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1.
Int J Mol Sci ; 22(11)2021 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-34067406

RESUMO

The use of reactive electrochemical membranes (REM) in flow-through mode during the anodic oxidation of organic compounds makes it possible to overcome the limitations of plate anodes: in the case of REM, the area of the electrochemically active surface is several orders of magnitude larger, and the delivery of organic compounds to the reaction zone is controlled by convective flow rather than diffusion. The main problem with REM is the formation of fouling and gas bubbles in the pores, which leads to a decrease in the efficiency of the process because the hydraulic resistance increases and the electrochemically active surface is shielded. This work aims to study the processes underlying the reduction in the efficiency of anodic oxidation, and in particular the formation of gas bubbles and the recharge of the REM pore surface at a current density exceeding the limiting kinetic value. We propose a simple one-dimensional non-stationary model of the transport of diluted species during the anodic oxidation of paracetamol using REM to describe the above effects. The processing of the experimental data was carried out. It was found that the absolute value of the zeta potential of the pore surface decreases with time, which leads to a decrease in the permeate flux due to a reduction in the electroosmotic flow. It was shown that in the solution that does not contain organic components, gas bubbles form faster and occupy a larger pore fraction than in the case of the presence of paracetamol; with an increase in the paracetamol concentration, the gas fraction decreases. This behavior is due to a decrease in the generation of oxygen during the recombination reaction of the hydroxyl radicals, which are consumed in the oxidation reaction of the organic compounds. Because the presence of bubbles increases the hydraulic resistance, the residence time of paracetamol-and consequently its degradation degree-increases, but the productivity goes down. The model has predictive power and, after simple calibration, can be used to predict the performance of REM anodic oxidation systems.


Assuntos
Gases/química , Compostos Orgânicos/química , Eletrodos , Radical Hidroxila/química , Membranas Artificiais , Oxirredução , Poluentes Químicos da Água/química
2.
Nat Commun ; 12(1): 3393, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099712

RESUMO

The iron gall ink-triggered chemical corrosion of hand-written documents is a big threat to Western cultural heritages, which was demonstrated to result from the iron gall (GA-Fe) chelate-promoted reactive oxygen species generation. Such a phenomenon has inspired us to apply the pro-oxidative mechanism of GA-Fe to anticancer therapy. In this work, we construct a composite cancer nanomedicine by loading gallate into a Fe-engineered mesoporous silica nanocarrier, which can degrade in acidic tumor to release the doped Fe3+ and the loaded gallate, forming GA-Fe nanocomplex in situ. The nanocomplex with a highly reductive ligand field can promote oxygen reduction reactions generating hydrogen peroxide. Moreover, the resultant two-electron oxidation form of GA-Fe is an excellent Fenton-like agent that can catalyze hydrogen peroxide decomposition into hydroxyl radical, finally triggering severe oxidative damage to tumors. Such a therapeutic approach by intratumoral synthesis of GA-Fe nano-metalchelate may be instructive to future anticancer researches.


Assuntos
Antineoplásicos/administração & dosagem , Ácido Gálico/administração & dosagem , Ferro/administração & dosagem , Nanopartículas Metálicas/administração & dosagem , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Catálise , Complexos de Coordenação/administração & dosagem , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Portadores de Fármacos/química , Feminino , Ácido Gálico/química , Ácido Gálico/metabolismo , Células HeLa , Células Endoteliais da Veia Umbilical Humana , Humanos , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Radical Hidroxila/química , Radical Hidroxila/metabolismo , Injeções Intravenosas , Ferro/química , Ferro/metabolismo , Ligantes , Nanopartículas Metálicas/química , Camundongos , Neoplasias/patologia , Oxirredução , Oxigênio/metabolismo , Dióxido de Silício/química , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Arch Biochem Biophys ; 705: 108901, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-33964248

