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1.
Adv Exp Med Biol ; 1155: 483-495, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468425

RESUMO

The loss of pancreatic ß-cells plays a central role in the pathogenesis of both type 1 and type 2 diabetes, and many studies have been focused on ways to improve glucose homeostasis by preserving, expanding and improving the function of ß-cell. Elevated levels of free fatty acids such as palmitate might contribute to the loss of ß-cells. A marine squid, Loliolus beka has long been used as a food in Korea, China, Japan and Europe due to its tender meat and high taurine content. Here, we investigated the protective effects of a hot water extract of Loliolus beka meat (LBM) against palmitate toxicity in Ins-1 cells, a rat ß-cell line. Treatment with LBM extract protected against palmitate-induced cytotoxicity and scavenged overproduction of nitric oxide, alkyl, and hydroxyl radicals. In addition, LBM extract protected against palmitate-induced DNA damage and ß-cell dysfunction. These findings suggest that LBM protects pancreatic ß-cells from palmitate-induced damage. LBM could be a potential therapeutic functional food for diabetes.


Assuntos
Extratos Celulares/farmacologia , Dano ao DNA , Decapodiformes/química , Radicais Livres/efeitos adversos , Células Secretoras de Insulina/efeitos dos fármacos , Palmitatos/efeitos adversos , Taurina/farmacologia , Animais , Apoptose , Linhagem Celular , Diabetes Mellitus , Carne , Ratos
2.
Kardiologiia ; 59(8): 47-53, 2019 Aug 08.
Artigo em Russo | MEDLINE | ID: mdl-31397229

RESUMO

PURPOSE: to study dynamics of indicators of oxidative stress and their role in development of cardiotoxicity in patients with lympho-proliferative diseases at the background of polychemotherapy. MATERIALS AND METHODS: We included into this study 30 patients with newly detected Non-Hodgkin lymphomas. The control group comprised 15 healthy volunteers. For registration of dynamics of formation of oxygen active forms (OAF), we used highly sensitive chemiluminescence assay. The state of initial stage of lipoperoxidation OAF and radicals of organic compounds) was assessed by dynamics of the leukocyte chemiluminescence. The state of final stage of lipoperoxidation (formation of nonmetabolizing lipid hydroperoxides and other compounds) was assessed by the level of malonic dialdehyde. We also determined indicator of leukocyte chemiluminescence intensity (both basal and zymosan-stimulated). For assessment of the cardiovascular system functional state before and after chemotherapy we used electrocardiography (ECG), echocardiography (EchoCG) and 24-hour ECG monitoring. RESULTS: The data obtained were indicative of increased generation of free radicals by leukocytes during polychemotherapy. After chemotherapy course we detected various types of cardiotoxicity. We noted substantial elevation of frequency of supraventricular and ventricular extrasystoles. There was direct correlation between rate of appearance of supraventricular extrasystoles and level of chemiluminescence of leukocytes (r=0.7; p=0.03). According to data of EchoCG although the left ventricular ejection fraction remained within the normal range during chemotherapy, there was a persistent tendency to its decrease (р<0.001). CONCLUSION: In this study we for the first time in patients with Non-Hodgkin lymphomas detected an elevation of level of free radical reactions and lipid peroxidation with simultaneous lowering of antiperoxidative activity of blood plasma and their relation to development of cardiotoxic effects. The results obtained indicate to necessity of search for novel early markers of oxidative stress activation, myocardial injury and disfunction able to help to substantially decrease risk of development of cardiovascular complications during and after chemotherapy.


Assuntos
Peroxidação de Lipídeos , Estresse Oxidativo , Ecocardiografia , Radicais Livres , Humanos , Função Ventricular Esquerda
3.
Biomed Khim ; 65(4): 331-338, 2019 Jun.
Artigo em Russo | MEDLINE | ID: mdl-31436175

