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1.
Molecules ; 26(5)2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33806630

RESUMO

While thiol-based catalysts are widely employed for chemical protein synthesis relying on peptide thioester chemistry, this is less true for selenol-based catalysts whose development is in its infancy. In this study, we compared different selenols derived from the selenocysteamine scaffold for their capacity to promote thiol-thioester exchanges in water at mildly acidic pH and the production of peptide thioesters from bis(2-sulfanylethyl)amido (SEA) peptides. The usefulness of a selected selenol compound is illustrated by the total synthesis of a biologically active human chemotactic protein, which plays an important role in innate and adaptive immunity.


Assuntos
Fatores Quimiotáticos/metabolismo , Quimiotaxia , Ésteres/síntese química , Compostos Organosselênicos/química , Fragmentos de Peptídeos/química , Biossíntese de Proteínas , Compostos de Sulfidrila/química , Catálise , Técnicas de Química Sintética , Humanos , Monócitos/citologia , Monócitos/fisiologia
2.
Nat Commun ; 11(1): 5340, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-33087708

RESUMO

Thiols are important precursors for the synthesis of a variety of pharmaceutically important sulfur-containing compounds. In view of the versatile reactivity of free thiols, here we report the development of a visible light-mediated direct decarboxylative thiolation reaction of alkyl redox-active esters to free thiols based on the abundant carboxylic acid feedstock. This transformation is applicable to various carboxylic acids, including primary, secondary, and tertiary acids as well as natural products and drugs, forging a general and facile access to free thiols with diverse structures. Moreover, the direct access to free thiols affords an advantage of rapid in situ diversification with high efficiency to other important thiol derivatives such as sulfide, disulfide, thiocyanide, thioselenide, etc.


Assuntos
Compostos de Sulfidrila/química , Compostos de Sulfidrila/síntese química , Descoberta de Drogas , Ésteres/síntese química , Ésteres/química , Modelos Químicos , Estrutura Molecular , Oxirredução , Processamento de Proteína Pós-Traducional , Bibliotecas de Moléculas Pequenas
3.
J Oleo Sci ; 69(10): 1281-1285, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32908100

RESUMO

In this study two different strategy were followed to obtain a D-fructose-oleic acid ester. One of the strategies has been well established enzymatic synthesis of an ester bond. The other strategy excluded the biocatalyst and only used a mixture of two organic solvents as the reaction media, 2-methyl-2-butanol / dimethyl sulfoxide or tert-butanol / dimethyl sulfoxide for the production of D-fructose-oleic acid ester. Ester products obtained were characterised by using FT-IR, NMR, by MS. Product yield was also assessed by HPLC. Results of structural analyses and yield measurement indicated that two approaches produced almost identical ester products.


Assuntos
Dimetil Sulfóxido/química , Ésteres/síntese química , Frutose/síntese química , Ácido Oleico/síntese química , Pentanóis/química , terc-Butil Álcool/química , Animais , Biocatálise , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Esterificação , Ésteres/química , Ésteres/toxicidade , Frutose/química , Frutose/toxicidade , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Ácido Oleico/química , Ácido Oleico/toxicidade , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Nature ; 585(7826): 530-537, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32968259

RESUMO

Post-translational modifications (PTMs) greatly expand the structures and functions of proteins in nature1,2. Although synthetic protein functionalization strategies allow mimicry of PTMs3,4, as well as formation of unnatural protein variants with diverse potential functions, including drug carrying5, tracking, imaging6 and partner crosslinking7, the range of functional groups that can be introduced remains limited. Here we describe the visible-light-driven installation of side chains at dehydroalanine residues in proteins through the formation of carbon-centred radicals that allow C-C bond formation in water. Control of the reaction redox allows site-selective modification with good conversions and reduced protein damage. In situ generation of boronic acid catechol ester derivatives generates RH2C• radicals that form the native (ß-CH2-γ-CH2) linkage of natural residues and PTMs, whereas in situ potentiation of pyridylsulfonyl derivatives by Fe(II) generates RF2C• radicals that form equivalent ß-CH2-γ-CF2 linkages bearing difluoromethylene labels. These reactions are chemically tolerant and incorporate a wide range of functionalities (more than 50 unique residues/side chains) into diverse protein scaffolds and sites. Initiation can be applied chemoselectively in the presence of sensitive groups in the radical precursors, enabling installation of previously incompatible side chains. The resulting protein function and reactivity are used to install radical precursors for homolytic on-protein radical generation; to study enzyme function with natural, unnatural and CF2-labelled post-translationally modified protein substrates via simultaneous sensing of both chemo- and stereoselectivity; and to create generalized 'alkylator proteins' with a spectrum of heterolytic covalent-bond-forming activity (that is, reacting diversely with small molecules at one extreme or selectively with protein targets through good mimicry at the other). Post-translational access to such reactions and chemical groups on proteins could be useful in both revealing and creating protein function.


