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1.
J Chromatogr A ; 1609: 460445, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31431357

RESUMO

The separation of 14 chiral sulfoxides was systematically studied on 12 cellulose-based chiral columns in acetonitrile and acetonitrile-water mobile phases. Out of all monosubstituted methylphenylcarbamates of cellulose the one having a methyl moiety in position 3 showed more universal chiral resolving ability compared to 2- and 4-substituted derivatives. Out of disubstituted phenylcarbamates of cellulose the ones with methyl substituents showed higher enantiomer resolving ability compared to chloro-substituted ones and substitution in positions 3 of the phenyl moiety was clearly advantageous. From disubstituted derivatives those possessing a combination of methyl- and chloro-substituents were advantageous compared to the ones having dimethyl- or dichloro-substituents. Chiral recognition ability of most chiral selectors towards studied sulfoxides was higher in pure acetonitrile compared to previously studied methanol. The effect of water addition to the mobile phase on analyte retention and enantioseparation was also quite different from that observed with methanol. In particular, with aqueous methanol by increasing the water content in the mobile phase retention increased in most cases and the separation factor improved. In contrast, with aqueous acetonitrile retention and separation factors decreased up to a certain water content in the mobile phase and then started to recover again for most of the studied analytes.


Assuntos
Acetonitrilos/química , Celulose/química , Cromatografia Líquida de Alta Pressão/métodos , Sulfóxidos/química , Sulfóxidos/isolamento & purificação , Água/química , Metanol/química , Fenilcarbamatos/química , Estereoisomerismo
2.
Biochimie ; 168: 190-197, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31711941

RESUMO

Interactions of Citrobacter freundii methionine γ-lyase (MGL) with sulfoxides of typical substrates were investigated. It was found that sulfoxides are suicide substrates of the enzyme. The products of the ß- and γ-elimination reactions of sulfoxides, thiosulfinates, oxidize three cysteine residues of the enzyme. Three-dimensional structures of MGL inactivated by dimethyl thiosulfinate and diethyl thiosulfinate were determined at 1.46 Šand 1.59 Šresolution. Analysis of the structures identified SH groups oxidized by thiosulfinates and revealed the structural bases of MGL inactivation. The extent of inactivation of MGL in the catalysis of the ß-elimination reaction depends on the length of the «tail¼ at oxidized Cys115. Oxidation of Cys115 results in MGL incapable to catalyze the stage of methyl mercaptan elimination of the physiological reaction.


Assuntos
Aminoácidos/química , Liases de Carbono-Enxofre/química , Citrobacter freundii/enzimologia , Cisteína/química , Sulfóxidos/química , Proteínas de Bactérias/química , Cinética , Ligantes , Modelos Moleculares
3.
Biomed Chromatogr ; 34(2): e4721, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31656058

RESUMO

Teneligliptin is a recently developed dipeptidyl peptidase-4 (DPP-4) inhibitor for the treatment of type 2 diabetes mellitus. To study simultaneous pharmacokinetics of teneligliptin and its major active metabolite, teneligliptin sulfoxide in human plasma, we developed and validated a LC-MS/MS method. The analytes were detected in the positive mode using multiple reaction monitoring (teneligliptin: m/z 427.2→243.1; teneligliptin-d8 : m/z 435.2→251.3; teneligliptin sulfoxide: m/z 443.2→68.2). The method demonstrated accuracy, precision, and linearity over the concentration range of 5 to 1000 ng/mL for teneligliptin and 2.5 to 500 ng/mL for teneligliptin sulfoxide. The developed method is the first fully validated method capable of simultaneous determination of teneligliptin and its active metabolite, teneligliptin sulfoxide in plasma. The suitability of the method was successfully demonstrated in terms of quantification of teneligliptin and teneligliptin sulfoxide pharmacokinetics in plasma samples collected from healthy volunteers. The measurement of plasma metabolite/parent ratio of teneligliptin was feasible by this method.


