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1.
Int J Mol Sci ; 21(1)2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31861265

RESUMO

The extraction of phenolic compounds from canola meal produces functional health products and renders the canola meal a more digestible animal feed. The extracted phenolics may have novel bioactivity worth investigation. In this study, several solvents were evaluated for their ability to extract phenolic compounds from canola meal: water (WE) and various 80% organic solvent/water mixtures of methanol (ME), acetone (AE), ethanol (EE), butanol (BE), chloroform (CE) and hexane (HE). The in vitro antioxidant and anti-obesity properties of various extracts were investigated. Anti-obesity properties were studied using adipogenic differentiation inhibition of a murine mesenchymal stem cell line (C3H10T1/2) and a pancreatic lipase inhibition assay. AE, ME, and BE showed significant (p < 0.05) adipogenesis and pancreatic lipase inhibitory activities and may have more pharmacological properties. AE down-regulated the gene expression of the major adipogenic transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ), correlating to phenolic content in a dose-dependent manner. The chemical characterization of AE revealed the presence of sinapic acid, ferulic acid, and kaempferol derivatives as main bioactive phenols.


Assuntos
Adipogenia/efeitos dos fármacos , Antioxidantes/farmacologia , Brassica napus/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Animais , Antioxidantes/química , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Regulação da Expressão Gênica/efeitos dos fármacos , Espaço Intracelular/metabolismo , Lipase/antagonistas & inibidores , Lipase/química , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos , PPAR gama/genética , Fenóis/química , Extratos Vegetais/química , Solventes , Espectrometria de Massas em Tandem
2.
Int J Mol Sci ; 20(1)2018 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-30598025

RESUMO

Alzheimer's disease (AD) is a major neurodegenerative disease, associated with the hallmark proteinacious constituent called amyloid beta (Aß) of senile plaques. Moreover, it is already established that metals (particularly copper, zinc and iron) have a key role in the pathogenesis of AD. In order to reduce the Aß plaque burden and overcome the side effects from the synthetic inhibitors, the current study was designed to focus on direct inhibition of with or without metal-induced Aß fibril formation and aggregation by using olive biophenols. Exposure of neuroblastoma (SH-SY5Y) cells with Aß42 resulted in decrease of cell viability and morphological changes might be due to severe increase in the reactive oxygen species (ROS). The pre-treated SH-SY5Y cells with olive biophenols were able to attenuate cell death caused by Aß42, copper- Aß42, and [laevodihydroxyphenylalanine (l-DOPA)] l-DOPA-Aß42-induced toxicity after 24 h of treatment. Oleuropein, verbascoside and rutin were the major anti-amyloidogenic compounds. Transgenic mice (APPswe/PS1dE9) received 50 mg/kg of oleuropein containing olive leaf extracts (OLE) or control diet from 7 to 23 weeks of age. Treatment mice (OLE) were showed significantly reduced amyloid plaque deposition (p < 0.001) in cortex and hippocampus as compared to control mice. Our findings provide a basis for considering natural and low cost biophenols from olive as a promising candidate drug against AD. Further studies warrant to validate and determine the anti-amyloid mechanism, bioavailability as well as permeability of olive biophenols against blood brain barrier in AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Glucosídeos/farmacologia , Iridoides/farmacologia , Fármacos Neuroprotetores/farmacologia , Fenóis/farmacologia , Rutina/farmacologia , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Linhagem Celular Tumoral , Glucosídeos/uso terapêutico , Humanos , Glucosídeos Iridoides , Iridoides/uso terapêutico , Masculino , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Olea/química , Fenóis/uso terapêutico , Presenilinas/genética , Rutina/uso terapêutico
3.
Molecules ; 22(11)2017 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-29109370