RESUMO

The effect of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline on markers of hepatocytes cytolysis (aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transpeptidase), parameters reflecting the state of oxidative status (intensity of biochemical luminescence and the content of diene conjugates), and the activity of oxidative metabolism enzymes (aconitate hydratase, glucose-6-phosphate dehydrogenase, NADP-isocitrate dehydrogenase) was studied in rats with CCl4-induced liver injury. The results obtained in the course of the work demonstrated the ability of the test compound to reduce the severity of oxidative stress and liver cells damage, as well as to change the activity of aconitate hydratase and NADP-generating enzymes in the direction of control values. 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline was more effective in normalizing CCl4-induced changes of the analyzed parameters that Carsil used as a reference compound. The tendency to normalize the state of oxidative status and enzyme activity of oxidative metabolism can attributed to hepatoprotective and antioxidant properties of the tested compound.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Estresse Oxidativo , Quinolinas/farmacologia , Animais , Antioxidantes/farmacologia , Radicais Livres , Fígado/enzimologia , Ratos
4.
Expert Opin Investig Drugs ; 28(7): 593-603, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31185180

RESUMO

INTRODUCTION: Oxidative stress toxicity (OST) has been implicated in almost all pathological conditions. Despite the widespread use of natural antioxidants, no pharmaceutical antioxidants have yet been developed or prescribed in medical practise. Antioxidant drugs such as Deferiprone and N-acetylcysteine can target essential pathways of OST in many pathological conditions. The pharmacological parameters required by antioxidant drugs in relation to the OST target characteristics include the determination of the therapeutic index, ADMET and drug interactions. Antioxidant drug development efforts are currently targeting the treatment of severe diseases with no proven effective therapies. AREAS COVERED: This article addresses the damaging effects of OST, prospects for the development of pharmaceutical antioxidants and clinical studies using other drugs with antioxidant potential. EXPERT OPINION: Effective antioxidant therapeutic strategies should include the design of protocols for the inhibition of OST through iron chelation, administration of synthetic and natural antioxidants and enhancement of the antioxidant defences by increasing the production of endogenous antioxidants and activation of antioxidant mechanisms. Different therapeutic strategies apply in the use of antioxidant drugs for one or more targets, for prevention, treatment, or of post-treatment effects and for systematic, long-term or short-term applications. The design of new antioxidant drugs and effective protocols which can include Deferiprone and N-acetylcysteine combinations, could lead to the development of a new class of therapeutics for clinical use.


Assuntos
Antioxidantes/farmacologia , Depuradores de Radicais Livres/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Acetilcisteína/administração & dosagem , Acetilcisteína/farmacologia , Animais , Antioxidantes/administração & dosagem , Deferiprona/administração & dosagem , Deferiprona/farmacologia , Desenho de Drogas , Desenvolvimento de Medicamentos/métodos , Depuradores de Radicais Livres/administração & dosagem , Radicais Livres , Humanos , Quelantes de Ferro/administração & dosagem , Quelantes de Ferro/farmacologia , Terapia de Alvo Molecular
5.
Chem Commun (Camb) ; 55(54): 7796-7799, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31214673

RESUMO

Disclosed herein is a novel, metal-free synthesis of γ-lactams through the radical-mediated nitration-aminocarbonylation of unactivated olefins. The reaction is initiated by a nitro radical generated from the homolysis of tert-butyl nitrite. The intramolecular cyanamide serves as the aminocarbonylating reagent. This protocol offers an environment-benign method to produce the synthetically valuable nitromethyl substituted γ-lactams.


Assuntos
Alcenos/química , Lactamas/síntese química , Cianamida/química , Ciclização , Radicais Livres/química , Química Verde/métodos , Modelos Químicos , Nitritos/química , Estereoisomerismo
6.
Phys Chem Chem Phys ; 21(25): 13453-13461, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31187821

RESUMO

Radical pair formation and decay are implicated in a wide range of biological processes including avian magnetoreception. However, studying such biological radical pairs is complicated by both the complexity and relative fragility of natural systems. To resolve open questions about how natural flavin-amino acid radical pair systems are engineered, and to create new systems with novel properties, we developed a stable and highly adaptable de novo artificial protein system. These protein maquettes are designed with intentional simplicity and transparency to tolerate aggressive manipulations that are impractical or impossible in natural proteins. Here we characterize the ultrafast dynamics of a series of maquettes with differing electron-transfer distance between a covalently ligated flavin and a tryptophan in an environment free of other potential radical centers. We resolve the spectral signatures of the cysteine-ligated flavin singlet and triplet states and reveal the picosecond formation and recombination of singlet-born radical pairs. Magnetic field-sensitive triplet-born radical pair formation and recombination occurs at longer timescales. These results suggest that both triplet- and singlet-born radical pairs could be exploited as biological magnetic sensors.


