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1.
Food Chem ; 333: 127537, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32683265

RESUMO

Antifungal bioplastic films were developed based on poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) blends as PLA60/PBAT40 (PLA/PBAT) and PBAT60/PLA40 (PBAT/PLA) with incorporated trans-cinnamaldehyde using cast-extrusion. Trans-cinnamaldehyde was more compatible in PLA which exhibited plasticization that increased molecular mobility, crystallinity, permeability but limited volatile release and reduced film strength. Interaction of trans-cinnamaldehyde modified CO functional groups of PLA and PBAT. Phase separation was higher in PBAT/PLA films due to less surface adhesion in PBAT networks. Higher release of trans-cinnamaldehyde enhanced bread crystallinity but gave lower rate of hardness increase due to plasticization of starch and protein and reduced lipid crystallinity. Increased bread hardness correlated with decreased water activity that was effectively prevented by higher release of trans-cinnamaldehyde. Films containing trans-cinnamaldehyde (2-10%) showed high antifungal efficacy against Penicillium sp. and Aspergillus niger but low effective against Rhizopus sp. Trans-cinnamaldehyde reduced bacterial and fungal growth in breads, extending shelf-life for 21 days.


Assuntos
Acroleína/análogos & derivados , Adipatos/química , Alcenos/química , Pão , Embalagem de Alimentos/métodos , Ácidos Ftálicos/química , Poliésteres/química , Acroleína/química , Antifúngicos/química , Pão/microbiologia , Permeabilidade , Amido/química
2.
Nature ; 583(7817): 548-553, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32480398

RESUMO

Tertiary stereogenic centres containing one fluorine atom are valuable for medicinal chemistry because they mimic common tertiary stereogenic centres containing one hydrogen atom, but they possess distinct charge distribution, lipophilicity, conformation and metabolic stability1-3. Although tertiary stereogenic centres containing one hydrogen atom are often set by enantioselective desymmetrization reactions at one of the two carbon-hydrogen (C-H) bonds of a methylene group, tertiary stereocentres containing fluorine have not yet been constructed by the analogous desymmetrization reaction at one of the two carbon-fluorine (C-F) bonds of a difluoromethylene group3. Fluorine atoms are similar in size to hydrogen atoms but have distinct electronic properties, causing C-F bonds to be exceptionally strong and geminal C-F bonds to strengthen one another4. Thus, exhaustive defluorination typically dominates over the selective replacement of a single C-F bond, hindering the development of the enantioselective substitution of one fluorine atom to form a stereogenic centre5,6. Here we report the catalytic, enantioselective activation of a single C-F bond in an allylic difluoromethylene group to provide a broad range of products containing a monofluorinated tertiary stereogenic centre. By combining a tailored chiral iridium phosphoramidite catalyst, which controls regioselectivity, chemoselectivity and enantioselectivity, with a fluorophilic activator, which assists the oxidative addition of the C-F bond, these reactions occur in high yield and selectivity. The design principles proposed in this work extend to palladium-catalysed benzylic substitution, demonstrating the generality of the approach.


Assuntos
Carbono/química , Flúor/química , Alcenos/química , Catálise , Cátions , Halogenação , Hidrogênio/química , Irídio/química , Compostos Organofosforados/química , Oxirredução , Paládio/química
3.
Nature ; 584(7819): 69-74, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32512577