Assuntos
Luz , Processamento de Proteína Pós-Traducional/efeitos da radiação , Proteínas/química , Proteínas/metabolismo , Alanina/análogos & derivados , Alanina/química , Alanina/metabolismo , Sítios de Ligação , Carbono/química , Carbono/metabolismo , Enzimas/química , Enzimas/metabolismo , Ésteres/síntese química , Ésteres/química , Células HeLa , Humanos , Hidrocarbonetos Fluorados/química , Hidrocarbonetos Fluorados/metabolismo , Indicadores e Reagentes/química , Oxirredução , Processos Fotoquímicos/efeitos da radiação , Domínios e Motivos de Interação entre Proteínas
5.
J Oleo Sci ; 69(8): 907-912, 2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32641616

RESUMO

D-ribose-oleic acid esters were produced with or without a biocatalyst, using in the same organic media, dimethyl sulfoxide (DMSO): tert-butanol (TBU) or 2-methyl-2-butanol (2M2B). The yield of the ester product was above 90% in both of the reactions. The biocatalyst used was lipase B of Candida antarctica. Molecular characterization was performed by using all the analytical methods available: IR, 1H-NMR and 13C-NMR, HSQC, and ESI-MS.


Assuntos
Biocatálise , Ésteres/síntese química , Proteínas Fúngicas/química , Lipase/química , Ácidos Oleicos/síntese química , Ribose/síntese química , Dimetil Sulfóxido/química , Esterificação , Ésteres/química , Ácidos Oleicos/química , Pentanóis/química , Ribose/química , terc-Butil Álcool/química
6.
J Oleo Sci ; 69(7): 693-701, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612019

RESUMO

Fatty acid sugar esters are non-ionic surfactant active agents with excellent performance and many uses. This work is devoted to the synthesis of sugar esters by the esterification reaction of sugar with mixed carboxylicpalmitic anhydrides using resin Amberlyst-15 as heterogeneous acid catalyst. These anhydrides should be stable and react as acylating agents. Influence of different reaction parameters, such as the molar ratio (sucrose/anhydride), the type of solvent and the reaction time on the yield of the esterification reaction were studied. The esterification reaction of sucrose with mixed palmitic benzoic anhydride leads to a mixture of sucrose esters of palmitic acid with a good percentage of conversion. The mixed anhydride was both reactive and selective for the preparation of fatty acid ester.


Assuntos
Benzoatos/química , Ácidos Carboxílicos/química , Técnicas de Química Sintética/métodos , Ésteres/síntese química , Ácidos Graxos/síntese química , Ácido Palmítico/química , Sacarose/síntese química , Acilação , Catálise , Esterificação , Solventes , Estirenos , Tensoativos/síntese química , Fatores de Tempo
7.
J Oleo Sci ; 69(7): 737-742, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612023

RESUMO

Esterification of D-glucose with oleic- and palmitic acids were carried out in the absence and presence of a biocatalyst, Candida antarctica lipase. The reaction medium was a mixture of dimethyl sulphoxide and tert-butanol (1:4, v/v). The reaction products were analysed by FTIR, 1H-NMR and 13C-NMR, HSQC, and by ESI-MS. Results indicated that the ester products formed were 6-O-glucose oleate and 6-O-glucose palmitate both in the absence and in the presence of the biocatalyst, with yields above 90%.


