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1.
Methods Mol Biol ; 2266: 105-124, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33759123

RESUMEN

Interactions between enzymes and small molecules lie in the center of many fundamental biochemical processes. Their analysis using molecular dynamics simulations have high computational demands, geometric approaches fail to consider chemical forces, and molecular docking offers only static information. Recently, we proposed to combine molecular docking and geometric approaches in an application called CaverDock. CaverDock is discretizing enzyme tunnel into discs, iteratively docking with restraints into one disc after another and searching for a trajectory of the ligand passing through the tunnel. Here, we focus on the practical side of its usage describing the whole method: from getting the application, and processing the data through a workflow, to interpreting the results. Moreover, we shared the best practices, recommended how to solve the most common issues, and demonstrated its application on three use cases.


Asunto(s)
Descubrimiento de Drogas/métodos , Simulación del Acoplamiento Molecular/métodos , Proteínas/química , Ácido Araquidónico/química , Sitios de Unión , Clorhidrinas/química , Sistema Enzimático del Citocromo P-450/química , Diseño de Fármacos , Etanol/análogos & derivados , Etanol/química , Dibromuro de Etileno/química , Hidrolasas/química , Ligandos , Simulación de Dinámica Molecular , Unión Proteica , Programas Informáticos , Relación Estructura-Actividad , Termodinámica
2.
Biophys Chem ; 251: 106190, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31146215

RESUMEN

In this review we discuss results from temperature and pressure dependent single-molecule Förster resonance energy transfer (smFRET) studies on nucleic acids in the presence of macromolecular crowders and organic osmolytes. As representative examples, we have chosen fragments of both DNAs and RNAs, i.e., a synthetic DNA hairpin, a human telomeric G-quadruplex and the microROSE RNA hairpin. To mimic the effects of intracellular components, our studies include the macromolecular crowding agent Ficoll, a copolymer of sucrose and epichlorohydrin, and the organic osmolytes trimethylamine N-oxide, urea and glycine as well as natural occurring osmolyte mixtures from deep sea organisms. Furthermore, the impact of mutations in an RNA sequence on the conformational dynamics is examined. Different from proteins, the effects of the osmolytes and crowding agents seem to strongly dependent on the structure and chemical make-up of the nucleic acid.


Asunto(s)
ADN/química , ARN/química , Temperatura , Clorhidrinas/química , Transferencia Resonante de Energía de Fluorescencia , Glicina/química , Humanos , Metilaminas/química , Conformación de Ácido Nucleico , Presión , Sacarosa/química , Urea/química
3.
Chem Commun (Camb) ; 53(25): 3579-3582, 2017 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-28289745

RESUMEN

Artificial enzymes are required to catalyse non-natural reactions. Here, a hybrid catalyst was developed by embedding a novel Ru complex in the transport protein NikA. The protein scaffold activates the bound Ru complex to produce a catalyst with high regio- and stereo-selectivity. The hybrid efficiently and stably produced α-hydroxy-ß-chloro chlorohydrins from alkenes (up to 180 TON with a TOF of 1050 h-1).


Asunto(s)
Alquenos/química , Clorhidrinas/química , Rutenio/química , Catálisis , Complejos de Coordinación/química , Conformación Molecular , Espectroscopía Infrarroja por Transformada de Fourier , Estereoisomerismo
4.
Mar Drugs ; 15(1)2017 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-28124983

RESUMEN

Pericosine E (6), a metabolite of Periconia byssoides OUPS-N133 was originally isolated from the sea hare Aplysia kurodai, which exists as an enantiomeric mixture in nature. The enantiospecific syntheses of both enantiomers of Periconia byssoides OUPS-N133 has been achieved, along with six stereoisomers, using a common simple synthetic strategy. For these efficient syntheses, highly regio- and steroselective processes for the preparation of bromohydrin and anti-epoxide intermediates were applied. In order to access the unique O-linked carbadisaccharide structure, coupling of chlorohydrin as a donor and anti-epoxide as an acceptor was achieved using catalytic BF3·Et2O. Most of the synthesized compounds exhibited selectively significant inhibitory activity against α-glycosidase derived from yeast. The strongest analog showed almost 50 times the activity of the positive control, deoxynojirimycin.