RESUMO

Enzymes are increasingly explored for use in asymmetric synthesis1-3, but their applications are generally limited by the reactions available to naturally occurring enzymes. Recently, interest in photocatalysis4 has spurred the discovery of novel reactivity from known enzymes5. However, so far photoinduced enzymatic catalysis6 has not been used for the cross-coupling of two molecules. For example, the intermolecular coupling of alkenes with α-halo carbonyl compounds through a visible-light-induced radical hydroalkylation, which could provide access to important γ-chiral carbonyl compounds, has not yet been achieved by enzymes. The major challenges are the inherent poor photoreactivity of enzymes and the difficulty in achieving stereochemical control of the remote prochiral radical intermediate7. Here we report a visible-light-induced intermolecular radical hydroalkylation of terminal alkenes that does not occur naturally, catalysed by an 'ene' reductase using readily available α-halo carbonyl compounds as reactants. This method provides an efficient approach to the synthesis of various carbonyl compounds bearing a γ-stereocentre with excellent yields and enantioselectivities (up to 99 per cent yield with 99 per cent enantiomeric excess), which otherwise are difficult to access using chemocatalysis. Mechanistic studies suggest that the formation of the complex of the substrates (α-halo carbonyl compounds) and the 'ene' reductase triggers the enantioselective photoinduced radical reaction. Our work further expands the reactivity repertoire of biocatalytic, synthetically useful asymmetric transformations by the merger of photocatalysis and enzyme catalysis.


Assuntos
Alcenos/química , Alcenos/metabolismo , Hidrogênio/química , Hidrogênio/metabolismo , Luz , Oxirredutases/metabolismo , Processos Fotoquímicos/efeitos da radiação , Álcoois/química , Álcoois/metabolismo , Alquilação/efeitos da radiação , Biocatálise/efeitos da radiação , Biomassa , Carboxiliases/metabolismo , Flavinas/metabolismo , Modelos Químicos , Modelos Moleculares , Estereoisomerismo
4.
Nat Commun ; 11(1): 1956, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32327665

RESUMO

The dehydrogenative alkenylation of C-H bonds with alkenes represents an atom- and step-economical approach for olefin synthesis and molecular editing. Site-selective alkenylation of alkanes and aldehydes with the C-H substrate as the limiting reagent holds significant synthetic value. We herein report a photocatalytic method for the direct alkenylation of alkanes and aldehydes with aryl alkenes in the absence of any external oxidant. A diverse range of commodity feedstocks and pharmaceutical compounds are smoothly alkenylated in useful yields with the C-H partner as the limiting reagent. The late-stage alkenylation of complex molecules occurs with high levels of site selectivity for sterically accessible and electron-rich C-H bonds. This strategy relies on the synergistic combination of direct hydrogen atom transfer photocatalysis with cobaloxime-mediated hydrogen-evolution cross-coupling, which promises to inspire additional perspectives for selective C-H functionalizations in a green manner.


Assuntos
Aldeídos/química , Alcanos/química , Alcenos/química , Alcenos/síntese química , Catálise , Técnicas de Química Sintética , Química Verde , Estrutura Molecular , Compostos Organometálicos/química , Processos Fotoquímicos , Estereoisomerismo
5.
Zhongguo Zhong Yao Za Zhi ; 45(3): 548-554, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32237512

RESUMO

Study the suitability of organic film for salvianolic acid in the ultrafiltration process of Danshen Dizhuye. UPLC was used to analyze the migration of nine phenolic active ingredients in Danshen Dizhuye during ultrafiltration of PES hollow fiber membrane and PS hollow fiber membrane. The structural composition of multi-components was analyzed by three different batches of Danshen Dizhuye before and after ultrafiltration of the two membranes. The results showed that 9 phenolic active ingredients in Danshen Dizhuye did not change significantly after ultrafiltration through PES membrane. However, after ultrafiltration through PS membrane, the content of sodium danshensu, protocatechualdehyde, caffeic acid, 3-hydroxy-4-methoxycinnamic acid and rosmarinic acid in Danshen Dizhuye did not change significantly, while salvianolic acid D, salvianolic acid B and lithospermic acid decreased by about 20%, and the content of salvianolic acid A decreased significantly. The final content in equilibrium was only about 20% of the original solution. Therefore, an in-depth study on the migration particularity of salvianolic acid A in ultrafiltration membrane was the focuse. The results showed that the loss of salvianolic acid A was caused by both membranes during ultrafiltration, and salvianolic acid A was lost more in PS membrane. When the membrane was washed and regenerated, it was found that salvianolic acid A was detected in the ethanol washing solution, but not in the washing liquid, indicating that the loss of salvianolic acid A during the ultrafiltration was mainly adsorptive action. The results suggested that the migration of phenolic active ingredients in Danshen Dizhuye during the membrane ultrafiltration process did not completely follow the molecular weight passing rule of the membrane pore size. At the same time, it may be affected by factors, such as the structure of the membrane material, and the interaction between the membrane structure and the structure of components, and exhibit different migration behaviors during the ultrafiltration of the membrane.


