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1.
J Agric Food Chem ; 67(35): 9840-9850, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31424924

RESUMO

In the present study, methanolysis of poplar biomass was conducted for the selective transformation of hemicellulose and lignin, which leads to methyl glycosides (mainly C5 glycosides) and lignin fragments in the liquefied products that can be separated according to their difference in hydrophilicity. The distribution of methyl glycosides and delignification was dependent on the presence of acid catalysts and reaction temperatures. The obtained lignin fraction was separated into solid lignin fragments and liquid lignin oil according to their molecular weight distribution. Subsequently, directional conversion of methyl C5 glycosides into methyl levulinate was performed with dimethoxymethane/methanol as the cosolvent. A yield of 12-30% of methyl levulinate yield (based on the methyl glycoside) was achieved under these conditions. The remaining cellulose-rich substrate showed enhanced susceptibility to enzymatic hydrolysis, resulting in a yield of glucose of above 70%. Overall, the described strategy shows practical implications for the effective valorization of biomass.


Assuntos
Fracionamento Químico/métodos , Glucose/isolamento & purificação , Ácidos Levulínicos/isolamento & purificação , Metanol/química , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Populus/química , Madeira/química , Catálise , Celulose/química , Celulose/isolamento & purificação , Glucose/química , Ácidos Levulínicos/química , Lignina/química , Lignina/isolamento & purificação , Fenóis/química , Extratos Vegetais/química
2.
J Agric Food Chem ; 67(33): 9295-9306, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31365237

RESUMO

As a result of an innovative olive fruit processing method involving stone removal and dehydration, a new kind of olive oil and olive flour are generated. The main objective of this work was to accomplish the comprehensive characterization of the minor compounds of both products and to evaluate the effect of the dehydration temperature on their composition. To this end, olive oil and flour samples obtained through the novel processing method were analyzed and compared with "conventional" virgin olive oils (VOO). The applied LC-MS methodology allowed the determination of 57 metabolites belonging to different chemical classes (phenolic compounds, pentacyclic trirterpenes, and tocopherols). Both the new oils and flours presented considerable amounts of olive fruit metabolites that are usually absent from VOO. Quantitative differences were found among VOOs and the new oils, probably due to the inhibition of some enzymes caused by the temperature increase or the absence of water during the processing.


Assuntos
Manipulação de Alimentos/métodos , Olea/química , Extratos Vegetais/química , Resíduos/análise , Cromatografia Líquida , Farinha/análise , Frutas/química , Azeite de Oliva/análise , Fenóis/química , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Espectrometria de Massas em Tandem , Tocoferóis/química , Tocoferóis/isolamento & purificação
3.
Food Chem ; 298: 125061, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260983

RESUMO

Buriti fruit, with high content in carotenoids and antioxidant compounds, is well appreciated for its organoleptic characteristics. However, its shell, an agroindustrial residue, is mostly discarded. Therefore, to verify the technological potential of the buriti shells, the aim of this this study was to evaluated the antioxidant potential of the extracts from buriti shell obtained by pressurized liquid extraction (PLE) with ethanol/water mixtures. PLE optimization was performed by response surface methodology, with all results maximized at the conditions of 71.21 °C and with 91.58% of ethanol. The yields values varied from 16.82 to 25.16%, total carotenoids from 23.38 to 1056.59 µg ß-carotene equivalent g-1, total phenolic content from 143.37 to 172.02 mg Gallic acid equivalent g-1, DPPH from 31.04 to 48.62 µg.mL-1, and ABTS from 1.87 to 2.70 mmol TEAC. g-1. Therefore, considering the lack of studies about buriti shell, the present work provides valuable results that confirm the PLE relevance to enhance the value of this neglected material.