Assuntos
Biocatálise , Ésteres/síntese química , Glucose/química , Ácido Oleico/síntese química , Ácidos Oleicos/química , Palmitatos/síntese química , Ácidos Palmíticos/química , terc-Butil Álcool/química , Dimetil Sulfóxido/química , Esterificação , Proteínas Fúngicas/química , Lipase/química
8.
Carbohydr Res ; 489: 107957, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32109775

RESUMO

Described are the development of a new synthetic method using ultrasonic irradiation and sodium methoxide as catalyst for a series of pyridinic sucrose esters (py-SEs), derived from transesterification of sucrose with picolinic, nicotinic and isonicotinic methyl esters. The reaction was optimized using a 32 x 2 experimental design, the reaction time, temperature and sucrose: methyl ester molar ratio being evaluated. The method proved to be efficient for obtaining monosubstituted esters (≥83%) with high methyl ester consumption (≥79%). The monosubstituted py-SEs were isolated by semipreparative HPLC, characterized by high-resolution mass spectrometry, calorimetry, vibrational spectroscopy, and 1H and 13C NMR. The py-SEs were tested against E. coli, S. aureos, and P. aeruginosa bacteria with minimum inhibitory concentration values equal or inferior to the reference drugs for both E. coli and P. aeruginosa.


Assuntos
Antibacterianos/farmacologia , Ésteres/farmacologia , Piridinas/farmacologia , Sacarose/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Escherichia coli/efeitos dos fármacos , Ésteres/síntese química , Ésteres/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Pseudomonas aeruginosa/efeitos dos fármacos , Piridinas/síntese química , Piridinas/química , Staphylococcus aureus/efeitos dos fármacos , Sacarose/síntese química , Sacarose/química
9.
Org Lett ; 22(2): 666-669, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31909622

RESUMO

A catalytic conjunctive cross-coupling reaction is developed that allows the construction of chiral organoboronic esters from alkylboron ate complexes and alkyl iodide electrophiles. The process occurs most efficiently with a Ni/Pybox-comprised catalyst and with an acenapthoquinone-derived boron ligand. Because of the broad functional group tolerance of this reaction, it can be a versatile tool for organic synthesis. Applications to the construction of (R)-coniine and (-)-indolizidine 209D are described.


Assuntos
Alcaloides/síntese química , Ácidos Borônicos/síntese química , Ésteres/síntese química , Indolizinas/síntese química , Níquel/química , Piperidinas/síntese química , Alcaloides/química , Ácidos Borônicos/química , Catálise , Ésteres/química , Indolizinas/química , Estrutura Molecular , Piperidinas/química
10.
Molecules ; 25(3)2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31973220

RESUMO

An alternative catalytic strategy for the preparation of benzylmethacrylate esters, key intermediates in the synthesis of coenzyme Q10 and derivatives, was reported. This strategy avoided undesirable stoichiometric reduction/oxidation processes by utilizing the catalytic formation of allylarenes and then cross-metathesis to selectively form E-benzylmethacrylate esters with good yields (58-64%) and complete E-selectivity. The ester intermediates were reduced to common key benzylallylic alcohols (90-92% yield), which were subsequently used in the formal syntheses of coenzyme Q10 and one derivative.


Assuntos
Ubiquinona/análogos & derivados , Álcool Benzílico/química , Catálise , Ésteres/síntese química , Ésteres/química , Oxirredução , Ubiquinona/síntese química , Ubiquinona/química
11.
Molecules ; 25(3)2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31973223

RESUMO

The synthesis of the alkaloid (-)-monophyllidin is described. The molecule is a hybrid of xanthoxyline and (S)-proline, accessible in one-step through a Mannich reaction. In the solid-state, defined structural arrangements with different physical properties are formed. Single crystal X-ray diffraction revealed structures of six distinct polymorphs. In the crystalline state, the alkaloid can host small polar molecules (preferably water), while the (S)-proline moiety is present in the zwitterionic state. Combined with the chelate, which is already present in the xanthoxyline substructure, an ideal disposition for multiple hydrogen bond networks evolve. Therefore, highly water-soluble polymorphs of monophyllidin can form. This structural flexibility explains the many faces of the molecule in terms of structure as well as analytical data. Furthermore, speculations about the biological role of the molecule, with regard to the manifold interactions with water, are presented.