Assuntos
Flavinas/química , Proteínas/química , Triptofano/química , Cisteína/química , Transporte de Elétrons , Radicais Livres/química , Cinética , Campos Magnéticos , Modelos Moleculares , Oxirredução
7.
Phys Chem Chem Phys ; 21(25): 13526-13538, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31210238

RESUMO

We present a theoretical analysis of the putative magnetosensitivity of lipid peroxidation. We focus on the widely accepted radical pair mechanism (RPM) and a recently suggested idea based on spin dynamics induced in three-radical systems by the mutual electron-electron dipolar coupling (D3M). We show that, contrary to claims in the literature, lipid peroxides, the dominant chain carriers of the autoxidation process, have associated non-zero hyperfine coupling interactions. This suggests that their recombination could, in principle, be magnetosensitive due to the RPM. While the RPM indeed goes a long way to explaining magnetosensitivity in these systems, we show that the simultaneous interaction of three peroxyl radicals via the D3M can achieve larger magnetic field effects (MFE), even if the third radical is remote from the recombining radical pair. For randomly oriented three-radical systems, the D3M induces a low-field effect comparable to that of the RPM. The mechanism furthermore immunizes the spin dynamics to the presence of large exchange coupling interactions in the recombining radical pair, thereby permitting much larger MFE at magnetic field intensities comparable to the geomagnetic field than would be expected for the RPM. Based on these characteristics, we suggest that the D3M could be particularly relevant for MFE at low fields, provided that the local radical concentration is sufficient to allow for three-spin radical correlations. Eventually, our observations suggest that MFEs could intricately depend on radical concentration and larger effects could ensue under conditions of oxidative stress.


Assuntos
Peroxidação de Lipídeos , Peróxidos Lipídicos/química , Modelos Moleculares , Radicais Livres/química , Campos Magnéticos , Oxirredução , Estresse Oxidativo , Teoria Quântica
8.
Vestn Oftalmol ; 135(2): 39-47, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31215533

RESUMO

Information about relationship between biochemical indexes of endothelial dysfunction in preeclampsia and morphometric parameters of macula is necessary for prediction of the risk of retinal vascular disorders. PURPOSE: To study the relationship between biochemical indexes of blood serum, lacrimal fluid (LF) and the macular retinal volume (MRV) in pregnant women with preeclampsia. MATERIAL AND METHODS: The study included 42 pregnant women aged 21 to 40 years with preeclampsia of different severity (the main group): 1st subgroup - mild degree (22 people); 2nd subgroup - average degree (12 people); 3rd subgroup - severe degree (8 people). The comparison group included 20 pregnant women aged 19 to 38 years experiencing physiologically natural pregnancy. RESULTS: By the 3rd trimester, in the 1st subgroup the index of MRV was between 6.4 and 9.5 mm3; the index of von Willebrand factor (vWF) - 88.9±7.3%; endothelin (ET) content in LF was 1.35±0.2 ng/ml; the indices of free radical oxidation (FRO) in lacrimal fluid (Ssp and Sind) were significantly higher than in the comparison group (p<0.01). In the 2nd subgroup: MRV was 7.4±0.5 mm3, ET - 2.2±0.3 ng/ml, and vWF - 117.2±8.5% (p<0.01); the indices of FRO were higher in comparison with the 1st subgroup. In the 3rd subgroup: MRV was 8.5±0.7 mm3, ET - 3.2±0.3 ng/ml, and vWF - 157±9.5% (difference with the 2nd subgroup p<0.01). The indices of FRO (Ssp, Sind and h) indices were maximum high (difference with the 2nd subgroup p<0.01). CONCLUSION: A trend of increase of MRV by the 3rd trimester correlating with the degrees of preeclampsia severity was found. In the main group (r from 0.71 to 0.83), strong, direct, statistically significant association was found between the increase of ET levels in LF, vWF and MRV on the one side, and FRO on the other side.