Assuntos
Alcenos/química , Medicamentos de Ervas Chinesas/química , Polifenóis/química , Salvia miltiorrhiza/química , Ultrafiltração , Cromatografia Líquida de Alta Pressão
6.
Chemosphere ; 252: 126413, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32197171

RESUMO

O3 and alkenes are important reactants in the formation of SOA in the atmosphere. The intermediates and reaction mechanism of ozonation of alkene is an important topic in atmospheric chemistry. In this study, the low-temperature matrix isolation was used to capture the intermediates such as Primary ozonides (POZs), Criegee Intermediates (CIs), and Secondary ozonides (SOZs) generated from ozonation of 2-methyl-1-butene (2M1B) and 2-methyl-2-butene (2M2B). The results have been identified by the vacuum infrared spectroscopy and theoretical calculation. Our results show that during the ozonation of asymmetric alkenes, two kinds of CIs and more than two kinds of SOZs were generated due to the different decomposition modes of POZs. The infrared absorption peaks of (CH3)2COO and CH3CH2C(CH3)OO for O-O telescopic vibration was determined to be 889 cm-1 and 913 cm-1, respectively. Using the merged jet method, it was found that a large amount of HCHO was produced during the ozonation of 2M1B, and glyoxal and methylglyoxal were produced in the ozonation of 2M2B. Our findings highlight the importance of asymmetric alkene ozonolysis reactions in producing CIs, further improving the understanding of the generation of CIs from ozonation of alkenes.


Assuntos
Alcenos/química , Modelos Químicos , Ozônio/química , Atmosfera , Compostos Heterocíclicos , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier
7.
J Vis Exp ; (156)2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-32150174

RESUMO

Lewis acid-activation of carbonyl-containing substrates is a fundamental basis for facilitating transformations in organic chemistry. Historically, characterization of these interactions has been limited to models equivalent to stoichiometric reactions. Here, we report a method utilizing in situ infrared spectroscopy to probe the solution interactions between Lewis acids and carbonyls under synthetically relevant conditions. Using this method, we were able to identify 1:1 complexation between GaCl3 and acetone and a highly ligated complex for FeCl3 and acetone. The impact of this technique on mechanistic understanding is illustrated by application to the mechanism of Lewis acid-mediated carbonyl-olefin metathesis in which we were able to observe competitive binding interactions between substrate carbonyl and product carbonyl with the catalyst.


Assuntos
Alcenos/química , Ácidos de Lewis/química , Espectrofotometria Infravermelho/métodos , Catálise
8.
Phytother Res ; 34(7): 1704-1720, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32185841

RESUMO

Microcirculation, which connects macrocirculation and cells between arterioles and venules, plays a major role in the early onset of a variety of diseases. In this article, a dextran-induced microcirculation dysfunction (MCDF) model rats were adopted to evaluate the effects and mechanism of Salvia miltiorrhiza stem-leaf extracts based on plasma and urine metabonomics. The results showed the effective components of S. miltiorrhiza stem-leaf could significantly improve the hemorheology and coagulation index of MCDF rats and callback the expression of endothelin-1 (ET-1), induciblenitric oxide synthase (iNOS), vascularendothelial growth factor (VEGF), P-Selectin, thromboxane A2, 6-keto-PGF1α , TNF-α, and interleukin-1ß to control group in MCDF rats. The decrease of microvessel density (MVD) in lung and thymus caused by MCDF was upgraded by Salvia miltiorrhiza stem-leaf. Based on the plasma and urine metabolic data, 20 potential biomarkers were identified. These biomarkers are mainly related to linoleic acid metabolism, glutathione metabolism, pantothenate and coenzyme A biosynthesis, pentose and glucuronate interconversions, pyruvate metabolism, glyoxylate and dicarboxylate metabolism, beta-alanine metabolism, and citrate cycle. The results indicated that the effective components of S. miltiorrhiza stem-leaf can improve the hemorheological disorder and vascular endothelial function. Meanwhile, the effective components can regulate potential biomarkers and correlated metabolic pathway, which can provide guidance for the research and development of new drugs for MCDF.