Assuntos
Alcaloides/química , Acetonitrilas/química , Alcaloides/síntese química , Cristalografia por Raios X , Ésteres/síntese química , Ésteres/química , Etanol/química , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Oxigênio/química , Solventes/química , Água/química
12.
Org Biomol Chem ; 18(7): 1377-1383, 2020 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-31998915

RESUMO

A methyl-substituted polycyclic cage dione containing the PCUD framework has undergone an unprecedented ring rearrangement approach. Here, the PCUD framework with the aid of a Lewis acid such as BF3·MeOH gave unusual fragmentation products. Two new products were isolated via the skeletal rearrangement process involving carbocation mediated intermediates. The substituents in the succinyl bond present in the strained PCUD skeleton produce a driving force for the rearrangement in an unprecedented manner. Interestingly, the cyclobutane ring was transformed to cyclopentane through the cleavage of the C1-C7 bond during the ring-expansion process of PCUD via the carbocation intermediates. Unexpectedly, solvent (benzene) was captured during the ring-homologation process due to the presence of methyl substituents placed at the cyclobutane ring of the cage framework. It appears that this is the first report where an unexpected ring-rearrangement, ring-homologation, and ring-fragmentation occur with the aid of the BF3·MeOH complex.


Assuntos
Ésteres/síntese química , Cetonas/química , Ácidos de Lewis/química , Compostos Policíclicos/química , Boranos/química , Catálise , Ésteres/química , Metanol/química
13.
Sci Rep ; 10(1): 599, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31953434

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disorder caused due to loss of dopaminergic neurons in substantia nigra pars compacta, which occurs the presence of Lewy bodies made up of Alpha-synuclein (ASN) aggregation resulting in neuronal death. This study aims to identify potent 7,8-Dihydroxyflavone (DHF) derivatives to inhibit the ASN aggregation from in silico analysis. Molecular docking study reveals that carbamic ester derivatives of DHF [DHF-BAHPC (8q), DHF-BAHPEC (8s), DHF-BAHEC (8p), DHF-BDOPC (8c), DHF-BAPEC (8n) and DHF-BAMC (8h)] have good binding affinity towards ASN, when compared with DHF and L-DOPA; their docking score values are -16.3120, -16.1875, -15.2223, -14.3118, -14.2893, -14.2810, -14.0383, and -9.1560 kcal/mol respectively. The in silico pharmacological evaluation shows that these molecules exhibit the drug-likeness and ADMET properties. Molecular dynamics simulation confirms the stability of the molecules with ASN. The intermolecular interaction analyzed under the dynamic condition, allows to identify the candidate which potentially inhibits ASN aggregation. Hence, we propose that DHF derivatives are the potential lead drug molecules and preclinical studies are needed to confirm the promising therapeutic ability against PD.


Assuntos
Carbamatos/síntese química , Ésteres/síntese química , Flavonas/química , alfa-Sinucleína/antagonistas & inibidores , Carbamatos/química , Carbamatos/farmacologia , Simulação por Computador , Desenho de Fármacos , Ésteres/química , Ésteres/farmacologia , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , alfa-Sinucleína/química
14.
Eur J Med Chem ; 185: 111783, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31732257

RESUMO

Over the past decade, many drug discovery endeavors have been invested in targeting the serine proteases prolyl oligopeptidase (POP) for the treatment of Alzheimer's and Parkinson's disease and, more recently, epithelial cancers. Our research group has focused on the discovery of reversible covalent inhibitors, namely nitriles, to target the catalytic serine residue in this enzyme. While there have been many inhibitors discovered containing a nitrile to covalently bind to the catalytic serine, we have been investigating others, particularly boronic acids and boronic esters, the latter of which have been largely unexplored as covalent warheads. Herein we report a series of computationally-designed POP boronic ester pro-drug inhibitors exhibiting nanomolar-potencies in vitro as their active boronic acid species. These easily-accessible (1-2 step syntheses) compounds could facilitate future biochemical and biological studies of this enzyme's role in neurodegenerative diseases and cancer progression.


Assuntos
Ácidos Borônicos/farmacologia , Descoberta de Drogas , Ésteres/farmacologia , Pró-Fármacos/farmacologia , Serina Endopeptidases/metabolismo , Ácidos Borônicos/síntese química , Ácidos Borônicos/química , Relação Dose-Resposta a Droga , Ésteres/síntese química , Ésteres/química , Humanos , Conformação Molecular , Simulação de Acoplamento Molecular , Pró-Fármacos/síntese química , Pró-Fármacos/química , Relação Estrutura-Atividade
15.
J Oleo Sci ; 68(12): 1251-1260, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31787673