Assuntos
Pré-Eclâmpsia , Adulto , Biomarcadores , Feminino , Radicais Livres , Humanos , Gravidez , Terceiro Trimestre da Gravidez , Retina , Adulto Jovem
9.
Ecotoxicol Environ Saf ; 180: 756-761, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31154200

RESUMO

Nitrated polycyclic aromatic hydrocarbons (Nitro-PAHs) as important organic pollutants are ubiquitous in the atmospheric environment, agricultural soils and aquatic environments to pose a severe polluting risk. However, little is known about the mechanism of Nitro-PAHs genotoxicity in plants. We analyzed seeds germination, seedlings growth, and toxicity mechanism following 1-Nitropyrene treatment in Hordeum vulgare. Our results reveal that 1-NP treatment could be an inhibited agent on seeds germination and growth of roots and shoots. Additionally, the reduction of mitotic index and the increasing frequency of micronucleus suggest that 1-NP may pose a potential risk of genotoxicity in the plant. We further clarify that O2- and H2O2 radicals contribute to 1-NP stimulation induced oxidative damage. Our study provides insights into the role of Nitro-PAHs exposure on growth processing toxicity and genotoxicity in plant and provided a useful reference for the surveillance and risk management of Nitro-PAHs in environments.


Assuntos
Hordeum/efeitos dos fármacos , Mutagênicos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes do Solo/toxicidade , Radicais Livres/metabolismo , Germinação/efeitos dos fármacos , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Óxidos de Nitrogênio/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Pirenos/toxicidade
10.
Dokl Biochem Biophys ; 485(1): 132-134, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31201633

RESUMO

It was established that recombinant human peroxiredoxins (Prx1, Prx2, Prx4, and Prx6) inhibit natural dicarbonyls formed during free radical peroxidation of unsaturated lipids (malonic dialdehyde) and oxidative transformations of glucose (glyoxal and methylglyoxal). A possible role of the decrease in the activity of peroxiredoxins under oxidative and carbonyl stress is discussed as an important factor that triggers the molecular mechanisms of vascular wall damage in atherosclerosis and diabetes mellitus.


Assuntos
Radicais Livres/química , Peroxidação de Lipídeos , Estresse Oxidativo , Peroxirredoxinas/química , Aldeído Pirúvico/química , Humanos
11.
J Agric Food Chem ; 67(26): 7455-7465, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31244196

RESUMO

The use of natural pigments such as betalains in food and health-related products is often limited by said pigments' relative oxidative stabilities in the products or physiological matrices. Determination of the mechanism of oxidation may inform future development and delivery of better stabilized molecules for improved outcomes. In order to best determine the oxidation mechanism of betanin, a natural food colorant, our efforts were directed toward structural elucidation (LCMS-IT-TOF and NMR) of previously tentatively identified key dehydrogenation products that had been generated as a result of betanin, decarboxylated betanin, and neobetanin oxidation by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radicals. The resultant oxidation products, the neo-derivatives, were the most stable and survived the preparative isolation and purification process. Structural analyses subsequently confirmed that these compounds, as well as neobetanin, were also the key products of alternative pathways of betanin and 2-decarboxy-betanin oxidation when catalyzed by Cu2+ cations in aqueous solutions at pH close to neutral. Therefore, the structures of the following five neo- or xanneo-derivatives (14,15- or 2,3,14,15-dehydrogenated derivatives, respectively) were confirmed: neobetanin, 2-decarboxy-neobetanin, 2-decarboxy-xanneobetanin, 2,17-bidecarboxy-xanneobetanin, and 2,15,17-tridecarboxy-xanneobetanin. This research confirmed that Cu2+-catalyzed oxidation of betanin and 2-decarboxy-betanin results in generation of neo-derivatives of betanin. In contrast, Cu2+-catalyzed oxidation of 17-decarboxy-betanin and 2,17-bidecarboxy-betanin resulted mostly in formation of betanin xan-derivatives. A relevant mechanism of Cu2+-catalyzed oxidation of the pigments is proposed herein that suggests that the oxidation of betanin can possibly occur in the region of the dihydropyridinic ring and can omit the stage of methide quinone formation in the dihydroindolic system.


