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1.
J Agric Food Chem ; 68(6): 1678-1683, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31957422

RESUMO

During submerged cultivation, the edible basidiomycete Fomitopsis betulina (previously Piptoporus betulinus) developed a fruity odor, strongly reminding of pineapple. Olfactometric analysis showed that this impression was mainly caused by the two (5E/Z,7E,9)-decatrien-2-ones. At the time of maximum concentration on the 5th day, the (5E/5Z)-ratio was 94:6. Three hypotheses were experimentally examined to shed light onto the genesis of the uncommon volatiles: first, an indirect effect of agro-industrial side-streams, such as cabbage cuttings, supporting good growth; second, an unsaturated odd-numbered fatty acid precursor; and third, a polyketide-like pathway. In the presence of 1-13C- or 2-13C-acetate up to five acetates were incorporated into the molecular ions of the C10-body. Addition of 1-13C-pyruvate or 1-13C-lactate did not confirm an odd-numbered starter of the polyketide chain. None of the methylketones was found in pineapple or any other food before.


Assuntos
Coriolaceae/química , Odorantes/análise , Compostos Orgânicos Voláteis/química , Acetatos/análise , Isótopos de Carbono/análise , Coriolaceae/crescimento & desenvolvimento , Coriolaceae/metabolismo , Cetonas/química , Compostos Orgânicos Voláteis/metabolismo
2.
Chem Commun (Camb) ; 55(100): 15145-15148, 2019 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-31790115

RESUMO

A lipase-triggered drug release nanoplatform (PGL-DPP-FLU NPs) for multi-modal antifungal therapy is developed. The lipases secreted by C. albicans can accelerate FLU release. The ROS and heat produced by PGL-DPP-FLU NPs make C. albicans more vulnerable to FLU, thereby PGL-DPP-FLU NPs exhibit high performance for combating azole-resistant C. albicans biofilms and wound infection.


Assuntos
Antifúngicos/farmacologia , Azóis/química , Candida albicans/efeitos dos fármacos , Lipase/metabolismo , Nanopartículas/química , Animais , Antifúngicos/química , Antifúngicos/uso terapêutico , Azóis/farmacologia , Candidíase/tratamento farmacológico , Candidíase/patologia , Candidíase/veterinária , Farmacorresistência Fúngica/efeitos dos fármacos , Etilenoglicóis/química , Fluconazol/química , Cetonas/química , Lasers , Camundongos , Fotoquimioterapia , Fototerapia , Poliésteres/química , Pirróis/química
3.
Top Curr Chem (Cham) ; 377(6): 38, 2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31732819

RESUMO

The concept of merging enamine activation catalysis with transition metal catalysis is an important strategy, which allows for selective chemical transformations not accessible without this combination. The amine catalyst activates the carbonyl compounds through the formation of a reactive nucleophilic enamine intermediate and, in parallel, the transition metal activates a wide range of functionalities such as allylic substrates through the formation of reactive electrophilic π-allyl-metal complex. Since the first report of this strategy in 2006, considerable effort has been devoted to the successful advancement of this technology. In this chapter, these findings are highlighted and discussed.


Assuntos
Aminas/química , Elementos de Transição/química , Alquilação , Alquinos/química , Catálise , Complexos de Coordenação/química , Ciclização , Cetonas/química , Estereoisomerismo
4.
J Agric Food Chem ; 67(43): 11839-11847, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31589436

RESUMO

4-Hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) is an important target site for discovering new bleaching herbicides. To explore novel HPPD inhibitors with excellent herbicidal activity, a series of novel N-aroyl diketone/triketone derivatives were rationally designed by splicing active groups and bioisosterism. Bioassays revealed that most of these derivatives displayed preferable herbicidal activity against Echinochloa crus-galli (EC) at 0.045 mmol/m2 and Abutilon juncea (AJ) at 0.090 mmol/m2. In particular, compound I-f was more potent compared to the commercialized compound mesotrione. Molecular docking indicated that the corresponding active molecules of target compounds and mesotrione shared similar interplay with surrounding residues, which led to a perfect interaction with the active site of Arabidopsis thaliana HPPD.