RESUMO

The Habanero pepper is characterized by its strong pungency and fruity aroma. The aim of the present study was to extract the volatile compounds of Habanero peppers, using solvent extraction and solvent-assisted flavor evaporation (SAFE) methods, and to analyze them using gas chromatography-mass spectrometry (GC-MS). The analysis detected 66 volatile compounds, including 6-methyl-(E)-4-heptenyl 3-methylbutanoate 1, which was reported previously, and 6-methyl-(E)-4-heptenyl 2-methylpropanoate 2, the corresponding butanoate 3, 2-methylbutanoate 4, and 6-methyl-(E)-4-heptenol 5, which were found in both Habanero and other peppers. 6-Methyl-(E)-4-heptenyl 3-methylbutanoate 1 and related compounds were synthesized. Furthermore, principal component analysis (PCA) and hierarchical cluster analysis (HCA) of the volatile profiles generally grouped the pepper samples by species and indicated that Habanero peppers are characterized by the presence of 6-methyl-(E)-4-heptenyl esters.


Assuntos
Capsicum/química , Compostos Orgânicos Voláteis/análise , Capsicum/classificação , Análise por Conglomerados , Ésteres/análise , Ésteres/síntese química , Cromatografia Gasosa-Espectrometria de Massas , Análise de Componente Principal
16.
Molecules ; 25(1)2019 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-31881750

RESUMO

The development of ionic liquids based on active pharmaceutical ingredients (API-ILs) is a possible solution to some of the problems of solid and/or hydrophobic drugs such as low solubility and bioavailability, polymorphism and an alternative route of administration could be suggested as compared to the classical drug. Here, we report for the first time the synthesis and detailed characterization of a series of ILs containing a cation amino acid esters and anion ketoprofen (KETO-ILs). The affinity and the binding mode of the KETO-ILs to bovine serum albumin (BSA) were assessed using fluorescence spectroscopy. All compounds bind in a distance not longer than 6.14 nm to the BSA fluorophores. The estimated binding constants (KA) are in order of 105 L mol-1, which is indicative of strong drug or IL-BSA interactions. With respect to the ketoprofen-BSA system, a stronger affinity of the ILs containing l-LeuOEt, l-ValOBu, and l-ValOEt cation towards BSA is clearly seen. Fourier transformed infrared spectroscopy experiments have shown that all studied compounds induced a rearrangement of the protein molecule upon binding, which is consistent with the suggested static mechanism of BSA fluorescence quenching and formation of complexes between BSA and the drugs. All tested compounds were safe for macrophages.


Assuntos
Líquidos Iônicos/síntese química , Líquidos Iônicos/metabolismo , Cetoprofeno/síntese química , Soroalbumina Bovina/metabolismo , Animais , Bovinos , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ésteres/síntese química , Ésteres/química , Transferência Ressonante de Energia de Fluorescência , Líquidos Iônicos/química , Líquidos Iônicos/toxicidade , Cetoprofeno/química , Cetoprofeno/toxicidade , Cinética , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Estrutura Secundária de Proteína , Células RAW 264.7 , Soroalbumina Bovina/química , Solubilidade , Solventes/química , Água/química
17.
Molecules ; 24(23)2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31775342

RESUMO

Schiff base liquid crystals, known as [4-(hexyloxy)phenylimino)methyl]phenyl palmitate (IA), [4-(hexyloxy)phenylimino)methyl]phenyl oleate (IIA) and [4-(hexyloxy)phenylimino)methyl]phenyl linoleate (IIIA), were synthesized from palmitic, oleic, and linoleic natural fatty acids. The prepared compounds have been investigated for their thermal and optical behavior as well as phase formation using differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Molecular structures of all studied compounds were confirmed via elemental analysis, FT-IR, 1H NMR, and 13C NMR. Smectic phase is the observed mesophase for all compounds; however, their type and range depend upon the terminal alkanoate chains attached to the phenyl ring. Computational calculations, Density functional theory (DFT), energy difference of the frontier molecular orbital (FMOs), as well as the thermodynamic parameters of different molecular configurations isomers were discussed. It was found that the mesophase behavior and the geometrical characteristics were affected by the degree of unsaturation of fatty terminal chains. Furthermore, the geometrical structure of the CH=N linkage plays an important role in the thermal stability and optical transition temperature.