Asunto(s)
Disacáridos/química , Inhibidores de Glicósido Hidrolasas/química , Ácido Shikímico/análogos & derivados , alfa-Glucosidasas/química , 1-Desoxinojirimicina/química , Alcoholes/química , Ascomicetos/química , Clorhidrinas/química , Compuestos Epoxi/química , Glucosamina/análogos & derivados , Glucosamina/química , Ácido Shikímico/química , Estereoisomerismo , Levaduras/química
5.
Expert Opin Drug Metab Toxicol ; 13(5): 513-524, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27936967

RESUMEN

INTRODUCTION: Adverse drug reactions (ADRs) pose a significant health problem and are generally attributed to reactive metabolites. Olefinic moieties in drugs can undergo cytochrome P450-mediated bioactivation to produce reactive metabolites but myeloperoxidase (MPO)-mediated bioactivation of these moieties has not been reported. Thus, small molecules of alkene hydrocarbons are used as model compounds to characterize the MPO-mediated metabolism. Areas covered: The authors focus on MPO-mediated metabolism of alkene hydrocarbons to form chlorohydrins and the potential role of chlorohydrins in alkene toxicity and carcinogenicity. A case study is presented, in which a carcinogenic alkene, 1,3-butadiene, is demonstrated to form 1-chloro-2-hydroxy-3-butene (CHB) through the MPO-mediated pathway. Further bioactivation of CHB yields a cross-linking metabolite, 1-chloro-3-buten-2-one (CBO), which is highly reactive toward glutathione, proteins, nucleosides, and DNA. Toxicity and mutagenicity of CHB and CBO are also presented. Expert opinion: Alkene hydrocarbons readily undergo MPO-mediated bioactivation to form chlorohydrins, which can further be biotransformed into proteins/DNA-modifying reactive metabolites. Therefore, chlorohydrin formation may play an important role in alkene toxicity and carcinogenicity. Olefinic moieties in drugs are expected to undergo similar bioactivation, which may contribute to ADRs. Studies to investigate the roles of MPO and chlorohydrin formation in ADRs are thus warranted.


Asunto(s)
Alquenos/metabolismo , Ácido Hipocloroso/metabolismo , Peroxidasa/metabolismo , Alquenos/efectos adversos , Alquenos/química , Animales , Butadienos/metabolismo , Butadienos/toxicidad , Carcinógenos/metabolismo , Carcinógenos/toxicidad , Clorhidrinas/efectos adversos , Clorhidrinas/química , Clorhidrinas/metabolismo , Humanos , Hidrocarburos/efectos adversos , Hidrocarburos/química , Hidrocarburos/metabolismo
6.
J Chromatogr A ; 1439: 89-96, 2016 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-26700153

RESUMEN

Reactive oxygen species (ROS) play important physiological roles and are of particular relevance in the pathogenesis of inflammatory diseases. At inflammatory conditions, the enzyme myeloperoxidase generates hypochlorous acid (HOCl) which adds to the double bonds of fatty acyl residues of (phospho)lipids under the formation of chlorohydrins. This may lead to the development of many inflammatory diseases, such as atherosclerosis or arthritis, if the ROS generation exceeds a certain extent. Using oleic acid as the simplest unsaturated fatty acid which contains just a single double bond, as a model system, we investigated all products - including the chlorohydrin - after its reaction with HOCl by a combination of thin-layer chromatography and electrospray ionization mass spectrometry. Unlike the general acceptance, the reaction of oleic acid and HOCl leads not exclusively to the formation of chlorohydrin (isomers) but is much more complex: there are also considerable amounts of dimeric and (to a minor extent) trimeric products which can be assigned to isomeric ethers and esters. The obtained products after oleic acid chlorination were also compared with the reaction products of 1-palmitoyl-2-oleoyl-sn-phosphatidylcholine (POPC) and HOCl. The reasons why different products are obtained will be discussed and the involvement of the carboxylic acid emphasized.


