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1.
Biomater Adv ; 138: 212855, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35913247

RESUMO

The use of chemically synthesized nanoparticles and crude plant extracts as antimicrobial -anticancer agents have many limitations. In this study, we have used Centella asiatica extract (CaE) having relatively less explored but tremendous medicinal properties, as reducing and stabilizing agents to green synthesize magnesium oxide nanoparticles (MgONPs) using magnesium nitrate. In comparison to the bulk material, capabilities of Ca-MgONPs as an improved antibacterial, antifungal, and anticancer agent in human prostatic carcinoma cells (PC3), as well as membranolytic capability in model cell membrane, were studied. The phyto-functionalized Ca-MgONPs were characterized using UV-Visible spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Spectroscopy (EDX), X-ray Diffraction (XRD), Fourier Transform Infra-Red Spectroscopy (FT-IR) and Atomic Force Microscopy (AFM). Observation of characteristic peaks by spectroscopic and microscopic analysis confirmed the synthesis of Ca-MgONPs. The Ca-MgONPs showed broad spectrum of bactericidal activity against both gram-positive and gram-negative bacteria and fungicidal activity against two species of the Candida fungus. The Ca-MgONPs also exhibited dose-dependent and selective inhibition of proliferating PC3 cells with IC50 of 123.65 ± 4.82 µg/mL at 24 h, however, without having any cytotoxicity toward non-cancerous HEK293 cells. Further studies aimed at understanding the probable mechanism of toxicity of Ca-MgONPs in PC3 cells, the results indicated a significant reduction in cell migration capacities, increment in cytosolic ROS, loss of mitochondrial transmembrane potential, DNA damage and S-phase cell cycle arrest. Ca-MgONPs also induced pore formation in a synthetic large unilamellar vesicle. Thus, Ca-MgONPs might be useful in the effective management of several human pathogens of concern and some more cancer types.


Assuntos
Anti-Infecciosos , Centella , Nanopartículas Metálicas , Antibacterianos/farmacologia , Anti-Infecciosos/química , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Química Verde , Células HEK293 , Humanos , Óxido de Magnésio/química , Nanopartículas Metálicas/uso terapêutico , Extratos Vegetais , Espectroscopia de Infravermelho com Transformada de Fourier , Triterpenos
2.
J Agric Food Chem ; 70(29): 9095-9105, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35838405

RESUMO

An Amadori rearrangement product (ARP) derived from ribose (Rib) and glutathione (GSH) was prepared and identified as N-(1-deoxy-d-ribulos-1-yl)-glutathione by ultraperformance liquid chromatography-tandem mass spectrometry and NMR. Thermal treatment of the ARP aqueous solution was conducted, and a relatively high temperature was found to accelerate the degradation of the ARP. The concentration of furans formed at 120 °C was more than 6.39 times that at 100 °C, and especially, the high temperature favored the formation of furfural and 4-hydroxy-5-methyl-3(2H)-furanone through deoxyosone dehydration. The promoting role of extra-added GSH or its constituent amino acids was investigated in the volatile formation during thermal processing of the ARP. Both, the added GSH and its constituent amino acids, could timely capture glyoxal (GO) and methylglyoxal (MGO) to facilitate Strecker degradation, which improved pyrazine formation. Compared with glycine and glutamic acid, cysteine was the most effective extra-added amino acid to react with GO and MGO to produce pyrazine and methylpyrazine. More importantly, the cysteine degraded from extra-added GSH effectively accelerated the generation of sulfur-containing volatile compounds through the reaction of cysteine degradation products with furans and shorter-chain α-dicarbonyl compounds.


Assuntos
Aminoácidos , Reação de Maillard , Aminoácidos/química , Cisteína/química , Furanos , Glutationa/química , Óxido de Magnésio , Pirazinas , Aldeído Pirúvico , Enxofre
3.
J Nanobiotechnology ; 20(1): 330, 2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35842630