RESUMO

Recent developments in electronics have enabled the medical applications of non-thermal plasma (NTP), which elicits reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as hydroxyl radical (●OH), hydrogen peroxide (H2O2), singlet oxygen (1O2), superoxide (O2●-), ozone, and nitric oxide at near-physiological temperatures. In preclinical studies or human clinical trials, NTP promotes blood coagulation, eradication of bacterial, viral and biofilm-related infections, wound healing, and cancer cell death. To elucidate the solution-phase biological effects of NTP in the presence of biocompatible reducing agents, we employed electron paramagnetic resonance (EPR) spectroscopy to quantify ●OH using a spin-trapping probe, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO); 1O2 using a fluorescent probe; and O2●- and H2O2 using luminescent probes in the presence of thiols or tempol. NTP-induced ●OH was significantly scavenged by dithiothreitol (DTT), reduced glutathione (GSH), and oxidized glutathione (GSSG) in 2 or 5 mM DMPO. NTP-induced O2●- was significantly scavenged by 10 µM DTT and GSH, while 1O2 was not efficiently scavenged by these compounds. GSSG degraded H2O2 more effectively than GSH and DTT, suggesting that the disulfide bonds reacted with H2O2. In the presence of 1-50 mM DMPO, NTP-induced H2O2 quantities were unchanged. The inhibitory effect of tempol concentration (50 and 100 µM) on H2O2 production was observed in 1 and 10 mM DMPO, whereas it became ineffective in 50 mM DMPO. Furthermore, DMPO-OH did not interact with tempol. These results suggest that DMPO and tempol react competitively with O2●-. Further studies are warranted to elucidate the interaction between NTP-induced ROS and biomolecules.


Assuntos
Óxidos N-Cíclicos/química , Peróxido de Hidrogênio/química , Gases em Plasma/química , Espectroscopia de Ressonância de Spin Eletrônica , Radical Hidroxila/química
4.
J Photochem Photobiol B ; 219: 112202, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33946027

RESUMO

This article reports the synthesis of a novel ternary Visible-Light-Driven (VLD) photocatalyst and antibacterial agent. The two-dimensional graphitic carbon nitride nanosheets (g-C3N4 NSs) and 7% molybdenum doped zinc oxide nanoparticles (Mo doped ZnO NPs) were used for the synthesis of the 65% g-C3N4 hybridized with 7% Mo doped ZnO novel ternary nanocomposite (Mo doped ZnO/g-C3N4 ternary NC). The synthesis process, as well as the structures, morphologies, photocatalytic and antibacterial properties of the synthesized ternary NC and constituents, were investigated by using several spectroscopic and microscopic techniques. It was revealed through the Transmission Electron Microscopy (TEM) characterization of the synthesized NC that the Mo doped ZnO NPs were found uniformly embedded upon the well-stacked g-C3N4NSs. It was further discovered by the bandgap analysis that the light absorbance ability of the ternary NC exists in the visible region of the light spectrum. The photocatalytic degradation of the methylene blue (MB) by the use of novel ternary NC in an aqueous medium was analyzed while using Ultra Violet-Visible (UV-Visible) spectroscopy. Trapping experiments of active species during the photodegradation and Electron Spin Resonance (ESR) experiment revealed that the superoxide and hydroxyl radicals were the leading species liable for MB deterioration. The ternary NC exhibited superior photocatalytic performance as compared with binary doped or hybridized nanomaterials (NMs) and mono photocatalysts due to the facility of effective migration and separation of the charge carriers across the (Mo doped ZnO NPs)/g-C3N4 NSs interface of the heterojunction. The increased generation of the reactive oxygen species (ROS), O2-, and •OH radicals the photogenerated charge carriers within the Mo doped ZnO/g-C3N4 NC were found responsible for its enhanced antibacterial performance.


Assuntos
Antibacterianos/síntese química , Grafite/química , Luz , Nanocompostos/química , Compostos de Nitrogênio/química , Fotólise/efeitos da radiação , Óxido de Zinco/química , Antibacterianos/farmacologia , Catálise , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Radical Hidroxila/química , Nanopartículas Metálicas/química , Azul de Metileno/química , Molibdênio/química , Nanocompostos/toxicidade
5.
Int J Mol Sci ; 22(9)2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33946289

RESUMO

Within the reactive oxygen species (ROS) generated by cellular metabolisms, hydroxyl radicals (HO•) play an important role, being the most aggressive towards biomolecules. The reactions of HO• with methionine residues (Met) in peptides and proteins have been intensively studied, but some fundamental aspects remain unsolved. In the present study we examined the biomimetic model made of Ac-Met-OMe, as the simplest model peptide backbone, and of HO• generated by ionizing radiation in aqueous solutions under anoxic conditions. We performed the identification and quantification of transient species by pulse radiolysis and of final products by LC-MS and high-resolution MS/MS after γ-radiolysis. By parallel photochemical experiments, using 3-carboxybenzophenone (CB) triplet with the model peptide, we compared the outcomes in terms of short-lived intermediates and stable product identification. The result is a detailed mechanistic scheme of Met oxidation by HO•, and by CB triplets allowed for assigning transient species to the pathways of products formation.