Assuntos
Beta vulgaris/química , Betacianinas/química , Corantes de Alimentos/química , Radicais Livres/química , Extratos Vegetais/química , Cromatografia Líquida de Alta Pressão , Descarboxilação , Oxirredução , Espectrometria de Massas por Ionização por Electrospray
12.
Food Chem ; 297: 124951, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253340

RESUMO

The shelf lives of hot-air-dried (HD) and freeze-dried (FD) Penaeus vannamei were predicted by accelerated storage testing combined with Arrhenius Equation. Meanwhile, the changes in lipid profiles and colour of the dried shrimps during storage were investigated. The predicted shelf life of FD shrimp was more than 1.47-fold than that of HD shrimp. Compared to HD shrimp, FD shrimp had lower levels of oxidation parameters such as peroxide value (POV) and thiobarbituric acid-reactive substances value (TBARS) during storage. In addition, FD shrimp had less reduction in lipid components such as triacylglycerol (TAG), phosphatidylcholine (PC), phosphatidylethanolamine (PE) and all fatty acids including saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) after storage. Moreover, FD shrimp showed a less significant decrease in redness value and increase in yellowness value. Therefore, FD shrimps have better quality stability during storage and then possess longer shelf life than HD shrimp.


Assuntos
Armazenamento de Alimentos/métodos , Lipídeos/química , Penaeidae/química , Frutos do Mar/análise , Animais , Cor , Ácidos Graxos/análise , Ácidos Graxos/química , Manipulação de Alimentos/métodos , Radicais Livres/análise , Radicais Livres/química , Liofilização , Lipídeos/análise , Valor Nutritivo , Oxirredução , Fosfatidilcolinas/análise , Fosfatidilcolinas/química , Triglicerídeos/análise , Triglicerídeos/química , Xantofilas/análise
13.
Eur J Med Chem ; 178: 687-704, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31228811

RESUMO

Free radicals generated due to exposure of radiation, environmental pollutants and as by-products of metabolised drugs. These free radicals are antagonized by molecules which are antioxidant in nature. Antioxidants are the substances which inhibit oxidation. They are moreover acknowledged as "free radical scavengers" as they form minor reactive species via radicals. Based on origin, they are categorised into two types: exogenous and endogenous antioxidants. An Antioxidant reduces the occurrence of different disorders like: aging, cancer, diabetes, inflammation, liver disease, cardiovascular disease, cataract and nephrotoxicity and neurodegenerative disorders. Dietary antioxidants are thought to have potential capacities to avert oxidative anxiety induced diseases. This review figures the various researches on pharmacological activity of natural along with synthetic antioxidant molecules.


Assuntos
Antioxidantes/farmacologia , Antioxidantes/química , Radicais Livres/química , Radicais Livres/farmacologia , Humanos , Estresse Oxidativo/efeitos dos fármacos
14.
Chemphyschem ; 20(15): 1912-1917, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31162781

RESUMO

Methyltriacetylene - the largest methylated polyacetylene detected in deep space - has been synthesized in the gas phase via the bimolecular reaction of the 1-propynyl radical with diacetylene under single-collision conditions. The barrier-less route to methyltriacetylene represents a prototype of a polyyne chain extension through a radical substitution mechanism and provides a novel low temperature route, in which the propynyl radical piggybacks a methyl group to be incorporated into methylated polyynes. This mechanism overcomes a key obstacle in previously postulated reactions of methyl radicals with unsaturated hydrocarbon, which fail the inclusion of methyl groups into hydrocarbons due to insurmountable entrance barriers thus providing a fundamental understanding on the electronic structure, chemical bonding, and formation of methyl-capped polyacetylenes. These species are key reactive intermediates leading to carbonaceous nanostructures in molecular clouds like TMC-1.