RESUMO

BACKGROUND: Radiodynamic therapy (RDT) holds the potential to overcome the shallow tissue penetration issue associated with conventional photodynamic therapy (PDT). To this end, complex and sometimes toxic scintillator-photosensitizer nanoconjugates are often used, posing barriers for large-scale manufacturing and regulatory approval. METHODS: Herein, we report a streamlined RDT strategy based on CsI(Na)@MgO nanoparticles and 5-aminolevulinic acid (5-ALA). 5-ALA is a clinically approved photosensitizer, converted to protoporphyrin IX (PpIX) in cancer cells' mitochondria. CsI(Na)@MgO nanoparticles produce strong ~ 410 nm X-ray luminescence, which matches the Soret band of PpIX. We hypothesize that the CsI(Na)@MgO-and-5-ALA combination can mediate RDT wherein mitochondria-targeted PDT synergizes with DNA-targeted irradiation for efficient cancer cell killing. Because scintillator nanoparticles and photosensitizer are administered separately, the approach forgoes issues such as self-quenching or uncontrolled release of photosensitizers. RESULTS: When tested in vitro with 4T1 cells, the CsI(Na)@MgO and 5-ALA combination elevated radiation-induced reactive oxygen species (ROS), enhancing damages to mitochondria, DNA, and lipids, eventually reducing cell proliferation and clonogenicity. When tested in vivo in 4T1 models, RDT with the CsI(Na)@MgO and 5-ALA combination significantly improved tumor suppression and animal survival relative to radiation therapy (RT) alone. After treatment, the scintillator nanoparticles, made of low-toxic alkali and halide elements, were efficiently excreted, causing no detectable harm to the hosts. CONCLUSIONS: Our studies show that separately administering CsI(Na)@MgO nanoparticles and 5-ALA represents a safe and streamlined RDT approach with potential in clinical translation.


Assuntos
Nanopartículas , Fotoquimioterapia , Ácido Aminolevulínico/farmacologia , Animais , Linhagem Celular Tumoral , Óxido de Magnésio , Nanopartículas/uso terapêutico , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico
4.
Zhongguo Zhong Yao Za Zhi ; 47(12): 3215-3223, 2022 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-35851114

RESUMO

Advanced glycation end products(AGEs) can lead to many diseases such as diabetes and its complications. In this study, an in vitro non-enzymatic glycosylation reaction model-bovine serum albumin/methylglyoxal(BSA/MGO) reaction system was constructed and incubated with Cortex Moutan extract. High performance liquid chromatography(HPLC) and ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS/MS) were used to detect and identify the active components that inhibited the formation of AGEs in the co-incubation solution of Cortex Moutan extract and MGO, and differential components such as salvianan, paeoniside, benzoylpaeoniflorin, mudanpioside J, galloyloxypaeoniflorin, benzoyloxy-paeoniflorin, 5-hydroxy-3 s-hydroxymethyl-6-methyl-2,3-dihydro benzofuran, and galloylpaeoniflorin were screened out, which were inferred to be the potential active components of Cortex Moutan extract to capture MGO. In addition, BSA-glucose reaction system was performed to investigate the influence of different concentrations of Cortex Moutan extract(decoction concentrations: 40, 80, 120, 160, and 200 mg·mL~(-1)) on inhibiting the production of AGEs in vitro. The inhibitory effects of Cortex Moutan extract and the differential components galloylpaeoniflorin and benzoyl paeoniflorin on the production of AGEs in human umbilical vein endothelial cells(HUVECs) induced by high glucose was further evaluated. Cell apoptosis was observed by acridine orange and ethidium bromide(AO/EB) double fluorescence staining. The results showed that Cortex Moutan Cortex extract and its differential components had certain inhibitory effects on the formation of AGEs, and could reduce cell apoptosis. This study provided reference for the treatment of diabetic vascular complications by Cortex Moutan inhibiting the toxic AGEs.


Assuntos
Medicamentos de Ervas Chinesas , Espectrometria de Massas em Tandem , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Glucose , Produtos Finais de Glicação Avançada , Células Endoteliais da Veia Umbilical Humana , Humanos , Óxido de Magnésio
5.
Artigo em Inglês | MEDLINE | ID: mdl-35805431

