Search results for "DPPH"
showing 7 items of 137 documents
Dažādu škīdinātāju mijiedarbība ar kolorimetrisko testu reaģentiem
2020
Veicot dažādus eksperimentos var būt nepieciešams izmantot vielas ar dažādu šķīdību ūdenī un organiskos šķīdinātājos. Nereti precīzai eksperimenta norisei nepieciešams noteikts pH līmenis, ko nākas izmainīt oriģinālajā šķīdumā. In vitro eksperimentos vielu šķīdībai ir ļoti liela nozīme, jo ir virkne priekšnosacījumu eksperimenta veikšanai, kas izriet no pašu eksperimentu būtības. Piemēram, eksperimentos ar šūnu līnijām jāizmanto barotnes un piedevas ar pH 7,4 un tām jābūt šķīdumiem ūdenī, jo organiskie šķīdinātāji dažādās koncentrācijās nonāvē šūnas. Eksperimentos ar izolētiem enzīmiem vai audu membrānām arī vienmēr šķīdinātāju kontroles ir obligātas. Eksperimentos in vitro visbiežāk izmant…
Ruta chalepensis L. (Rutaceae) leaf extract: chemical composition, antioxidant and hypoglicaemic activities.
2017
Ruta chalepensis L. (Rutaceae) leaf extract was investigated for its chemical profile and antioxidant and hypoglycaemic properties. The antioxidant effects were investigated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), Chi-carotene bleaching, and metal chelating activity assays. The carbohydrate-hydrolysing enzymes inhibition assay was used to test the hypoglycaemic potential. R. chalepensis showed a high content of hesperidin and rutin with values of 591.9 and 266.7 mg/g dry extract, respectively. The extract exhibited a promising protection of lipid peroxidation (IC50 value of 16.9 mu g/mL) and inhibited both alpha-amylase and alpha-glucosidase enzymes in a concentration-dependent manner. The…
Antioxidant Potential of Extracts Obtained from Macro- (Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata) and Micro-Algae (Chlorella v…
2018
Background: Natural antioxidants, which can replace synthetic ones due to their potential implications for health problems in children, have gained significant popularity. Therefore, the antioxidant potential of extracts obtained from three brown macroalgae (Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata) and two microalgae (Chlorella vulgaris and Spirulina platensis) using ultrasound-extraction as an innovative and green approach was evaluated. Methods: Algal extracts were obtained by ultrasound-assisted extraction using water/ethanol (50:50, v:v) as the extraction solvent. The different extracts were compared based on their antioxidant potential, measuring the extraction …
Ceiba speciosa (A. St.-Hil.) Seeds Oil: Fatty Acids Profiling by GC-MS and NMR and Bioactivity
2020
This study aimed to evaluate the chemical composition by gas chromatography-mass spectrometry (GC-MS) and Nuclear Magnetic Resonance (NMR) analyses, the antioxidant activities evaluated by different in vitro assays namely 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2&prime
NMR-based quantification of rosmarinic and carnosic acids, GC-MS profile and bioactivity relevant to neurodegenerative disorders of Rosmarinus offici…
2013
Abstract A comparative study of phytochemicals content and biological properties of eight Rosmarinus officinalis (rosemary) populations (RO1–RO8) collected in different areas of Tunisia was carried out. Two of the main rosemary constituents, rosmarinic and carnosic acids, were quantified by an NMR technique. Carnosic acid content was higher than that of rosmarinic acid. The non-polar constituents were examined by GC and GC–MS. Total phenols and flavonoids content were also determined in order to discuss the possible correlation between these phytochemicals and bioactivity. Antioxidant activity was investigated through different in vitro assays. Sample RO3 from a sub-humid area showed the hi…
Evaluation of the spectral characteristics, purity and antioxidant activity of C-phycocyanin from the cyanobacteria collected in Kaunas Lagoon (Lithu…
2022
The physicochemical characteristics of phycocyanin extracted from cyanobacteria collected in Kaunas Lagoon were studied (spectrum characteristics, C-PC content in the dry mass and chemical purity). It was determined that the tested concentrations of C-PC in purified water should be in the range of 0.02–0.16% for measuring C-PC content in the dry mass and its spectrum characteristics. The two clear absorption maxima were detected in the spectrum of C-PC at the wavelengths of 277 and 619 nm. The content of C-PC in the dry powder form was in the range of 7.25% to 9.30% depending on its concentration in the solution and type of spectrophotometer. Furthermore, a purity factor of 1.5 was calculat…
Polyphenols and Pharmacological Screening of a Monarda fistulosa L. dry Extract Based on a Hydrodistilled Residue By-Product
2021
This study aimed to determine the composition and content of polyphenols in the dry extract obtained from the hydrodistilled residue by-product of the wild bergamot (Monarda fistulosa L., Lamiaceae Martinov family) herb (MFDE) and to evaluate its safety and pharmacological properties. The total phenolic content (TPC) in the MFDE was 120.64 mg GAE/g. The high-performance liquid chromatography (HPLC) analysis showed the presence of a plethora of phenolic compounds, including hydroxycinnamic acids and flavone derivatives in the MFDE, with rosmarinic acid and luteolin-7-O-glucoside being the main components. With an IC50 value of 0.285 mg/mL, it was found to be a strong DPPH radical scavenger. …