Assuntos
Radical Hidroxila/química , Metionina/química , Peptídeos/química , Raios gama , Oxirredução , Fotólise , Radiólise de Impulso
6.
Food Chem ; 361: 130089, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34029907

RESUMO

The polysaccharide of yam was extracted by hot water method and purified by column chromatography. The physicochemical properties of Chinese yam polysaccharide were analyzed by UV, IR, GPC, 1D-NMR and 2D-NMR spectra. The results showed that Chinese yam polysaccharide had α-d-Gluc-(1 â†’ 4) glycoside bond, and the C2 hydroxyl group was replaced by ethoxyl group. The average molecular weight was determined to be 7.28 × 104. It showed that The scavenging effect of yam polysaccharide on hydroxyl radicals was similar to VC. The sulfated polysaccharide (SP), phosphorylated polysaccharide (PP), carboxymethylated polysaccharide (CP) and acetylated polysaccharide (A-P) were identified by IR and NMR. The results showed that P and its derivatives showed good antioxidant activity. Especially, their scavenging ability to hydroxyl radicals reached the level of VC. This laid a theoretical foundation for the development of yam polysaccharide-related foods.


Assuntos
Antioxidantes/química , Dioscorea/química , Polissacarídeos/química , Sequestradores de Radicais Livres/química , Radical Hidroxila/química , Metilação , Peso Molecular , Sulfatos/química
7.
Angew Chem Int Ed Engl ; 60(26): 14324-14328, 2021 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-33822451

RESUMO

Despite the great efforts of using DNAzyme for gene therapy, its clinical success is limited by the lack of simple delivery systems and limited anticancer efficacy. Here, we develop a simple approach for the synthesis of hybrid nanostructures that exclusively consist of DNAzyme and Cu2+ with ultra-high loading capacity. The Cu-DNAzyme nanohybrids allow to effectively co-deliver DNAzyme and Cu2+ into cancer cells for combinational catalytic therapy. The released Cu2+ can be reduced to Cu+ by glutathione and then catalyze endogenous H2 O2 to form cytotoxic hydroxyl radicals for chemodynamic therapy (CDT), while the 10-23 DNAzyme enables the catalytic cleavage of VEGFR2 mRNA and activates gene silencing for gene therapy. We demonstrate that the system can efficiently accumulate in the tumor and exhibit amplified cascade antitumor effects with negligible systemic toxicity. Our work paves an extremely simple way to integrate DNAzyme with CDT for the dual-catalytic tumor treatment.


Assuntos
Antineoplásicos/uso terapêutico , Cobre/metabolismo , DNA Catalítico/metabolismo , Radical Hidroxila/uso terapêutico , Nanoestruturas/química , Neoplasias/tratamento farmacológico , Fotoquimioterapia , Antineoplásicos/química , Antineoplásicos/metabolismo , Cobre/química , DNA Catalítico/química , Humanos , Radical Hidroxila/química , Radical Hidroxila/metabolismo , Neoplasias/metabolismo
8.
J Phys Chem Lett ; 12(16): 4032-4037, 2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33881870

RESUMO

We report the existence of two distinct oxygen-radical-containing Mn4CaO5/6 conformations with short O···O bonds in the crystal structures of the oxygen-evolving enzyme photosystem II (PSII), obtained using an X-ray free electron laser (XFEL). A short O···O distance of <2.3 Å between the O4 site of the Mn4CaO5 complex and the adjacent water molecule (W539) in the proton-conducting O4-water chain was observed in the second flash-induced (2F) XFEL structure (2F-XFEL), which may correspond to S3. By use of a quantum mechanical/molecular mechanical approach, the OH• formation at W539 and the short O4···OW539 distance (<2.3 Å) were reproduced in S2 and S3 with reduced Mn1(III), which lacks the additional sixth water molecule O6. As the O•- formation at O6 and the short O5···O6 distance (1.9 Å) have been reported in another 2F-XFEL structure with reduced Mn4(III), two distinct oxygen-radical conformations exist in the 2F-XFEL crystals.


