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1.
Food Chem ; 312: 126085, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31896460

RESUMO

The effects of hydroxycinnamic acids such as cinnamic acid (CNA), p-coumaric acid(CMA), caffeic acid (CFA), and chlorogenic acid (CGA) on the reduction of furan in canned-coffee model systems (CCMS) containing α-dicarbonyls [glyoxal (GO) or methylglyoxal (MGO)] were investigated. The concentration of furan in CCMS containing GO, which was 59.76 µg/L, was reduced by the addition of CFA and CGA to 48.31 µg/L and 41.38 µg/L, respectively; similarly, the furan concentration in model system containing MGO was 45.79 µg/L, and this decreased to 35.41 µg/L (by CFA) and 32.65 µg/L (by CGA), respectively. In addition, the effects of hydroxycinnamic acids on the trapping of GO and MGO were determined. CFA and CGA greatly reduced the concentration of GO to 303.51 µg/L and 267.80 µg/L, respectively (compared to 515.79 µg/L in the control), whereas that of MGO was decreased to 207.01 µg/L and 219.14 µg/L (compared to 417.14 µg/L in the control). The trapping of α-dicarbonyls such as GO and MGO by CFA and CGA could be closely related to furan reduction in CCMS.


Assuntos
Ácidos Cumáricos/química , Furanos/química , Aldeído Pirúvico/química , Ácido Clorogênico/química , Café/química , Glioxal/química
2.
J Med Microbiol ; 69(2): 195-206, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31971503

RESUMO

Micro-organisms use quorum sensing (QS), a cell density-dependent process, to communicate. This QS mode of interchange leads to the production of a variety of virulence factors, co-ordination of complex bacterial behaviours, such as swarming motility, degradation of host tissue and biofilm formation. QS is implicated in numerous human infections and consequently researchers have sought ways of effectively inhibiting the process in pathogenic bacteria. Two decades ago, furanones were the first class of chemical compounds identified as Pseudomonas aeruginosa QS inhibitors (QSIs). P. aeruginosa is a ubiquitous organism, capable of causing a wide range of infections in humans, including eye and ear infections, wound infections and potentially fatal bacteraemia and thus novel treatments against this organism are greatly needed. This review provides a brief background on QS and the use of furanones as QSIs. Based on the effectiveness of action, both in vivo and in vitro, we will explore the use of furanones as potential antimicrobial therapeutics and conclude with open questions.


Assuntos
Antibacterianos/administração & dosagem , Furanos/administração & dosagem , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Animais , Antibacterianos/química , Furanos/química , Humanos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/fisiologia
3.
J Agric Food Chem ; 68(1): 332-339, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31814399

RESUMO

Thermal treatment of food leads to the formation of melanoidins by reactions of carbohydrates with free amino acids or proteins in the late stage of Maillard reaction. The aim of this study was the identification of reaction mechanisms responsible for the formation of melanoidins involving active methylenes with the heterocyclic structure and the structural characterization of the resulting products. For this purpose, norfuraneol was incubated with the aldehydes pyrrole-2-aldehyde or furfural at 125 °C. With the help of high-resolution mass spectrometry, the structural composition of oligomers of up to fifteen C5-units could be described for the first time. Aldol and Michael reactions could be identified as crucial steps for the formation of new C-C-bonds. With increasing heating time, the elimination of water from the products was facilitated, and oxidation reactions of integrated reductone structures lead to the expansion of conjugated double-bond systems responsible for the color formation of the samples.