Assuntos
Cromatografia Líquida/métodos , Pirazóis/sangue , Espectrometria de Massas em Tandem/métodos , Tiazolidinas/sangue , Estabilidade de Medicamentos , Humanos , Limite de Detecção , Modelos Lineares , Pirazóis/química , Pirazóis/metabolismo , Pirazóis/farmacocinética , Reprodutibilidade dos Testes , Sulfóxidos/sangue , Sulfóxidos/química , Sulfóxidos/metabolismo , Sulfóxidos/farmacocinética , Tiazolidinas/química , Tiazolidinas/metabolismo , Tiazolidinas/farmacocinética
4.
J Chromatogr A ; 1610: 460572, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31606155

RESUMO

Recently it has been reported that immobilized chlorinated-type chiral stationary phases based on cellulose tris(3,5-dichlorophenylcarbamate) are able to express an outstanding enantioselectivity towards the structure of 2-(benzylsulfinyl)benzamide. We now introduce two homologue series of chiral sulfoxides based on the same 2-(sulfinyl)benzoyl core as the prototype of new selectands for HPLC, whose enantioselectivity could be modulable through the replacement of the benzyl group with an unbranched alkyl chain varying in length from 1 to 5 carbon atoms. HPLC parameters such as mobile phase composition and column temperature have been carefully evaluated in order to get pertinent structure-enantioselectivity relationships. The enantiomer elution order was unambiguously determined by a combined strategy involving theoretical and experimental procedures. Two cases of temperature-dependent inversion of the elution order of enantiomers in the operative temperature range of chiral chromatographic support were observed.


Assuntos
Benzamidas/química , Benzamidas/isolamento & purificação , Celulose/análogos & derivados , Cromatografia Líquida de Alta Pressão/métodos , Fenilcarbamatos/química , Fenilcarbamatos/isolamento & purificação , Celulose/química , Celulose/isolamento & purificação , Entropia , Estereoisomerismo , Sulfóxidos/química , Temperatura
5.
Eur J Med Chem ; 183: 111667, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31536893

RESUMO

Hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRT) is a recognized target for antimalarial chemotherapeutics. It synthesises all of the 6-oxopurine nucleoside monophosphates, IMP, GMP and XMP needed by the malarial parasite, Plasmodium falciparum (Pf). PfHGXPRT is also indirectly responsible for the synthesis of the adenosine monophosphate, AMP. The acyclic nucleoside phosphonates (ANPs) are a class of PfHGXPRT inhibitors. Prodrugs of these compounds are able to arrest the growth of Pf in cell culture. In the search for new inhibitors of PfHGXPRT, a series of sulfur containing ANPs (thia-ANPs) has been designed and synthesized. These compounds are based on the structure of 2-(phosphonoethoxy)ethylguanine (PEEG) and PEEHx which consist of a purine base (i.e. guanine or hypoxanthine) linked to a phosphonate group by five atoms i.e. four carbons and one oxygen. Here, PEEG and PEEHx were modified by substituting a sulfide, sulfoxide or a sulfone bridge for the oxygen atom in the linker. The effect of these substitutions on the Ki values for human HGPRT and PfHGXPRT was investigated and showed that most of the thia-ANPs distinctively favour PfHGXPRT. For example, the thia-analogue of PEEHx has a Ki value of 0.2 µM for PfHGXPRT, a value 25-fold lower than for the human counterpart. Prodrugs of these compounds have IC50 values in the 4-6 µM range in antimalarial cell-based assays, making them attractive compounds for further development as antimalarial drug leads.


Assuntos
Antimaláricos/síntese química , Nucleosídeos/síntese química , Organofosfonatos/síntese química , Pentosiltransferases/antagonistas & inibidores , Plasmodium falciparum/enzimologia , Sulfetos/química , Sulfonas/química , Sulfóxidos/química , Antimaláricos/farmacologia , Humanos , Estrutura Molecular , Nucleosídeos/farmacologia , Organofosfonatos/farmacologia , Oxirredução , Plasmodium falciparum/efeitos dos fármacos , Pró-Fármacos/síntese química , Pró-Fármacos/farmacologia , Relação Estrutura-Atividade , Termodinâmica
6.
Int J Mol Sci ; 20(18)2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31533205