Assuntos
Antioxidantes/química , Arecaceae/química , Antioxidantes/isolamento & purificação , Arecaceae/metabolismo , Carotenoides/análise , Carotenoides/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Frutas/química , Frutas/metabolismo , Extração Líquido-Líquido , Fenóis/análise , Fenóis/isolamento & purificação , Extratos Vegetais/química , Espectrometria de Massas por Ionização por Electrospray
4.
Fitoterapia ; 137: 104252, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31271787

RESUMO

The stems of Fissistigma polyanthoides (A.DC.) Merr. are traditionally used for the treatment of rheumatism and for recuperating women after childbirth. In our continuous phytochemical investigation of this plant, four new (1, 2, 5, and 19) and fifteen known (3, 4, and 6-18) phenolic compounds were isolated. The structures of all compounds were elucidated based on extensive spectroscopic analyses (1D-, 2D-NMR, and MS), and in comparison with reported literature data. The new natural products showed to be two poly-methoxylated chalcones (1 and 2) and two flavonoid glycosides, with 19 containing an uncommon sugar moiety (quinovose). Compounds with sufficient amount were tested for their anti-oxidant activity in a cell-based assay using the human bronchial epithelial cell line BEAS-2B. The compounds' capacity to inhibit the peroxyl radical triggered formation of dichlorofluorescein (DCF) was investigated in a dose-dependent manner. Both, anti-oxidant (3, 4, 6, 8-12, and 14) and pro-oxidative (5 and 16) properties were found for the investigated substances. The half maximal concentrations (IC50) for the inhibition of ROS formation ranged between 18.8 µM and 63.5 µM. Compounds, which acted protectively in the cellular antioxidant activity (CAA) assay and did not negatively affect cell viability, could be interesting targets for further investigations.


Assuntos
Annonaceae/química , Antioxidantes/farmacologia , Células Epiteliais/efeitos dos fármacos , Fenóis/farmacologia , Antioxidantes/isolamento & purificação , Linhagem Celular , Chalconas/isolamento & purificação , Chalconas/farmacologia , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Humanos , Estrutura Molecular , Fenóis/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Caules de Planta/química , Espécies Reativas de Oxigênio/metabolismo , Vietnã
5.
Plant Foods Hum Nutr ; 74(3): 399-404, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31273641

RESUMO

A simple and efficient ultrasonic-assisted extraction (UAE) technique was developed in order to find optimal conditions for the extraction of total phenolic compounds, flavonoids and anthocyanins in wild raspberry (Rubus idaeus L.) fruits. Several extraction variables, including methanol composition (v/v, %), solid-solvent ratio (g/mL), time (min) and extraction temperature (°C) were optimized using response surface methodology (RSM). Under optimal conditions for extraction, the total phenolics were found in the concentration of 383 mg GAE/100 g of fresh fruit weight, while HPLC-PDA analysis of the optimized extract showed the presence of cyanidin-3-glucoside, cyanidin-3-sophoroside, catechin, gallic and ellagic acid. The experimental values of DPPH and ABTS radical scavenging activities were 29.0 and 39.5 µmol Trolox/g of fresh fruit weight, respectively. In vitro simulated gastrointestinal digestion showed great raspberry phenolics stability. Our study assessed the bioaccessible phenolics in wild raspberry fruits and showed optimal conditions for the effective extraction of bioactive compounds for their analysis.


Assuntos
Flavonoides/análise , Frutas/química , Fenóis/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Rubus/química , Antocianinas/análise , Antocianinas/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Flavonoides/isolamento & purificação , Fenóis/análise , Compostos Fitoquímicos/análise , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Sonicação
6.
Plant Foods Hum Nutr ; 74(3): 430-435, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31302831