Assuntos
Aldeídos/química , Furanos/química , Compostos Heterocíclicos/química , Polímeros/química , Furaldeído/química , Reação de Maillard , Estrutura Molecular , Oxirredução
4.
Biomed Chromatogr ; 34(1): e4717, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31634986

RESUMO

A sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was established to analyze furanodienone in rat plasma. In the process of chromatographic separation, selected reaction monitoring transitions for furanodienone and patchouli alcohol (internal standard, IS) were m/z 231.1 → 83.2 and m/z 205.1 → 95.1, respectively. Great linearity of furanodienone in plasma samples was found in the corresponding concentration range (r > 0.995). Intra- and inter-day precisions (RSD, %) were <11.3% in plasma, and the accuracy (RE, %) was within ±10.7%. This method was used to the furanodienone study on rat pharmacokinetics after a single oral dose of 10 mg/kg of furanodiene. The results indicated that the maximum observed plasma concentration was 52.4 ± 19.1 ng/ml at 1.2 ± 0.7 h with an elimination half-life of 2.2 ± 0.7 h. The obtained data indicated that furanodienone could be moderately distributed and eliminated.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Furanos/sangue , Sesquiterpenos/sangue , Espectrometria de Massas em Tandem/métodos , Animais , Estabilidade de Medicamentos , Furanos/química , Furanos/farmacocinética , Modelos Lineares , Masculino , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Sesquiterpenos/química , Sesquiterpenos/farmacocinética
5.
Eur J Med Chem ; 186: 111855, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31740051

RESUMO

There is an increasing interest in the field of cancer therapy for small compounds targeting pyrimidine biosynthesis, and in particular dihydroorotate dehydrogenase (DHODH), the fourth enzyme of this metabolic pathway. Three available DHODH structures, featuring three different known inhibitors, were used as templates to screen in silico an original chemical library from Erevan University. This process led to the identification of P1788, a compound chemically related to the alkaloid cerpegin, as a new class of pyrimidine biosynthesis inhibitors. In line with previous reports, we investigated the effect of P1788 on the cellular innate immune response. Here we show that pyrimidine depletion by P1788 amplifies cellular response to both type-I and type II interferons, but also induces DNA damage as assessed by γH2AX staining. Moreover, the addition of inhibitors of the DNA damage response led to the suppression of the P1788 stimulatory effects on the interferon pathway. This demonstrates that components of the DNA damage response are bridging the inhibition of pyrimidine biosynthesis by P1788 to the interferon signaling pathway. Altogether, these results provide new insights on the mode of action of novel pyrimidine biosynthesis inhibitors and their development for cancer therapies.


Assuntos
Furanos/farmacologia , Piridinas/farmacologia , Piridonas/farmacologia , Pirimidinas/antagonistas & inibidores , Células Cultivadas , Dano ao DNA , Relação Dose-Resposta a Droga , Furanos/síntese química , Furanos/química , Células HEK293 , Humanos , Modelos Moleculares , Estrutura Molecular , Piridinas/síntese química , Piridinas/química , Piridonas/química , Pirimidinas/biossíntese , Relação Estrutura-Atividade
6.
Food Chem ; 303: 125406, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472386

RESUMO

This study reports the heat-induced formation of furan by decarboxylation of 2-furoic acid, and 2-methylfuran by dehydration of furfuryl alcohol under dry conditions. Model systems were incubated at temperatures up to 190 °C, followed by quantitative determination of furan and 2-methylfuran performed by isotope dilution headspace gas chromatography-mass spectrometry. Results show that 2-furoic acid decarboxylation and furfuryl alcohol dehydration are activated as from about 140-160 °C. Furfuryl alcohol and 2-furoic acids were measured in a selection of roasted coffee products by isotope dilution liquid chromatography-high resolution mass spectrometry, and the data evidenced a strong correlation between the two compounds, suggesting an intimate mechanistic relationship between them. The possible oxidation of furfuryl alcohol to furfural and 2-furoic acid in heated food is raised with particular emphasis on coffee roasting. These findings are relevant for better understanding the formation of furan and alkylfurans in food, and ultimately opening avenues for mitigation.


