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1.
Bol. latinoam. Caribe plantas med. aromát ; 18(5): 518-526, sept. 2019. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-1008290

RESUMO

Valeriana amurensis Smir. ex Kom. widely distributed in the northeast region of China and some region in Russia and Korea, and its underground parts (roots and rhizomes) being used to cure nervous system diseases such as insomnia. The active components including the essential oil and iridoids of underground parts were investigated in different harvest periods in order to evaluate the quality for the roots and rhizomes of V. amurensis. The content of the essential oil was obtained by hydrodistillation and bornyl acetate in the oil was quantitated by GC-EI. The iridoids, valepotriates were determined by potentiometric titration and the main component, valtrate was quantitated by HPLC-UV. The factors of biomass were considered in the determination of collection period. Statistical analysis of results showed that, the highest content of the essential oil per plant was 22.69 µl in withering period and then 21.58 µl in fruit ripening period, while the highest contents of bornyl acetate, valepotriates and valtrate per plant were 2.82 mg, 31.90 mg and 0.98 mg in fruit ripening period separately. Fruit ripening period was decided as the best harvest period for the content of active constituents and output of drug, and it would provide scientific basis for the artificial cultivation of V. amurensis.


Valeriana amurensis Smir. ex Kom. Se distribuye ampliamente en la región noreste de China y en algunas regiones de Rusia y Corea, y sus partes subterráneas (raíces y rizomas) se utilizan para curar enfermedades del sistema nervioso como el insomnio. Se investigaron los componentes activos, incluidos el aceite esencial y los iridoides de las partes subterráneas de V. amurensis en diferentes períodos de cosecha para evaluar la calidad de las raíces y rizomas. El contenido del aceite esencial se obtuvo mediante hidrodestilación y el acetato de bornilo en el aceite se cuantificó por GC-EI. Los iridoides, valepotriatos se determinaron mediante valoración potenciométrica y el componente principal, el valtrato se cuantificó por HPLC-UV. Los factores de biomasa fueron considerados en la determinación del período de recolección. El análisis estadístico de los resultados mostró que el mayor contenido de aceite esencial por planta fue de 22,69 µl en el período de marchitación y luego de 21,58 µl en el período de maduración de la fruta, mientras que el mayor contenido de acetato de bornilo, valepotriatos y valtrato por planta fue de 2.82 mg, 31.90 mg y 0,98 mg, respectivamente, en el período de maduración de la fruta por separado. Se definió el período de maduración de la fruta como el mejor período de cosecha para el contenido de constituyentes activos y la producción de droga, lo cual proporcionaría una base científica para el cultivo artificial de V. amurensis.


Assuntos
Valeriana/química , Óleos Voláteis/química , Raízes de Plantas/química , Estações do Ano , Bornanos/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray , Rizoma/química , Iridoides/análise
3.
Chem Biodivers ; 16(8): e1900318, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31364803

RESUMO

Sponges from freshwater environments, unlike marine's, are poorly known producers of natural compounds with medicinal purposes. Amazonian sponges produce massive large specimens and are widely spread, taxonomically diverse and their metabolites could represent a new frontier on unusual natural products to treat diseases such as Alzheimer's and Malaria. Species of Metania and Drulia (Metaniidae) genera are major contributors to the fauna of Amazonian freshwater sponges. Methanolic extracts from several species from these genera had their inhibitory activities evaluated in vitro, for parasite Plasmodium falciparum and acetyl and butyrylcholinesterase enzymes (AChE and BChE). All extracts were able to inhibit AChE, although no activity was observed towards BChE. Drulia uruguayensis extract was the most potent, inhibiting AChE with IC50 =1.04 mg/mL. For antiplasmodial activity, all species showed inhibition to P. falciparum, but Metania reticulata being the most efficient with IC50 =2.7 µg/mL. Mass spectrometry analyses evidenced the presence of fatty acids and sterols in active extracts.