Assuntos
Alcenos/química , Células Endoteliais/efeitos dos fármacos , Flavonoides/química , Hemorreologia/efeitos dos fármacos , Microcirculação/efeitos dos fármacos , Folhas de Planta/química , Caules de Planta/química , Polifenóis/química , Salvia miltiorrhiza/química , Animais , Masculino , Ratos , Ratos Wistar
9.
Dalton Trans ; 49(8): 2407-2411, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32022087

RESUMO

Enynes are important synthetic intermediates that are also found in a variety of natural products and other biologically relevant molecules. The most atom economical synthetic route to enynes is via the direct coupling of readily available terminal alkyne precursors. Towards this goal, we demonstrate the formation of 1,3-enynes from terminal alkynes facilitated by a reduced ZrIV/Co-I heterobimetallic complex. An intermediate is trapped as a tBuNC adduct, revealing that bimetallic activation of the terminal C-H bond of the alkyne is an essential mechanistic step.


Assuntos
Alcenos/química , Alquinos/química , Cobalto/química , Zircônio/química , Catálise , Dimerização , Estrutura Molecular , Estereoisomerismo
10.
Chem Commun (Camb) ; 56(20): 3039-3042, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32048637

RESUMO

We report synthesis and enzymatic assays on human histone lysine methyltransferase catalysed methylation of histones that possess lysine and its geometrically constrained analogues containing rigid (E)-alkene (KE), (Z)-alkene (KZ) and alkyne (Kyne) moieties. Methyltransferases G9a and GLP do have a capacity to catalyse methylation in the order K ≫ KE > KZ ∼ Kyne, whereas monomethyltransferase SETD8 catalyses only methylation of K and KE.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Lisina/metabolismo , Alcenos/química , Alcenos/metabolismo , Alquinos/química , Alquinos/metabolismo , Biocatálise , Humanos , Lisina/análogos & derivados , Lisina/química , Metilação , Conformação Molecular
11.
J Environ Sci (China) ; 90: 352-363, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32081331

RESUMO

Coal-based olefin (CTO) industry as a complement of traditional petrochemical industry plays vital role in China's national economic development. However, high CO2 emission in CTO industry is one of the fatal problems to hinder its development. In this work, the carbon emission and mitigation potentials by different reduction pathways are evaluated. The economic cost is analyzed and compared as well. According to the industry development plan, the carbon emissions from China's CTO industry will attain 189.43 million ton CO2 (MtCO2) and 314.11 MtCO2 in 2020 and 2030, respectively. With the advanced technology level, the maximal carbon mitigation potential could be attained to 15.3% and 21.9% in 2020 and 2030. If the other optional mitigation ways are combined together, the carbon emission could further reduce to some extent. In general, the order of mitigation potential is followed as: feedstock alteration by natural gas > CO2 hydrogenation with renewable electricity applied > CCS technology. The mitigation cost analysis indicates that on the basis of 2015 situation, the economic penalty for feedstock alteration is the lowest, ranged between 186 and 451 CNY/tCO2, and the cost from CCS technology is ranged between 404 and 562 CNY/tCO2, which is acceptable if the CO2 enhanced oil recovery and carbon tax are considered. However, for the CO2 hydrogenation technology, the cost is extremely high and there is almost no application possibility at present.