RESUMO

Adsorption is an efficient technology for removing phosphorus from wastewater to control eutrophication. In this work, MgO-modified biochars were synthesized by a solvent-free ball milling method and used to remove phosphorus. The MgO-modified biochars had specific surface areas 20.50-212.65 m2 g-1 and pore volume 0.024-0.567 cm3 g-1. The as-prepared 2MgO/BC-450-0.5 had phosphorus adsorption capacities of 171.54 mg g-1 at 25 °C and could remove 100% of phosphorus from livestock wastewater containing 39.51 mg L-1 phosphorus. The kinetic and isotherms studied show that the pseudo-second-order model (R2 = 0.999) and Langmuir models (R2 = 0.982) could describe the adoption process well. The thermodynamic analysis indicated that the adsorption of phosphorus on the MgO-modified biochars adsorbent was spontaneous and endothermic. The effect of pH, FTIR spectra and XPS spectra studies indicated that the phosphorus adsorption includes a protonation process, electrostatic attraction and precipitation process. This study provides a new strategy for biochar modification via a facile mechanochemical method.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Cinética , Óxido de Magnésio , Fósforo , Solventes , Águas Residuárias/análise , Poluentes Químicos da Água/análise
6.
Int J Mol Sci ; 23(13)2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35806141

RESUMO

The impairment of the angiopoietin-1 (Ang-1)/Tie-2 signaling pathway has been thought to play a critical role in diabetic complications. However, the underlying mechanisms remain unclear. The present study aims to investigate the effects of Tie-2 glycation on Ang-1 signaling activation and Ang-1-induced angiogenesis. We identified that Tie-2 was modified by advanced glycation end products (AGEs) in aortae derived from high fat diet (HFD)-fed mice and in methylglyoxal (MGO)-treated human umbilical vein endothelial cells (HUVECs). MGO-induced Tie-2 glycation significantly inhibited Ang-1-evoked Tie-2 and Akt phosphorylation and Ang-1-regulated endothelial cell migration and tube formation, whereas the blockade of AGE formation by aminoguanidine remarkably rescued Ang-1 signaling activation and Ang-1-induced angiogenesis in vitro. Furthermore, MGO treatment markedly increased AGE cross-linking of Tie-2 in cultured aortae ex vivo and MGO-induced Tie-2 glycation also significantly decreased Ang-1-induced vessel outgrow from aortic rings. Collectively, these data suggest that Tie-2 may be modified by AGEs in diabetes mellitus and that Tie-2 glycation inhibits Ang-1 signaling activation and Ang-1-induced angiogenesis. This may provide a novel mechanism for Ang-1/Tie-2 signal dysfunction and angiogenesis failure in diabetic ischaemic diseases.


Assuntos
Angiopoietina-1 , Receptor TIE-2 , Angiopoietina-1/metabolismo , Angiopoietina-2/metabolismo , Animais , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Óxido de Magnésio/farmacologia , Camundongos , Neovascularização Patológica/metabolismo , Receptor TIE-2/metabolismo , Transdução de Sinais
7.
Int J Mol Sci ; 23(13)2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35806484

RESUMO

The reliable and cost-effective production of high-performance film electrodes for hydrogen evolution reactions remains a challenge for the laser surface modification community. In this study, prior to a thermal imidization reaction, a small number of Fe3O4 nanoparticles were vortexed into a poly(amic acid) (PAA) prepolymer, and the achieved flat composite film was then ablated by a 1064 nm fiber laser. After laser irradiation, the hierarchical architectures of carbon nanosheets decorated with Fe3O4 nanoparticles were generated. Although pure polyimide (PI) film and laser carbonized PI film, as well as bare Fe3O4, showcase poor intrinsic catalytic activity toward alkaline hydrogen evolution reactions, our laser-derived Fe3O4/carbon nanosheet hybrid film demonstrated enhanced electrocatalytic activity and stability in 1 M KOH electrolyte; the overpotential(η10) reached 247 mV when the current density was 10 mA cm-2 with a slight current decay in the chronoamperometric examination of 12 h. Finally, we proposed that the substitution of N to O in Fe-O sites of trans spinel structured magnetite would be able to modulate the free energy of hydrogen adsorption (ΔGH*) and accelerate water dissociation.


Assuntos
Carbono , Nitrogênio , Óxido de Alumínio , Eletrodos , Hidrogênio , Lasers , Óxido de Magnésio
8.
PLoS One ; 17(7): e0272376, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35901185