RESUMO

We present the evaluation of a sulfoxide-based polymer (poly(propylene sulfoxide), PPSO) as a potential 'stealth' macromolecule, and at the same time as a pharmacologically active (anti-inflammatory/anti-oxidant) material. The combination of these two concepts may at first seem peculiar since the gold standard polymer in biomaterials and drug delivery, poly(ethylene glycol) (PEG), is 'stealth' due to its chemical and biological inertness, which makes it hardly biologically active. Polysulfoxides, on the contrary, may couple a substantial inertness towards biomolecules under homeostatic conditions, with the possibility to scavenge reactive oxygen species (ROS) associated to inflammation. Polysulfoxides, therefore, are rather uniquely, 'active' 'stealth' polymers. Here, we describe the synthesis of PPSO through controlled oxidation of poly(propylene sulfide) (PPS), which on its turn was obtained via anionic ring-opening polymerization. In vitro, PPSO was characterized by a low toxicity (IC50 ~7 mg/mL at 24 h on human dermal fibroblasts) and a level of complement activation (in human plasma) and macrophage uptake slightly lower than PEG of a similar size. Importantly, and differently from PEG, on LPS-activated macrophages, PPSO showed a strong and dose-dependent ROS (hydrogen peroxide and hypochlorite)-scavenging activity, which resulted in a corresponding reduction of cytokine production.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Biopolímeros/farmacologia , Sulfóxidos/farmacologia , Animais , Anti-Inflamatórios/química , Antioxidantes/química , Biopolímeros/química , Sobrevivência Celular/efeitos dos fármacos , Fenômenos Químicos , Fibroblastos , Humanos , Camundongos , Estrutura Molecular , Peso Molecular , Polimerização , Células RAW 264.7 , Espécies Reativas de Oxigênio/metabolismo , Sulfóxidos/química
7.
Phys Med Biol ; 64(20): 205017, 2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31505477

RESUMO

A gel dosimeter has been developed utilising a recently reported system for reducing Fe3+ diffusion in a Fricke gel dosimeter which chelates xylenol orange to the gelling agent poly(vinyl alcohol) (PVA). Formulations were investigated using both gelatin and PVA as the gelling agent, along with the inclusion of glyoxal. The resulting gel had an optical density dose response of 0.0031 Gy-1, an auto-oxidation rate of 0.000 23 h-1, and a diffusion rate of 0.132 mm2 h-1 which is a significant improvement over previously reported gelatin based Fricke gel dosimeters. The gel was also shown to be energy and dose-rate independent and could be reused after irradiation. Thus, this gel dosimeter has the potential to provide a safe and practical solution to three dimensional radiation dosimetry in the medical environment.


Assuntos
Géis/química , Dosímetros de Radiação/normas , Difusão , Géis/efeitos da radiação , Fenóis/química , Álcool de Polivinil/química , Radiometria/instrumentação , Radiometria/métodos , Sulfóxidos/química
8.
Phys Med Biol ; 64(20): 205016, 2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31505483

RESUMO

Radiation therapy in the presence of a strong magnetic field is known to cause regions of enhanced and reduced dose at interfaces of materials with varying densities, in a phenomenon known as the electron return effect (ERE). In this study, a novel low-density gel dosimeter was developed to simulate lung tissue and was used to measure the ERE at the lung-soft tissue interface. Low-density gel dosimeters were developed with Fricke xylenol orange gelatin (FXG) and ferrous oxide xylenol orange (FOX) gels mixed with polystyrene foam beads of various sizes. The gels were characterized based on CT number, MR signal intensity, and uniformity. All low-density gels had CT numbers roughly equivalent to lung tissue. The optimal lung-equivalent gel formulation was determined to be FXG with <1 mm polystyrene beads due to the higher signal intensity of FXG compared to FOX and the higher uniformity with the small beads. Dose response curves were generated for the optimal low-density gel and conventional FXG. The change in spin-lattice relaxation rate (R1) before and after irradiation was linear with dose for both gels. Next, phantoms consisting of concentric cylinders with low-density and conventional FXG were created to simulate the lung-soft tissue interface. The phantoms were irradiated in a conventional linear accelerator (linac) and in a linac combined with a 1.5 T magnetic resonance imaging (MRI) unit (MR-linac) to measure the effects of the magnetic field on the dose distribution. Hot and cold spots were observed in the dose distribution at the boundaries between the gels for the phantom irradiated in the MR-linac but not the conventional linac, consistent with the ERE.