Assuntos
4-Hidroxifenilpiruvato Dioxigenase/antagonistas & inibidores , Inibidores Enzimáticos/química , Herbicidas/química , Cetonas/química , Proteínas de Plantas/antagonistas & inibidores , 4-Hidroxifenilpiruvato Dioxigenase/química , 4-Hidroxifenilpiruvato Dioxigenase/metabolismo , Domínio Catalítico , Echinochloa/efeitos dos fármacos , Echinochloa/enzimologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Herbicidas/síntese química , Herbicidas/farmacologia , Cetonas/farmacologia , Malvaceae/efeitos dos fármacos , Malvaceae/enzimologia , Simulação de Acoplamento Molecular , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/enzimologia , Relação Estrutura-Atividade
5.
J Food Sci ; 84(10): 2758-2776, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31509249

RESUMO

The changes of volatile compounds in soy sauce during long-term fermentation (12 months) were investigated using solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE). A total of 144 and 129 compounds were identified in soy sauce with long-term fermentation by SPME and SBSE, respectively. The contents of most compounds, such as acids, aldehydes, benzene and benzene derivatives, esters, lactones, pyrazines, pyrones, and pyrroles, showed a tendency to increase, whereas those of alcohols and ketones decreased according to long-term fermentation. In addition, principal component analysis and partial least squares discriminant analysis were applied to discriminate soy sauce samples according to fermentation periods and determine key volatile compounds related to long-term fermentation. The initial fermentation stages were mainly associated with some alcohols, ketones, and lactones, whereas the later stages were strongly associated with most esters, some phenols, benzene and benzene derivatives, and pyrroles. Moreover, the key volatile compounds associated with long-term fermentation in soy sauce samples were ethyl 3-methylbutanoate (ethyl isovalerate), ethyl pentanoate (ethyl valerate), 1-octen-3-yl acetate, 3-(methylthio)-1-propanol (methionol), ethyl benzoate, ethyl 2-phenylacetate, 1-(1H-pyrrol-2-yl)ethanone (2-acetylpyrrole), and 5-pentyl-2-oxolanone (γ-nonalactone). PRACTICAL APPLICATION: This study investigated changes of volatile compounds in soy sauce during long-term fermentation (12 months) using solid-phase microextraction and stir bar sorptive extraction. In addition, the key volatile compounds associated with long-term fermentation in soy sauce samples were determined. These results may help to predict the effective contributors related to long-term fermentation of soy sauce and improve the quality of soy sauce during long-term fermentation.


Assuntos
Alimentos de Soja/análise , Compostos Orgânicos Voláteis/química , Álcoois/química , Álcoois/isolamento & purificação , Aldeídos/química , Aldeídos/isolamento & purificação , Fermentação , Cetonas/química , Cetonas/isolamento & purificação , Lactonas/química , Lactonas/isolamento & purificação , Microextração em Fase Sólida , Soja/química , Compostos Orgânicos Voláteis/isolamento & purificação
6.
Eur J Med Chem ; 183: 111687, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31539776

RESUMO

Conjugated α,ß-unsaturated ketones are very useful compounds associated with diverse medicinal properties. This review outlines α,ß-unsaturated ketones as candidate cytotoxic agents which affect mitochondrial function. Both naturally occurring compounds and synthetic chemicals have been discussed which exert their cytotoxic effects, at least in part, by acting on mitochondria. Biochemical differences between tumour mitochondria and this organelle in non-malignant cells have been exploited to investigate various compounds that can cause greater toxicity to neoplasms than normal cells. On a number of instances, correlations between the structures of various α,ß-unsaturated ketones and cytotoxic potencies have been observed. The aspiration is that this review will assist drug designers to create compounds which are significantly more toxic to neoplasms than normal tissues.