RESUMO

Variation in the antibacterial potency of manuka honey has been reported in several published studies. However, many of these studies examine only a few honey samples, or test activity against only a few bacterial isolates. To address this deficit, a collection of 29 manuka/Leptospermum honeys was obtained, comprising commercial manuka honeys from Australia and New Zealand and several Western Australian Leptospermum honeys obtained directly from beekeepers. The antibacterial activity of honeys was quantified using several methods, including the broth microdilution method to determine minimum inhibitory concentrations (MICs) against four species of test bacteria, the phenol equivalence method, determination of antibacterial activity values from optical density, and time kill assays. Several physicochemical parameters or components were also quantified, including methylglyoxal (MGO), dihydroxyacetone (DHA), hydroxymethylfurfural (HMF) and total phenolics content as well as pH, colour and refractive index. Total antioxidant activity was also determined using the DPPH* (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing-antioxidant power) assays. Levels of MGO quantified in each honey were compared to the levels stated on the product labels, which revealed mostly minor differences. Antibacterial activity studies showed that MICs varied between different honey samples and between bacterial species. Correlation of the MGO content of honey with antibacterial activity showed differing relationships for each test organism, with Pseudomonas aeruginosa showing no relationship, Staphylococcus aureus showing a moderate relationship and both Enterococcus faecalis and Escherichia coli showing strong positive correlations. The association between MGO content and antibacterial activity was further investigated by adding known concentrations of MGO to a multifloral honey and quantifying activity, and by also conducting checkerboard assays. These investigations showed that interactions were largely additive in nature, and that synergistic interactions between MGO and the honey matrix did not occur.


Assuntos
Mel , Leptospermum , Antibacterianos/química , Antibacterianos/farmacologia , Austrália , Escherichia coli , Leptospermum/química , Óxido de Magnésio , Nova Zelândia , Aldeído Pirúvico
9.
Sci Rep ; 12(1): 12806, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35896658

RESUMO

In this study, we investigated the process of preconcentrate and determine trace amounts of Auramine O (AO) and methylene blue (MB) dyes in environmental water samples. For this purpose, the ultrasound-assisted dispersive-magnetic nanocomposites-solid-phase microextraction (UA-DMNSPME) method was performed to extract AO and MB from aqueous samples by applying magnesium oxide nanoparticles (MgO-NPs). The proposed technique is low-cost, facile, fast, and compatible with many existing instrumental methods. Parameters affecting the extraction of AO and MB were optimized using response surface methodology (RSM). Short extraction time, low experimental tests, low consumption of organic solvent, low limits of detection (LOD), and high preconcentration factor (PF) was the advantages of method. The PF was 44.5, and LOD for AO and MB was 0.33 ng mL-1 and 1.66 ng mL-1, respectively. The linear range of this method for AO and MB were 1-1000 ng mL-1 and 5-2000 ng mL-1, respectively. In addition, the relative standard deviation (RSD; n = 5) of the mentioned analytes was between 2.9% and 3.1%. The adsorption-desorption studies showed that the efficiency of adsorbent extraction had not declined significantly up to 6 recycling runs, and the adsorbent could be used several times. The interference studies revealed that the presence of different ions did not interfere substantially with the extraction and determination of AO and MB. Therefore, UA-DMNSPME-UV/Vis method can be proposed as an efficient method for preconcentration and extraction of AO and MB from water and wastewater samples.


Assuntos
Azul de Metileno , Nanopartículas , Benzofenoneídio , Óxido de Magnésio , Extração em Fase Sólida/métodos , Microextração em Fase Sólida , Água
10.
Molecules ; 27(15)2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35897930

RESUMO

Epilepsy is a neurological disorder involving persistent spontaneous seizures and uncontrolled neuronal excitability that leads to cognitive impairments and blood-brain barrier (BBB) disruption. Currently available antiepileptic drugs present side effects and researchers are trying to discover new agents with properties to overcome these drawbacks. The aim was to synthesize magnesium oxide (MgO) and zinc oxide (ZnO) nanoparticles from Datura alba fresh leaf extracts and evaluate their anti-epileptic potential in mice kindling or a repetitive seizures model. The phytoassisted synthesized nanoparticles were characterized using spectroscopy; FT-IR, XRD, SEM, and EDX. Analysis of the NPs confirmed the crystalline pleomorphic shape using the salts of both zinc and magnesium possibly stabilized, functionalized and reduced by bioactive molecules present in plant extract. By using several characterization techniques, NPs were confirmed. UV-Vis spectroscopy of biologically produced ZnO and MgO revealed distinctive peaks at 380 nm and 242 nm, respectively. Our findings categorically demonstrated the reductive role of biomolecules in the formation of ZnO and MgO NPs. The mice kindling model was induced using seven injections of Pentylenetetrazole (PTZ, 40 mg/kg, i.p) for 15 days alternatively. The results showed that mice post-treated with either ZnO or MgO nanoparticles (10 mg/kg, i.p) significantly improved in respect of behavior and memory as confirmed in the Morris water maze (MWM), open field (OF), novel object recognition (NOR) test compared with PTZ treated mice. Furthermore, the ZnO and MgO nanoparticle treatment also maintained the integrity of the BBB, reducing the leakage, as confirmed by Evans blue dye (EBD) compared with PTZ treated mice only. In summary, the current finding demonstrates that green synthesized ZnO and MgO nanoparticles have neuroprotective, ant-epileptic potential, molecular mechanisms, and clinical implications need to be further explored.