Assuntos
Furanos/análise , Furanos/química , Coffea/química , Culinária , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Temperatura Alta , Sementes/química
7.
Biochim Biophys Acta Proteins Proteom ; 1868(1): 140293, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31676448

RESUMO

Furan-2,5-dicarboxylic acid (FDCA) is a building block of biodegradable plastics that can be used to replace those derived from fossil carbon sources. In recent years, much interest has focused on the synthesis of FDCA from the bio-based 5-hydroxymethylfurfural (HMF) through a cascade of enzyme reactions. Aryl-alcohol oxidase (AAO) and 5-hydroxymethylfurfural oxidase (HMFO) are glucose-methanol-choline flavoenzymes that may be used to produce FDCA from HMF through three sequential oxidations, and without the assistance of auxiliary enzymes. Such a challenging process is dependent on the degree of hydration of the original aldehyde groups and of those formed, the rate-limiting step lying in the final oxidation of the intermediate 5-formyl-furancarboxylic acid (FFCA) to FDCA. While HMFO accepts FFCA as a final substrate in the HMF reaction pathway, AAO is virtually incapable of oxidizing it. Here, we have engineered AAO to perform the stepwise oxidation of HMF to FDCA through its structural alignment with HMFO and directed evolution. With a 3-fold enhanced catalytic efficiency for HMF and a 6-fold improvement in overall conversion, this evolved AAO is a promising point of departure for further engineering aimed at generating an efficient biocatalyst to synthesize FDCA from HMF.


Assuntos
Oxirredutases do Álcool/química , Ácidos Dicarboxílicos/química , Furaldeído/análogos & derivados , Furanos/química , Biocatálise , Furaldeído/química , Oxirredução , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética
8.
Biosci Biotechnol Biochem ; 84(1): 25-30, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31516064

RESUMO

The Japanese orange fly, Bactrocera tsuneonis, infests various citrus crops. While male pheromone components accumulated in the rectal glands are well characterized for Bactrocera, but information regarding the chemical factors involved in the life cycles of B. tsuneonis remains scarce. Herein, several volatile chemicals including a γ-decalactone, (3R,4R)-3-hydroxy-4-decanolide [(3R,4R)-HD], were identified as major components, along with acetamide and spiroketals as minor components in the rectal gland complexes of male B. tsuneonis flies. The lactone (3R,4R)-HD was also identified in female rectal gland complexes. The amount of this compound in mature males was significantly higher than those observed in females and immature males. The lactone (3R,4R)-HD was detected in flies fed with sucrose only, indicating that this lactone is not derived from dietary sources during adulthood, but biosynthesized in vivo. The predominant accumulation of (3R,4R)-HD in mature males also suggests a possible role in reproductive behavior.


Assuntos
Lactonas/química , Glândula de Sal/química , Tephritidae/fisiologia , Acetamidas/síntese química , Acetamidas/química , Animais , Cromatografia Gasosa , Citrus , Dieta , Feminino , Furanos/síntese química , Furanos/química , Japão , Lactonas/síntese química , Masculino , Espectrometria de Massas , Reprodução/fisiologia , Atrativos Sexuais/química , Comportamento Sexual Animal/fisiologia , Compostos de Espiro/síntese química , Compostos de Espiro/química , Sacarose
9.
J Sci Food Agric ; 100(1): 110-118, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31436316

RESUMO

BACKGROUND: Pectin is an intriguing polymer, which is usually regarded as a byproduct from agricultural and biological processes. In previous studies, ultrasound treatment has been explored to improve the functionality of pectin but most of that work focused on aspects of molecular structure and the chemical properties of pectin. In this study, we utilized ultrasound treatment to modify the physiochemical properties of pectin. Using ultrasound treatment, we evaluated the emulsifying capability of pectin as a function of ultrasonic time and power density, using a response surface approach. A very potent yet unstable coffee-like aroma compound, 2-furfurylthiol, was also used for comparing the encapsulation feasibility of emulsion made with original pectin and ultrasound-treated pectin. RESULTS: Our results showed that the particle size of pectin was highly correlated with power density and ultrasound time. Approximately 370 nm of pectin particle size could be reached at a power density of 1.06 W mL-1 for 40 min. Ultrasound treatment increased emulsion droplet size but significantly improved emulsifying capacities, such as centrifugal stability and surface loading, although it was highly dependent upon the ultrasound treatment condition. When used as the encapsulation wall material, the ultrasound-modified pectin had significantly enhanced performance compared with the original, in terms of flavor retention over time at 45 °C and 65 °C. CONCLUSION: Ultrasound treatment was able to modify the physiochemical properties of pectin, which thus improved emulsification stability and encapsulation feasibility by forming a thicker layer at the oil / water interface to protect the core materials. © 2019 Society of Chemical Industry.