Assuntos
Antiprotozoários/química , Inibidores da Colinesterase/química , Poríferos/química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Animais , Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/química , Plasmodium falciparum/efeitos dos fármacos , Poríferos/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Esteróis/química
4.
J Enzyme Inhib Med Chem ; 34(1): 1426-1438, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31401883

RESUMO

Anaplastic lymphoma kinase (ALK) has been recognised as a promising molecular target of targeted therapy for NSCLC. We performed SAR study of pyrazolo[3,4-b]pyridines to override crizotinib resistance caused by ALK-L1196M mutation and identified a novel and potent L1196M inhibitor, 10g. 10g displayed exceptional enzymatic activities (<0.5 nM of IC50) against ALK-L1196M as well as against ALK-wt. In addition, 10g is an extremely potent inhibitor of ROS1 (<0.5 nM of IC50) and displays excellent selectivity over c-Met. Moreover, 10g strongly suppresses proliferation of ALK-L1196M-Ba/F3 and H2228 cells harbouring EML4-ALK via apoptosis and the ALK signalling blockade. The results of molecular docking studies reveal that, in contrast to crizotinib, 10g engages in a favourable interaction with M1196 in the kinase domain of ALK-L1196M and hydrogen bonding with K1150 and E1210. This SAR study has provided a useful insight into the design of novel and potent inhibitors against ALK gatekeeper mutant.


Assuntos
Quinase do Linfoma Anaplásico/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Pirazóis/farmacologia , Piridinas/farmacologia , Quinase do Linfoma Anaplásico/metabolismo , Apoptose/efeitos dos fármacos , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Linhagem Celular Transformada , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida , Cristalografia por Raios X , Inibidores Enzimáticos/química , Humanos , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Espectroscopia de Prótons por Ressonância Magnética , Pirazóis/química , Piridinas/química , Transdução de Sinais/efeitos dos fármacos , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-Atividade
5.
J Enzyme Inhib Med Chem ; 34(1): 1457-1464, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31411080

RESUMO

Carbonic anhydrases (CAs, EC 4.2.1.1) are crucial metalloenzymes that are involved in diverse bioprocesses. We report the synthesis and biological evaluation of novel series of benzenesulfonamides incorporating un/substituted ethyl quinoline-3-carboxylate moieties. The newly synthesised compounds were in vitro evaluated as inhibitors of the cytosolic human (h) isoforms hCA I and II. Both isoforms hCA I and II were inhibited by the quinolines reported here in variable degrees: hCA I was inhibited with KIs in the range of 0.966-9.091 µM, whereas hCA II in the range of 0.083-3.594 µM. The primary 7-chloro-6-flouro substituted sulphfonamide derivative 6e (KI = 0.083 µM) proved to be the most active quinoline in inhibiting hCA II, whereas, its secondary sulfonamide analog failed to inhibit the hCA II up to 10 µM, confirming the crucial role of the primary sulphfonamide group, as a zinc-binding group for CA inhibitory activity.


Assuntos
Anidrase Carbônica II/antagonistas & inibidores , Anidrase Carbônica I/antagonistas & inibidores , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/farmacologia , Sulfonamidas/síntese química , Sulfonamidas/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Inibidores da Anidrase Carbônica/química , Humanos , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-Atividade , Sulfonamidas/química
6.
J Agric Food Chem ; 67(35): 9916-9925, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31398025

RESUMO

Targeted analysis confirmed the presence of new phytosterol degradation products in fully hydrogenated commercial samples. EI-MS, APCI-MS, and 1D-NMR experiments led to the identification of 10 novel markers of catalytic hydrogenation, among which 5α-sitostan-3-one and 5α-campestan-3-one, isomers of saturated and monounsaturated steroidal hydrocarbons, were reported in edible oils for the first time. Examination of the phytosterol degradation mechanism was done by the catalytic transfer deuteration technique. The mitigation strategy of potentially detrimental compounds included optimization of processing parameters. The effect of catalyst dosage (≤0.1% based on Ni basis) and temperature region (>180 °C) were the most crucial factors in phytosterol degradation control.