Assuntos
Cetonas/farmacologia , Mitocôndrias/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Animais , Humanos , Cetonas/química , Mitocôndrias/metabolismo , Neoplasias/metabolismo
7.
Eur J Med Chem ; 182: 111669, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31494473

RESUMO

A series of 2,8-diazaspiro[4.5]decan-1-one derivatives were designed, synthesized and screened for their inhibition activities against chitin synthase (CHS) and antimicrobial activities in vitro. The biological assays revealed that compounds 4a, 4e, 4h, 4j, 4o, 4q and 4r exhibited moderated to excellent potency against CHS with IC50 values ranging from 0.12 to 0.29 mM. Compounds 4e, 4j with IC50 value of 0.13 mM, 0.12 mM respectively, showed excellent inhibition potency among these compounds, which were similar to that of polyoxin B whose IC50 value was 0.08 mM. Meanwhile, the screening of the antifungal activity showed that compounds 4j and 4r had the same potency of inhibiting the growth of A. fumigatus with MIC value of 0.08 mmol/L. Compound 4d displayed excellent activity against C. albicans (ATCC 90023) with MIC value of 0.04 mmol/L, which was superior to fluconazole (0.104 mmol/L) and polyoxin B (0.129 mmol/L). The result of antibacterial assay showed that these compounds had little potency against those selected bacteria strains including three Gram-positive bacteria and three Gram-negative bacteria. Furthermore, the combination use of 4c-fluconazole, 4i-fluconazole, 4j-fluconazole, and 4o-fluconazole against C. albicans,A. fumigatus and A. flavus showed additive or synergistic effects. These results indicated that the designed compounds serve as potential chitin synthase inhibitors and have selectively antifungal activities.


Assuntos
Antifúngicos/farmacologia , Aspergillus flavus/efeitos dos fármacos , Aspergillus fumigatus/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Quitina Sintase/antagonistas & inibidores , Desenho de Drogas , Inibidores Enzimáticos/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Compostos Aza/síntese química , Compostos Aza/química , Compostos Aza/farmacologia , Quitina Sintase/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Cetonas/síntese química , Cetonas/química , Cetonas/farmacologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Compostos de Espiro/síntese química , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Relação Estrutura-Atividade
8.
Mater Sci Eng C Mater Biol Appl ; 104: 109948, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499957

RESUMO

Macrophages play an important role in foreign body reaction (FBR), and exhibit a detrimental or beneficial function in tissue repair while polarized into different phenotypes. The objective of this work is to evaluate the effect of three-dimensional (3D) porous polyetheretherketone (PEEK) on macrophage polarization through sulfonating PEEK and establishing a mouse air pouch model. The in vivo results show that the sulfonated PEEK induced higher levels of anti-inflammatory cytokine together with lower levels of pro-inflammatory cytokine. In addition, it was found that a relatively mild infiltration of inflammatory cells was caused and there were more M2 macrophages and less M1 ones when compared with PEEK. It indicates that 3D porous PEEK induces a shift to M2 macrophages and has large potential in regenerative medicine application.


Assuntos
Cetonas/administração & dosagem , Cetonas/química , Macrófagos/efeitos dos fármacos , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/química , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/química , Citocinas/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Porosidade
9.
Int J Mol Sci ; 20(15)2019 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-31382697

RESUMO

Polyether-ether-ketone (peek) is one of the most common materials used for load-bearing orthopedic devices owing to its radiolucency and favorable mechanical properties. However, current smooth-surfaced peek implants can lead to fibrous capsule formation. To overcome this issue, here, peek specimens with well-defined internal cross-linked structures (macropore diameters of 1.0-2.0 mm) were fabricated using a three-dimensional (3D) printer, and an acid-etched microporous surface was achieved using injection-molding technology. The cell adhesion properties of smooth and microporous peek specimens was compared in vitro through a scanning electron microscope (SEM), and the soft tissue responses to the both microporous and cross-linked structure of different groups were determined in vivo using a New Zealand white rabbit model, and examined through histologic staining and separating test. The results showed that the acid-etched microporous surface promoted human skin fibroblasts (HSF) adherence, while internal cross-linked structure improved the ability of the peek specimen to form a mechanical combination with soft tissue, especially with the 1.5 mm porous specimen. The peek specimens with both the internal cross-linked structure and external acid-etched microporous surface could effectively promote the close integration of soft tissue and prevent formation of fibrous capsules, demonstrating the potential for clinical application in surgical repair.