RESUMO

Plant biophenols have been shown to be effective in the modulation of Alzheimer's disease (AD) pathology resulting from free radical-induced oxidative stress and imbalance of the redox chemistry of transition metal ions (e.g., iron and copper). On the basis of earlier reported pharmacological activities, olive biophenols would also be expected to have anti-Alzheimer's activity. In the present study, the antioxidant activity of individual olive biophenols (viz. caffeic acid, hydroxytyrosol, oleuropein, verbascoside, quercetin, rutin and luteolin) were evaluated using superoxide radical scavenging activity (SOR), hydrogen peroxide (H2O2) scavenging activity, and ferric reducing ability of plasma (FRAP) assays. The identification and antioxidant activities in four commercial olive extracts-Olive leaf extractTM (OLE), Olive fruit extractTM (OFE), Hydroxytyrosol ExtremeTM (HTE), and Olivenol plusTM (OLP)-were evaluated using an on-line HPLC-ABTS•+ assay, and HPLC-DAD-MS analysis. Oleuropein and hydroxytyrosol were the predominant biophenols in all the extracts. Among the single compounds examined, quercetin (EC50: 93.97 µM) and verbascoside (EC50: 0.66 mM) were the most potent SOR and H2O2 scavengers respectively. However, OLE and HTE were the highest SOR (EC50: 1.89 µg/mL) and H2O2 (EC50: 115.8 µg/mL) scavengers among the biophenol extracts. The neuroprotection of the biophenols was evaluated against H2O2-induced oxidative stress and copper (Cu)-induced toxicity in neuroblastoma (SH-SY5Y) cells. The highest neuroprotection values (98% and 92%) against H2O2-induced and Cu-induced toxicities were shown by the commercial extract HTETM. These were followed by the individual biophenols, caffeic acid (77% and 64%) and verbascoside (71% and 72%). Our results suggest that olive biophenols potentially serve as agents for the prevention of neurodegenerative diseases such as AD, and other neurodegenerative ailments that are caused by oxidative stress.


Assuntos
Olea/química , Antioxidantes/farmacologia , Ácidos Cafeicos/química , Ácidos Cafeicos/farmacologia , Linhagem Celular Tumoral , Cobre/farmacologia , Sequestradores de Radicais Livres/metabolismo , Glucosídeos/química , Glucosídeos/farmacologia , Humanos , Peróxido de Hidrogênio/farmacologia , Glucosídeos Iridoides , Iridoides/química , Iridoides/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Quercetina/química , Quercetina/farmacologia
4.
Phytother Res ; 30(3): 503-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26931616

RESUMO

The antimicrobial properties of olive leaf extract (OLE) have been well recognized in the Mediterranean traditional medicine. Few studies have investigated the antimicrobial properties of OLE. In this preliminary study, commercial OLE and its major phenolic secondary metabolites were evaluated in vitro for their antimicrobial activities against Escherichia coli and Staphylococcus aureus, both individually and in combination with ampicillin. Besides luteolin 7-O-glucoside, OLE and its major phenolic secondary metabolites were effective against both bacteria, with more activity on S. aureus. In combination with ampicillin, OLE, caffeic acid, verbascoside and oleuropein showed additive effects. Synergistic interaction was observed between ampicillin and hydroxytyrosol. The phenolic composition of OLE and the stability of olive phenols in assay medium were also investigated. While OLE and its phenolic secondary metabolites may not be potent enough as stand-alone antimicrobials, their abilities to boost the activity of co-administered antibiotics constitute an imperative future research area.


Assuntos
Ampicilina/farmacologia , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Interações Ervas-Drogas , Olea/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Ácidos Cafeicos/farmacologia , Sinergismo Farmacológico , Escherichia coli/efeitos dos fármacos , Flavonas/farmacologia , Glucosídeos/farmacologia , Glucosídeos Iridoides , Iridoides/farmacologia , Medicina Tradicional , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/farmacologia , Extratos Vegetais/metabolismo , Folhas de Planta/química , Staphylococcus aureus/efeitos dos fármacos
5.
Nutrients ; 12(5)2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-32397683