Assuntos
Hidrocarbonetos/química , Óleos Vegetais/química , Catálise , Temperatura Alta , Hidrogenação , Isomerismo , Espectroscopia de Ressonância Magnética , Fitosteróis/química , Espectrometria de Massas por Ionização por Electrospray
7.
Food Chem ; 298: 125013, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260999

RESUMO

The determination of cocoa shell content (Theobroma cacao L.) in cocoa products using a metabolomics approach was accomplished via high performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS). The developed method was used to separately analyze the polar and non-polar metabolome of the cocoa testa (cocoa shell) and the cocoa cotyledons (cocoa nibs) of cocoa samples from 15 different geographic origins, harvest years, and varieties in positive and negative ion mode. Potential key metabolites were selected which are exclusively contained in the cocoa shell or with significant higher concentration in the cocoa shell than in the cocoa nibs. The pool of potential key metabolites was filtered by established selection criteria, such as temperature stability, fermentations stability, and independence from the geographic origin. Based on these key metabolites an inverse sparse partial least square regression (SPLS) was used for the prediction of the cocoa shell content.


Assuntos
Cacau/metabolismo , Chocolate/análise , Espectrometria de Massas , Metaboloma , Calibragem , Cromatografia Líquida de Alta Pressão , Fermentação , Frutas/metabolismo , Geografia , Metabolômica , Padrões de Referência , Espectrometria de Massas por Ionização por Electrospray , Temperatura Ambiente
8.
Chem Pharm Bull (Tokyo) ; 67(7): 707-712, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257326

RESUMO

Hypobromous acid (HOBr) is generated not only by eosinophils but also by neutrophils in the presence of Br- at the plasma concentration. Reactivity of HOBr is greatly modulated by coexistent compounds such as amines and amides. In this study, we investigated effects of urea in the reaction of nucleosides with HOBr. When nucleosides were incubated with HOBr without urea in potassium phosphate buffer at pH 7.4 and 37°C, the reactions almost completed within 10 min, with consumptions in the order of 2'-deoxyguanosine > 2'-deoxycytidine > 2'-deoxythymidine > 2'-deoxyadenosine, generating 8-bromo-2'-deoxyguanosine and 5-bromo-2'-deoxycytidine. In the presence of urea, the reaction of nucleosides with HOBr was relatively slow, continuing over several hours. When HOBr was preincubated without urea in potassium phosphate buffer at pH 7.4 and 37°C for 48 h, the preincubated HOBr solution did not react with nucleosides. However, a similar preincubated solution of HOBr with urea reacted with nucleosides to generate 8-bromo-2'-deoxyguanosine and 5-bromo-2'-deoxycytidine. These results imply that a reactive bromine compound with a long life, probably bromourea, is generated by HOBr in neutral urea solution and reacts with nucleosides, resulting in brominated nucleosides.


Assuntos
Bromatos/química , Nucleosídeos/química , Ureia/química , Cromatografia Líquida de Alta Pressão , Desoxicitidina/química , Desoxiguanosina/análogos & derivados , Desoxiguanosina/análise , Desoxiguanosina/química , Halogenação , Fosfatos/química , Compostos de Potássio/química , Espectrometria de Massas por Ionização por Electrospray , Timidina/química
9.
J Enzyme Inhib Med Chem ; 34(1): 1210-1217, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31286781

RESUMO

In this study, a series of 4,5-bis(substituted phenyl)-4H-1,2,4-triazol-3-amine compounds was designed, synthesised, and evaluated to determine their potential as anti-lung cancer agents. According to the results of screening of lung cancer cell lines A549, NCI-H460, and NCI-H23 in vitro, most of the synthesised compounds have potent cytotoxic activities with IC50 values ranging from 1.02 to 48.01 µM. Particularly, compound 4,5-bis(4-chlorophenyl)-4H-1,2,4-triazol-3-amine (BCTA) was the most potent anti-cancer agent, with IC50 values of 1.09, 2.01, and 3.28 µM against A549, NCI-H460, and NCI-H23 cells, respectively, meaning many-fold stronger anti-lung cancer activity than that of the chemotherapeutic agent 5-fluorouracil. We also explored the effects of BCTA on apoptosis in lung cancer cells by flow cytometry and western blotting. Our results indicated that BCTA induced apoptosis by upregulating proteins BAX, caspase 3, and PARP. Thus, the potential application of compound BCTA as a drug should be further examined.