RESUMO

The beneficial health effects of apple consumption are well known, however, little is known about the potential of its phenolic fractions to inhibit α-glucosidases and thereafter to treat diseases related to the carbohydrate metabolism, such as postprandial hyperglycemia and diabetes. In the present study, the α-glucosidase inhibition and antioxidant activity of different phenolic fractions of apple were evaluated using the 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging activity. Moreover, the phenolic fractions were chemically characterized by LC-MS in order to identify the compounds responsible for the biological properties. The purified extract (not fractionated) had the highest α-glucosidase and hydroxyl radical inhibitions. The purified extract and fractions III and IV were more active against the enzyme activity than the positive control acarbose, the drug used by diabetic patients to treat postprandial hyperglycaemia. Our results show that apple phenolic extracts strongly inhibit α-glucosidase acitivity, validating their potential to be used in the management of type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores de Glicosídeo Hidrolases/farmacologia , Hiperglicemia/tratamento farmacológico , Malus/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Metabolismo dos Carboidratos , Fenóis/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/isolamento & purificação , alfa-Glucosidases/metabolismo
7.
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
8.
Ceska Slov Farm ; 68(2): 48-68, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31331175

RESUMO

This review deals with cytotoxic and antiproliferative activity of fifty seven prenylated phenols isolated from Morus alba. Prenyl side chain, which can be variously modified, increases lipophilicity of the substances, thereby improving their penetration through biological membranes and thus results in an increased bioavailability. The objective was to describe the relationship between structure of the prenylated phenols and their cytotoxic effect and to clarify various mechanisms by which cytotoxic prenylated phenols induce apoptosis. The conclusions showed that the cytotoxicity of the substances increases with increasing number of the prenyl side chains and ketal groups. Conversely, modification of the prenyl side chain, such as hydroxylation, reduces cytotoxicity. The cytotoxic activity is also influenced by the presence of prenyl and hydroxyl groups at specific positions.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Citotoxinas/farmacologia , Morus/química , Fenóis/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Citotoxinas/isolamento & purificação , Estrutura Molecular , Fenóis/isolamento & purificação , Prenilação
9.
Bol. latinoam. Caribe plantas med. aromát ; 18(4): 347-358, jul. 2019. ilus
Artigo em Inglês | LILACS | ID: biblio-1008172

RESUMO

Manilkara zapota (Sapotaceae), commonly known as Sapodilla, is widely known for its delicious fruit. Various parts of this plant are also used in folk medicine to treat a number of conditions including fever, pain, diarrhoea, dysentery, haemorrhage and ulcers. Scientific studies have demonstrated analgesic, anti-inflammatory, antioxidant, cytotoxic, antimicrobial, antidiarrheal, anti-hypercholesteremic, antihyperglycemic and hepatoprotective activities in several parts of the plant. Phytochemical studies have revealed the presence of phenolic compounds including protocatechuic acid quercitrin, myricitrin, catechin, gallic acid, vanillic acid, caffeic acid, syringic acid, coumaric acid, ferulic acid, etc. as main constituents of the plant. Several fatty acids, carotenoids, triterpenes, sterols, hydrocarbons and phenylethanoid compounds have also been isolated from M. zapota. The present review is a comprehensive description focused on pharmacological activities and phytochemical constituents of M. zapota.


Manilkara zapota (Sapotaceae), comúnmente conocida como Sapodilla, es ampliamente conocida por su delicioso fruto. Variadas partes de esta planta se usan en medicina popular para tratar una serie de afecciones, como fiebre, dolor, diarrea, disentería, hemorragia y úlceras. Estudios científicos han demostrado actividad analgésica, antiinflamatoria, antioxidante, citotóxica, antimicrobiana, antidiarreica, antihipercolesterolémica, antihiperglucémica y hepatoprotectora en diferentes partes de la planta. Los estudios fitoquímicos han revelado la presencia de compuestos fenólicos que incluyen ácido protocatechúico, quercitrina, miricitrina, catequina, ácido galico, ácido vanílico, ácido cafeico, ácido sirínico, ácido cumárico, ácido fúnico y ácido ferúlico como componentes principales de la planta. Varios ácidos grasos, carotenoides, triterpenos, esteroles, hidrocarburos y compuestos feniletanoides también han sido aislados de M. zapota. La presente revisión es una descripción exhaustiva centrada en las actividades farmacológicas y los constituyentes fitoquímicos de M. zapota.