Assuntos
Radical Hidroxila/química , Oxigênio/química , Complexo de Proteína do Fotossistema II/química , Proteínas de Bactérias/química , Lasers , Manganês/química , Conformação Proteica , Thermosynechococcus/enzimologia
9.
Molecules ; 26(6)2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33804057

RESUMO

As nutrition and a health tonic for both medicine and food, the protein content of Oviductus Ranae is more than 40%, making it an ideal source to produce antioxidant peptides. This work evaluated the effects of six different proteases (pepsin, trypsin, papain, flavourzyme, neutral protease and alcalase) on the antioxidant activity of Oviductus Ranae protein, and analyzed the relationship between the hydrolysis time, the degree of hydrolysis (DH) and the antioxidant activity of the enzymatic hydrolysates. The results showed that the antioxidant activity of Oviductus Ranae protein was significantly improved and the optimal hydrolysis time was maintained between 3-4 h under the action of different proteases. Among them, the protein hydrolysate which was hydrolyzed by pepsin for 180 min had the strongest comprehensive antioxidant activity and was most suitable for the production of antioxidant peptides. At this time, the DH, the DPPH radical scavenging activity, the absorbance value of reducing power determination and the hydroxyl radical scavenging activity corresponding to the enzymatic hydrolysate were 13.32 ± 0.24%, 70.63 ± 1.53%, 0.376 ± 0.009 and 31.96 ± 0.78%, respectively. Correlation analysis showed that there was a significant positive correlation between the hydrolysis time, the DH and the antioxidant activity of the enzymatic hydrolysates, further indicating that the hydrolysates of Oviductus Ranae protein had great antioxidant potential. The traditional anti-aging efficacy of Oviductus Ranae is closely related to the scavenging of reactive oxygen species, and its hydrolysates have better antioxidant capacity, which also provides support for further development of its traditional anti-aging efficacy.


Assuntos
Antioxidantes/química , Materia Medica/química , Peptídeo Hidrolases/química , Hidrolisados de Proteína/química , Sequestradores de Radicais Livres/química , Hidrólise , Radical Hidroxila/química , Pepsina A/química , Espécies Reativas de Oxigênio/química
10.
Molecules ; 26(7)2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33915907

RESUMO

Ascorbic acid (AA) has antioxidant properties. However, in the presence of Fe2+/Fe3+ ions and H2O2, it may behave as a pro-oxidant by accelerating and enhancing the formation of hydroxyl radicals (•OH). Therefore, in this study we evaluated the effect of AA at concentrations of 1 to 200 µmol/L on •OH-induced light emission (at a pH of 7.4 and temperature of 37 °C) from 92.6 µmol/L Fe2+-185.2 µmol/L EGTA (ethylene glycol-bis (ß-aminoethyl ether)-N,N,N',N'-tetraacetic acid)-2.6 mmol/L H2O2, and 92.6 µmol/L Fe3+-185.2 µmol/L EGTA-2.6 mmol/L H2O2 systems. Dehydroascorbic acid (DHAA) at the same range of concentrations served as the reference compound. Light emission was measured with multitube luminometer (AutoLumat Plus LB 953) for 120 s after automatic injection of H2O2. AA at concentrations of 1 to 50 µmol/L and of 1 to 75 µmol/L completely inhibited light emission from Fe2+-EGTA-H2O2 and Fe3+-EGTA-H2O2, respectively. Concentrations of 100 and 200 µmol/L did not affect chemiluminescence of Fe3+-EGTA-H2O2 but tended to increase light emission from Fe2+-EGTA-H2O2. DHAA at concentrations of 1 to 100 µmol/L had no effect on chemiluminescence of both systems. These results indicate that AA at physiological concentrations exhibits strong antioxidant activity in the presence of chelated iron and H2O2.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Ácido Ascórbico/química , Ácido Ascórbico/farmacologia , Ácido Egtázico/química , Compostos Férricos/química , Compostos Ferrosos/química , Peróxido de Hidrogênio/química , Radical Hidroxila/efeitos adversos , Radical Hidroxila/antagonistas & inibidores , Radical Hidroxila/química , Luminescência , Medições Luminescentes
11.
Molecules ; 26(9)2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33922609