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with an unclear cause. It appears that multiple factors participate in the process of neuronal damage including oxidative stress and accumulation of the protein amyloid ß (Aß) in the brain. The search for a treatment for this disorder is essential as current medications are limited to alleviating symptoms and palliative effects. The aim of this study is to investigate the effects of mint extracts on selected mechanisms implicated in the development of AD. To enable a thorough investigation of mechanisms, including effects on ß-secretase (the enzyme that leads to the formation of Aß), on Aß aggregation, and on oxidative stress and apoptosis pathways, a neuronal cell model, SH-SY5Y cells, was selected. Six Mentha taxa were investigated for their in vitro ß-secretase (BACE) and Aß-aggregation inhibition activities. Moreover, their neuroprotective effects on H2O2-induced oxidative stress and apoptosis in SH-SY5Y cells were evaluated through caspase activity. Real-time PCR and Western blot analysis were carried out for the two most promising extracts to determine their effects on signalling pathways in SH-SY5Y cells. All mint extracts had strong BACE inhibition activity. M. requienii extracts showed excellent inhibition of Aß-aggregation, while other extracts showed moderate inhibition. M. diemenica and M. requienii extracts lowered caspase activity. Exposure of SH-SY5Y cells to M. diemenica extracts resulted in a decrease in the expression of pro-apoptotic protein, Bax, and an elevation in the anti-apoptotic protein, Bcl-xL, potentially mediated by down-regulation of the ASK1-JNK pathway. These results indicate that mint extracts could prevent the formation of Aß and also could prevent their aggregation if they had already formed. M. diemenica and M. requienii extracts have potential to suppress apoptosis at the cellular level. Hence, mint extracts could provide a source of efficacious compounds for a therapeutic approach for AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Apoptose/efeitos dos fármacos , Peróxido de Hidrogênio/efeitos adversos , Mentha/química , Fármacos Neuroprotetores , Fitoterapia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Doença de Alzheimer/etiologia , Secretases da Proteína Precursora do Amiloide/efeitos adversos , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Apoptose/genética , Linhagem Celular , Humanos , MAP Quinase Quinase Quinase 5/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais , Proteína X Associada a bcl-2/metabolismo , Proteína bcl-X/metabolismo
6.
Chem Res Toxicol ; 22(1): 227-34, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19099401

RESUMO

The major biophenols in olives and the crude extract and ethyl acetate fraction from olive mill waste were studied for their ability to counteract different stages of oxidative damage, that is, hydrogen peroxide, superoxide radical (SOR), and hydroxyl radical in vitro. Antiproliferative activity on colon cancer (HT-29) and gastric cancer (AGS) cell lines was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide bioassay. Emphasis was given to how the observed in vitro activity is controlled by the structural feature of biophenols and possible synergism and antagonism. While in some bioassays, for example, 2,2'-diphenyl-1-picrylhydrazyl, the nonphenolic moiety had minimal affect, it had a significant role in the SOR scavenging bioassay. Verbascoside was more active than caffeic acid or hydroxytyrosol evaluated individually or in equimolar mixtures in some bioassays. Mixtures of biophenols were more active than individual biophenols as antiproliferative agents. Overall, the mixture of hydroxytyrosol/caffeic acid and the biophenol extracts were more effective in protecting DNA from oxidative damage and inhibiting the growth of cancer cells.


Assuntos
Antioxidantes/farmacologia , Fenóis/farmacologia , Óleos de Plantas/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Antioxidantes/química , Linhagem Celular Tumoral , Sequestradores de Radicais Livres/farmacologia , Humanos , Azeite de Oliva , Fenóis/análise , Fenóis/química , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/química , Álcool Feniletílico/farmacologia , Piranos/química , Piranos/farmacologia
7.
J Agric Food Chem ; 56(11): 3925-32, 2008 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-18457398

RESUMO

The impact of two- and three-phase processing systems and malaxation conditions on phenol content (both total and individual phenols) and antioxidant capacity of laboratory-generated olive mill waste (OMW) was assessed. Two-phase olive processing generated a waste with higher phenol content and antioxidant capacity. Using the two-phase system, both malaxation time and temperature affected the phenol content and antioxidant capacity. The effects of different prestorage drying treatments on phenol content and antioxidant capacity were also compared. Air drying and drying at 60 degrees C resulted in a substantial decrease in the phenol content and antioxidant capacity. Drying at 105 degrees C and freeze-drying produced less degradation. The phenol content and antioxidant capacity of OMW stored at 4 degrees C and of OMW preserved by 40% w/w ethanol and 1% w/w acetic acid and stored at 4 degrees C were monitored for 30 days and compared with those of OMW stored at room temperature. None of these storage conditions could prevent the rapid decrease in phenolic concentrations and antioxidant capacity, which happened within the first 24 h.