Assuntos
Extratos Vegetais/farmacologia , Manilkara/química , Fenóis/isolamento & purificação , Fenóis/farmacologia , Saponinas/isolamento & purificação , Saponinas/farmacologia , Esteróis/isolamento & purificação , Esteróis/farmacologia , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Carotenoides/isolamento & purificação , Carotenoides/farmacologia , Sapotaceae/química , Compostos Fenólicos/análise , Medicina Tradicional
10.
Fitoterapia ; 137: 104244, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31220578

RESUMO

Five new caffeoyl cyclobutantetraol esters (1-5) and one hydroxycinnamoyl cyclobutantetraol ester (6), were isolated from Scindapsus officinalis (Roxb.) Schott, which were the first reported phenolic metabolites incorporating a cyclobutantetraol in nature. Structures of the isolated compounds, including absolute configurations, were elucidated by spectroscopic analysis, especially 2D NMR techniques and exciton chirality CD (ECCD) method. All isolates were evaluated for cytotoxic activity toward MCF-7 human breast cancer cell, anti-inflammatory activity against nitric oxide (NO) production, and their antioxidative activity in the 1,1-diphenyl-2-picrylhydrazyl assay in vitro. Compound 1 showed strong antioxidative activity with IC50 value of 59.2 µM, and compounds 1-6 exhibited weak inhibitory effects on NO production, while hardly showing any cytotoxic effects against MCF-7 cell.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Araceae/química , Ésteres/farmacologia , Fenóis/farmacologia , Animais , Anti-Inflamatórios/isolamento & purificação , Antioxidantes/isolamento & purificação , Ésteres/isolamento & purificação , Humanos , Células MCF-7 , Camundongos , Estrutura Molecular , Óxido Nítrico/metabolismo , Fenóis/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Células RAW 264.7
11.
J Sci Food Agric ; 99(13): 6001-6010, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31225640

RESUMO

BACKGROUND: In this study, we aimed to evaluate the influence of different extraction procedures [decoction, homogenizer-assisted extraction (HAE), infusion, maceration, Soxhlet and ultrasound-assisted extraction (UAE)] on the chemical profiling and biological properties of methanol and water extracts of Pulicaria dysenterica (L.) Bernh. The chemical profiles of the extracts were evaluated by high-performance liquid chromatography coupled to electrospray ionization and time-of-flight mass spectrometry (HPLC-ESI-TOF-MS). The antioxidant properties and enzymes (lipase, α-amylase, α-glucosidase, tyrosinase and cholinesterases) inhibitory potential of the extracts were evaluated. RESULTS: The chemical profiles were dependent on the type of extraction methods as well as on the type of solvent. The methanolic extracts showed higher levels of total phenolic, flavonoid, and phenolic acid content, while the highest total flavonol content was observed in the HAE-water extract. Forty different compounds were identified from P. dysenterica. In relation to the potential in vitro anti-diabetic effects, the highest activity against the studied key enzymes was observed for the macerated extract (α-amylase: 0.58 ± 0.03 and α- glucosidase: 1.65 ± 0.03 mmol ACAE g-1 ). The HAE-methanol extract was the most potent inhibitor of cholisterases, whereas the highest activities against tyrosinase were observed for UAE-methanol extract, followed by macerated and Soxhlet. The inhibitory activity of the studied extracts against lipase were in the order: soxhlet > macerated> HAE-methanol > UAE-methanol. CONCLUSION: This study has established scientific baseline data on the therapeutic properties of P. dysentrica, thereby advocating the need for further investigations in an endeavour to develop novel pharmaceuticals from this plant. © 2019 Society of Chemical Industry.