Assuntos
Disfunção Cognitiva , Datura , Nanopartículas Metálicas , Nanopartículas , Óxido de Zinco , Animais , Antibacterianos/farmacologia , Barreira Hematoencefálica , Disfunção Cognitiva/tratamento farmacológico , Magnésio/farmacologia , Óxido de Magnésio/farmacologia , Nanopartículas Metálicas/química , Camundongos , Nanopartículas/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Espectroscopia de Infravermelho com Transformada de Fourier , Óxido de Zinco/química , Óxido de Zinco/farmacologia
11.
Anal Chem ; 94(28): 10198-10205, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35786854

RESUMO

Phenol and its derivatives, known as persistent organic pollutants, have long threatened human health and environmental safety. There is an urgent need to develop convenient, low-cost, and multiplex analytical methods. Since phenols are substrates of laccase, they can be detected via laccase-catalyzed colorimetric assays. Nevertheless, the laccase-based assays cannot distinguish different phenols. Moreover, natural laccases suffer from high cost and low stability issues. To meet these needs, here we developed a laccase-like nanozyme sensor array for phenol detection and differentiation, which takes advantage of both nanozymes and cross-reactive sensor arrays. First, we examined a series of spinel-type transition metal oxides and found that manganese on octahedral sites profoundly affects the laccase-like activity of the materials. Based on the developed manganese-based spinel oxides (i.e., Mn3O4, Zn0.4Li0.6Mn2O4, and LiMn2O4), a colorimetric sensor array was constructed. The sensor array could effectively identify and discriminate phenol and its derivatives and showed good performance in the identification and differentiation of phenols in tap water samples. This work provides an important guidance for the development of laccase-like nanozymes and a promising methodology for pollutant monitoring.


Assuntos
Poluentes Ambientais , Lacase , Óxido de Alumínio , Humanos , Óxido de Magnésio , Manganês , Óxidos , Fenol , Fenóis/análise
12.
Proc Natl Acad Sci U S A ; 119(30): e2202682119, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35858430

RESUMO

Heterogeneous peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) have shown a great potential for pollutant degradation, but their feasibility for large-scale water treatment application has not been demonstrated. Herein, we develop a facile coprecipitation method for the scalable production (∼10 kg) of the Cu-Fe-Mn spinel oxide (CuFeMnO). Such a catalyst has rich oxygen vacancies and symmetry-breaking sites, which endorse it with a superior PMS-catalytic capacity. We find that the working reactive species and their contributions are highly dependent on the properties of target organic pollutants. For the organics with electron-donating group (e.g., -OH), high-valent metal species are mainly responsible for the pollutant degradation, whereas for the organics with electron-withdrawing group (e.g., -COOH and -NO2), hydroxyl radical (•OH) as the secondary oxidant also plays an important role. We demonstrate that the CuFeMnO-PMS system is able to achieve efficient and stable removal of the pollutants in the secondary effluent from a municipal wastewater plant at both bench and pilot scales. Moreover, we explore the application prospect of this PMS-based AOP process for large-scale wastewater treatment. This work describes an opportunity to scalably prepare robust spinel oxide catalysts for water purification and is beneficial to the practical applications of the heterogeneous PMS-AOPs.