Assuntos
Alcenos/química , Dióxido de Carbono , Carbono , Carvão Mineral , Poluição Ambiental/prevenção & controle , Indústria Química , China , Poluição Ambiental/economia
12.
Adv Pharmacol ; 87: 1-41, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32089230

RESUMO

Danshen, the dried root of Salvia miltiorrhiza Bge, is a common medicinal herb in Traditional Chinese Medicine, which has been used for the treatment of a number of diseases for thousands of years. More than 2000 years ago, the Chinese early pharmacy monograph "Shennong Materia Medica" recorded that Danshen could be used for the treatment of gastrointestinal diseases, cardiovascular diseases, certain gynecological diseases, etc. Since then, Danshen has been widely used clinically in many different prescriptions for many different diseases, especially for the treatment of cardiovascular diseases. Nowadays, many pharmacological studies about the water-soluble components from Danshen have been reported, especially salvianolic acids. It turned out that salvianolic acids showed strong anti-lipid peroxidation and anti-thrombic activities, and among them, SalAA and SalAB were the most potent. This review focused on the achievements in research of salvianolic acids regarding their bioactivities and pharmacological effects. These studies not only shed light on the water-soluble active components of Danshen and their mechanisms at the molecular level, but also provided theoretical information for the development of new medicines from Danshen for the treatment of cardiovascular and cerebrovascular diseases, inflammatory diseases, metabolic diseases, etc.


Assuntos
Alcenos/análise , Alcenos/farmacologia , Medicamentos de Ervas Chinesas/química , Polifenóis/isolamento & purificação , Alcenos/química , Alcenos/farmacocinética , Animais , Apoptose/efeitos dos fármacos , Humanos , Medicina Tradicional Chinesa , Polifenóis/análise , Polifenóis/química , Polifenóis/farmacocinética , Polifenóis/farmacologia , Salvia miltiorrhiza/química
13.
Org Biomol Chem ; 18(7): 1279-1336, 2020 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-32025682

RESUMO

Enantio- and diastereodivergent routes to marine-origin natural products with different sizes of cyclic ethers and lactones have been used in order to assign stereochemical features. Kainoid amino acids such as isodomoic acids have been synthesized using diastereodivergent routes. The bis(indole) alkaloid dragmacidin F has been prepared by enantiodivergent strategies as well as furanoterpenes and the tetracyclic agelastatin A. Natural products containing five-membered lactones like quercus lactones, muricatacins, goniofufuranones, methylenolactocins and frenolicin B have been synthesized using stereodivergent routes. Macrolides are very abundant lactones and have been mainly prepared from the corresponding seco-acids by lactonization, such as lasiodiplodin, zaeralanes, macrosphelides and haloprins, or by ring-closing metathesis, such as aspercyclides, microcarpalides, macrolides FD-891 and 892, and tetradic-5-en-9-olides. Other natural products including cyclic ethers (such as sesamin, asarinin, acetogenins, centrolobines and nabilones), alcohols (such as sulcatol), esters (such as methyl jasmonates), polycyclic precursors of fredericamycin, amino alcohols (such as ambroxol and sphingosines), isoprostanes, isofurans, polyketide precursors of anachelins, brevicomins, gummiferol, shikimic acid and the related compounds, and the pheromone disparlure have been synthesized stereodivergently. Heterocyclic systems such as epoxides, theobroxides and bromoxones, oxetan-3-ones, 5- to 8-membered cyclic ethers, azetidones, γ-lactams, oxazolidinones, bis(oxazolines), dihydropyridoisoindolines and octahydroisoquinolines have been prepared following stereodivergent routes. Stereodivergent routes to unnatural compounds such as alkenes, dienes, allenes, cyclopropanes, alcohols, aldols, amines, amino alcohols, ß-amino acids, carboxylic acids, lactones, nitriles and α-amino nitriles have been considered as well.


Assuntos
Produtos Biológicos/síntese química , Compostos Heterocíclicos/síntese química , Lactonas/síntese química , Álcoois/síntese química , Álcoois/química , Alcenos/síntese química , Alcenos/química , Aminas/síntese química , Aminas/química , Aminoácidos/síntese química , Aminoácidos/química , Produtos Biológicos/química , Ácidos Carboxílicos/síntese química , Ácidos Carboxílicos/química , Compostos Heterocíclicos/química , Lactonas/química , Estrutura Molecular , Nitrilos/síntese química , Nitrilos/química , Estereoisomerismo
14.
Molecules ; 25(1)2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31947731