Assuntos
Elétrons , Géis/efeitos da radiação , Aceleradores de Partículas , Dosímetros de Radiação/normas , Planejamento da Radioterapia Assistida por Computador/métodos , Compostos Ferrosos/química , Géis/química , Humanos , Pulmão/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Imagens de Fantasmas , Fenóis/química , Radiometria/métodos , Radioterapia/instrumentação , Radioterapia/métodos , Planejamento da Radioterapia Assistida por Computador/instrumentação , Sulfóxidos/química
9.
Chem Commun (Camb) ; 55(70): 10480-10483, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31411608

RESUMO

A new enzymatic assay for the preparation of chiral sulfoxides that is enantiocomplementary to the known (S)-enantiomer-reducing activity of methionine sulfoxide reductase A (MsrA) is described. To this end, we have utilized the enzyme DMSO reductase (DmsABC), recently discovered by us being highly upregulated in stationary phase E. coli bacteria.


Assuntos
Sulfóxidos/química , Escherichia coli/metabolismo , Proteínas com Ferro-Enxofre/química , Cinética , Metionina Sulfóxido Redutases/química , Oxirredutases/química , Estereoisomerismo
10.
Mikrochim Acta ; 186(8): 496, 2019 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-31270596

RESUMO

Carboxylic acids (CAs) have been reported as potential biomarkers of specific diseases or human body odors. A visual sensor array is described here that is based on indicator displacement assays (IDAs). The arrays were prepared by spotting solutions of the following metal complexes: Murexide-Ni(II), murexide-Cu(II), zincon-Zn(II) and xylenol orange-Cu(II), with the capability of discrimination of 15 carboxylic acids (CAs) and the quantitation of pyruvic acid (PA). Clear differences can be observed through distinctive difference maps obtained within 5 min by subtraction of red, green and blue (RGB) values of digital images after and before exposure to analytes. After an analysis of multidimensional data by pattern recognition algorithms including HCA, PCA and LDA, excellent classification specificity, and accuracy of >96% were obtained for all samples. The IDA array exhibited a linear range from 10 to 1500 µM with a theoretical detection limit of 3.5 µM towards PA. Recoveries of real samples varied from 84.8% to 114.3%. As-fabricated IDA sensor array showed an excellent selectivity among other organic interfering substances and a good batch to batch reproducibility, demonstrating its robustness. All these observations suggested that the IDA sensor array is one of the most promising paths for the discrimination of CAs. Graphical abstract Schematic diagram of indicator displacement assay (a), the procedure for acquisition of difference maps (b), and pattern recognitions for CAs (c). The method uses hierarchical cluster analysis (HCA), principal component analysis (PCA) and linear discriminant analysis (LDA).


Assuntos
Ácidos Carboxílicos/análise , Ácidos Carboxílicos/sangue , Ácidos Carboxílicos/química , Análise por Conglomerados , Colorimetria , Cobre/química , Análise Discriminante , Corantes Fluorescentes/química , Humanos , Murexida/química , Níquel/química , Fenóis/química , Análise de Componente Principal , Sulfóxidos/química , Zinco/química
11.
Mater Sci Eng C Mater Biol Appl ; 103: 109814, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31349404

RESUMO

A mixed nano-metal oxides of Cu-Ni-Co has been synthesized. Several characterization techniques (EDS, XRD, TEM, and SEM) have been used to provide insight into the nature and structure of the catalyst. The size of this mixed metal oxide is 22 nm. The SEM images indicate that the sample with spherical particles, of which spherical assembly is comprised of elongated rod/needle-like subunits pointing radially outward, creates a needle ball-like structure. To efficiently catalyze the selective oxidation of sulfide towards sulfoxide, this heterogeneous catalyst uses an oxidizing agent (hydrogen peroxide- H2O2) and a solvent (acetonitrile) in mild conditions. The influence of reaction temperature and sulfide/oxidant molar ratio was evaluated with respect to sulfide conversion and chemoselectivity towards the sulfoxide product. Under optimized conditions, product yields in the range from 70 to 97% were obtained.