RESUMO

Psychoactive drugs are classified as contaminants of emerging concern but there is limited information on their fate in surface waters. Here, we studied the photodegradation of three psychoactive drugs (sertraline, clozapine, and citalopram) in the presence of organic matter (WEOM) extracted under mild conditions from sediment of Lake Pamvotis, Greece. Spectral characterization of WEOM confirmed its humic-like nature. Preliminary experiments using chemical probes showed that WEOM was able to produce oxidant triplet excited state (3WEOM*), singlet oxygen (1O2), and hydroxyl radicals under irradiation with simulated solar light. Then, WEOM at 5 mgC L-1 was irradiated in the presence of the three drugs. It enhanced their phototransformation by a factor of 2, 4.2, and 16 for sertraline, clozapine, and citalopram, respectively. The drastic inhibiting effect of 2-propanol (5 × 10-3 M) on the reactions demonstrated that hydroxyl radical was the key intermediate responsible for drugs photodegradation. A series of photoproducts were identified by ultra-high performance liquid chromatography (UHPLC) coupled to high resolution mass spectrometry (HR-MS). The photodegradation of the three drugs proceeded through several pathways, in particular oxidations of the rings with or without O atom inclusion, N elimination, and substitution of the halogen by OH. The formation of halogenated aromatics was observed for sertraline. To conclude, sedimental natural organic matter can significantly phototransform the studied antidepressant drugs and these reactions need to be more investigated. Finally, ecotoxicity was estimated for the three target analytes and their photoproducts, using the Ecological Structure Activity Relationships (ECOSAR) computer program.


Assuntos
Radical Hidroxila/química , Fotólise , Psicotrópicos/química , Poluentes Químicos da Água/química
12.
Int J Mol Sci ; 22(8)2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33920018

RESUMO

In this paper, the kinetics of the reaction of phenyl isocyanate with crosslinking agents such as sucrose, sorbitol, and glycerol are reported. Crosslinking agents were used in high molar excess to isocyanate to obtain pseudo-first-order rate dependencies, and the reaction products were separated by high-performance liquid chromatography and detected by UV spectroscopy and mass spectrometry. It was found that the glycerol's primary hydroxyl groups were approximately four times reactive than the secondary ones. However, in the case of sorbitol, the two primary OH groups were found to be the most reactive, and the reactivity of hydroxyl groups decreased in the order of kOH(6)(8.43) > kOH(1)(6.91) > kOH(5)(1.19) > kOH(2)(0.98) > kOH(3)(0.93) > kOH(4)(0.64), where the numbers in the subscript and in the brackets denote the position of OH groups and the pseudo-first-order rate constants, respectively. The Atomic Polar Tenzor (APT) charges of OH groups and dipole moments of monosubstituted sorbitol derivatives calculated by density functional theory (DFT) also confirmed the experimental results. On the other hand, the reactions of phenyl isocyanate with crosslinking agents were also performed using high excess isocyanate in order to determine the number of OH-groups participating effectively in the crosslinking process. However, due to the huge number of derivatives likely formed in these latter reactions, a simplified reaction scheme was introduced to describe the resulting product versus reaction time distributions detected by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). Based on the results, the kinetically equivalent functionality (fk) of each crosslinking agent was determined and found to be 2.26, 2.6, and 2.96 for glycerol, sorbitol, and sucrose, respectively.


Assuntos
Materiais Biocompatíveis/química , Reagentes para Ligações Cruzadas/química , Poliuretanos/química , Cromatografia Líquida de Alta Pressão , Glicerol/química , Radical Hidroxila/química , Isocianatos/química , Cinética , Sorbitol/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Sacarose/química
13.
Phys Chem Chem Phys ; 23(9): 5069-5073, 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33655288