Assuntos
Alquinos/síntese química , Radicais Livres/química , Gases/química , Temperatura Baixa , Modelos Químicos , Termodinâmica
15.
Biochemistry (Mosc) ; 84(Suppl 1): S206-S224, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31213203

RESUMO

Reactive carbonyl compounds (RCC) are a group of compounds with clearly pronounced electrophilic properties that facilitate their spontaneous reactions with numerous nucleophilic reaction sites in proteins, lipids, and nucleic acids. The biological functions of RCC are determined by their concentration and governed by the hormesis (biphasic reaction) principle. At low concentrations, RCC act as signaling molecules activating defense systems against xenobiotics and oxidizers, and at high concentrations, they exhibit the cytotoxic effect. RCC participate in the formation of cell adaptive response via intracellular signaling pathways involving regulation of gene expression and cytoplasmic mechanisms related to the structure-functional rearrangements of proteins. Special attention in this review is given to the functioning of electrophiles as mediators of cell general adaption syndrome manifested as the biphasic response. The hypothesis is proposed that electrophilic signaling can be a proto-signaling system.


Assuntos
Aldeídos/metabolismo , Radicais Livres/metabolismo , Cetonas/metabolismo , Mutagênese/fisiologia , Estresse Oxidativo/fisiologia , Transdução de Sinais/fisiologia , Animais , Humanos , Oxirredução , Processamento de Proteína Pós-Traducional
16.
Int J Nanomedicine ; 14: 2963-2971, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31118615

RESUMO

Purpose: Tumor oxygenation is a critical parameter influencing the efficacy of cancer therapy. Low levels of oxygen in solid tumor have been recognized as an indicator of malignant progression and metastasis, as well as poor response to chemo- and radiation therapy. Being able to measure oxygenation for an individual's tumor would provide doctors with a valuable way of identifying optimal treatments for patients. Methods: Electron paramagnetic resonance imaging (EPRI) in combination with an oxygen-measuring paramagnetic probe was performed to measure tumor oxygenation in vivo. Triarylmethyl (trityl) radical exhibits high specificity, sensitivity, and resolution for quantitative measurement of O2 concentration. However, its in vivo applications in previous studies have been limited by the required high dosage, its short half-life, and poor intracellular permeability. To address these limitations, we developed high-capacity nanoformulated radicals that employed fluorescein isothiocyanate-labeled mesoporous silica nanoparticles (FMSNs) as trityl radical carriers. The high surface area nanostructure and easy surface modification of physiochemical properties of FMSNs enable efficient targeted delivery of highly concentrated, nonself-quenched trityl radicals, protected from environmental degradation and dilution. Results: We successfully designed and synthesized a tumor-targeted nanoplatform as a carrier for trityl. In addition, the nanoformulated trityl does not affect oxygen-sensing capacity by a self-relaxation or broadening effect. The FMSN-trityl exhibited high sensitivity/response to oxygen in the partial oxygen pressure range from 0 to 155 mmHg. Furthermore, MSN-trityl displayed outstanding intracellular oxygen mapping in both in vitro and in vivo animal studies. Conclusion: The highly sensitive nanoformulated trityl spin probe can profile intracellular oxygen distributions of tumor in a real-time and quantitative manner using in vivo EPRI.


Assuntos
Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres/química , Imagem Tridimensional , Nanopartículas/química , Neoplasias/metabolismo , Oximetria/métodos , Oxigênio/metabolismo , Animais , Linhagem Celular Tumoral , Fluorescência , Humanos , Masculino , Camundongos Nus , Nanopartículas/ultraestrutura , Neoplasias/patologia , Consumo de Oxigênio , Porosidade , Dióxido de Silício/química
17.
Chem Soc Rev ; 48(12): 3279-3319, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31123728

RESUMO

The well-known tendency of sulfur to catenate is exemplified by an extensive series of polysulfide dianions [Sn]2- (n = 2-9) and related radical monoanions [Sn]˙-. The dianions can be isolated as crystalline salts with appropriate cations and structurally and spectroscopically characterized. Although the smaller radical monoanions may be stabilized in zeolitic matrices, they are usually formed in solution via disproportionation or partial dissociation of the dianions as well as by electrochemical reduction of elemental sulfur. An understanding of the fundamental chemistry of these homoatomic species is key to unravelling their behaviour in a broad variety of chemical environments. This review will critically evaluate the techniques used to characterize polysulfide dianions and radical anions both in solution and in the solid state, i.e. Raman, UV-visible, EPR, NMR and X-ray absorption spectroscopy, X-ray crystallography, mass spectrometry, chromatography and high-level quantum-chemical calculations. This is followed by a discussion of recent advances in areas in which these anionic sulfur species play a crucial role, viz. alkali-metal-sulfur batteries, organic syntheses, biological chemistry, geochemical processes including metal transport, coordination complexes, atmospheric chemistry and materials science.