Assuntos
Antioxidantes/análise , Manipulação de Alimentos/métodos , Conservação de Alimentos/métodos , Resíduos Industriais/análise , Olea/química , Fenóis/análise , Frutas/química , Azeite de Oliva , Óleos de Plantas
8.
Fitoterapia ; 128: 118-129, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29772299

RESUMO

The focus of this study was on inhibition of enzymes involved in the pathogenesis Alzheimer's disease (AD) including prime amyloid beta (Aß) producing enzyme (ß-secretase: BACE-1) and disease progression enzymes including acetylcholinesterase (AChE), butyrylcholinesterase (BChE), histone deacetylase (HDAC), and tyrosinase along with the catecholamine L-DOPA, by using olive biophenols. Here we report the strongest inhibition of BACE-1 from rutin (IC50: 3.8 nM) followed by verbascoside (IC50: 6.3 nM) and olive fruit extract (IC50: 18 ng), respectively. Olive biophenol, quercetin exhibited strongest enzyme inhibitory activity against tyrosinase (IC50: 10.73 µM), BChE (IC50: 19.08 µM), AChE (IC50: 55.44 µM), and HDAC (IC50: 105.1 µM) enzymes. Furthermore, olive biophenol verbascoside (IC50: 188.6 µM), and hydroxytyrosol extreme extract (IC50: 66.22 µg) were showed the highest levels of inhibition against the HDAC enzyme. Neuroprotective capacity against levodopa-induced toxicity in neuroblastoma (SH-SY5Y) cells of olive biophenols were assessed, where rutin indicated the highest neuroprotection (74%), followed by caffeic acid (73%), and extract hydroxytyrosol extreme (97%), respectively. To the best of our knowledge, this is the first in vitro report on the enzymes inhibitory activity of olive biophenols. Taken together, our in vitro results data suggest that olive biophenols could be a promising natural inhibitor, which may reduce the enzyme-induced toxicity associated with the oxidative stress involved in the progression of AD. CHEMICAL COMPOUNDS USED IN THE STUDY: Acetylthiocholine iodide (PubChem CID: 74629); S-Butyrylthiocholine chloride (PubChem CID: 3015121); Caffeic acid (PubChem CID: 689043); Dimethyl sulfoxide (DMSO) (PubChem: 679); L-3,4-Dihydroxyphenylalanine (L-DOPA) (PubChem CID: 6047); 5,5'-Dithiobis (2-nitrobenzoic acid) (DTNB) (PubChem CID: 6254); Epigallocatechin gallate (EGCG) (PubChem CID: 65064); Ethylenediamine tetraacetic acid (EDTA) (PubChem CID: 6049); Galantamine hydrobromide (PubChem CID: 121587); l-Glutamine (PubChem CID: 5961); Hydroxytyrosol (PubChem CID: 82755); Kojic acid (PubChem CID: 3840); Luteolin (PubChem CID: 5280445); Oleuropein (PubChem CID: 5281544); Penicillin-streptomycin (PubChem CID: 131715954); Quercetin (PubChem CID: 5280343); Rutin (PubChem CID: 5280805); Tris-HCl buffer (PubChem: 93573); Trypan blue (PubChem: 9562061).


Assuntos
Inibidores Enzimáticos/isolamento & purificação , Olea/química , Fenóis/isolamento & purificação , Doença de Alzheimer/enzimologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Linhagem Celular Tumoral , Inibidores da Colinesterase/isolamento & purificação , Frutas/química , Glucosídeos/isolamento & purificação , Inibidores de Histona Desacetilases/isolamento & purificação , Humanos , Monofenol Mono-Oxigenase/antagonistas & inibidores , Fármacos Neuroprotetores/isolamento & purificação , Estresse Oxidativo , Fenóis/farmacologia , Quercetina/isolamento & purificação , Rutina/isolamento & purificação
9.
J Agric Food Chem ; 55(8): 2848-53, 2007 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-17373814

RESUMO

A new biophenolic secoiridoid was identified in Australian Frantoio olive mill waste (OMW) extracts. Isolation, purification, and structure elucidation were performed. Hydroxytyrosyl acyclodihydroelenolate, the first nonaldehydic acyclic secoiridoid, is reported. A second compound was identified as p-coumaroyl-6'-secologanoside (comselogoside), and although it has been identified recently in OMW and leaves, this is the first time it has been identified in both OMW and olive fruits. UV, mass spectral, and NMR data are given for both compounds. The two compounds were quantified by HPLC-DAD, and their antioxidant potential was assessed against the classical olive biophenols, hydroxytyrosol and oleuropein, by the in vitro DPPH radical scavenging assay.