Assuntos
Nanopartículas Metálicas/química , Sulfetos/química , Sulfóxidos/química , Catálise , Cobalto/química , Cobre/química , Peróxido de Hidrogênio/química , Microscopia Eletrônica de Varredura , Níquel/química , Oxirredução , Óxidos/química , Temperatura , Difração de Raios X
12.
Molecules ; 24(7)2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30935001

RESUMO

A simple and efficient protocol for the oxidation of trifluoromethyl, mono- and difluoromethyl sulfides to the corresponding sulfoxides without over-oxidation to sulfones, using TFPAA prepared in situ from trifluoroacetic acid and 15% H2O2 aqueous solution was developed. The methodology is suitable for a wide range of aromatic and aliphatic substrates in milligram and multigram scales.


Assuntos
Compostos de Flúor/síntese química , Óxidos/síntese química , Sulfetos/química , Catálise , Peróxido de Hidrogênio/química , Oxirredução , Sulfonas/química , Sulfóxidos/química , Água/química
13.
Org Biomol Chem ; 17(13): 3381-3388, 2019 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-30860233

RESUMO

Here we report a methionine sulfoxide reductase A (MsrA) homologue with extremely high substrate tolerance and a wide substrate scope for the biocatalytic preparation of enantiopure sulfoxides. This MsrA homologue which was obtained from Pseudomonas alcaliphila (named paMsrA) showed good activity and enantioselectivity towards a series of aryl methyl/ethyl sulfoxides 1a-1k, with electron-withdrawing or electron-donating substituents at the aromatic ring. Chiral sulfoxides in the R configuration were prepared with approximately 50% of yield and up to 99% enantiomeric excess through the asymmetric reductive resolution of racemic sulfoxide catalyzed by the recombinant paMsrA protein. More importantly, kinetic resolution has been successfully accomplished with high enantioselectivity (E > 200) at initial substrate concentrations up to 320 mM (approximately 45 g L-1), which represents a great improvement in the aspect of the substrate concentration for the biocatalytic preparation of chiral sulfoxides.


Assuntos
Metionina Sulfóxido Redutases/análise , Sulfóxidos/metabolismo , Cinética , Metionina Sulfóxido Redutases/metabolismo , Estrutura Molecular , Pseudomonas/enzimologia , Sulfóxidos/química
14.
Med Chem ; 15(6): 685-692, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30727905

RESUMO

BACKGROUND: Malaria, caused by the deadly Plasmodium falciparum strain, claims the lives of millions of people annually. The emergence of drug-resistant strains of P. falciparum to the artemisinin-based combination therapy (ACT), the last line of defense against malaria, is worrisome and urges for the development of new chemo-types with a new mode of action. In the search of new antimalarial agents, hybrids of triazoles and other known antimalarial drugs have been reported to possess better activity than either of the parent compounds administered individually. Despite their better activity, no hybrid antimalarial drugs have been developed so far. OBJECTIVE: In the hope of developing new antimalarial prototypes, we propose the design, synthesis and antimalarial evaluation of novel sulfoximine-triazole hybrids owing to their interesting biological and physiological properties. METHODS: The sulfoximine part of the hybrid will be synthesized via imidation of the corresponding sulfoxide. Propargylation of the NH moiety of the sulfoximine followed by copper-catalyzed click chemistry with benzyl azide was envisaged to provide the target sulfoximine-triazole hybrids. RESULTS: Five novel sulfoximine-triazole hybrids possessing various substituents on the sulfoximine moiety have been successfully synthesized and evaluated for their antiplasmodial and cytotoxicity activities. The results revealed that the co-presence of the sulfoximine and triazole moieties along with a lipophilic alkyl substituent on the sulfur atom impart significant activity. CONCLUSION: Sulfoximine-triazole hybrids could be used as a prototype for the synthesis of new derivatives with better antiplasmodial activities.