Assuntos
Fontes de Energia Elétrica , Sulfetos/química , Ânions/química , Complexos de Coordenação/química , Cristalografia por Raios X , Radicais Livres/química , Metais Alcalinos/química , Teoria Quântica
18.
Free Radic Res ; 53(2): 125, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31074685
19.
Chemphyschem ; 20(14): 1793-1798, 2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31081986

RESUMO

Glucose oxidase is a flavoprotein that is relatively well-studied as a physico-chemical model system. The flavin cofactor is surrounded by several aromatic acid residues that can act as direct and indirect electron donors to photoexcited flavin. Yet, the identity of the photochemical product states is not well established. We present a detailed full spectral reinvestigation of this issue using femtosecond fluorescence and absorption spectroscopy. Based on a recent characterization of the unstable tyrosine cation radical TyrOH•+ , we now propose that the primary photoproduct involves this species, which was previously not considered. Formation of this product is followed by competing charge recombination and radical pair stabilization reactions that involve proton transfer and radical transfer to tryptophan. A minimal kinetic model is proposed, including a fraction of TyrOH.+ that is stabilized up to the tens of picoseconds timescale, suggesting a potential role of this species as intermediate in biochemical electron transfer reactions.


Assuntos
Radicais Livres/química , Glucose Oxidase/química , Glucose Oxidase/efeitos da radiação , Aspergillus niger/enzimologia , Flavina-Adenina Dinucleotídeo/química , Flavina-Adenina Dinucleotídeo/efeitos da radiação , Proteínas Fúngicas/química , Proteínas Fúngicas/efeitos da radiação , Cinética , Luz , Fotoquímica/métodos , Espectrometria de Fluorescência/métodos , Tirosina/química
20.
Wiad Lek ; 72(4): 539-542, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31055528

RESUMO

OBJECTIVE: Introduction: In recent years in Ukraine, as in the entire world, there has been an increase in cases of domestic injuries with a raise in the number of patients with craniocerebral trauma and its consequences. The aim of our research was to study clinical symptoms, the state of free radical oxidation, aggregate and hemocoagulative properties of blood in patients with mild craniocerebral trauma. PATIENTS AND METHODS: Materials and methods: We conducted comprehensive clinical and laboratory examination of 34 patients with mild craniocerebral trauma and 20 apparently healthy patients (the control group). The diagnosis was made under ICD-10. The verification of the diagnosis was based on data from clinical examination, neurological status of neuroimaging (computer tomography and magnetic resonance imaging). The study group included 24 men and 10 women aged from 19 to 40. In addition, 20 apparently healthy individuals of the same age were examined, who comprised the control group (14 men and 6 women). In the blood parameters of all patients, we examined free radical oxidation, hemostasis and aggregation properties of platelets. RESULTS: Results: The conducted study revealed clinical disturbances, changes in the parameters of free radical lipid oxidation, coagulation and microcirculatory hemostasis. CONCLUSION: Conclusions: All patients with mild craniocerebral trauma, develop disturbances in the form of symptoms of microorganic lesion of the central nervous system: convergence weakness in 100% of patients, Mann's symptom (76.4%), disruption of the function of the cranial nerves (58.8%), signs of pyramidal insufficiency (68.4%), vestibular disorders (94.1%), autonomic vascular dysfunction (100%). Mild craniocerebral trauma is accompanied by the activation of free radical lipid oxidation processes, decreased activity of antioxidant enzymes, hypercoagulation, and increased aggregation properties of platelets.


Assuntos
Coagulação Sanguínea , Traumatismos Craniocerebrais/patologia , Radicais Livres/sangue , Adulto , Estudos de Casos e Controles , Traumatismos Craniocerebrais/sangue , Feminino , Humanos , Metabolismo dos Lipídeos , Masculino , Microcirculação , Ucrânia , Adulto Jovem
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