Assuntos
Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Impressão Tridimensional , Próteses e Implantes/efeitos adversos , Animais , Materiais Biocompatíveis/química , Éter/química , Éter/farmacologia , Humanos , Cetonas/química , Cetonas/farmacologia , Polietilenoglicóis/química , Porosidade , Coelhos , Propriedades de Superfície
10.
Phys Chem Chem Phys ; 21(33): 18105-18118, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31396604

RESUMO

With the emergence of drug-resistant Plasmodium falciparum, the treatment of malaria has become a significant challenge; therefore, the development of antimalarial drugs acting on new targets is extremely urgent. In Plasmodium falciparum, type II nicotinamide adenine dinucleotide (NADH) dehydrogenase (NDH-2) is responsible for catalyzing the transfer of two electrons from NADH to flavin adenine dinucleotide (FAD), which in turn transfers the electrons to coenzyme Q (CoQ). As an entry enzyme for oxidative phosphorylation, NDH-2 has become one of the popular targets for the development of new antimalarial drugs. In this study, reliable motion trajectories of the NDH-2 complex with its co-factors (NADH and FAD) and inhibitor, RYL-552, were obtained by comparative molecular dynamics simulations. The influence of cofactor binding on the global motion of NDH-2 was explored through conformational clustering, principal component analysis and free energy landscape. The molecular interactions of NDH-2 before and after its binding with the inhibitor RYL-552 were analyzed, and the key residues and important hydrogen bonds were also determined. The results show that the association of RYL-552 results in the weakening of intramolecular hydrogen bonds and large allosterism of NDH-2. There was a significant positive correlation between the angular change of the key pocket residues in the NADH-FAD-pockets that represents the global functional motion and the change in distance between NADH-C4 and FAD-N5 that represents the electron transfer efficiency. Finally, the possible non-competitive inhibitory mechanism of RYL-552 was proposed. Specifically, the association of inhibitors with NDH-2 significantly affects the global motion mode of NDH-2, leading to widening of the distance between NADH and FAD through cooperative motion induction; this reduces the electron transfer efficiency of the mitochondrial respiratory chain. The simulation results provide useful theoretical guidance for subsequent antimalarial drug design based on the NDH-2 structure and the respiratory chain electron transfer mechanism.


Assuntos
Antimaláricos/química , Cetonas/química , NADH Desidrogenase/antagonistas & inibidores , Plasmodium falciparum/enzimologia , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/química , Quinolinas/química , Transporte de Elétrons , Flavina-Adenina Dinucleotídeo/química , Ligações de Hidrogênio , Modelos Moleculares , Estrutura Molecular , NAD/química , NADH Desidrogenase/química , Oxirredução , Ligação Proteica , Relação Estrutura-Atividade , Termodinâmica
11.
Molecules ; 24(14)2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31319482

RESUMO

Distribution of volatile compounds in different fruit structures were analyzed in four tomato cultivars by headspace-solid-phase microextraction (SPME)-gas chromatography-mass spectrometry (GC-MS). A total of 36 volatile compounds were identified in fruit samples, which were primarily aldehydes, hydrocarbons, alcohols, ketones, furans, esters, nitrogen compounds, and sulfur and nitrogen-containing heterocyclic compounds. The volatile compositions in pericarp (PE), septa and columella (SC), locular gel and seeds (LS), and stem end (SE) tissues showed different profiles. The PE tissue showed the highest total volatile concentration due to a high abundance of aldehydes, especially cis-3-hexenal and benzaldehyde. Meanwhile, it showed higher aromatic proportion and herbaceous series intensity than other tissues. Floral and fruity series showed higher intensity in SC and LS tissues. The concentration of alcohols in the LS was higher than that in other tissues in association with the higher abundances of 2-methyl propanol, 3-methyl butanol, and 2-methyl butanol. However, the numbers and concentrations of volatile compounds, especially cis-3-hexenal, benzaldehyde, and geranyl acetone were lower in SE than in the other tissues, indicating less tomato aromas in SE. SE tissues were also lacking in floral and fruity characteristic compounds, such as geranyl acetone, 1-nitro-pentane, and 1-nitro-2-phenylethane. "FL 47" contained more volatile compounds than the other three, and the contents of aldehydes, ketones and oxygen-containing heterocyclic compounds in the "Tygress" fruit were higher than the other cultivars.