Assuntos
Antimaláricos/farmacologia , Iminas/farmacologia , Sulfóxidos/farmacologia , Triazóis/farmacologia , Antimaláricos/síntese química , Antimaláricos/química , Antimaláricos/toxicidade , Desenho de Fármacos , Células HeLa , Humanos , Iminas/síntese química , Iminas/química , Iminas/toxicidade , Estrutura Molecular , Testes de Sensibilidade Parasitária , Plasmodium falciparum/efeitos dos fármacos , Sulfóxidos/síntese química , Sulfóxidos/química , Sulfóxidos/toxicidade , Triazóis/síntese química , Triazóis/química , Triazóis/toxicidade
15.
Chemosphere ; 223: 196-203, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30780030

RESUMO

In this study, peroxydisulfate (PDS) was successfully activated by nanoscale zero-valent iron (nZVI) for the degradation of sulfamethoxazole (SMX, antibiotic frequently detected in the environment) in agricultural soils. The results indicated that the degradation of SMX was affected by the nZVI dose, the ratio of SMX/PDS, the ratio of soil/water and reaction temperature, and in cinnamon soils 87.6% of SMX degradation can be achieved within 4 h at 30 °C when the initial nZVI dose was 0.03 g g-1 soil, the molar ratio of SMX/PDS = 1/75 and the soil/water = 1/1. The results of radical scavenger experiments and electron spin resonance (ESR) tests showed that hydroxyl radical (OH) was the dominant reactive species in this system. The ecotoxicity tests of the soil by germination test, luminescent bacteria experiment and enzyme activity test indicated that the ecotoxicity of soil after treatment was obviously lower than the contaminated soil. In addition, there was almost no effect on plant growth when compared with original soil. Furthermore, this system exhibited a great degradation capacity for SMX in different types of agricultural soils, and the degradation efficiencies of SMX in other four soils were 90.6% (yellow brown earths), 80.8% (brown earths), 86.5% (black soils) and 96.1% (red earths), respectively. This work provides an optional method for agricultural soil pollution control.


Assuntos
Poluição Ambiental/prevenção & controle , Ferro/química , Solo/química , Sulfametoxazol/química , Sulfóxidos/química , Agricultura , Anti-Infecciosos/química , Ecotoxicologia/métodos , Radical Hidroxila/análise , Poluentes do Solo/química , Sulfatos/química
16.
Top Curr Chem (Cham) ; 377(2): 8, 2019 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-30746619

RESUMO

Since the original idea was explored by James in 1976, the use of chiral sulfoxides as ligands with transition metals in asymmetric catalysis has undergone a long period of development. There have been many studies into their properties, design and application in various kinds of asymmetric transformations. In this article, we document the literatures on chiral sulfoxide ligands in asymmetric catalytic reactions.


Assuntos
Sulfóxidos/química , Elementos de Transição/química , Catálise , Ligantes
17.
Chem Biol Drug Des ; 93(6): 1026-1035, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30701670

RESUMO

Reactive oxygen species are crucial to normal cell function, but are also part of the pathogenesis of multiple modern maladies. As such, sensitive, fast, and reliable methods of appreciating redox status are needed. We aimed to optimize the Amplex Red (AR) and ferric-xylenol orange (FOX) methods using human serum samples, rat tissue homogenates, and mitochondrial preparations. For AR, we intended to reduce probe concentration, maintaining method sensitivity, as well as extending its use from isolated lipoproteins samples, and readjust it for a high-throughput application. Also, we evaluated the usefulness of a modified xylenol orange-based spectrophotometric protocol, comparing and contrasting these methods in terms of clinical relevance and suitability for their further use in assessing redox status of various biological samples in different pathological conditions. Our results show that these optimized protocols are suitable for complex in vivo studies, as they require low quantities of sample and reagents, and are sensitive, rapid, and economical, with the option of adapting them for high-throughput analysis. For a better assessment of oxidative status of serum-derived samples, the two methods can be used concurrently, while for tissue-derived ones, either can be employed for the measurement of a global redox status.