Assuntos
Extratos Vegetais/química , Pulicaria/química , Antioxidantes/química , Antioxidantes/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Flavonoides/química , Flavonoides/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/química , Análise Multivariada , Fenóis/química , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , alfa-Glucosidases/química
12.
BMC Complement Altern Med ; 19(1): 149, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31238921

RESUMO

BACKGROUND: The kidney is an essential organ required by the body to perform several important functions. Nephrotoxicity is one of the most prevailing kidney complications that result from exposure to an extrinsic or intrinsic toxicant, which increase the need for the acquisition of proper remedies. Recently, natural remedies are gaining great attention owed to the fact that they have fewer side effects than most conventional drugs. METHODS: The current study recorded a new therapeutic role of the well-known medicinal plants for kidney stones [Ammi visnaga (AVE), Petroselinum crispum (PCE), Hordeum vulgare (HVE), and Cymbopogon schoenanthus (CSE)]. Hence, the aqueous extracts of these plants examined against CCl4-induced toxicity in mammalian kidney (Vero) cells. RESULTS: These extracts showed the presence of varying amounts of phenolic and triterpenoid compounds, as well as vitamin C. Owing to the antioxidant potential of these constituents, the extracts suppressed the CCl4-induced oxidative stress significantly (p < 0.05) by scavenging the reactive oxygen species and enhancing the cellular antioxidant indices. In addition, these extracts significantly (p < 0.05) reduced the CCl4-induced inflammation by inhibiting the gene expression of NF-кB, iNOS, and in turn the level of nitric oxide. Consequently, the morphological appearance of Vero cells, cellular necrosis, and the gene expression of kidney injury molecule-1 (a marker of renal injury) after these treatments were improved. The AVE improved CCl4-induced oxidative and inflammatory stress in Vero cells and showed a more potent effect than the commonly used alpha-Ketoanalogue drug (ketosteril) in most of the studied assays. CONCLUSION: Thus, the studied plant extracts, especially AVE can be considered as promising extracts in the management of nephrotoxicity and other chronic diseases associated with oxidative stress and inflammation.


Assuntos
Ammi/química , Cymbopogon/química , Hordeum/química , Rim/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Petroselinum/química , Extratos Vegetais/farmacologia , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Cercopithecus aethiops , Rim/imunologia , NF-kappa B/genética , NF-kappa B/imunologia , Óxido Nítrico/imunologia , Fenóis/química , Fenóis/isolamento & purificação , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Sementes/química , Células Vero
13.
BMC Complement Altern Med ; 19(1): 148, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31238930

RESUMO

BACKGROUND: Sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson, SBT) is a valuable plant because of its medical and therapeutic potential. Different bioactive compounds in SBT berries are of special interest to various researchers. However, not only sea buckthorn berries, but also leaves of this plant (both fresh and dried) contain a lot of nutrients and bioactive compounds, including phenolic compounds. The present study was carried out in order to investigate antioxidant and anticoagulant properties of sea buckthorn twig and leaf extracts (0.5-50 µg/mL) by using various in vitro models. Moreover, the aim of present experiments was to compare the biological activity of SBT leaf extract and SBT twig extract with selected berry extracts (a rich source of phenolic compounds): SBT berry extract (flavonoids being the dominant components), a commercial extract from the berries of Aronia melanocarpa (Aronox®), and a grape seed extract. METHODS: We determined the effect of plant extracts on the oxidative stress using selected markers of this process, i.e. the level of carbonyl groups in proteins. Additionally, we analysed the potential mechanism of modulation of hemostatic properties of human plasma (using selected coagulation times). RESULTS: SBT twig and leaf extracts were observed to exhibit an antioxidant activity against two strong biological oxidants: hydrogen peroxide (H2O2) and H2O2/Fe (the donor of hydroxyl radicals), which induced human plasma lipid peroxidation and protein carbonylation. Both extracts also showed anticoagulant properties. CONCLUSIONS: Our present results have demonstrated that extracts from different parts of SBT, especially berries and twigs, in comparison to well-known berries (aronia and grape), may also be viewed as a good source of active substances - antioxidants for pharmacological or cosmetic applications. Moreover, it is very important from an economic point of view to know that there is a possibility of obtaining phenolic compounds not only from the berries or leaves, but also from twigs, which constitute a production waste.