Assuntos
Frutas/química , Lycopersicon esculentum/química , Compostos Orgânicos Voláteis/classificação , Compostos Orgânicos Voláteis/isolamento & purificação , Álcoois/química , Aldeídos/química , Ésteres/química , Cromatografia Gasosa-Espectrometria de Massas , Cetonas/química , Odorantes/análise , Sementes/química , Microextração em Fase Sólida , Compostos Orgânicos Voláteis/química
12.
ACS Appl Mater Interfaces ; 11(31): 27503-27511, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31291088

RESUMO

Poly(ether ether ketone) (PEEK) is a promising material in biomedical engineering due to its suitable mechanical properties and excellent chemical resistance and biocompatibility. However, the biological inertness of PEEK limits its applications. In this study, we developed a facile approach of immersion to generate a biocompatible and bioactive PEEK that induced osteodifferentiation. First, micropores on the surface of PEEK were introduced by concentrated sulfuric acid and subsequent water immersion, followed by the hydrothermal treatment to reduce residual sulfuric acid. Subsequently, the sulfonated PEEK surface was activated by the oxygen plasma treatment and then coated with a poly(dopamine) (PDA) layer by immersion into the dopamine solution. Finally, the tripeptide Arg-Gly-Asp (RGD) was integrated onto the PDA-coated surface of PEEK by immersion into the RGD peptide solution. The surface characteristics (physical chemistry and biological properties) and the ability to form bonelike apatite were systematically investigated by scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle analysis, the Archimedes' fluid saturation method, ellipsometry, a quartz crystal microbalance with dissipation monitoring, cell proliferation, real-time reverse transcription polymerase chain reaction analysis, alizarin red staining, immunocytochemistry staining, and simulated body fluid immersion. Collectively, the modified PEEK showed a significantly improved ability to promote cell proliferation, osteogenic differentiation, and bonelike apatite formation in vitro as compared to the PEEK control. These results demonstrate that combined facile surface modifications for PEEK enhance its bioactivity and biocompatibility, and induce osteodifferentiation. This study presents a strategy for broadening the use of PEEK in the application of orthopedic implants and could be industrially scalable in future.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Materiais Revestidos Biocompatíveis , Cetonas , Oligopeptídeos , Osteoblastos/metabolismo , Osteogênese/efeitos dos fármacos , Polietilenoglicóis , Animais , Linhagem Celular , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Cetonas/química , Cetonas/farmacologia , Camundongos , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Osteoblastos/citologia , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Propriedades de Superfície
13.
Food Chem ; 298: 125064, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260954

RESUMO

Edible films based on gelatin and chitosan have high gas and aroma barrier properties. This study focused on their capability to sorbed/retain aroma compounds (1-hexanal, 2-hexen-1-ol, 1-hexanol, 3-hexanone and phenol) at three relative humidity level (≤2%, 53% or 84% RH). Whatever the relative humidity condition, the order of sorption is keton (3-hexanone) < aldehyde (1-hexanal) < aliphatic alcohols (2-hexen-1-ol and 1-hexanol) < phenol. This order could be related to the intrinsic chemical properties of aroma compounds. The increase in moisture enhanced the sorption at the highest RH for all the aroma compounds. However, a competition between water and aliphatic alcohols is observed at 53%RH. All compounds have an ideal sorption behaviour (logarithmic increase) except 1-hexanal. The sorption of 1-hexanal, 1-hexanol, 2-hexen-1-ol and 3-hexanone induced an antiplasticization of the network by increasing the film Tg by more than 5 °C. On the contrary, phenol was an efficient plasticizer at least as high as moisture.