RESUMO

The original goal of this research was to study stereochemistry of selenium dihalides addition to cycloalkenes and properties of obtained products. Remarkable alkene-to-alkene and alkene-to-alkyne transfer reactions of selenium dibromide and PhSeBr were discovered during this research. The adducts of selenium dibromide with alkenes or cycloalkenes easily exchange SeBr2 with other unsaturated compounds, including acetylenes, at room temperature, in acetonitrile. Similar alkene-to-alkene and alkene-to-alkyne transfer reactions of the PhSeBr adducts with alkenes or cycloalkenes take place. The supposed reaction pathway includes the selenium group transfer from seleniranium species to alkenes or alkynes. It was found that the efficient SeBr2 and PhSeBr transfer reagents are Se(CH2CH2Br)2 and PhSeCH2CH2Br, which liberate ethylene, leading to a shift in equilibrium. The regioselective and stereoselective synthesis of bis(E-2-bromovinyl) selenides and unsymmetrical E-2-bromovinyl selenides was developed based on the SeBr2 and PhSeBr transfer reactions which proceeded with higher selectivity compared to analogous addition reactions of SeBr2 and PhSeBr to alkynes under the same conditions.


Assuntos
Alcenos/química , Alquinos/química , Brometos/química , Cicloparafinas/química , Compostos de Selênio/química , Catálise , Ciclização
15.
Chem Commun (Camb) ; 56(13): 2012-2015, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-31961351

RESUMO

Here, we describe one simple Ir/hydrosilane catalytic system for chemoselective isomerization of 2-substituted allylic ethers. This facile strategy shows high efficiency towards a variety of substrates, including derivatives from bioactive molecules. The substituent at the α position of the olefins is supposed to be critical in retarding the alkene hydrosilylation process and leading the reaction to go through the isomerization pathway.


Assuntos
Éteres/química , Irídio/química , Silanos/química , Alcenos/química , Catálise , Complexos de Coordenação/química , Isomerismo
16.
Top Curr Chem (Cham) ; 378(1): 11, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31903506

RESUMO

The dramatic increase in atmospheric carbon dioxide (CO2) concentrations has attracted human attention and many strategies about converting CO2 into high-value chemicals have been put forward. Metal-organic frameworks (MOFs), as a class of versatile materials, have been widely used in CO2 capture and chemical conversion, due to their unique porosity, multiple active centers and good stability and recyclability. Herein, we focused on the processes of chemical conversion of CO2 by MOFs-based catalysts, including the coupling reactions of epoxides, aziridines or alkyne molecules, CO2 hydrogenation, and other CO2 conversion reactions. The synthesized methods and high catalytic activity of MOFs-based materials were also analyzed systematically. Finally, a brief perspective on feasible strategies is presented to improve the catalytic activity of novel MOFs-based materials and explore the new CO2 conversion reactions.


Assuntos
Dióxido de Carbono/química , Estruturas Metalorgânicas/química , Alcenos/química , Aminas/química , Aziridinas/química , Catálise , Compostos de Epóxi/química , Hidrogenação , Líquidos Iônicos/química
17.
Proc Natl Acad Sci U S A ; 117(3): 1419-1428, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31896585

RESUMO

By constructing an in vivo-assembled, catalytically proficient peroxidase, C45, we have recently demonstrated the catalytic potential of simple, de novo-designed heme proteins. Here, we show that C45's enzymatic activity extends to the efficient and stereoselective intermolecular transfer of carbenes to olefins, heterocycles, aldehydes, and amines. Not only is this a report of carbene transferase activity in a completely de novo protein, but also of enzyme-catalyzed ring expansion of aromatic heterocycles via carbene transfer by any enzyme.