Asunto(s)
Ácido Hipocloroso/química , Ácido Oléico/química , Clorhidrinas/química , Cromatografía en Capa Delgada , Dimerización , Ésteres , Halogenación , Isomerismo , Oxidación-Reducción , Fosfatidilcolinas/química , Espectrometría de Masa por Ionización de Electrospray
7.
J Am Chem Soc ; 137(38): 12343-51, 2015 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-26336030

RESUMEN

Four new chlorobromohydrins, mollenynes B-E, were isolated from the marine sponge Spirastrella mollis collected from Hogsty Reef, Bahamas. Their structures were elucidated by integrated analysis of NMR, MS, and computational methods. A high-resolution band-selective HSQC experiment was developed to identify (13)C NMR signals in samples at the nanomole-scale that arise from Cl-substituted (13)C by exploiting the (35)Cl/(37)Cl isotope shift.


Asunto(s)
Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Clorhidrinas/química , Clorhidrinas/aislamiento & purificación , Poríferos/química , Teoría Cuántica , Animales , Conformación Molecular , Estereoisomerismo
8.
J Org Chem ; 80(15): 7752-6, 2015 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-26147718

RESUMEN

A Darzens reaction between tert-butoxycarbonyl alaninal and chloromethyl phenyl sulfone afforded chlorohydrins, which were converted into epoxysulfones by reaction with sodium tert-butoxide. Epoxysulfone 10 and chloroketone 14 derived from chlorohydrins by oxidation proved to be inhibitors of cathepsins H, S, and C as determined by competitive activity-based protein profiling.


Asunto(s)
Alanina/análogos & derivados , Clorhidrinas/química , Proteasas de Cisteína/síntesis química , Inhibidores de Cisteína Proteinasa/química , Compuestos Epoxi/síntesis química , Alanina/química , Proteasas de Cisteína/química , Inhibidores de Cisteína Proteinasa/farmacología , Compuestos Epoxi/química , Estructura Molecular , Oxidación-Reducción
9.
Angew Chem Int Ed Engl ; 54(25): 7295-8, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-25950284

RESUMEN

The search to understand the origin of homochirality in nature has been ongoing since the time of Pasteur. Previous work has shown that DNA can act as a spin filter for low-energy electrons and that spin-polarized secondary electrons produced by X-ray irradiation of a magnetic substrate can induce chiral selective chemistry. In the present work it is demonstrated that secondary electrons from a substrate that are transmitted through a chiral overlayer cause enantiomeric selective chemistry in an adsorbed adlayer. We determine the quantum yields (QYs) for dissociation of (R)- or (S)-epichlorohydrin adsorbed on a chiral self-assembled layer of DNA on gold and on bare gold (for control). The results show that there is a significant difference in the QYs between the two enantiomers when adsorbed on DNA, but none when they are adsorbed on bare Au. We propose that the effect results from natural spin filtering effects cause by the chiral monolayer.


Asunto(s)
Clorhidrinas/química , Ácidos Nucleicos Inmovilizados/química , Adsorción , Electrones , Oro/química , Modelos Moleculares , Espectroscopía de Fotoelectrones , Estereoisomerismo , Propiedades de Superficie , Rayos X
10.
Biotechnol Prog ; 31(3): 724-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25826799

