Search results for "analytical"
showing 10 items of 9586 documents
Increased Stress Resistance and Lifespan in Chaenorhabditis elegans Wildtype and Knockout Mutants—Implications for Depression Treatment by Medicinal …
2021
Depression and anxiety disorders are widespread diseases, and they belong to the leading causes of disability and greatest burdens on healthcare systems worldwide. It is expected that the numbers will dramatically rise during the COVID-19 pandemic. Established medications are not sufficient to adequately treat depression and are not available for everyone. Plants from traditional medicine may be promising alternatives to treat depressive symptoms. The model organism Chaenorhabditis elegans was used to assess the stress reducing effects of methanol/dichlormethane extracts from plants used in traditional medicine. After initial screening for antioxidant activity, nine extracts were selected f…
Salmon (Salmo salar) side streams as a bioresource to obtain potential antioxidant peptides after applying pressurized liquid extraction (PLE)
2021
The pressurized liquid extraction (PLE) technique was used to obtain protein extracts with antioxidant capacity from salmon muscle remains, heads, viscera, skin, and tailfins. A protein recovery percentage ≈28% was obtained for all samples except for viscera, which was ≈92%. These values represented an increase of 1.5–4.8-fold compared to stirring extraction (control). Different SDS-PAGE profiles in control and PLE extracts revealed that extraction conditions affected the protein molecular weight distribution of the obtained extracts. Both TEAC (Trolox equivalent antioxidant capacity) and ORAC (oxygen radical antioxidant capacity) assays showed an outstanding antioxidant activity for viscer…
Polyphenols pattern and correlation with antioxidant activities of berries extracts from four different populations of SicilianSambucus nigraL.
2014
Sambucus nigra L. (Caprifoliaceae) is wide spread in temperate and sub-tropical zones. The consumption of its berries has been associated with health benefits especially for its high content of natural antioxidants such as polyphenols, in particular anthocyanins. In this work we investigated the polyphenolic composition and the in vitro antioxidant activities (ABTS, DPPH, BCB and FRAP-ferrozine (FRAP-FZ) assays) of S. nigra berries, collected in four different Sicilian areas (Italy). Elderberries are considered one of the fruits with highest anthocyanins content, the amount of phenolic compounds, other than anthocyanins, is approximately 1.5 times greater than the latter. The LC–MS analyses…
Extraction of polyphenols in Himanthalia elongata and determination by high performance liquid chromatography with diode array detector prior to its …
2016
Abstract Several studies have demonstrated the antioxidant capacity of seaweeds, which can be used for the development of biopharmaceuticals with extensive medical application. Antioxidant therapies appear to attenuate the organic deterioration originated by an excessive oxidative stress, which could prevent the harmful effects of various injuries such as ischemia-reperfusion (I/R) among others. Marine brown seaweeds play a significant role, as they are the only organisms on earth producing phlorotannins, which are polyphenols that exhibit important biological activity. To ensure obtaining an extract with the greatest antioxidant activity, some variables that affect the extraction of polyph…
Molecular Characterization of White Wines Antioxidant Metabolome by Ultra High Performance Liquid Chromatography High-Resolution Mass Spectrometry
2020
International audience; The knowledge about the molecular fraction contributing to white wines oxidative stability is still poorly understood. However, the role of S- and N-containing compounds, like glutathione and other peptides, as a source of reductant in many oxidation reactions, and acting against heavy metals toxicity, or lipid and polyphenol oxidation as ROS-scavenger is today very well established. In that respect, the aim of the present study is to introduce an original analytical tool for the direct determination of the available nucleophilic compounds in white wine under acidic pH conditions. One step derivatization of nucleophiles has been realized directly in wines using 4-met…
Chemical Profiling of Polyfloral Belgian Honey: Ellagic Acid and Pinocembrin as Antioxidants and Chemical Markers
2017
Chemical profiling of northern Belgian polyfloral honeys was performed to analyse their phenolic compound content (flavonoids and phenolic acids). First, samples were subjected to a standard analysis of their physicochemical properties, and then, the phenolic fraction was isolated and analysed using a HPLC/PAD method. All of the tested honeys showed a common and specific phenolic profile that could be the basis for the differentiation of polyfloral honeys of the Antwerp region from other polyfloral honeys. Chromatographic data indicated a high content of ellagic acid (9.13–13.66 mg/100 g honey), as well as the flavonoid pinocembrin (1.60–1.85 mg/100 g honey) in these honeys. Ellagic acid, a…
Accelerated Solvent Extraction and Pulsed Electric Fields for Valorization of Rainbow Trout (Oncorhynchus mykiss) and Sole (Dover sole) By-Products: …
2021
Fishery by-products are rich in biologically active substances and the use of green and efficient extraction methods to recover these high-added-value compounds is of particular importance. In this study, head, skin and viscera of rainbow trout and sole were used as the target matrices and accelerated solvent extraction (ASE) (45–55 °C, 15 min, pH 5.2–6.8, 103.4 bars) and pulsed electric fields (PEF) (1–3 kV/cm, 123–300 kJ/kg, 15–24 h) were applied as extraction technologies. The results showed that ASE and PEF significantly increased the protein extract efficiency of the fish by-products (p < 0.05) by up to 80%. SDS-PAGE results showed that ASE and PEF treatments changed the molecular size…
Ultrasonically-Assisted and Conventional Extraction from Erodium Glaucophyllum Roots Using Ethanol:Water Mixtures: Phenolic Characterization, Antioxi…
2020
The paper presents experimental results concerning the ultrasonically-assisted extraction of bioactive compounds from Erodium glaucophyllum roots. A comparison with conventional methodology is presented, and thereby the phytochemical composition and the antioxidant and anti-inflammatory activities of extracts are evaluated. The phenolic profile of Erodium extracts was analyzed by TOF&ndash
Comparative chemical composition, free radical-scavenging and cytotoxic properties of essential oils of six Stachys species from different regions of…
2009
Abstract The chemical composition of essential oils of six Stachys species, S. cretica L. ssp. vacillans Rech. fil., S. germanica L., S. hydrophila Boiss., S. nivea Labill., S. palustris L. and S. spinosa L., obtained by hydrodistillation, was studied by GC and GC–MS. All the oils have in common a great percentage of fatty acids and esters (24.2–58.5%) and a high amount of sesquiterpenes (16–35.9%), with the exception of the oil from S. palustris , which consisted mainly of carbonylic compounds (25.4%). The antioxidant activity by DPPH test and the antiproliferative activity on a series of human cancer cell lines (C32, amelanotic melanoma and ACHN, renal cell adenocarcinoma) were investigat…
Caseinophosphopeptides exert partial and site-specific cytoprotection against H2O2-induced oxidative stress in Caco-2 cells
2011
Abstract Caseinophosphopeptides can sequester prooxidant metals and scavenge free radicals, and may thus be used as functional food ingredients. The total antioxidant capacity (TEAC and ORAC) of two pools of caseinophosphopeptides (1–3 mg/ml), obtained from casein subjected to simulated gastrointestinal digestion (at two different pH values) and selective precipitation, was evaluated to determine dose–response activity. Pool B (which showed the highest antioxidant capacity due to the presence of more antioxidant amino acids) was used to test its cytoprotective effect against H2O2-induced oxidative stress in Caco-2 cells. Caseinophosphopeptides protected the cells against oxidative damage by…