RESUMO

UVA-induced deleterious effect of thiopurine prodrugs including azathioprine, 6-mercaptopurine and 6-thioguanine (6-TG) increases the risk of cancer development due to the incorporation of 6-TG in patients' DNA. The catalytic mechanism by which thiobases act as a sustained oxidant producer has yet to be explored, especially through the Type I electron transfer pathway that produces superoxide radicals (O2˙-). Under Fenton-like conditions O2˙- radicals convert to extremely reactive hydroxyl radicals (˙OH), thus carrying even higher risk of biological damage than that induced by the well-studied type II reaction. By monitoring 6-TG/UVA-induced photochemistry in mass spectra and superoxide radicals (O2˙-) via nitro blue tetrazolium (NBT) reduction, this work provides two new findings: (1) in the presence of reduced glutathione (GSH), the production of O2˙-via the type I reaction is enhanced 10-fold. 6-TG thiyl radicals are identified as the primary intermediate formed in the reaction of 6-TG with O2˙-. The restoration of 6-TG and concurrent generation of O2˙- occur via a 3-step-cycle: 6-TG type I photosensitization, O2˙- oxidation and GSH reduction. (2) In the absence of GSH, 6-TG thiyl radicals undergo oxygen addition and sulfur dioxide removal to form carbon radicals (C6) which further convert to thioether by reacting with 6-TG molecules. These findings help explain not only thiol-regulation in a biological system but chemoprevention of cancer.


Assuntos
DNA/química , DNA/efeitos da radiação , Glutationa/química , Superóxidos/química , Tioguanina/química , Catálise , Dimerização , Radicais Livres/química , Deleção de Genes , Humanos , Radical Hidroxila/química , Oxirredução , Oxigênio/química , Transtornos de Fotossensibilidade , Sulfetos/química , Raios Ultravioleta
14.
Food Chem ; 351: 129344, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33647688

RESUMO

Protein oxidation is considered as an important factor affecting the texture quality of surimi. In this work, the myofibrillar protein (MP) from shrimp (Penaeus vannamei) was subjected to a hydroxyl radical generating system at various concentrations of H2O2, to simulate the oxidative environment during surimi processing. After the hydroxyl radical oxidation, it was found that the carbonyl content, surface hydrophobicity, and MP aggregation increased. Meanwhile, the a-helix decreased, but ß-sheet increased after oxidation. The moderate oxidation led to a dense network microstructure, increased water holding capacity (WHC) and decreased water mobility, which ultimately enhanced textural (hardness and springiness increased by 0.51- and 0.06-fold, respectively) and rheological properties of MP gel (MPG). However, excessive oxidation could reduce the mechanical properties of MPG. The microstructure, WHC and water distribution played a key role in the mechanical properties of MPG. This study can provide a theoretical basis for processing of shrimp surimi products.


Assuntos
Anostraca , Fenômenos Químicos , Radical Hidroxila/química , Proteínas Musculares/química , Animais , Géis , Interações Hidrofóbicas e Hidrofílicas , Oxirredução , Reologia , Alimentos Marinhos , Água/química
15.
PLoS One ; 16(3): e0248487, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33735216

RESUMO

A gas-phase Advanced Oxidation Process (gAOP) was evaluated for decontaminating N95 and surgical masks. The continuous process was based on the generation of hydroxyl-radicals via the UV-C (254 nm) photo-degradation of hydrogen peroxide and ozone. The decontamination efficacy of the gAOP was dependent on the orientation of the N95 mask passing through the gAOP unit with those positioned horizontally enabling greater exposure to hydroxyl-radicals compared to when arranged vertically. The lethality of gAOP was independent of the applied hydrogen peroxide concentration (2-6% v/v) but was significantly (P<0.05) higher when H2O2 was introduced into the unit at 40 ml/min compared to 20 ml/min. A suitable treatment for N95 masks was identified as 3% v/v hydrogen peroxide delivered into the gAOP reactor at 40 ml/min with continuous introduction of ozone gas and a UV-C dose of 113 mJ/cm2 (30 s processing time). The treatment supported >6 log CFU decrease in Geobacillus stearothermophilus endospores, > 8 log reduction of human coronavirus 229E, and no detection of Escherichia coli K12 on the interior and exterior of masks. There was no negative effect on the N95 mask fitting or particulate efficacy after 20 passes through the gAOP system. No visual changes or hydrogen peroxide residues were detected (<1 ppm) in gAOP treated masks. The optimized gAOP treatment could also support >6 log CFU reduction of endospores inoculated on the interior or exterior of surgical masks. G. stearothermophilus Apex spore strips could be applied as a biological indicator to verify the performance of gAOP treatment. Also, a chemical indicator based on the oxidative polymerization of pyrrole was found suitable for reporting the generation of hydroxyl-radicals. In conclusion, gAOP is a verifiable treatment that can be applied to decontaminate N95 and surgical masks without any negative effects on functionality.