RESUMEN

The optically active C3 synthetic blocks are remarkably versatile intermediates for the synthesis of numerous pharmaceuticals and agrochemicals. This work provides a simple and efficient enzymatic synthetic route for the environment-friendly synthesis of C3 chiral building blocks. Chloroperoxidase (CPO)-catalyzed enantioselective halo-hydroxylation and epoxidation of chloropropene and allyl alcohol was employed to prepare C3 chiral building blocks in this work, including (R)-2,3-dichloro-1-propanol (DCP*), (R)-2,3-epoxy-1-propanol (GLD*), and (R)-3-chloro-1-2-propanediol (CPD*). The ee values of the formed C3 chiral building blocks DCP*, CPD*, and glycidol were 98.1, 97.5, and 96.7%, respectively. Moreover, the use of small amount of imidazolium ionic liquid enhanced the yield efficiently due to the increase of solubility of hydrophobic organic substrates in aqueous reaction media, as well as the improvement of affinity and selectivity of CPO to substrate.


Asunto(s)
Biocatálisis , Cloruro Peroxidasa/metabolismo , Complemento C3/metabolismo , Líquidos Iónicos/química , Clorhidrinas/química , Compuestos Epoxi/química , Hidroxilación , Propanoles/química , alfa-Clorhidrina/química
11.
Arch Biochem Biophys ; 548: 1-10, 2014 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-24607806

RESUMEN

Electrophilic attack of hypochlorous acid on unsaturated bonds of fatty acyl chains is known to result mostly in chlorinated products that show cytotoxicity to some cell lines and were found in biological systems exposed to HOCl. This study aimed to investigate more deeply the products and the mechanism underlying cytotoxicity of phospholipid-HOCl oxidation products, synthesized by the reaction of HOCl with 1-stearoyl-2-oleoyl-, 1-stearoyl-2-linoleoyl-, and 1-stearoyl-2-arachidonyl-phosphatidylcholine. Phospholipid chlorohydrins were found to be the most abundant among obtained products. HOCl-modified lipids were cytotoxic towards HUVEC-ST (endothelial cells), leading to a decrease of mitochondrial potential and an increase in the number of apoptotic cells. These effects were accompanied by an increase of the level of active caspase-3 and caspase-7, while the caspase-3/-7 inhibitor Ac-DEVD-CHO dramatically decreased the number of apoptotic cells. Phospholipid-HOCl oxidation products were shown to affect cell proliferation by a concentration-dependent cell cycle arrest in the G0/G1 phase and activating redox sensitive p38 kinase. The redox imbalance observed in HUVEC-ST cells exposed to modified phosphatidylcholines was accompanied by an increase in ROS level, and a decrease in glutathione content and antioxidant capacity of cell extracts.


Asunto(s)
Clorhidrinas/química , Clorhidrinas/toxicidad , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Fosfolípidos/química , Fosfolípidos/toxicidad , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Caspasa 7/metabolismo , Puntos de Control del Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/citología , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Ácido Hipocloroso/química , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Oxidación-Reducción/efectos de los fármacos
12.
Chemistry ; 19(38): 12649-52, 2013 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-23956022

RESUMEN

Structural reassignment: A total synthesis of the proposed structure of (-)-laurefurenyne A has been accomplished that relies on organocatalytic aldehyde α-chlorination and a flexible chlorohydrin-based strategy for stereocontrolled access to the bis-tetrahydrofuran core of the natural product. Analysis of incongruities between the (1) H NMR spectra of synthetic and natural material led to a configurational reassignment for the natural product, which was also confirmed by total synthesis.


Asunto(s)
Productos Biológicos/química , Furanos/síntesis química , Productos Biológicos/síntesis química , Catálisis , Clorhidrinas/química , Furanos/química , Halogenación , Laurencia/química , Laurencia/metabolismo , Espectroscopía de Resonancia Magnética , Estereoisomerismo
13.
Org Biomol Chem ; 11(36): 6195-207, 2013 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-23933681

RESUMEN

A regioselective high yielding monochloro substitution (chlorohydrin formation) via Mitsunobu reaction is reported. In carbohydrates and sterically hindered non-sugars, only the primary hydroxyl group is chlorinated, whereas in the non-sugar 1,2- and 1,3-alcohols, predominantly the secondary chloride substitution occurs. The versatile methodology provides indirect access to epoxides with the retention of configuration, as against conventional Mitsunobu reaction which generates epoxides with inversion. The methodology was successfully used as a key step in the synthesis of optically active diastereoisomers of the antidepressant drug reboxetine from (R)-2,3-O-cyclohexylidene-d-glyceraldehyde in ∼43% overall yields.