Assuntos
Quitosana/química , Gelatina/química , Compostos Orgânicos Voláteis/química , Adsorção , Álcoois/química , Varredura Diferencial de Calorimetria , Cromatografia Gasosa , Umidade , Cetonas/química , Cinética , Fenol/química , Temperatura Ambiente
14.
Food Chem ; 298: 125060, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31261004

RESUMO

Typical ketone flavours (with variations in chain length, position and number of keto group, branched chain) were selected to investigate the effect of molecule structure of ketones on their interactions with myofibrillar proteins (MPs). Results showed that 2,3-pentanedione quenched the fluorescence of MPs more effectively than 2-pentanone and 3-pentanone due to the number of keto group. There was no significant difference between 5-methyl-2-hexanone and 2-heptanone, which was attributed to their similar molecular size and polarity. The quenching effect of homologous ketone flavours increased with carbon chain growth due to the higher hydrophobic interaction. Dynamic quenching played a major role in the fluorescence quenching process of MPs by 2-pentanone, 3-pentanone, 5-methyl-2-hexanone, 2-heptanone and 2-octanone. The α-helix content decreased gradually with the increase of ketones concentration. Results of GC/MS were in accordance with the fluorescence quenching analysis generally, whereas 2,3-pentanedione and 2-nonanone exhibited some differences due to their higher steric hindrance effects.


Assuntos
Aromatizantes/química , Cetonas/química , Proteínas Musculares/química , Animais , Dicroísmo Circular , Aromatizantes/análise , Aromatizantes/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Cetonas/metabolismo , Proteínas Musculares/metabolismo , Ligação Proteica , Microextração em Fase Sólida , Espectrometria de Fluorescência , Suínos
15.
Molecules ; 24(13)2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31288408

RESUMO

Demand for the development of novel polymers derived from biomass that can replace petroleum resources has been increasing. In this study, biomass-derived isosorbide was used as a monomer in the polymerization of poly(arylene ether ketone)s, and its synthetic characteristics were investigated. As a phase-transfer catalyst, crown ether has increased the weight-average molecular weight of polymers over 100 kg/mol by improving the reaction efficiency of isosorbide and minimizing the effect of moisture. By controlling the experimental parameters such as halogen monomer, polymerization solvent, time, and temperature, the optimal conditions were found to be fluorine-type monomer, dimethyl sulfoxide, 24 h, and 155 °C, respectively. Biomass contents from isosorbide-based polymers were determined by nuclear magnetic resonance and accelerator mass spectroscopy. The synthesized polymer resulted in a high molecular weight that enabled the preparation of transparent polymer films by the solution casting method despite its weak thermal degradation stability compared to aromatic polysulfone. The melt injection molding process was enabled by the addition of plasticizer. The tensile properties were comparable or superior to those of commercial petrochemical specimens of similar molecular weight. Interestingly, the prepared specimens exhibited a significantly lower coefficient of thermal expansion at high temperatures over 150 °C compared to polysulfone.


Assuntos
Biomassa , Isossorbida/análogos & derivados , Isossorbida/química , Cetonas/química , Plásticos/química , Catálise , Éteres/química , Temperatura Alta , Peso Molecular , Sulfonas/química
16.
Food Chem Toxicol ; 130 Suppl 1: 110588, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31216429

RESUMO

There are insufficient toxicity data on the target material propanal diethyl acetal (CAS # 4744-08-5). Hence, in silico evaluation was conducted to determine read-across analogs for this material. Based on structural similarity, reactivity, metabolism data, physical-chemical properties, and expert judgment, analogs acetal (CAS # 105-57-7) and butane, 1,1'-[methylenebis(oxy)]bis- (CAS # 2568-90-3) were identified as read-across materials with sufficient data for toxicological evaluation of genotoxicity.