Assuntos
Antioxidantes , Resíduos Industriais/análise , Iridoides/análise , Iridoides/farmacologia , Olea/química , Antioxidantes/farmacologia , Manipulação de Alimentos , Frutas/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray
10.
J Nutr Biochem ; 47: 1-20, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28301805

RESUMO

Self-assembly of amyloid beta peptide (Aß) into the neurotoxic oligomers followed by fibrillar aggregates is a defining characteristic of Alzheimer's disease (AD). Several lines of proposed hypotheses have suggested the mechanism of AD pathology, though the exact pathophysiological mechanism is not yet elucidated. The poor understanding of AD and multitude of adverse responses reported from the current synthetic drugs are the leading cause of failure in the drug development to treat or halt the progression of AD and mandate the search for safer and more efficient alternatives. A number of natural compounds have shown the ability to prevent the formation of the toxic oligomers and disrupt the aggregates, thus attracted much attention. Referable to the abundancy and multitude of pharmacological activities of the plant active constituents, biophenols that distinguish them from the other phytochemicals as a natural weapon against the neurodegenerative disorders. This review provides a critical assessment of the current literature on in vitro and in vivo mechanistic activities of biophenols associated with the prevention and treatment of AD. We have contended the need for more comprehensive approaches to evaluate the anti-AD activity of biophenols at various pathologic levels and to assess the current evidences. Consequently, we highlighted the various problems and challenges confronting the AD research, and offer recommendations for future research.


Assuntos
Doença de Alzheimer/prevenção & controle , Suplementos Nutricionais , Modelos Neurológicos , Fármacos Neuroprotetores/uso terapêutico , Nootrópicos/uso terapêutico , Fenóis/uso terapêutico , Extratos Vegetais/uso terapêutico , Doença de Alzheimer/metabolismo , Animais , Antioxidantes/uso terapêutico , Pesquisa Biomédica/métodos , Suplementos Nutricionais/efeitos adversos , Flavonoides/efeitos adversos , Flavonoides/metabolismo , Flavonoides/uso terapêutico , Humanos , Neurônios/metabolismo , Fármacos Neuroprotetores/efeitos adversos , Fármacos Neuroprotetores/metabolismo , Nootrópicos/efeitos adversos , Nootrópicos/metabolismo , Estresse Oxidativo , Fenóis/efeitos adversos , Fenóis/metabolismo , Compostos Fitoquímicos/efeitos adversos , Compostos Fitoquímicos/metabolismo , Compostos Fitoquímicos/uso terapêutico , Extratos Vegetais/efeitos adversos , Extratos Vegetais/metabolismo , Projetos de Pesquisa , Estilbenos/efeitos adversos , Estilbenos/metabolismo , Estilbenos/uso terapêutico
11.
J Agric Food Chem ; 53(26): 9911-20, 2005 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-16366674

RESUMO

Olive mill waste is a potential source for the recovery of phytochemicals with a wide array of biological activities. Phytochemical screening of hexane, methanol, and water extracts revealed a diversity of compounds, perhaps overlooked in previous studies through intensive cleanup procedures. Methanol and water extracts contained large amounts of biophenols, and further testing of polar extraction solvents, including ethyl acetate, ethanol, propanol, acetone, acetonitrile, and water/methanol mixtures, highlighted the latter as the solvent of choice for extraction of the widest array of phenolic compounds. Stabilization of the resulting extract was best achieved by addition of 2% (w/w) sodium metabisulfite. Quantitative data are reported for nine biophenols extracted using 60% (v/v) methanol in water with 2% (w/w) sodium metabisulfite. Six compounds had recoveries of greater than 1 g/kg of freeze-dried waste: hydroxytyrosol glucoside, hydroxytyrosol, tyrosol, verbascoside, and a derivative of oleuropein.


Assuntos
Resíduos Industriais/análise , Fenóis/análise , Óleos de Plantas/análise , Austrália , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Indicadores e Reagentes , Luz , Azeite de Oliva , Padrões de Referência , Espectrofotometria Ultravioleta
12.
J Agric Food Chem ; 53(4): 823-37, 2005 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-15712986

RESUMO

Biophenols have attracted increasing attention during the past few years due to their biological activities and natural abundance and are potential targets for the food and pharmaceutical industries. Olive mill waste (OMW) is rich in biophenols and typically contains 98% of the total phenols in the olive fruit, making value addition to OMW an attractive enterprise. The phenolic profile of OMW is complex, yet this complexity has not been fully exploited in the valorization of the waste. Most work on the bioactivity of OMW has focused on antioxidant and antimicrobial activities. The analytical techniques used to identify and quantify active biophenols are also reviewed.


