Search results for " Scavenging"
showing 10 items of 23 documents
Phenolic Compounds Characterization and Antioxidant Properties of Monocultivar Olive Oils from Northeast Algeria
2020
In Algeria, the olive tree is one of the main fruit species and plays a very important socioeconomic role. The objective of this study was firstly, to identify and quantify the phenolics of some Algerian olive oils, and secondly, to assess the antioxidant activity of the samples. The olive oils used in this study were derived from Algerian cultivars, including Tefahi, Gelb Elfarroudj, Chemlal, and imported cultivar Manzanilla and Zebboudj. For this purpose, gas chromatography&mdash
Reactive oxygen species (ROS) generation inhibited by aporphine and phenanthrene alkaloids semi-synthesized from natural boldine.
2004
Four phenanthrene and one aporphine alkaloids semi-synthesized from boldine were evaluated for their inhibitory effect on reactive oxygen species (ROS) generation. ROS generation by neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine was inhibited in a concentration dependent manner. Alkaloids exerted similar inhibitory effect in the hypoxanthine-xanthine oxidase system than in stimulated neutrophils, which could be attributed to a direct ROS scavenging activity. None of the alkaloids assayed had any effect on xanthine oxidase activity. Therefore the synthesized alkaloids might constitute an alternative therapy in inflammation disorders in which ROS generation is involved.
Use of concentrated fruit juice extracts to improve the antioxidant properties in a soft drink formulation
2023
Three juices obtained respectively from pomegranate, prickly pear and orange fruit were separately concentrated using an innovative technique, that allow to obtain a final product with high content of bioactive compounds and elevate antioxidant activity. The concentrated juices were employed in the formulation of a soft drink to improve its bioactive properties. Despite a low amount of each concentrated juice was used, the experimental soft drink obtained evidenced a high content of total polyphenols. The antioxidant activity detected was similar to that of tea commonly considered a healthy beverage with strong radical scavenging activity. The sensory analysis of the soft drink showed a con…
Polysaccharides from Pleurotus eryngii var. elaeoselini (Agaricomycetes), a New Potential Culinary-Medicinal Oyster Mushroom from Italy.
2020
Three water-soluble glucans (PELPS-A1, PELPS-A2, and PELPS-A3) purified from the hot water extract of the basidiomata of an edible mushroom Pleurotus eryngii var. elaeoselini by chromatography on DEAE-cellulose 32 and Sephadex G-100 column were found to consist of only D-glucose as monosaccharide constituent. Structural investigation was carried out by acid hydrolysis, periodate oxidation, and NMR experiments (1H-NMR, 13C-NMR, DQF-COSY, TOCSY, ROESY, HMQC, and HMBC). On the basis of these experiments, the structures of the repeating unit of the three isolated polysaccharides were established as follows: (1) PELPS-A1: {[→3)-α-D-Glcp-(1→]3→4)-α-D-Glcp-(1→2)-α-D-Glcp-(1→6)-α-D-Glcp-(1[→6)-β-D-…
CHARACTERIZATION OF ANTIOXIDANT ACTIVITY AND TOTAL PHENOLIC COMPOUND CONTENT OF BIRCH OUTER BARK EXTRACTS USING MICRO PLATE ASSAY
2017
In modern plants, 2.7 to 2.8 m3 of solid volume veneer blocks are consumed to produce 1 m3 of plywood. After the hydrothermal treatment and debarking of blocks, waste bark is obtained, which makes up 12.5% of the wood mass, while 16-20% of bark is composed of birch outer bark (BOB). Recalculating, BOB makes up 2.0-3.4% of the veneer log mass. Bark is currently burned in boiler houses that is not rational. BOB contains large amount of valuable extractives (up to 34% from o.d. BOB) consisting of various secondary metabolites such as terpenes, flavonoids, hydrocarbons, polyphenols, tannins etc. BOB extractives exhibit antioxidant properties as well as wound-healing and anti-inflammatory activi…
Improvement of oxidation resistance of polymer-based nanocomposites through sonication of carbonaceous nanoparticles
2020
Abstract The work aim is focused on two different aspects: first, the investigation of the effect of extended ultra-sound-assisted treatment (us) of carbonaceous nanoparticles, such as carbon nanotubes (CNTs) and carbon black (CB), on their radical scavenging activity, and second, the investigation of the oxidative resistance of polymer-based nanocomposites, containing us-treated CNTs and CB. Particularly, the CNTs and CB have been subjected to us sonication for different time intervals and the performed analysis reveals that both kinds of nanoparticles show decreased average hydrodynamic diameters and large content of surface defects. Really, the increased content of CNTs and CB defects, a…
Nano-hybrids based on quercetin and carbon nanotubes with excellent anti-oxidant activity
2016
Abstract Multi-functional nano-hybrids based on Quercetin (Q), a natural antioxidant, and functionalized Carbon Nanotubes (CNTs) have been formulated and used to prepare Ultra High Molecular Weight PolyEthylene (UHMWPE)-based nanocomposites. The study of the nanocomposites rheological behaviour shows that the immobilization of Q molecules onto CNTs outer surface leads to a beneficial effect on the state of the interface between polymer and nanoparticles. Additionally, the investigation of the thermo- and photo-oxidation processes reveals that the hybrids nanoparticles are able to exert a remarkable stabilizing action, due to strong physical interaction between Q and CNTs. In particular, the…
Influence of oxidation level of graphene oxide on the mechanical performance and photo-oxidation resistance of a polyamide 6
2019
The aim of this work is to study the relationship between the chemical-physical properties of graphene oxide (GO) and the performance of a polyamide 6 (PA6) in terms of mechanical reinforcement and resistance to UV-exposure. For this purpose, two samples of GO possessing different oxidation degrees were added (0.75 wt.%) to PA6 by way of a two-step technique and the materials achieved were carefully analysed from a morphological, chemical-physical, mechanical point of view. Photo-oxidation tests were carried out to assess the performance of this class of nanohybrids after 240 h of UV-exposure. The results reveal that both nanocomposites exhibit enhanced mechanical performance and durability…
Water as a Solvent of Election for Obtaining Oleuropein-Rich Extracts from Olive (Olea europaea) Leaves
2021
Leaves from Olea europaea represent one of the main by-products of the olive oil industry, containing a plethora of bioactive compounds with several promising activities for human health. An organic solvent-free extraction method was developed for the recovery of olive leaf phenols, which obtained an extract containing oleuropein in high amounts. A comparison of various extraction media is reported, together with the total phenolic content, DPPH (2,2-Diphenyl-1-picrylhydrazyl) content, ORAC (oxygen radical absorbance capacity), and polyphenol oxidase activity of the corresponding extracts. The polyphenol profiles and content of the most representative extracts have also been studied. Extrac…
Radical scavenging activity of ultrasound-treated Carbon Nanotubes
2016
Carbon nanotubes (CNTs) having controlled radical activity have been achieved tuning the content of their lattice defects induced by an ultra-sound (us) treatment.