Assuntos
Peroxidação de Lipídeos , Espectrometria de Fluorescência/métodos , Espectrofotometria Ultravioleta/métodos , Idoso , Animais , Biomarcadores/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Estresse Oxidativo , Fenóis/química , Projetos Piloto , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Sulfóxidos/química
18.
Anal Bioanal Chem ; 411(6): 1211-1218, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30617407

RESUMO

Loop-mediated isothermal amplification (LAMP) has been developed as a versatile method for nucleic acid analysis in many applications. However, non-specific LAMP leading to false-positive outcomes has been observed frequently. To solve this problem, we selected six molecules as the additives for evaluating their effects on the improvement of the LAMP specificity. Experimental results show that bovine serum albumin (BSA) and DL-dithiothreitol (DTT) have negative effects on the LAMP specificity; dimethyl sulfoxide (DMSO), tetramethylene sulfoxide (TMSO), and glycerol could inhibit the non-specific LAMP moderately. Surprisingly, pullulan shows an ability to inhibit the non-specific amplification of LAMP significantly without affecting the sample amplification of LAMP, and this inhibitory effect is concentration dependent. Thus, pullulan could be considered as the most promising additive to improve the amplification specificity in the LAMP-based detection and analysis of nucleic acids.


Assuntos
Glucanos/química , Técnicas de Amplificação de Ácido Nucleico/métodos , Ácidos Nucleicos/análise , Animais , Sequência de Bases , Bovinos , Dimetil Sulfóxido/química , Ditiotreitol/química , Glicerol/química , Indicadores e Reagentes/química , Soroalbumina Bovina/química , Sulfóxidos/química , Tiofenos/química
19.
J Microbiol Methods ; 156: 9-14, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30502368

RESUMO

Loop-mediated isothermal amplification (LAMP) can amplify DNA specifically and sensitively. Under minimal buffering conditions, it produces hydrogen ions that lower the pH of the solution upon DNA amplification. This characteristic was applied to visually detect amplified DNA of Escherichia coli through the use of Xylenol Orange, a pH-dependent dye. Under the optimal conditions, 120 min at 63 °C, the Xylenol orange-dependent colorimetric LAMP revealed a detection limit as low as 1 CFU, namely 100,000 times more sensitive than typical multiplex PCR, and showed no cross-reactions with other foodborne pathogens. The colorimetric assay was successfully exploited to detect E. coli contaminations in milk samples, showing high reliability and the same high sensitivity with naked-eye readout. Together with robustness, simplicity, and visual detectability of amplification, this assay can serve as an alternative tool to PCR for detecting E. coli, which is suitable for both laboratory and on-field applications.


Assuntos
Colorimetria/métodos , DNA Bacteriano/análise , Escherichia coli/isolamento & purificação , Microbiologia de Alimentos/métodos , Leite/microbiologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Animais , Fenóis/química , Sulfóxidos/química
20.
J Nat Med ; 73(2): 397-403, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30535771

RESUMO

Sulfur-containing compounds, allicin and ajoene, etc., were isolated from Allium species. In a recent study, some sulfur-containing cyclic compounds were isolated from A. sativum, A. cepa, and A. fistulosum. Four new compounds with multiple rings with methyl disulfide or propyl disulfide at the side chain of the 7-position, kujounins A3 (1), B1 (2), B2 (3) and B3 (4), and two new thiolane type compounds with methoxy and methyl sulfoxide moiety at the 2- and 5-positions, and allium sulfoxides A2 (5) and A3 (6), were isolated from the acetone extract of the fresh white parts of Allium fistulosum 'Kujou' with three known compounds, kujounin A1 (7) and A2 (8), and allium sulfoxide A1 (9). The chemical structures of the new compounds were elucidated on the basis of physicochemical evidence. The kujounins had a rare molecular skeleton, which was tetrahydro-2H-difuro[3,2-b:2',3'-c]furan-5(5aH)-one.


Assuntos
Allium/química , Compostos de Enxofre/química , Compostos de Enxofre/isolamento & purificação , Dissulfetos/isolamento & purificação , Estrutura Molecular , Extratos Vegetais/química , Sulfóxidos/química , Sulfóxidos/isolamento & purificação , Enxofre
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