Assuntos
Aminas/química , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Triazóis/síntese química , Triazóis/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Triazóis/química
10.
J Enzyme Inhib Med Chem ; 34(1): 1247-1258, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31286782

RESUMO

A series of N1,N3-bis (1-oxopropan-2-yl) isophthalamide-based derivatives 4-16 were prepared and their structures were confirmed by different spectral tools. The cytotoxic potentiality of novel compounds 4-16 was assessed by the MTT assay method on colon, lung and breast tumour cell lines. Compound 5 gave the most significant specificity anticancer activity with safety response on normal cell lines. In vitro enzyme assay and several apoptotic parameters were examined to elucidate the mode of action of compound 5. Molecular docking studies also were simulated to put insight and give better understanding to its structural features.


Assuntos
Aminoácidos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Simulação de Acoplamento Molecular , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Infravermelho , Relação Estrutura-Atividade
11.
J Enzyme Inhib Med Chem ; 34(1): 1233-1246, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31286784

RESUMO

Neratinib is an oral pan HER inhibitor, that irreversibly inhibits EGFR and HER2 and was proven to be effective against multiple EGFR mutations. In previous study, we reported spiro [indoline-3, 4'-piperidine]-2-ones as anticancer agents. In this study, we designed aminopyridine-containing spiro [indoline-3,4'-piperidine] derivatives A1-A4 using Neratinib and spiro [indoline-3, 4'-piperidine]-2-one compound patented as lead structure, then replaced piperidine with cyclopropane to obtain B1-B7 and replaced indoline with benzmorpholine to get C1-C4 and D1-D2. We synthesized these compounds and evaluated their residual activities under 0.5 M drug concentration on EGFR and ERBB2. Most of compounds showed stronger inhibition on EGFR-wt and ERBB2, in which A1-A4 showed excellent inhibitory activity with inhibition percentage on EGFR-wt kinase of 7%, 6%, 19%, 27%, respectively and 9%, 5%, 12%, 34% on ERBB2 kinase compared with 2% and 6% of Neratinib.


Assuntos
Aminopiridinas/química , Descoberta de Drogas , Fator de Crescimento Epidérmico/antagonistas & inibidores , Mutação , Compostos de Espiro/farmacologia , Fator de Crescimento Epidérmico/genética , Simulação de Acoplamento Molecular , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Compostos de Espiro/química
12.
J Agric Food Chem ; 67(32): 8819-8838, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31322880

RESUMO

Recent studies about hot-water extracts from sugar maple (Acer saccharum Marsh.) bark and buds demonstrated that they contain high amounts of phenolic structures that may be used as antioxidant food additives. However, the detailed chemical composition of these maple-derived extracts has yet to be determined. By performing high-performance liquid chromatography-diode array detector-high-resolution mass spectrometry (HPLC-DAD-HRMS)-based dereplication, we were able to spike and classify almost 100 metabolites in each hot-water extract. The sugar maple bark hot-water extract is rich in simple phenolic compounds and phenylpropanoid derivatives, while bud extract contains predominantly flavonoids, benzoic acids, and their complex derivatives (condensed and hydrolyzable tannins). Among those chemical structures, we tentatively identified 69 phenolic compounds potentially reported for the first time in the genus Acer. Considering the growing commercial demand in natural products, the phenolic fingerprints of sugar maple bark and bud hot-water extracts will help in promoting these two maple-derived products as new sources of bioactive compounds in the food, nutraceutical, and cosmetic industries.