Assuntos
Manipulação de Alimentos , Resíduos Industriais/análise , Olea/química , Fenóis/análise , Fenóis/farmacologia , Antibacterianos/análise , Antibacterianos/farmacologia , Antioxidantes/análise , Antioxidantes/farmacologia , Manipulação de Alimentos/métodos , Frutas/química
13.
J Agric Food Chem ; 61(38): 9176-84, 2013 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-23889116

RESUMO

During the extraction of canola oil, large quantities of meal are produced. Extracting biophenols from Australian canola meal (ACM) adds value to an otherwise low-value agro-industrial byproduct. This study examined the biophenol content and the antioxidant activity of ACM, the impact of extraction conditions, and varietal differences. Sinapine was the principal biophenol in ACM. In crude and hydrolyzed extracts, 31 compounds were identified: 2 dihexosides, 2 organic acids, 4 glucosinolates, 17 sinapic acid derivatives, 2 cyclic spermidine alkaloids, caffeic acid and its dihexoside, kaempferol, and its C-glucoside. ACM showed significant free radical scavenging activity in DPPH(•) and ABTS(•+) assays. Sinapine was the chief contributor to ACM antioxidant activity, whereas kaempferol sinapoyl triglucoside isomer was the most potent antioxidant. Biophenol content ranged between 12.8 and 15.4 mg GAE/g DW. Differences among studied cultivars were generally quantitative. The Tarcoola cultivar showed the highest biophenol content and antioxidant activity.


Assuntos
Antioxidantes/análise , Brassica napus/química , Fenóis/análise , Extratos Vegetais/análise , Austrália
14.
J Agric Food Chem ; 60(13): 3381-8, 2012 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-22435921

RESUMO

Lolium perenne is a major forage and turf grass, which is often naturally infected with a "wild-type" strain (E(WT)) of the fungal endophyte Neotyphodium lolii , establishing a symbiotic relationship. In this study, the impacts of different strains wild type E(WT), AR1 (E(AR1)) and AR37 (E(AR37)), of N. lolii on the phenolic profile, phenolic content, and antioxidant capacity of L. perenne were examined. Samples could be ranked according to their phenol content as follows: E(AR1) > E(AR37) ≥ E(-) > E(WT). Radical-scavenging assays showed the same relative ranking of extracts. Flavonoid glycosides and hydroxycinnamic acids were the most abundant polyphenols in L. perenne extracts. Chlorogenic acid and its derivatives were the major compounds responsible for the antioxidant activity. Infection with N. lolii significantly influenced L. perenne phenolic content and antioxidant activity. In conclusion, changes in phenolic composition were merely quantitative. Endophyte infection can have zero, positive, or negative effect on phenol content depending on the endophyte strain.


Assuntos
Antioxidantes/metabolismo , Endófitos/fisiologia , Lolium/microbiologia , Lolium/fisiologia , Neotyphodium/fisiologia , Polifenóis/metabolismo , Antioxidantes/análise , Lolium/química , Poaceae/microbiologia , Poaceae/fisiologia , Polifenóis/análise , Simbiose
15.
Food Chem ; 132(1): 222-9, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-26434284

RESUMO

Antioxidant potential of four methanol extracts from three selected plant species, namely Salvia nubicola (Lamiaceae), Acer oblongifolium (Aceraceae) and Hedera nepalensis (Araliaceae) was measured using assays in aqueous and lipid systems. Antioxidant activities were investigated in aqueous systems by using DPPH radical-scavenging assay, ABTS radical-scavenging assay and DNA protection assay, while antioxidant activity in a lipid system was determined by using the thiobarbituric acid-reactive substances (TBARS) assay. Additionally, the Folin-Ciocalteu method was used to measure total phenolic content. Methanol extracts of leaves and flowers of S. nubicola showed the highest Trolox equivalent (TE) values in the case of the DPPH assay, 2484±4.9mmol TE/g extract, as well as total phenolic content, 139±0.2mg gallic acid equivalents/g extract. Three fractions (A-C) of the methanol extract of S. nubicola leaves and flowers were produced by semi-preparative HPLC. Fraction B was found to be the most active in the DPPH radical-scavenging assay and had the highest total phenol content. HPLC-DAD and LC-MS revealed rosmarinic acid in S. nubicola extracts and chlorogenic acid and rutin in H. nepalensis extracts as the main phenolic antioxidants.