Assuntos
Óxido de Alumínio , Óxido de Magnésio , Peróxidos , Poluentes da Água , Purificação da Água , Óxido de Alumínio/química , Catálise , Óxido de Magnésio/química , Peróxidos/química , Poluentes da Água/química , Purificação da Água/métodos
13.
Nanotoxicology ; 16(3): 393-407, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35818303

RESUMO

The use of metal oxide nanoparticles (NPs) is steadily spreading, leading to increased environmental exposures to many organisms, including humans. To improve our knowledge of this potential hazard, we have evaluated the genotoxic risk of cerium oxide (CeO2NPs) and magnesium oxide (MgONPs) nanoparticle exposures using Drosophila as an in vivo assay model. In this study, two well-known assays, such as the wing somatic mutation and recombination test (wing-spot assay) and the single-cell gel electrophoresis test (comet assay) were used. As a novelty, and for the first time, changes in the expression levels of a wide panel of DNA repair genes were also evaluated. Our results indicate that none of the concentrations of CeO2NPs increased the total spot frequency in the wing-spot assay, while induction was observed at the highest dose of MgONPs. Regarding the comet assay, both tested NPs were unable to induce single DNA strand breaks or oxidative damage in DNA bases. Nevertheless, exposure to CeO2NPs induced significant increases in the expression levels of the Mlh1 and Brca2 genes, which are involved in the double-strand break repair pathway, together with a decrease in the expression levels of the MCPH1 and Rad51D genes. Regarding the effects of MgONPs exposure, the expression levels of the Ercc1, Brca2, Rad1, mu2, and stg genes were significantly increased, while Mlh1 and MCPH1 genes were decreased. Our results show the usefulness of our approach in detecting mild genotoxic effects by evaluating changes in the expression of a panel of genes involved in DNA repair pathways.


Assuntos
Cério , Nanopartículas Metálicas , Nanopartículas , Animais , Proteínas de Ciclo Celular , Cério/toxicidade , Ensaio Cometa , Proteínas do Citoesqueleto , DNA , Dano ao DNA , Drosophila , Humanos , Óxido de Magnésio/toxicidade , Nanopartículas Metálicas/toxicidade , Nanopartículas/toxicidade , Óxidos
14.
Proc Natl Acad Sci U S A ; 119(31): e2201607119, 2022 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35878043

RESUMO

Nonradical Fenton-like catalysis offers opportunities to overcome the low efficiency and secondary pollution limitations of existing advanced oxidation decontamination technologies, but realizing this on transition metal spinel oxide catalysts remains challenging due to insufficient understanding of their catalytic mechanisms. Here, we explore the origins of catalytic selectivity of Fe-Mn spinel oxide and identify electron delocalization of the surface metal active site as the key driver of its nonradical catalysis. Through fine-tuning the crystal geometry to trigger Fe-Mn superexchange interaction at the spinel octahedra, ZnFeMnO4 with high-degree electron delocalization of the Mn-O unit was created to enable near 100% nonradical activation of peroxymonosulfate (PMS) at unprecedented utilization efficiency. The resulting surface-bound PMS* complex can efficiently oxidize electron-rich pollutants with extraordinary degradation activity, selectivity, and good environmental robustness to favor water decontamination applications. Our work provides a molecule-level understanding of the catalytic selectivity and bimetallic interactions of Fe-Mn spinel oxides, which may guide the design of low-cost spinel oxides for more selective and efficient decontamination applications.


Assuntos
Elétrons , Óxidos , Óxido de Alumínio , Catálise , Óxido de Magnésio/química , Óxidos/química , Peróxidos/química
15.
Chin J Physiol ; 65(3): 125-135, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35775531

RESUMO

Cajanus cajan (L.) Millsp., known as pigeon pea, is one of the major grain legume crops of the tropical world. It recognizes as an ethnomedicine to possess various functions, such as helping in healing wound and cancer therapy. We investigated whether 95% ethanol extracts from C. cajan root (EECR) protect against methylglyoxal (MGO)-induced insulin resistance (IR) and hyperlipidemia in male Wistar rats and explored its possible mechanisms. The hypoglycemic potential of EECR was evaluated using α-amylase, α-glucosidase activities, and advanced glycation end products (AGEs) formation. For in vivo study, the rats were divided into six groups and orally supplemented with MGO except for Group 1 (controls). Group 2 was supplemented with MGO only, Group 3: MGO + metformin, Group 4: MGO + Low dose-EECR (L-EECR; 10 mg/kg bw), Group 5: MGO + Middle dose-EECR (M-EECR; 50 mg/kg bw), and Group 6: MGO + High dose-EECR (H-EECR; 100 mg/kg bw). EECR possessed good inhibition of α-glucosidase, α-amylase activities, and AGEs formation (IC50 = 0.12, 0.32, and 0.50 mg/mL), respectively. MGO significantly increased serum levels of blood glucose (GLU), glycosylated hemoglobin, homeostasis model assessment of IR, AGEs, lipid biochemical values, and atherogenic index, whereas EECR decreased these levels in a dose-dependent manner. EECR can also act as an insulin sensitizer, which significantly decreased (47%, P < 0.05) the blood GLU levels after intraperitoneal injection of insulin in the insulin tolerance tests. The hypoglycemic and antihyperlipidemic mechanisms of EECR are likely through several possible pathways including the inhibition of carbohydrate-hydrolyzing enzymes (α-glucosidase and α-amylase) and the enhancement of MGO-trapping effects on inhibition of AGEs formation.