Assuntos
Furanos/química , Pectinas/química , Compostos de Sulfidrila/química , Composição de Medicamentos , Emulsificantes/química , Emulsificantes/efeitos da radiação , Emulsões/química , Tamanho da Partícula , Pectinas/efeitos da radiação , Ultrassom
11.
Molecules ; 24(24)2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31847286

RESUMO

Highly functionalized furans are the key scaffolds of many pharmaceuticals and bioactive natural products. Herein, we disclose a new fruitful synthesis of polyfunctionalized furans starting from ß-nitroenones and α-functionalized ketones. The protocol involves two steps promoted by solid supported species, and it provides the title targets from satisfactory to very good overall yields and in an excellent diastereomeric ratios.


Assuntos
Furanos/síntese química , Ciclização , Furanos/química , Estrutura Molecular , Estereoisomerismo
12.
Int J Mol Sci ; 20(24)2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31842355

RESUMO

Strigolactones (SLs) and karrikins (KARs) are both butenolide molecules that play essential roles in plant growth and development. SLs are phytohormones, with SLs having known functions within the plant they are produced in, while KARs are found in smoke emitted from burning plant matter and affect seeds and seedlings in areas of wildfire. It has been suggested that SL and KAR signaling may share similar mechanisms. The α/ß hydrolases DWARF14 (D14) and KARRIKIN INSENSITIVE 2 (KAI2), which act as receptors of SL and KAR, respectively, both interact with the F-box protein MORE AXILLARY GROWTH 2 (MAX2) in order to target SUPPRESSOR OF MAX2 1 (SMAX1)-LIKE/D53 family members for degradation via the 26S proteasome. Recent reports suggest that SLs and/or KARs are also involved in regulating plant responses and adaptation to various abiotic stresses, particularly nutrient deficiency, drought, salinity, and chilling. There is also crosstalk with other hormone signaling pathways, including auxin, gibberellic acid (GA), abscisic acid (ABA), cytokinin (CK), and ethylene (ET), under normal and abiotic stress conditions. This review briefly covers the biosynthetic and signaling pathways of SLs and KARs, compares their functions in plant growth and development, and reviews the effects of any crosstalk between SLs or KARs and other plant hormones at various stages of plant development. We also focus on the distinct responses, adaptations, and regulatory mechanisms related to SLs and/or KARs in response to various abiotic stresses. The review closes with discussion on ways to gain additional insights into the SL and KAR pathways and the crosstalk between these related phytohormones.


Assuntos
4-Butirolactona/análogos & derivados , Adaptação Biológica/efeitos dos fármacos , Furanos/metabolismo , Lactonas/metabolismo , Desenvolvimento Vegetal/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Piranos/metabolismo , Estresse Fisiológico/efeitos dos fármacos , 4-Butirolactona/farmacologia , Furanos/química , Lactonas/química , Fenômenos Fisiológicos Vegetais , Piranos/química , Transdução de Sinais , Relação Estrutura-Atividade
13.
Molecules ; 24(20)2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31614645