Assuntos
Acer/química , Casca de Planta/química , Extratos Vegetais/química , Acer/metabolismo , Cromatografia Líquida de Alta Pressão , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonoides/metabolismo , Fenóis/química , Fenóis/isolamento & purificação , Fenóis/metabolismo , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/metabolismo , Espectrometria de Massas por Ionização por Electrospray
13.
Se Pu ; 37(7): 742-749, 2019 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-31271014

RESUMO

A two-dimensional separation and analysis method, based on liquid chromatography-electrospray ionization-ion mobility spectrometry (LC-ESI-IMS), is developed for the determination of seven indicative ingredients (danshensu, glycyrrhizic acid, gastrodin, chlorogenic acid, puerarin, baicalin, and rutin) in oral liquids of Chinese medicine. The sample was first separated on an ACQUITY UPLC BEH C18 column (50 mm×1 mm, 1.7 µm). The post-column effluent was directed to an adjustable flow splitter with a split ratio of 50:1. The low-flow and high-flow outlets were connected to an ion mobility spectrometer and a triple quadrupole mass spectrometer, respectively. The experimental conditions for LC, spray voltage, drift tube temperature, gas pre-heating temperature, and drift gas velocity were systematically optimized. The limits of detection (LODs) and quantitation (LOQs) for the seven analytes were 2-10 µg/mL and 5-25 µg/mL, respectively. The proposed method was applied for the analysis of real oral liquids of Chinese medicine samples. By coupling LC and IMS, two-dimensional separation could be achieved based on hydrophobicity difference and ionic mobility disparity, thus providing more comprehensive measurement information than LC or IMS used alone.


Assuntos
Medicamentos de Ervas Chinesas/análise , Espectrometria de Mobilidade Iônica , Álcoois Benzílicos/análise , Ácido Clorogênico/análise , Cromatografia Líquida , Flavonoides/análise , Glucosídeos/análise , Ácido Glicirrízico/análise , Isoflavonas/análise , Lactatos/análise , Limite de Detecção , Espectrometria de Massas , Rutina/análise , Espectrometria de Massas por Ionização por Electrospray
14.
J Agric Food Chem ; 67(31): 8677-8688, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31293164

RESUMO

Reversed-phase ultrahigh-performance-liquid chromatography-mass spectrometry (UPLC-MS) is the typical method for the lipidomic analysis of most of biological samples, which was rarely used for the comprehensive lipidomic analysis of marine shellfish. Thus, a range of columns, modifiers, and resuspension solvents were evaluated using UPLC-electrospray ionization-quadrupole time-of-flight-MS to facilitate the ionization efficiency in both the positive and negative electrospray ionization (ESI(+)/(-)) modes for abalone lipids. Optimal lipidomic coverage was acquired with 10 mM ammonium formate in both ESI(+)/(-) modes. The selected resuspension solvents also influenced ionization efficiency through the matrix effect, and resuspension in methanol enhanced the signal intensities by reducing ion suppression. Because of the higher glycerophospholipid content in shellfish, bridged ethylene hybrid C8 columns showed clear advantages over charged surface hybrid C18 columns. A series of glycerophospholipids, lyso-glycerophospholipids, glycerolipids, and fatty acids in different shellfish can be annotated and semiquantified in one injection by the optimized method.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Lipídeos/química , Frutos do Mar/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Cromatografia Líquida de Alta Pressão/instrumentação , Ácidos Graxos/química , Glicerofosfolipídeos/química , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Espectrometria de Massas em Tandem
15.
Chem Commun (Camb) ; 55(62): 9188-9191, 2019 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-31305808

RESUMO

The metal salts ubiquitously present in biological samples cause serious ion suppression, capillary clogging and signal fluctuation in ESI/nESI. Herein, a current-limited high voltage polarity reversing approach was applied for the online separation of intrinsic metal ions in biological samples, resulting in the generation of protonated analytes at the nESI tip for mass analysis without interference from salt cations. Stable and durable signals (∼30-60 s) were observed for protonated proteins, peptides and metabolites in complex biological samples, including liquids, solids and viscous samples, even with very high salt concentration (100 mM NaCl), allowing comprehensive tandem MS analysis with on average ca. 5-times higher analyte signal intensities compared to the conventional nESI analysis. Therefore this approach offers improved performance of nESI/ESI for the sensitive molecular analysis of untreated biological samples, opening new possibilities in various disciplines, including biology, medicine, chemistry, life sciences, etc.


