had good inhibitory activity against three Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes) and one Gram-negative bacterium (Escherichia coli) and good cytotoxic activity toward the tested cancer cells (A549, HeLa and SGC-7901). CuG2 showed higher antimicrobial and cytotoxic activities than CuG1, which was consistent with their binding strength and cleavage ability to DNA, indicating that their antimicrobial and cytotoxic activities may be related to the DNA interaction. Moreover, the cell-based mechanism studies have indicated that CuG1 and CuG2 could arrest the cell cycle at G2/M phase, elevate the levels of intracellular reactive oxygen species (ROS) and decrease the mitochondrial membrane potential (MMP). The results showed that the complexes could induce apoptosis through DNA-damaged and ROS-mediated mitochondrial dysfunction pathways. Finally, the in vivo antitumor study revealed that CuG2 inhibited tumor growth by 50.44%, which is better than that of cisplatin (40.94%).


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Cobre/farmacologia , DNA/efeitos dos fármacos , Gluconatos/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Bacillus subtilis/efeitos dos fármacos , Sítios de Ligação/efeitos dos fármacos , Bovinos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Cobre/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Escherichia coli/efeitos dos fármacos , Gluconatos/química , Humanos , Listeria monocytogenes/efeitos dos fármacos , Modelos Moleculares , Estrutura Molecular , Solubilidade , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Água/química
20.
Colloids Surf B Biointerfaces ; 198: 111472, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33257157

RESUMO

We investigated mixed-protein gels made from sodium caseinate and ovalbumin at different ratios with use of the acidification agent glucono-δ-lactone. Dynamic viscoelastic measurements revealed that increasing the ovalbumin content decreased the mechanical properties of the gel but accelerated onset time of the phase transition. Ultrasound spectroscopy during gelation revealed that the relative velocity gradually decreased, whereas the ultrasonic attenuation increased during the whole acidification process until gelation was complete, although these changes were much smaller than those observed with heat-induced gelation. Confocal laser scanning microscopy along with scanning electron microscopy revealed that although uniform mixing of sodium caseinate and ovalbumin was observed, sodium caseinate is likely to mainly lead formation of the gel network, and the porosity of the resulting gel network depends on the ratio of these two components. The results demonstrate that confocal laser scanning microscopy is a useful tool for analyzing both the networks within mixed-protein gels and the contribution of each protein to the network and gelation.


Assuntos
Caseínas , Géis , Gluconatos , Concentração de Íons de Hidrogênio , Lactonas , Ovalbumina , Reologia
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