Assuntos
Antioxidantes/química , Fenóis/química , Extratos Vegetais/química , Plantas Medicinais/química , Bioprospecção , Oxirredução , Paquistão
16.
J Agric Food Chem ; 56(19): 8851-8, 2008 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-18781756

RESUMO

Olive mill waste (OMW) contains substantial amounts of valuable antioxidant biophenols that can be recovered for possible applications in food, pharmaceutical, and cosmetic industries. However, the impact of cultivar, harvesting time, and seasonal variation on the phenolic composition of OMW has not yet been assessed. Total phenols, antioxidant activity, and phenol profiles of OMW extracts from five different Australian-grown cultivars (Barnea, Correggiola, Manzanillo, Mission, and Paragon) were studied at four different harvesting times in the 2004 season. The impact of seasonal variation was assessed by comparing total phenol content, antioxidant activity, and phenol profile of two cultivars (Correggiola and Mission) harvested in the 2004 and 2005 seasons. The phenol content and antioxidant activity at different harvesting times were mainly a function of the olive cultivar. Harvesting time had a quantitative effect rather than a qualitative effect on the phenol profile. Intercultivar and harvesting time variation accounted for a 2-5-fold change in the total phenol and antioxidant capacity, while levels of individual biophenols experienced up to 50-fold change. The phenol content and antioxidant capacity of OMW significantly changed between seasons with different variation patterns for different cultivars.


Assuntos
Antioxidantes/análise , Frutas/química , Resíduos Industriais/análise , Olea , Fenóis/análise , Estações do Ano , Cromatografia Líquida de Alta Pressão , Especificidade da Espécie , Fatores de Tempo
17.
Nat Prod Rep ; 25(6): 1167-79, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19030607

RESUMO

The genus Olea contains the economically important European olive tree (Olea europaea L.). This species is also of chemotaxonomic interest because of the presence of various phenol-conjugated oleosidic secoiridoids or oleosides. The chemistry of these phenolic oleosides is diverse and complicated, and it is only in recent years that attention has been given to their biosynthesis and the biotransformations during the processing and storage of olive products. Many questions regarding these processes remain unanswered, and yet these have significant impact on the quality and value of olive products such as olive oil.


Assuntos
Iridoides , Olea/química , Fenóis/metabolismo , Biotransformação , Iridoides/química , Iridoides/isolamento & purificação , Iridoides/metabolismo , Estrutura Molecular , Fenóis/química
18.
Anal Chim Acta ; 603(2): 176-89, 2007 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-17963838

RESUMO

Chemical screening using reversed phase HPLC-photodiode array detection (RPLC-DAD) and RPLC-electrospray ionisation mass spectrometry (RPLC-ESI-MS) is widely applied as an approach to streamline natural products research. The full potential of this approach is demonstrated in this paper by application to the chemical screening of olive products including olive mill waste (OMW). Out of 100 biophenols previously reported in olive products, the on-line RPLC-DAD-ESI-MS was able to confirm the presence of 52 compounds in OMW. This included a number of simple phenols, flavonoids and secoiridoids. By careful examination of the combined DAD and ESI-MS data, extra information was elucidated including: the site of glycosidation on the phenol ring of hydroxytyrosol; the identity of the other luteolin-glucoside isomer as luteolin-4'-O-glucoside; identifying rutin rather than the previously reported hesperidin (and the reasons for possible mis-assignment); and the detection of diastereomers of 4-hydroxyphenylethyl alcohol-deacetoxy elenolic acid dialdehyde (4-HPEA-DEDA) and 3,4-dihydroxyphenylethyl alcohol-deacetoxy elenolic acid dialdehyde (3,4-DHPEA-DEDA).


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Olea/química , Fenóis/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Cromanos/análise , Flavonoides/análise , Iridoides/análise , Lignanas/análise , Azeite de Oliva , Óleos de Plantas/química
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