Assuntos
Peptídeos/análise , Proteínas/análise , Cloreto de Sódio/química , Íons/análise , Peptídeos/metabolismo , Proteínas/metabolismo , Prótons , Espectrometria de Massas por Ionização por Electrospray/instrumentação
16.
J Photochem Photobiol B ; 197: 111549, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31302348

RESUMO

Light is a key factor influencing growth and development in plants. Specific irradiance and light quality can improve development and production of secondary compounds such as carotenoids during plant tissue culture. Bixin and norbixin, two apocarotenoids obtained from the seeds of Bixa orellana L. (annatto), are used as natural dyes in various industries. While annatto tissue culture has been successful, the effect of light in this species remains poorly understood. Here, we analyze for the first time the effect of irradiance regime (50, 150, 50 + 150, 200, 50 + 200 µmol m-2 s-1) and light spectral quality (fluorescent, white, blue/red LED) on in vitro development of apexes and bixin content in two contrasting bixin-producing varieties of B. orellana, namely 'Piave Vermelha' and 'UESB74'. The number of leaves per plant, stomatal density, leaf area, leaf expansion, chlorophylls and carotenoids content, malondialdehyde and bixin content were analyzed in the leaves of both cultivars. 'Piave Vermelha' produced 1.6-fold more bixin than 'UESB74'. Stomata cells of both cultivars had a paracytic arrangement with peltate trichomes along the adaxial and abaxial leaf surfaces. 'Piave Vermelha' preferred blue/red LED light; whereas fluorescent light was optimal for 'UESB74'. Under fluorescent light, an irradiance of 50 µmol m-2 s-1 is indicated for both cultivars. LED light increased bixin content only in 'Piave Vermelha', suggesting that the dye biosynthetic pathway is genotype-dependent. The present findings suggest the possibility of using light to modulate the bixin biosynthetic pathway.


Assuntos
Bixaceae/metabolismo , Carotenoides/análise , Luz , Bixaceae/efeitos da radiação , Carotenoides/metabolismo , Clorofila/análise , Fluorescência , Malondialdeído/análise , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Espectrometria de Massas por Ionização por Electrospray
17.
J Agric Food Chem ; 67(28): 7821-7831, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31260293

RESUMO

The mechanism of inhibition of advanced glycation end product (AGE) formation by protocatechuic acid and 3,4-dihydroxyphenylacetic acid (DHPA) has been studied using a widespread applied in vitro model system composed of bovine serum albumin (BSA) and supraphysiological glucose concentrations. Protocatechuic acid and DHPA inhibited the formation of Amadori compounds, fluorescent AGEs (IC50 = 62.1 ± 1.4 and 155.4 ± 1.1 µmol/L, respectively), and Nε-(carboxymethyl)lysine (IC50 = 535.3 ± 1.1 and 751.2 ± 1.0 µmol/L, respectively). BSA was pretreated with the two phenolic acids, and the formation of BSA-phenolic acid adducts was estimated by nanoflow liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry. Results showed that the tested phenolic acids bound key sites of glycation in BSA through a metal-catalyzed oxidative mechanism. The antiglycative activity mechanism involved the formation of BSA-phenolic acid adducts, and it is unlikely that this occurs in vivo. These results raise the problem to design in vitro models closer to physiological conditions to reach biologically sound conclusions.


Assuntos
Ácido 3,4-Di-Hidroxifenilacético/química , Hidroxibenzoatos/química , Lisina/química , Metais/química , Soroalbumina Bovina/química , Animais , Catálise , Bovinos , Cromatografia Líquida , Glicosilação , Oxirredução , Espectrometria de Massas por Ionização por Electrospray
18.
Chem Commun (Camb) ; 55(63): 9311-9314, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31310244

RESUMO

Discrimination between cysteine and homocysteine at the single-molecule level is achieved within a K238Q mutant aerolysin nanopore, which provides a confined space for high spatial resolution to identify the amino acid difference with a 5'-benzaldehyde poly(dA)4 probe. Our strategy allows potential detection and characterization of various amino acids and their modifications, and provides a crucial step towards developing nanopore protein sequencing devices.