Assuntos
Elaeagnaceae/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Caules de Planta/química , Anticoagulantes/química , Anticoagulantes/isolamento & purificação , Anticoagulantes/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Frutas/química , Humanos , Fenóis/química , Fenóis/isolamento & purificação , Fenóis/farmacologia , Photinia/química , Extratos Vegetais/isolamento & purificação , Tempo de Protrombina
14.
Phytochemistry ; 165: 112049, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31229788

RESUMO

Five undescribed phenolic compounds, inclusing a depsidone derivative, hyperwightin A, a flavone derivative, hyperwightin B, and three benzophenone glycosides, hyperwightins C-E, along with four known ones were isolated from the 95% EtOH extract of the whole plants of Hypericum wightianum. Structures of the obtained compounds were elucidated by spectroscopic analyses. The protective effects of the isolates against corticosterone-induced PC12 cell injury were assessed. Hyperwightin E, petiolin G and hyperxanthone exhibited noticeable neuroprotection at 10 µM.


Assuntos
Hypericum/química , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fenóis/farmacologia , Compostos Fitoquímicos/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Corticosterona/antagonistas & inibidores , Corticosterona/farmacologia , Estrutura Molecular , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/isolamento & purificação , Células PC12 , Fenóis/química , Fenóis/isolamento & purificação , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Ratos
15.
Ultrason Sonochem ; 57: 22-28, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31208615

RESUMO

Bisphenol A (BPA) is an important emerging contaminant with endocrine-disrupting potential that has frequently been detected in aquatic environments. In this study, two types of hierarchically structured manganese dioxide/biochar nanocomposites (MnO2/BCs) were prepared for the first time via facile hydrothermal synthesis. The hydrothermal reaction was maintained at 100 °C for 6 h or 12 h, after which an ultrasound-assisted heterogeneous Fenton-like process was used to catalyze the removal of BPA under neutral pH condition. The characterization results indicated that MnO2 nanoparticles were successfully formed on the nanocomposite surfaces and had flower-like (δ-MnO2, 6 h) and urchin-like (α-MnO2, 12 h) morphology. This enabled a significant improvement in the catalytic activity of BPA removal by the reversible redox reaction. A series of experiments confirmed that the crystalline properties of the nanocomposites affected their catalytic activity. In particular, the α-MnO2/BCs exhibited catalytic activity in the ultrasound-assisted heterogeneous Fenton-like process and completely removed BPA within 20 min under the following conditions: [BPA]0 = 100 µM; [H2O2]0 = 10 mM; [catalyst]0 = 0.5 g/L; ultrasound = 20 kHz (130 W) at 40% amplitude; pH = 7.0 ±â€¯0.1; and temperature = 25 ±â€¯1 °C. This efficiency may have been due to the synergistic effect of ultrasound and α-MnO2/BCs, which simultaneously induce the effective generation of reactive free radicals and increase the mass transfer rate at the solid-liquid interface. Overall, these results demonstrated that hierarchical urchin-like α-MnO2/BCs have significant potential as an efficient and low-cost catalyst in ultrasound-assisted heterogeneous Fenton-like systems.