Assuntos
Cetonas/química , Perfumes/química , Perfumes/toxicidade , Testes de Toxicidade/métodos , Animais , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Humanos , Estrutura Molecular , Medição de Risco
17.
Org Biomol Chem ; 17(24): 5913-5915, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31165124

RESUMO

A method for (hetero)arylboration of alkynes is presented. The reaction allows for the synthesis of densely functionalized tetrasubstituted alkenes with control of regioselectivity and diastereoselectivity. The conversion of the products to the corresponding α,α-bis(hetero)arylketones is also shown.


Assuntos
Alquinos/química , Compostos de Boro/química , Cetonas/química , Cetonas/síntese química , Estrutura Molecular , Estereoisomerismo
18.
Chem Pharm Bull (Tokyo) ; 67(6): 519-526, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31155556

RESUMO

Chiral phosphine oxides successfully catalyze asymmetric cross-aldol reactions of various carbonyl compounds in a highly enantioselective manner. The phosphine oxide catalysts coordinate to chlorosilanes to form chiral hypervalent silicon complexes in situ, which activate both aldol donors and acceptors, thus realizing cross-aldol reactions between a ketone and an aldehyde, between two aldehydes, between two ketones, and of 2,6-diketones. The use of phosphine oxide catalysis can be further extended to achieve the first catalytic enantioselective double aldol reactions, realizing one-pot stereoselective construction of up to four stereogenic centers.


Assuntos
Aldeídos/química , Fosfinas/química , Catálise , Ciclização , Cetonas/química , Óxidos/química , Silício/química , Estereoisomerismo
19.
Food Chem ; 293: 120-126, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151591

RESUMO

The effects of the natural ingredients Angelica sinensis (AS) and Codonopsis pilosula (CP) on the shelf life of chicken seasoning were investigated. Color differences and sensory evaluation were used to indicate sensory differences. Changes in volatiles were monitored. The rate of increase in the color value a* of the AS and CP samples was lower than that in the control. Rancid flavor appeared later in the AS and CP samples than in the control. The levels of aldehydes, ketones, and alkenes increased during storage. A kinetic model was built based on the proportion of aldehydes (main marker), to predict shelf life. The predicted shelf life at room temperature was 60 days for the control, 114 days for AS, and 89 days for CP. The shelf life of chicken seasoning could be prolonged with AS and CP. This kinetic model can be used to predict the shelf life of chicken seasoning.


Assuntos
Aromatizantes/química , Aldeídos/química , Aldeídos/metabolismo , Alcenos/química , Alcenos/metabolismo , Angelica sinensis/química , Angelica sinensis/metabolismo , Animais , Galinhas , Codonopsis/química , Codonopsis/metabolismo , Cor , Aromatizantes/metabolismo , Armazenamento de Alimentos , Cetonas/química , Cetonas/metabolismo , Cinética , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo
20.
Food Chem ; 293: 333-339, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151620

RESUMO

The volatile compounds of Volvariella volvacea mushroom were investigated by solvent assisted flavor evaporation (SAFE)/gas chromatography-mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O), odor activity value (OAV), combined with aroma reconstitution and omission. The results showed that a total of 63 compounds were detected after SAFE extraction. A total of 26 compounds were determined after GC-O and 17 compounds whose OAV greater than 1 were subjected to reconstitution and omission experiments. The results showed that dihydro-ß-ionone, 1-octen-3-one, 1-octen-3-ol, γ-undecalactone, 3-octanol, 2-octanone, hexanal, 2-methylbutanal, camphene, carvone, 2-nonanone, and phenylacetaldehyde have been successfully identified as the key aroma compounds. More significantly, dihydro-ß-ionone as a key aroma compound was first found in Volvariella volvacea mushroom.


Assuntos
Álcoois/análise , Cetonas/análise , Odorantes/análise , Volvariella/química , Adulto , Aldeídos/análise , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Cetonas/química , Masculino , Octanóis , Olfatometria/métodos , Paladar , Compostos Orgânicos Voláteis/análise
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