Assuntos
Ésteres/química , Ácidos Graxos/química , Cristais Líquidos/química , Bases de Schiff/química , Varredura Diferencial de Calorimetria , Ésteres/síntese química , Ácidos Graxos/síntese química , Espectroscopia de Ressonância Magnética , Conformação Molecular , Estrutura Molecular , Óptica e Fotônica/métodos , Bases de Schiff/síntese química , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Temperatura de Transição
18.
Molecules ; 24(19)2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31591297

RESUMO

With raising prevalence of obesity, the regulation of human body fat is increasingly relevant. The modulation of fatty acid uptake by enterocytes represents a promising target for body weight maintenance. Recent results demonstrated that the trigeminal active compounds capsaicin, nonivamide, and trans-pellitorine dose-dependently reduce fatty acid uptake in differentiated Caco-2 cells as a model for the intestinal barrier. However, non-pungent alternatives have not been investigated and structural determinants for the modulation of intestinal fatty acid uptake have not been identified so far. Thus, based on the previous results, we synthesized 23 homovanillic acid esters in addition to the naturally occurring capsiate and screened them for their potential to reduce intestinal fatty acid uptake using the fluorescent fatty acid analog Bodipy-C12 in differentiated Caco­2 cells as an enterocyte model. Whereas pre-incubation with 100 µM capsiate did not change fatty acid uptake by Caco-2 enterocytes, a maximum inhibition of -47% was reached using 100 µM 1­methylpentyl-2-(4-hydroxy-3-methoxy-phenyl)acetate. Structural analysis of the 24 structural analogues tested in the present study revealed that a branched fatty acid side chain, independent of the chain length, is one of the most important structural motifs associated with inhibition of fatty acid uptake in Caco-2 enterocytes. The results of the present study may serve as an important basis for designing potent dietary inhibitors of fatty acid uptake.


Assuntos
Ésteres/química , Ésteres/farmacologia , Ácidos Graxos/metabolismo , Ácido Homovanílico/química , Transporte Biológico/efeitos dos fármacos , Células CACO-2 , Capsaicina/análogos & derivados , Capsaicina/síntese química , Capsaicina/química , Diferenciação Celular , Enterócitos/metabolismo , Ésteres/síntese química , Ácido Homovanílico/metabolismo , Humanos
19.
Lipids ; 54(11-12): 715-723, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31658495

RESUMO

Growing health awareness has resulted in the increased use of dietary supplements derived from plants and marine sources, leaving consumers unsure of their best options. There were three objectives of the present study. The first was to design and evaluate an efficient derivatization procedure. The second was to perform a comparative analysis of liquid oils and their corresponding capsules of hemp, chia, and flax seeds. The final objective was to determine the fatty acid (FA) composition of six fish oil products and compare it to the one provided on the label. For the FA profiling, we implemented two efficient, one-step, sustainable methods with high percentage recovery for the synthesis of FA methyl esters (FAME), which use base catalysis and microwave-assisted heating. Our results found no difference in nutritional value between liquid oils and capsules of the seed supplements, with flaxseed and chia offering a higher, beneficial n-3:n-6 ratio compared to hemp oil. Four of the fish oils analyzed contained significantly less eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than their reported label, and the other two not only agreed with the manufacturers' declaration but were able to fulfill the daily adequate intake (AI) with fewer capsules.


Assuntos
Ésteres/síntese química , Ácidos Graxos/síntese química , Óleos de Peixe/análise , Hidróxidos/química , Micro-Ondas , Compostos de Potássio/química , Sementes/química , Catálise , Suplementos Nutricionais/análise , Ésteres/química , Ácidos Graxos/química , Estrutura Molecular
20.
Org Lett ; 21(19): 7952-7955, 2019 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-31524414

RESUMO

Allenyl esters activated by titanium(IV) underwent additions to a wide range of aldehydes in high regio- and diastereoselectivities leading to products containing an all-carbon quaternary center bearing an α-vinyl group that was installed with high selectivity for the Z-geometry. An aldol product was also converted to an indanone offering a new route to this important compound class. Product triple diastereoselectivity has been rationalized using a concerted transition-state model.


Assuntos
Alcadienos/química , Ésteres/síntese química , Aldeídos/química , Catálise , Cristalografia por Raios X , Ésteres/química , Modelos Moleculares , Estrutura Molecular , Estereoisomerismo , Titânio/química
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