Assuntos
Descontaminação/métodos , Máscaras/virologia , Gases/química , Humanos , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Respiradores N95/virologia , Oxirredução , Ozônio/química , Fotólise
16.
Food Chem ; 352: 129399, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33662918

RESUMO

The objective of this study was to investigate the antioxidant properties of cottonseed peptides. Results indicated that cottonseed peptides prepared by enzymatic hydrolysis and microbial fermentation both showed antioxidant properties. The cottonseed protein enzymatic hydrolysate with molecular weight less than 3 kDa exhibited excellent DPPH, ABTS and hydroxyl radical scavenging activity and ferrous ion chelating activity with EC50 values of 0.49 ± 0.02, 2.05 ± 0.02, 2.21 ± 0.12, and 0.99 ± 0.03 mg/mL, respectively. Amino acid composition analysis revealed that cottonseed protein hydrolysates are rich in acidic/basic and aromatic amino acids. In addition, among the 19 identified cottonseed protein-derived peptides, YSNQNGRF had the lowest CDOCKER energy and formed hydrogen bonds with Tyr334, Arg380, Arg415, Ser508, and Ser602, and van der Waals interactions with Asn382, Tyr525, Gln530, and Ser555, which all located in the binding site of Keap1-Nrf2 interaction. These findings suggested that the antioxidant peptides from cottonseed protein had the potential as functional ingredients in foods.


Assuntos
Antioxidantes/análise , Gossypium/química , Peptídeos/química , Proteínas de Plantas/química , Sementes/química , Antioxidantes/química , Sítios de Ligação , Ligação de Hidrogênio , Hidrólise , Radical Hidroxila/química , Peso Molecular
17.
J Photochem Photobiol B ; 216: 112112, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33524930

RESUMO

For the first time, using sturgeon sperm as a model system, sensitive to optical radiation, the comparative studies of biological effect of continuous wave, quasi-continuous wave, nano- and picosecond laser radiation under conditions with equal average irradiance (3 mW/cm2) and wavelength (532 nm) have been carried out. Analyzing the parameters of spermatozoa motion it has been shown that, depending on the energy dose and mode of laser operation, the radiation may have both stimulatory and inhibitory effect on the velocity of motion and spermatozoa motility duration as well as on sustaining of functional characteristics of cold-stored sperm. The possibility of increasing the fertilization rate due to use of the sperm preliminary treated with laser radiation is demonstrated. For the first time, the possibility of enhancement of biological effect going from continuous wave to quasi-continuous wave laser radiation at equal irradiance and wavelength has experimentally been proven. It is shown that the difference in biological effect of continuous wave, quasi-continuous wave, nano- and picosecond laser radiation is due to amplitude (peak) values of intensity. Using fluorescence analysis and luminol-dependent chemiluminescence assay, evidence for the participation of endogenous flavins and metal-free porphyrins in sensitized ROS formation (singlet oxygen, hydrogen peroxide, and hydroxyl radicals) in sturgeon sperm was obtained. Mechanisms of photochemical and photothermal reactions explaining the difference in efficacy of action of laser radiation in above modes are discussed.


Assuntos
Fertilização/efeitos da radiação , Fármacos Fotossensibilizantes/química , Espermatozoides/efeitos da radiação , Animais , Cordados , Relação Dose-Resposta à Radiação , Flavinas/química , Flavinas/metabolismo , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Radical Hidroxila/química , Radical Hidroxila/metabolismo , Lasers , Medições Luminescentes , Masculino , Processos Fotoquímicos , Porfirinas/química , Porfirinas/metabolismo , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Motilidade Espermática/efeitos da radiação , Nanomedicina Teranóstica
18.
Nat Commun ; 12(1): 812, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33547279

RESUMO

Carbon dots (CDs) are photoluminescent nanomaterials with wide-ranging applications. Despite their photoactivity, it remains unknown whether CDs degrade under illumination and whether such photodegradation poses any cytotoxic effects. Here, we show laboratory-synthesized CDs irradiated with light degrade into molecules that are toxic to both normal (HEK-293) and cancerous (HeLa and HepG2) human cells. Eight days of irradiation photolyzes 28.6-59.8% of the CDs to <3 kilo Dalton molecules, 1431 of which are detected by high-throughput, non-target high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Molecular network and community analysis further reveal 499 cytotoxicity-related molecules, 212 of which contain polyethylene glycol, glucose, or benzene-related structures. Photo-induced production of hydroxyl and alkyl radicals play important roles in CD degradation as affected by temperature, pH, light intensity and wavelength. Commercial CDs show similar photodegraded products and cytotoxicity profiles, demonstrating that photodegradation-induced cytotoxicity is likely common to CDs regardless of their chemical composition. Our results highlight the importance of light in cytocompatibility studies of CDs.