Assuntos
Biocatálise , Proteínas de Escherichia coli/química , Metano/análogos & derivados , Peroxidases/química , Aldeídos/química , Alcenos/química , Aminas/química , Escherichia coli , Proteínas de Escherichia coli/metabolismo , Metano/química , Peroxidases/metabolismo , Especificidade por Substrato
18.
J Microbiol Biotechnol ; 30(3): 325-332, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-31893611

RESUMO

Methyl linderone (ML), a cyclo-pentenedione, was isolated from the fruit of Lindera erythrocarpa Makino (family Lauraceae). This plant has well-known anti-inflammatory effects; however, the anti-cancer effects of ML have not yet been reported. Thus, in the present study we investigated the effects of ML on the metastasis of human breast cancer cells. We used 12-O-tetradecanoyl phorbol-13-acetate (TPA)-stimulated MCF-7 cells as the cell model to study the effects of ML on invasion and migration. ML was found to reduce the invasion and migration rate of TPA-stimulated MCF-7 cells. Moreover, it inhibited two metastasis-related factors, matrix metalloproteinase-9 (MMP-9) and interleukin-8 (IL-8), at the mRNA and protein expression levels, in TPA-treated MCF-7 cells. The mechanism by which ML exerted these effects was through the inhibition of translocation of activator protein-1 (AP-1) and signal transducer and activator of transcription-3 (STAT3), mediated via phosphorylation of extracellular signal-regulated kinase (ERK). Taken together, our findings indicated that ML attenuated the TPA-stimulated invasion and migration of MCF-7 cells by suppressing the phosphorylation of ERK and its downstream factors, AP-1 and STAT3. Therefore, ML is a potential agent for the treatment of breast cancer metastasis.


Assuntos
Alcenos/farmacologia , Neoplasias da Mama/metabolismo , Ciclopentanos/farmacologia , Interleucina-8/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metaloproteinase 9 da Matriz/metabolismo , Alcenos/química , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Movimento Celular , Ciclopentanos/química , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Interleucina-8/genética , Células MCF-7 , Metaloproteinase 9 da Matriz/genética , Ácidos Ftálicos/farmacologia , Fator de Transcrição STAT3/metabolismo
19.
Chem Commun (Camb) ; 56(10): 1557-1560, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-31930253

RESUMO

A difunctionalization of alkenes through sequential addition of a radical and a nucleophile has been developed, which is suggested to proceed by a radical chain mechanism not requiring a catalyst. An electron transfer step to the oxidant benzoyl peroxide is facilitated by protonation with a strong acid.


Assuntos
Alcenos/química , Estirenos/química , Peróxido de Benzoíla/química , Técnicas Eletroquímicas , Transporte de Elétrons , Nitrogênio/química , Oxirredução , Oxigênio/química
20.
Biochim Biophys Acta Biomembr ; 1862(5): 183207, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987867

RESUMO

Amphiphilic maleic acid-containing copolymers account for a recent methodical breakthrough in the study of membrane proteins. Their application enables a detergent-free extraction of membrane proteins from lipid bilayers, yielding stable water-soluble, discoidal lipid bilayer particles with incorporated proteins, which are wrapped with copolymers. Although many studies confirm the potential of this approach for membrane protein research, the interactions between the maleic acid-containing copolymers and extracted lipids, as well as possible effects of the copolymers on lipid-embedded proteins deserve further scrutinization. Here, we combine electron paramagnetic resonance spectroscopy and coarse-grain molecular dynamics simulations to compare the distribution and dynamics of lipids in lipid particles of phospholipid bilayers encased either by an aliphatic diisobutylene/maleic acid copolymer (DIBMALPs) or by an aromatic styrene/maleic acid copolymer (SMALPs). Nitroxides located at the 5th, 12th or 16th carbon atom positions in phosphatidylcholine-based spin labels experience restrictions of their reorientational motion depending on the type of encasing copolymer. The dynamics of the lipids was less constrained in DIBMALPs than in SMALPs with the affinity of spin labeled lipids to the polymeric rim being more pronounced in SMALPs.


Assuntos
Bicamadas Lipídicas/química , Maleatos/química , Nanopartículas/química , Alcenos/química , Dimiristoilfosfatidilcolina/química , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Proteínas de Membrana/química , Simulação de Dinâmica Molecular , Fosfatidilcolinas/química , Fosfolipídeos , Polímeros/química , Poliestirenos/química , Marcadores de Spin/síntese química
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