Asunto(s)
Alcoholes/química , Carbohidratos/química , Clorhidrinas/síntesis química , Morfolinas/síntesis química , Antidepresivos/síntesis química , Antidepresivos/química , Clorhidrinas/química , Conformación Molecular , Morfolinas/química , Reboxetina , Estereoisomerismo
14.
J Clin Invest ; 123(7): 2948-60, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23722902

RESUMEN

Hormone therapies for advanced prostate cancer target the androgen receptor (AR) ligand-binding domain (LBD), but these ultimately fail and the disease progresses to lethal castration-resistant prostate cancer (CRPC). The mechanisms that drive CRPC are incompletely understood, but may involve constitutively active AR splice variants that lack the LBD. The AR N-terminal domain (NTD) is essential for AR activity, but targeting this domain with small-molecule inhibitors is complicated by its intrinsic disorder. Here we investigated EPI-001, a small-molecule antagonist of AR NTD that inhibits protein-protein interactions necessary for AR transcriptional activity. We found that EPI analogs covalently bound the NTD to block transcriptional activity of AR and its splice variants and reduced the growth of CRPC xenografts. These findings suggest that the development of small-molecule inhibitors that bind covalently to intrinsically disordered proteins is a promising strategy for development of specific and effective anticancer agents.


Asunto(s)
Antagonistas de Receptores Androgénicos/farmacología , Antineoplásicos Hormonales/farmacología , Compuestos de Bencidrilo/farmacología , Clorhidrinas/farmacología , Neoplasias de la Próstata/tratamiento farmacológico , Receptores Androgénicos/metabolismo , Antagonistas de Receptores Androgénicos/química , Animales , Antineoplásicos Hormonales/química , Compuestos de Bencidrilo/química , Células COS , Proliferación Celular/efectos de los fármacos , Chlorocebus aethiops , Clorhidrinas/química , Química Clic , Expresión Génica , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Genes Reporteros , Humanos , Luciferasas/biosíntesis , Luciferasas/genética , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Orquiectomía , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Unión Proteica , Estructura Terciaria de Proteína , Receptores Androgénicos/química , Receptores Androgénicos/genética , Estereoisomerismo , Activación Transcripcional/efectos de los fármacos , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
15.
Talanta ; 103: 81-5, 2013 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-23200361

RESUMEN

We developed a rapid and selective method for determination of free chlorine in aqueous solution by gas chromatography/mass spectrometry for the first time. Free chlorine was converted to styrene chlorohydrin using electrophilic addition to styrene in sodium acetate buffer solution (pH 5). The chlorine derivative obtained was extracted with chloroform, and then analyzed by GC/MS. The calibration curve showed good linearity from 0.2-100 µg/mL (as available chlorine). The detection limit was 0.1 µg/mL, and the intra- and interday accuracy were measured at concentrations of 10, 50, and 75 µg/mL to be -1.3 to 6.9% (intraday) and 3.8-8.0% (interday) as % Bias. The precision was between 1.4 and 4.5% as % RSD. These results indicate that this method is a superior technique for the identification of free chlorine. This method was successfully applied to quantification in commercial samples and in samples of a criminal case.