Assuntos
Carbono/toxicidade , Citotoxinas/toxicidade , Pontos Quânticos/toxicidade , Derivados de Benzeno/química , Derivados de Benzeno/toxicidade , Carbono/química , Carbono/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Citotoxinas/química , Glucose/química , Glucose/toxicidade , Células HEK293 , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Radical Hidroxila/química , Radical Hidroxila/toxicidade , Cinética , Luz , Fotólise , Polietilenoglicóis/química , Polietilenoglicóis/toxicidade , Pontos Quânticos/química , Pontos Quânticos/efeitos da radiação , Temperatura
19.
Chem Rev ; 121(4): 1981-2019, 2021 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-33492935

RESUMO

Since the first connection between Fenton chemistry and biomedicine, numerous studies have been presented in this field. Comprehensive presentation of the guidance from Fenton chemistry and a summary of its representative applications in cancer therapy would help us understand and promote the further development of this field. This comprehensive review first supplies basic information regarding Fenton chemistry, including Fenton reactions and Fenton-like reactions. Subsequently, the current progress of Fenton chemistry is discussed, with some corresponding representative examples presented. Furthermore, the current strategies for further optimizing the performance of chemodynamic therapy guided by Fenton chemistry are highlighted. Most importantly, future perspectives on the combination of biomedicine with Fenton chemistry or a wider range of catalytic chemistry approaches are presented. We hope that this review will attract positive attention in the chemistry, materials science, and biomedicine fields and further tighten their connections.


Assuntos
Compostos Férricos/química , Compostos Ferrosos/química , Peróxido de Hidrogênio/química , Ferro/química , Animais , Catálise , Humanos , Radical Hidroxila/química , Nanoestruturas/química , Neoplasias/metabolismo , Neoplasias/terapia , Oxirredução
20.
Theranostics ; 11(5): 2334-2348, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33500728

RESUMO

Activatable theranostics, integrating high diagnostic accuracy and significant therapeutic effect, holds great potential for personalized cancer treatments; however, their chemodynamic modality is rarely exploited. Herein, we report a new in situ activatable chemodynamic theranostics PAsc/Fe@Cy7QB to specifically recognize and eradicate cancer cells with H2O2-catalyzed hydroxyl radical (•OH) burst cascade. Methods: The nanomicelles PAsc/Fe@Cy7QB were constructed by self-assembly of acid-responsive copolymers incorporating ascorbates and acid-sensitive Schiff base-Fe2+ complexes as well as H2O2-responsive adjuvant Cy7QB. Results: Upon systematic delivery of PAsc/Fe@Cy7QB into cancer cells, the acidic microenvironment triggered disassembly of the nanomicelles. The released Fe2+ catalyzed the oxidation of ascorbate monoanion (AscH-) to efficiently produce H2O2. The released H2O2, together with the endogenous H2O2, could be converted into highly active •OH via the Fenton reaction, resulting in enhanced Fe-mediated T1 magnetic resonance imaging (MRI). The synchronously released Cy7QB was activated by H2O2 to produce a glutathione (GSH)-scavenger quinone methide to boost the •OH yield and recover the Cy7 dye for fluorescence and photoacoustic imaging. Conclusion: The biodegradable PAsc/Fe@Cy7QB designed for tumor-selective multimodal imaging and high therapeutic effect provides an exemplary paradigm for precise chemodynamic theranostic.


Assuntos
Peróxido de Hidrogênio/farmacologia , Radical Hidroxila/química , Nanopartículas/administração & dosagem , Neoplasias/tratamento farmacológico , Nanomedicina Teranóstica , Animais , Apoptose , Proliferação de Células , Feminino , Glutationa/metabolismo , Células Hep G2 , Humanos , Ferro/química , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/química , Neoplasias/metabolismo , Neoplasias/patologia , Oxidantes/farmacologia , Oxirredução , Ensaios Antitumorais Modelo de Xenoenxerto
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