Assuntos
Compostos Benzidrílicos/isolamento & purificação , Carvão Vegetal/química , Compostos de Manganês/química , Nanocompostos/química , Óxidos/química , Fenóis/isolamento & purificação , Ondas Ultrassônicas , Catálise , Peróxido de Hidrogênio/química , Cinética , Oxirredução
16.
J Agric Food Chem ; 67(25): 7174-7182, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31240931

RESUMO

Intake of endocrine-disrupting chemicals (EDCs) by humans could disturb the metabolism of hormones, induce cancer, and damage the liver and other organs. Phthalate acid esters (PAEs) and alkylphenols (APs) are important EDCs and environmental contaminants. With the increasing use of plastics and nonionic surfactants worldwide, PAEs and APs have entered environmental water and accumulated in edible fish, which are finally consumed by humans. In this study, a coated direct inlet probe (CDIP) based on an atmospheric solid analysis probe, which can rapidly and simultaneously extract both PAEs and APs in fish, was developed. Twelve PAEs and APs were quantified by using a stable-isotope-labeled internal standard. Standard curves of the PAEs and APs having correlation coefficients of R2 ≥ 0.9837 were obtained. The limit of detection of the PAEs and APs was distributed from 0.01 to 40 ng g-1. The relative recovery of the method was 78-120% between low, medium, and high spiked levels. Combined with principal component analysis, PAE- and AP-contaminated Carassius auratus from different habitats could be identified. Multiple sample analysis mode allowed the extraction of up to 12 samples at once, and the total analysis time (including sample pretreatment, extraction, and analysis time) was less than 10 min per sample, which indicates that CDIP is useful for rapid quantitative analysis.


Assuntos
Ésteres/análise , Carpa Dourada , Ensaios de Triagem em Larga Escala/métodos , Fenóis/análise , Ácidos Ftálicos/análise , Animais , Disruptores Endócrinos/análise , Disruptores Endócrinos/isolamento & purificação , Ésteres/isolamento & purificação , Carpa Dourada/metabolismo , Ensaios de Triagem em Larga Escala/instrumentação , Limite de Detecção , Fenóis/isolamento & purificação , Ácidos Ftálicos/isolamento & purificação , Extração em Fase Sólida
17.
Bioelectrochemistry ; 129: 154-161, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31174109

RESUMO

A bioelectrochemical system (BES) is a technology with potential for accelerating the degradation of recalcitrant compounds, the components and configurations of which are important for treatment performance. In the present work, a membraneless sleeve-type BES (termed BioE) was designed for the treatment of synthetic coal gasification wastewater (CGW, phenol as a model pollutant) and real CGW. Compared with the biological control (termed Bio), the phenol removal rate and COD removal efficiency increased by 2.6 and 2.1 fold in the BioE, respectively. However, the coulombic efficiency of this system was relatively low, ranging from 0.42% to 2.6%. This combination of results indicated that anode respiration was not the main process in the BioE. The increased CH4 production and higher levels of methanogens obtained from the BioE confirmed that the methanogenic process proceeded, possibly facilitated by the diffusion of H2 from the cathode to the anode. This study provides new insight into biocathode function for COD oxidation removal in BESs. Moreover, this study indicates that pursuing a high coulombic efficiency may not be necessary for wastewater treatment, as it consumes less energy at the lower value.


Assuntos
Reatores Biológicos/microbiologia , Carvão Mineral/análise , Fenóis/isolamento & purificação , Eliminação de Resíduos Líquidos/instrumentação , Águas Residuárias/análise , Poluentes Químicos da Água/isolamento & purificação , Análise da Demanda Biológica de Oxigênio , Eletrodos , Desenho de Equipamento
18.
J Chromatogr A ; 1602: 237-245, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31147155