Asunto(s)
Blanqueadores/análisis , Cloro/análisis , Clorhidrinas/química , Desinfectantes/análisis , Cromatografía de Gases y Espectrometría de Masas , Estireno/química , Agua/análisis , Calibración , Humanos , Japón , Límite de Detección
16.
Molecules ; 17(9): 10864-74, 2012 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-22964502

RESUMEN

(R)-1-Chloro-3-(1-naphthyloxy)-2-propanol, which is the key intermediate of (S)-propranolol, was successfully prepared via enantioselective transesterification catalyzed by lipase under ultrasound irradiation. Compared with conventional shaking, the enzyme activity and enantioselectivity were dramatically increased under ultrasound exposure. Effects of various reaction conditions on the synthetic activity of enzyme as well as enantioselectivity, including the type of enzyme, ultrasound power, solvent, acyl donor, temperature and substrate molar ratio, were investigated. Pseudomonas sp. lipase (PSL) showed an excellent catalytic performance under optimum conditions (enzyme activity: 78.3 ± 3.2 µmol·g⁻¹·min⁻¹, E value: 98 ± 6).


Asunto(s)
Clorhidrinas/metabolismo , Lipasa/metabolismo , Naftalenos/metabolismo , Propranolol/química , Sonido , Biocatálisis , Clorhidrinas/química , Esterificación , Ondas de Choque de Alta Energía , Lipasa/efectos de la radiación , Naftalenos/química , Pseudomonas/enzimología , Estereoisomerismo , Ultrasonido
17.
Chembiochem ; 13(1): 137-48, 2012 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-22109980

RESUMEN

We used directed evolution to obtain enantiocomplementary haloalkane dehalogenase variants that convert the toxic waste compound 1,2,3-trichloropropane (TCP) into highly enantioenriched (R)- or (S)-2,3-dichloropropan-1-ol, which can easily be converted into optically active epichlorohydrins-attractive intermediates for the synthesis of enantiopure fine chemicals. A dehalogenase with improved catalytic activity but very low enantioselectivity was used as the starting point. A strategy that made optimal use of the limited capacity of the screening assay, which was based on chiral gas chromatography, was developed. We used pair-wise site-saturation mutagenesis (SSM) of all 16 noncatalytic active-site residues during the initial two rounds of evolution. The resulting best R- and S-enantioselective variants were further improved in two rounds of site-restricted mutagenesis (SRM), with incorporation of carefully selected sets of amino acids at a larger number of positions, including sites that are more distant from the active site. Finally, the most promising mutations and positions were promoted to a combinatorial library by using a multi-site mutagenesis protocol with restricted codon sets. To guide the design of partly undefined (ambiguous) codon sets for these restricted libraries we employed structural information, the results of multiple sequence alignments, and knowledge from earlier rounds. After five rounds of evolution with screening of only 5500 clones, we obtained two strongly diverged haloalkane dehalogenase variants that give access to (R)-epichlorohydrin with 90 % ee and to (S)-epichlorohydrin with 97 % ee, containing 13 and 17 mutations, respectively, around their active sites.


Asunto(s)
Clorhidrinas/metabolismo , Hidrolasas/metabolismo , Propano/análogos & derivados , Biocatálisis , Clorhidrinas/química , Hidrolasas/química , Hidrolasas/genética , Modelos Moleculares , Estructura Molecular , Mutagénesis Sitio-Dirigida , Propano/química , Propano/metabolismo , Estereoisomerismo , Temperatura
18.
Molecules ; 16(3): 2065-74, 2011 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-21368718

RESUMEN

The anticipated worldwide increase in biodiesel production will result in an accumulation of glycerol for which there are insufficient conventional uses. The surplus of this by-product has increased rapidly during the last decade, prompting a search for new glycerol applications. We describe here the synthesis of dissymmetric chlorohydrin esters from symmetric 1,3-dichloro-2-propyl esters obtained from glycerol. We studied the influence of two solvents: 1,4-dioxane and 1-butanol and two bases: sodium carbonate and 1-butylimidazole, on the synthesis of dissymmetric chlorohydrin esters. In addition, we studied the influence of other bases (potassium and lithium carbonates) in the reaction using 1,4-dioxane as the solvent. The highest yield was obtained using 1,4-dioxane and sodium carbonate.