Assuntos
Cajanus , Diabetes Mellitus Experimental , Animais , Cajanus/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Produtos Finais de Glicação Avançada/metabolismo , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Hipolipemiantes/farmacologia , Hipolipemiantes/uso terapêutico , Insulina , Óxido de Magnésio , Masculino , Aldeído Pirúvico/metabolismo , Aldeído Pirúvico/farmacologia , Ratos , Ratos Wistar , alfa-Amilases , alfa-Glucosidases
16.
Chemosphere ; 304: 135318, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35709833

RESUMO

It is an urgent need to develop new environmentally friendly spinel ferrites with high catalytic efficiency. In this work, a series of Mg-Fe-Al-O spinels with different ratios of Mg/Al were successfully synthesized by the reaction sintering method and were used as a heterogeneous photo-Fenton catalyst for degradation of Rhodamine B (RhB). The effect of different ratios of Mg/Al on the properties of Mg-Fe-Al-O spinel was characterized and analyzed through a range of advanced characterization techniques and DFT calculations. The influence factors on the photo-Fenton reaction catalyzed by Mg-Fe-Al-O spinels were systematically investigated. The results showed that the prepared Mg-Fe-Al-O spinels had larger lattice parameters, wider bandgap, and stronger magnetism, with the Mg content increased. Among them, Mg-9 (Mg0.88Fe1.88Al0.23O4) had the best catalytic performance in the photo-Fenton reaction. The degradation efficiency of RhB reached 98.45%, and the TOC removal efficiency was 83.47%. The elemental valence and PDOS of Mg-9 (Mg0.88Fe1.88Al0.23O4) spinels were closer to MgFe2O4. The photo-generated holes could directly oxidize water and hydroxyl to generate reactive oxygen species ·OH, improving the catalytic activity.


Assuntos
Peróxido de Hidrogênio , Ferro , Óxido de Alumínio , Catálise , Óxido de Magnésio , Rodaminas
17.
Bioresour Technol ; 359: 127500, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35724913

RESUMO

The aim of this work was to study on MgO-modified KOH activated biochar (AC) catalysts, in the pyrolysis of sawdust for the direct production of bio-jet fuels using a tandem micro-pyrolyzer. AC catalysts with various MgO contents (5 to 20 wt%) were synthesized using an impregnation method. The mesopores generated (4 to 18 nm) in the carbon has a great potential in the conversion of oxygenated to jet fuel. The importance of basic nature in the catalysts is demonstrated with the maximum bio-jet fuel yield of 29 % at 10 % MgO. Further, the temperature of 600 °C and a catalyst/sawdust ratio of 10 are identified as the optimal conditions. The nanosize of MgO and the synergism of acid and base sites seemed to enhance deoxygenation, via decarboxylation and decarbonylation, and oligomerization, which are required for jet fuel formation in high amounts from sawdust pyrolysis.


Assuntos
Óxido de Magnésio , Pirólise , Biocombustíveis , Carvão Vegetal , Temperatura Alta
18.
Sci Rep ; 12(1): 10647, 2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35739169