RESUMO

This work seeks to explore and understand the effects of column orientation and degree of modification of continuous stationary phase gradient columns under a mobile phase gradient using both simulations and experiments. Peak parameters such as retention times, peak widths and resolution are obtained for five phenolic compounds on a C18-silica gradient stationary phase. Simulations show that peak widths for the solutes are dependent upon the fractional composition of C18 and orientation of the stationary phase gradient when coupled to a mobile phase gradient. Also, when compared to a simulated uniform mixed-mode column, peak widths reach a minimum on the gradient column with a coverage higher than 50% C18 where the column is oriented to have the C18 dense region at the end. Experimentally, continuous stationary phase gradients were fabricated to have a total C18 composition of 78% of the original uniform column with an exponential profile using a previously described destructive controlled rate infusion method. Under gradient mobile phase conditions, experimental retention times for the gradient column showed a significant increase compared to the original 100% C18 column. Simulations with a similar C18 composition, however, predicted decreased retention times from the original C18 column. A statistical increase in the retention time of protocatechuic acid and decrease in the peak width of tyrosol, caffeic acid, and coumaric acid were noted when the gradient column was oriented to have the C18 dense region located near the detector. Collectively, combining gradients in both the mobile and stationary phases can yield interesting neighboring ligand effects and peak broadening/focusing effects.


Assuntos
Cromatografia/métodos , Fenóis/química , Dióxido de Silício/química , Simulação de Dinâmica Molecular , Fenóis/isolamento & purificação
19.
Food Chem ; 297: 124994, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253277

RESUMO

Improving the extraction efficiency and stability of red beet compounds has gained the attention of researchers due to their high nutritional and health benefits. In this study, ß-cyclodextrin (ß-CD) enhanced ultrasound assisted extraction was used for the extraction of red beet extract, and lyophilized extracts were characterized with FTIR and DSC analyses. The samples extracted with aqueous 5% ß-CD solutions revealed the highest content of betanin (2.243 ±â€¯0.04 mg) and total phenolic compounds (20.03 ±â€¯1.28 mg GAE/g DW), and the highest DPPH inhibition activity (59.87 ±â€¯4.94%). Additionally, complexation with ß-CD significantly enhanced the stability of betanin, phenolic compounds and antiradical activity in the stored beverage and gummy candy models at various pH and temperature conditions during 28 days. In conclusion, ß-CD-enhanced ultrasound assisted extraction is a suitable approach to extracting and stabilizing the red beet compounds for application in food, nutraceutical, and medical fields.


Assuntos
Beta vulgaris/química , Extratos Vegetais/química , Extração em Fase Sólida/métodos , Sonicação , beta-Ciclodextrinas/química , Antioxidantes/química , Beta vulgaris/metabolismo , Betacianinas/análise , Betacianinas/isolamento & purificação , Varredura Diferencial de Calorimetria , Armazenamento de Alimentos , Liofilização , Concentração de Íons de Hidrogênio , Fenóis/análise , Fenóis/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente
20.
Food Chem ; 294: 160-170, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126448

RESUMO

An effective method has been developed for the simultaneous determination of four bisphenols (bisphenol A, S, F and B) in various foodstuffs. The contaminants were extracted by QuEChERS-based strategy and subjected to ion-exchange solid-phase extraction for further clean-up. The critical variables were screened by Plackett-Burman design and then optimized by central composite design. Under the optimized conditions, satisfactory accuracy (recoveries 76%-116%) and precision (RSDs < 12%) were achieved. The established method was then used to assess the contamination status of 379 real samples. Bisphenol A was demonstrated to be the predominant bisphenol with highest incidence (79.7%) and average concentration (14.3 µg/kg). The positive rates (mean concentration) of bisphenol S, F and B were 37.7% (1.6 µg/kg), 26.9% (1.4 µg/kg) and 0.0% (not detected), respectively. Finally, the daily dietary intakes of ∑4bisphenolsfor adult residents were estimated (55.9-76.1 ng/kg bw/day) according to the contamination concentrations and the daily recommended intakes.


Assuntos
Compostos Benzidrílicos/análise , Análise de Alimentos/métodos , Fenóis/análise , Sulfonas/análise , Compostos Benzidrílicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Exposição Dietética , Humanos , Limite de Detecção , Fenóis/isolamento & purificação , Extração em Fase Sólida , Sulfonas/isolamento & purificação , Espectrometria de Massas em Tandem
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