RESUMO

The effects of hydrogen bonds on the molecular structure of water-tetrahydrofuran (H2O-THF), water-dimethyl sulfoxide (H2O-DMSO), and water-tetrahydrofuran-dimethyl sulfoxide (H2O-THF-DMSO) in binary aqueous solutions and ternary aqueous solutions were studied using Raman spectroscopy. The results indicate that in the binary aqueous solution, the addition of THF and DMSO will generate hydrogen bonds with water molecules, resulting in changes in the peak positions of S=O bonds and C-O bonds. Compared with the binary aqueous solutions, the hydrogen bonds between DMSO and THF, and the hydrogen bonds between DMSO and H2O in the ternary aqueous solutions are competitive, and the hydrogen bond competition is susceptible to water content. In addition, the formation of hydrogen bonds will destroy the fully hydrogen-bonded water and make it change to the partially hydrogen-bonded water. By fitting the spectra into the three Gaussian components assigned to water molecules with different hydrogen bonding (HB) environments, these spectral features are interpreted by a mechanism that H2O in different solution systems has equal types of water molecules with similar HB degrees-fully hydrogen-bonded H2O (FHW) and partially hydrogen-bonded H2O (PHW). The ratio of the intensity transition from FHW to PHW is determined based on Gaussian fitting. Therefore, the variation of hydrogen bond competition can be supplemented by the intensity ratio of PHW/FHW ((IC2 + IC3)/IC1). This study provides an experimental basis for enriching the hydrogen bonding theory of multivariate aqueous solution systems.


Assuntos
Dimetil Sulfóxido/química , Furanos/química , Ligação de Hidrogênio , Água/química , Estrutura Molecular , Soluções/química , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman
14.
J Agric Food Chem ; 67(43): 11867-11876, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31584805

RESUMO

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv oryzae (Xoo) is considered as the most destructive disease of rice. The use of bactericides is among the most widely used traditional methods to control this destructive disease. The excessive and repeated use of the same bactericides is also becoming the reason behind the development of bactericide resistance. The widely used method for finding the new antimicrobial agents often involves the bacterial virulence factors as a target without affecting bacterial growth. Type III secretion system (T3SS) is a protein appendage and is considered as having essential virulence factors in most Gram-negative bacteria. Due to the conserved construct, T3SS has been regarded as an important mark for the blooming of novel antimicrobial drugs. Toward the search of new T3SS inhibitors, an alternative series of 1,3-thiazole derivatives were designed and synthesized. Their structures were characterized and confirmed by 1H NMR, 13C NMR, MS, and elemental analysis. All the title compounds inhibited the promoter activity of hpa1 gene significantly. Eight of them showed better inhibition than our previous T3SS inhibitor TS006 (o-coumaric acid, OCA). The treatment of Xoo with eight compounds significantly attenuated HR without affecting bacterial growth. The mRNA levels of some representative genes (hrp/hrc genes) were reduced up to different extents. In vivo bioassay results showed that eight T3SS inhibitors could reduce bacterial leaf blight and bacterial leaf streak symptoms on rice, significantly.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Furanos/farmacologia , Oryza/microbiologia , Doenças das Plantas/microbiologia , Sistemas de Secreção Tipo III/antagonistas & inibidores , Xanthomonas/efeitos dos fármacos , Antibacterianos/síntese química , Antibacterianos/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Furanos/química , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Sistemas de Secreção Tipo III/genética , Sistemas de Secreção Tipo III/metabolismo , Xanthomonas/genética , Xanthomonas/metabolismo
15.
J Agric Food Chem ; 67(42): 11788-11795, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31565927

RESUMO

Furan fatty acids (FuFAs) are a class of naturally occurring minor fatty acids with fish as the richest food source. Typically, FuFA analysis is cumbersome and involves several steps. We developed a quantitative 1H NMR method (qNMR) in which fish oil samples were directly measured after dilution with CDCl3 stabilized with silver (which was essential to prevent formation of radicals) and addition of an internal standard. The singlet at δ = 1.89 ppm was suitable for quantitation of monomethyl FuFAs, whereas the signal at δ = 1.83 ppm was suitable to quantitate dimethyl FuFAs. Using standard NMR tubes with 650 µL solvent, the limit of quantitation was 0.5 µg (dimethyl FuFAs) and 1.0 µg (monomethyl FuFAs). Applied to three fish oil and two enriched fish oil samples (sample weight, 10 mg), the final qNMR method resulted in similar total FuFA contents as determined in parallel by gas chromatography coupled to mass spectrometry.