RESUMO

MgO-Bi2-xCrxO3 nanocomposites for x = 0 and 0.07 were fabricated using the solvent-deficient route. X-ray diffraction method, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDXA) and UV-Vis spectroscopy were employed to study the properties. The samples were also evaluated for the antibacterial activity. The x = 0 sample showed a dominant monoclinic crystalline structure of [Formula: see text] phase. No peaks attributed to MgO were observed. Cr-doped [Formula: see text] in which Bi was substituted showed that [Formula: see text] phase was also present in the [Formula: see text] composite. The Scherrer formula was employed to determine the crystallite size of the samples. The Cr-doped sample showed a decrease in the crystallite size. The microstructures of the non-doped MgO-Bi2O3 and MgO-Bi1.93Cr0.07O3 composites consisted of micrometer sized grains and were uniformly distributed. Direct transition energy gap, [Formula: see text] decreased from 3.14 to 2.77 eV with Cr-doping as determined from UV-Vis spectroscopy. The Cr-doped [Formula: see text] nanocomposites exhibited two energy gaps at 2.36 and 2.76 eV. The antibacterial activity was determined against gram-negative bacteria (Salmonella typhimurium and Pseudomonas aeruginosa) and gram-positive bacteria (Staphylococcus aureus) by disc diffusion method. Cr-doping led to a decrease in inhibitory activity of MgO-Bi2-xCrxO3 nanocomposite against the various types of bacteria.


Assuntos
Óxido de Magnésio , Nanocompostos , Antibacterianos/química , Antibacterianos/farmacologia , Óxido de Magnésio/farmacologia , Nanocompostos/química , Solventes , Staphylococcus aureus
19.
Int J Mol Sci ; 23(11)2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35682865

RESUMO

Late vascular complications play a prominent role in the diabetes-induced increase in morbidity and mortality. Diabetes mellitus is recognised as a risk factor driving atherosclerosis and cardiovascular mortality; even after the normalisation of blood glucose concentration, the event risk is amplified-an effect called "glycolytic memory". The hallmark of this glycolytic memory and diabetic pathology are advanced glycation end products (AGEs) and reactive glucose metabolites such as methylglyoxal (MGO), a highly reactive dicarbonyl compound derived mainly from glycolysis. MGO and AGEs have an impact on vascular and organ structure and function, contributing to organ damage. As MGO is not only associated with hyperglycaemia in diabetes but also with other risk factors for diabetic vascular complications such as obesity, dyslipidaemia and hypertension, MGO is identified as a major player in the development of vascular complications in diabetes both on micro- as well as macrovascular level. In diabetes mellitus, the detoxifying system for MGO, the glyoxalase system, is diminished, accounting for the increased MGO concentration and glycotoxic load. This overview will summarise current knowledge on the effect of MGO and AGEs on vascular function.


Assuntos
Doenças Cardiovasculares , Diabetes Mellitus , Angiopatias Diabéticas , Hiperglicemia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/metabolismo , Angiopatias Diabéticas/etiologia , Angiopatias Diabéticas/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Humanos , Óxido de Magnésio , Aldeído Pirúvico/metabolismo
20.
Anal Biochem ; 653: 114739, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35644223

RESUMO

Here, four new sorbents based on dimethylglyoxime (DMG) functionalized silica-coated magnetic iron/graphene oxides (Fe3O4/MGO) were synthesized. A comparative study was performed among them to evaluate the different substrates and the role of the spacer in improving the lead extraction efficiency and selecting the most efficient sorbent. Based on experimental results, MGO@SiO2@3-chloropropyltrimethoxysilane@DMG was selected for magnetic dispersive µSPE of lead followed by flame (FAAS) and graphite furnace atomic absorption spectroscopy (GFAAS). The sorbents were characterized by FT-IR, FE-SEM, EDX, TEM, and Zeta potential. Sorbent amount (40.5 mg), sample pH (7.7), sonication time of adsorption and desorption procedures (9 min), and volume and acid concentration (2.2 mL of 2.7 mol L-1 nitric acid) were optimized using experimental design. Linearity of 20.0-600.0 ng mL-1 and 0.5-3.0 ng mL-1 resulted by FAAS and GFAAS, respectively. LODs were 7.0 and 0.2 ng mL-1 by FAAS and GFAAS, respectively. Intra- and inter-day RSDs% (n = 3) at two concentration levels of 3.0 and 100.0 ng mL-1 were below 7.6%.The adsorption capacity was 45.05 mg g-1. The adsorption isotherm showed a better fitting with the Langmuir model. Relative recoveries (%) of 87.8-115.1% were obtained for measuring trace amounts of lead in water, hair, and nail samples.


Assuntos
Grafite , Poluentes Químicos da Água , Adsorção , Grafite/química , Ferro/análise , Limite de Detecção , Óxido de Magnésio , Fenômenos Magnéticos , Óxidos/química , Oximas , Dióxido de Silício/química , Extração em Fase Sólida/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise
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