Assuntos
Toxinas Bacterianas/química , Cisteína/análise , Homocisteína/análise , Nanoporos , Proteínas Citotóxicas Formadoras de Poros/química , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Cromatografia Líquida de Alta Pressão , Mutagênese Sítio-Dirigida , Poli A/química , Proteínas Citotóxicas Formadoras de Poros/genética , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Espectrometria de Massas por Ionização por Electrospray
19.
Zhongguo Zhong Yao Za Zhi ; 44(9): 1889-1894, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31342718

RESUMO

To search for the active diuretic fractions of Clematidis Armandii Caulis( CAC) and determine its main active chemical components by using liquid chromatography-mass spectrometry( LC-MS) and diuretic activity evaluation. CAC 75% ethanol extracts and extracts from different polar solvents were orally administered to saline-loaded rats at different doses. 6 h urinary volume,p H and contents of electrolyte Na+,K+and Cl-were measured. The chemical components of the active fractions were separated and identified by ultra performance liquid chromatography-electrospray ionization-quadrupole time of flight-mass spectrometry( UPLC-ESI-Q-TOF-MS/MS) method. As compared with the control group,the urine volume was increased by 44%( P< 0. 01) and 34%( P < 0. 05) in CAC75% ethanol extract 57. 74 and 28. 8 mg·kg-1 groups respectively; the Na+excretion was increased by 52%( P< 0. 01) and 45%( P<0. 05),respectively; while the Cl-excretion was increased by 101%( P<0. 01) and 85%( P<0. 05),respectively. The urine volume,Na+excretion and Cl-excretion were increased by 50%( P< 0. 01),58%( P< 0. 05),and 65%( P< 0. 05) respectively in petroleum ether extract 70. 98 mg·kg-1 group as compared with the control group. While for the n-butanol extract 194. 18 mg·kg-1 group,the urine volume,Na+and Cl-excretion were increased by 42%( P<0. 01),41%( P<0. 05) and 97%( P<0. 01),respectively. The diuretic activity of other fractions was not obvious. There was no statistical difference in K+excretion in all groups. The results of LC-MS analysis showed that six compounds,including two sterols,one chromogen and three fatty acids,were identified from petroleum ether extract.Fourteen compounds,including six triterpenoid saponins,six lignin glycosides,one sterol glycoside and one phenolic glycoside,were identified from the n-butanol extract. All the results suggested that the ethanol extract of CAC had remarkable diuretic activity and its main effective components included sterol,triterpenoid saponin and lignin glycosides.


Assuntos
Ascomicetos/química , Diuréticos/farmacologia , Materia Medica/farmacologia , Animais , Ratos , Solventes , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
20.
Food Chem ; 298: 125086, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31272050

RESUMO

Methylglyoxal (MGO) is a highly reactive ɑ-dicarbonyl compound that may adversely impact food quality and human health by modifying proteins. The kinetics of the reaction of naringenin with MGO was studied at pH 6-8 and 37 °C by UV-Vis spectrophotometry and reaction products were characterized by liquid chromatography-mass spectrometry (LC-MS/MS). The apparent second order rate constant (k2) increased at pH above the lowest pKa value of naringenin, indicating deprotonated naringenin as the main reactant. A Lederer-Manasse type reaction mechanism is suggested, with dehydration of the MGO-dihydrate as a rate determining step. The quantitative data obtained in the present study was used to simulate the competitive reaction between MGO and nucleophilic amino acid residues (Lys, Arg and Cys) and naringenin in milk. It is predicted that naringenin will be able to efficiently trap MGO during storage of milk, although the reversible trapping of MGO by Cys residues is initially kinetically favourable.


Assuntos
Flavanonas/química , Aldeído Pirúvico/química , Aminoácidos/química , Cromatografia Líquida , Concentração de Íons de Hidrogênio , Cinética , Proteínas do Leite/química , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Ultravioleta , Espectrometria de Massas em Tandem
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