Assuntos
Ácidos Graxos/química , Óleos de Peixe/química , Furanos/química , Espectroscopia de Prótons por Ressonância Magnética/métodos , Cromatografia Gasosa-Espectrometria de Massas
16.
J Agric Food Chem ; 67(40): 11005-11017, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31532657

RESUMO

The limited number of agrochemicals targeting plant bacterial diseases has driven us to develop highly efficient, low-cost, and versatile antibacterial alternatives. Herein, a novel type of simple furan-functionalized quinazolin-4-amines was systematically fabricated and screened for their antibacterial activity. Bioassay results revealed that compounds C1 and E4 could substantially block the growth of two frequently mentioned pathogens Xanthomonas oryzae pv oryzae and X. axonopodis pv citri in vitro, displaying appreciable EC50 values of 7.13 and 10.3 mg/L, respectively. This effect was prominently improved by comparing those of mainly used agrochemicals. An in vivo experiment against bacterial blight further illustrated their viable applications as antimicrobial ingredients. Quantitative proteomics demonstrated that C1 possessed a remarkable ability to manipulate the upregulation and downregulation of expressed proteins, which probably involved d-glucose and biotin metabolic pathways. This finding was substantially verified by parallel reaction monitoring analysis. Scanning electron microscopy images and fluorescence spectra also indicated that the designed compounds had versatile capacities for destroying the integrity of bacteria. Given these remarkable characteristics, furan-functionalized quinazoline hybrids can serve as a viable platform for developing innovative antibiotic alternatives against bacterial infections.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Furanos/farmacologia , Quinazolinas/farmacologia , Xanthomonas/efeitos dos fármacos , Antibacterianos/síntese química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Furanos/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Doenças das Plantas/microbiologia , Proteômica , Quinazolinas/química , Relação Estrutura-Atividade , Xanthomonas/genética , Xanthomonas/crescimento & desenvolvimento , Xanthomonas/metabolismo
17.
Ecotoxicol Environ Saf ; 184: 109605, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31505406

RESUMO

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) remain of particular concern owing to their extensive toxicity towards health and accumulation in the environment. Atmospheric oxidation (by ambient oxygen molecules) of this class of persistent environmental pollutants has little to no kinetic feasibility due to very sizable activation energies in the entrance channel. The current control measures involve energy-intensive source incineration of contaminated materials at high temperatures as high as 850 °C. This study finds an alternative low-energy approach of destroying dioxin-like compounds, proposing that advanced oxidation by highly reactive singlet oxygen (O21Δg, originated from chemical, surface-mediated and photochemical processes) can initiate low-temperature remediation of these pollutants. This contribution completes the first milestone in mapping out the mechanisms of the electrophilic addition of singlet oxygen to unsubstituted and chlorinated dibenzo-p-dioxin (DBD) and dibenzofuran (DBF) structures, according to density functional theory DFT-B3LYP method in conjunction with the 6-311+g(d,p) basis set, as well as energy refinements based on the approximate spin-projection scheme. The [2+2]-cycloaddition mechanism appears dominant for singlet oxidation of dibenzo-p-dioxin with a fitted rate constant of k(T) = 5.01 × 10-14 exp(-98000/RT). On the other hand, the addition of singlet oxygen to the aromatic ring of dibenzofuran primarily transpires via [4+2]-cycloaddition channel with a fitted rate constant of k(T) = 2.16 × 10-13 exp(-119000/RT). The results suggest that application of singlet oxygen can reduce the energy cost of recycling halogenated and flame retarded materials.