Asunto(s)
Clorhidrinas/química , Glicerol/química , Espectroscopía de Resonancia Magnética , Espectrometría de Masa por Ionización de Electrospray , Espectroscopía Infrarroja por Transformada de Fourier
19.
Postepy Biochem ; 56(2): 201-8, 2010.
Artículo en Polaco | MEDLINE | ID: mdl-20873115

RESUMEN

Reactive oxygen and nitrogen species are attributed to initiation and propagation of many diseases. The demonstration of elevated activity of myeloperoxidase and the level of 3-chlorotyrosine in atherosclerosis, kidney diseases and chronic inflammations brought about the interest in the biological role of another strong oxidant--hypochlorite. Concentration of this compound is extremely difficult to estimate in vivo and in vitro because of its high reactivity. The reaction of hypochlorite with biological compounds lead to formation of chlorohydrins, glutathione sulfonamides, chloramines, 3- and 3,5-dichlorotyrosines and chlorinated DNA bases (8-chloroadenine, 8-chloroguanine, 5-chlorocytosine and 5-chlorouracil). At least some of these products of hypochlorite action are believed to provide specific HOCl-biomarkers, useful especially in the analysis of clinical samples, using sensitive detection techniques.


Asunto(s)
Cloratos/química , Cloratos/aislamiento & purificación , Animales , Biomarcadores/análisis , Cloraminas/química , Cloraminas/aislamiento & purificación , Clorhidrinas/química , Clorhidrinas/aislamiento & purificación , Glutatión/análogos & derivados , Glutatión/química , Glutatión/aislamiento & purificación , Humanos , Ácido Hipocloroso/química , Ácido Hipocloroso/aislamiento & purificación , NADP/metabolismo , Oxidación-Reducción , Sulfonas/química , Sulfonas/aislamiento & purificación
20.
J Mass Spectrom ; 45(9): 996-1002, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20814904

RESUMEN

Epoxidized soybean oil (ESBO) is used as an authorized plasticizer and a stabilizer for plastic polymers such as poly(vinyl chloride) (PVC). Recently, however, there has been a concrete effort devoted to its substitution for other plasticizers such as polyadipates. ESBO is exploited particularly in food closure gaskets for metal lids used to seal glass jars and bottles. The closure gaskets form an airtight seal necessary to prevent microbiological contamination. Thus, there are potential uses for food sterilization and storage. Additionally, the main pathway of PVC degradation involves the elimination of HCl, which can react with the epoxy groups of ESBO to give mono-, polychlorohydrins and/or other cyclic derivatives. The European Food Safety Authority noted that not enough analytical and toxicological data exist to express a formal opinion on the significance for the health effects of such derivatives. At present in the scientific literature, there are only a few indicative results of direct measurements of ESBO derivatives and there are no official analytical methods available for the determination of chlorohydrins directly from foodstuffs. This study presents the first example of the analysis of commercial food sauces for the detection of ESBO-chlorohydrins (as methyl esters). The results are obtained by a dedicated development of an ultraperformance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method. Sample preparation was based on the following main steps: organic extraction, transesterification and solid-phase extraction clean up. In particular, four isomers for 18-E-OHCl chlorohydrin and eight isomers for 18-2OHCl chlorohydrin were separated and identified. Different food sauces samples closed in glass jars with twist-off caps were subjected to qualitative determination, which yielded positive results for 18-E-OHCl, whereas no traces of 18-2OHCl were found.


Asunto(s)
Clorhidrinas/análisis , Cromatografía Líquida de Alta Presión/métodos , Análisis de los Alimentos/métodos , Aceite de Soja/química , Espectrometría de Masa por Ionización de Electrospray/métodos , Clorhidrinas/química , Clorhidrinas/aislamiento & purificación , Embalaje de Alimentos , Espectrometría de Masas en Tándem/métodos
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