Assuntos
Dioxinas/química , Poluentes Ambientais/química , Recuperação e Remediação Ambiental/métodos , Furanos/química , Oxigênio Singlete/química , Oxirredução , Temperatura
18.
ChemSusChem ; 12(21): 4764-4768, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31490638

RESUMO

Furancarboxylic acids are promising biobased building blocks in pharmaceutical and polymer industries. In this work, dual-enzyme cascade systems composed of galactose oxidase (GOase) and alcohol dehydrogenases (ADHs) are constructed for controlled synthesis of 5-formyl-2-furancarboxylic acid (FFCA) and 2,5-furandicarboxylic acid (FDCA) from 5-hydroxymethylfurfural (HMF), based on the catalytic promiscuity of ADHs. The byproduct H2 O2 , which is produced in GOase-catalyzed oxidation of HMF to 2,5-diformylfuran (DFF), is used for horseradish peroxidase (HRP)-mediated regeneration of the oxidized nicotinamide cofactors for subsequent oxidation of DFF promoted by an ADH, thus implementing H2 O2 internal recycling. The desired products FFCA and FDCA are obtained with yields of more than 95 %.


Assuntos
Álcool Desidrogenase/metabolismo , Furaldeído/análogos & derivados , Furanos/síntese química , Biocatálise , Ácidos Dicarboxílicos/síntese química , Furaldeído/química , Furanos/química , Galactose Oxidase , Peróxido de Hidrogênio , Oxirredução
19.
Eur J Pharm Sci ; 140: 105058, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31472255

RESUMO

The biofilm formation of Pseudomonas aeruginosa (P. aeruginosa) is regulated by a phenomenon of quorum sensing (QS). With 5-hydroxyl-3,4-halogenated-5H-furan-2-ones as beginning, analogs bearing alkyl chains, vinyl bromide, or aromatic rings were designed and synthesized. The minimum inhibitory concentration (MIC) of the compounds against P. aeruginosa was assayed and the biofilm inhibition ratio was determined at different concentrations lower than the MIC. C-5 aromatic substituted furanones showed remarkable biofilm formation as well as inhibition of virulence factor production in P. aeruginosa. Fluorescence report analysis identified the QS regulatory mechanism of the most active compound 29. This study provides us a novel candidate for combating drug resistant bacteria strains by merely inhibiting biofilm formation. Without suppressing the regular life cycle of the bacteria, bacterial resistance mechanisms may not be activated.


Assuntos
Furanos/química , Furanos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Animais , Biofilmes/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Halogenação , Camundongos , Testes de Sensibilidade Microbiana , Células RAW 264.7 , Fatores de Virulência/metabolismo
20.
Molecules ; 24(18)2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31540241

RESUMO

Phytochemical investigation of the whole plant of Tradescantia albiflora Kunth led to the isolation and characterization of a butanolide, rosmarinosin B (1), that was isolated from natural sources for the first time, a new butenolide, 5-O-acetyl bracteanolide A (2), and a new apocarotenoid, 2ß-hydroxyisololiolide (11), together with 25 known compounds (compounds 3-10 and 12-28). The structures of the new compounds were elucidated by analysis of their spectroscopic data, including MS, 1D, and 2D NMR experiments, and comparison with literature data of known compounds. Furthermore, four butenolides 4a-4d were synthesized as novel derivatives of bracteanolide A. The isolates and the synthesized derivatives were evaluated for their preliminary anti-inflammatory activity against lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production in RAW 264.7 cells. Among them, the synthesized butenolide derivative n-butyl bracteanolide A (4d) showed enhanced NO inhibitory activity compared to the original compound, with an IC50 value of 4.32 ± 0.09 µg/mL.


Assuntos
Anti-Inflamatórios/farmacologia , Furanos/farmacologia , Lipopolissacarídeos/efeitos adversos , Tradescantia/química , 4-Butirolactona/análogos & derivados , Animais , Anti-Inflamatórios/química , Furanos/química , Concentração Inibidora 50 , Camundongos , Estrutura Molecular , Óxido Nítrico/metabolismo , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Células RAW 264.7
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