OH Scavenger Research Articles

Chemometrics-Driven Variability Evaluation of Phenolic Composition, Antioxidant Capacity, and α-Glucosidase Inhibition of Sorbus aucuparia L. Fruits from Poland: Identification of Variability Markers for Plant Material Valorization.

Sorbus aucuparia L. (rowan tree) is a widely distributed European plant, valued for its nutritional and medicinal qualities. The medicinal application of rowanberries, relying particularly on their antioxidant and antidiabetic effects, is closely connected with the presence of numerous phenolic compounds. However, the broad geographical occurrence of rowan trees may contribute to fluctuations in fruit composition, influencing their biological properties. This study aimed to identify the constituents most involved in this variability to facilitate effective quality control. The investigation encompassed 20 samples collected from diverse locations across Poland, evaluated in terms of the variation in composition and bioactivity. The UHPLC-PDA-ESI-MSn study identified 45 different constituents, including flavonoids, phenolic acid and flavon-3-ols. The detected compounds were quantitatively assessed by HPLC-PDA, alongside spectrophotometric evaluation of total phenolic content and the content of high-molecular-weight proanthocyanidins (TPA). Additionally, •OH scavenging capacity and α-glucosidase inhibition were included as bioactivity parameters. Chemometric analyses, including hierarchical cluster analysis and principal component analysis, revealed geographically dependent variability, with low to moderate variation observed for most factors (variation coefficients 20.44-44.97%), except for flavonoids (variation coefficients 45-76%). They also enabled the selection of seven constituents and TPA as the key markers of variability and biological activity of rowanberries. These markers could be employed for quality control of the fruits, offering a more efficient and cost-effective approach compared to full phytochemical analysis.

The dynamics of bioactive compounds and their contributions to the antioxidant activity of postharvest chive (Allium schoenoprasum L.)

Organosulfur compounds, phenolic compounds, and ascorbic acids (AsA) are known to account for the bulk of chive’s (Allium schoenoprasum L.) antioxidant properties. This study uncovered the contribution of each of these compounds to the chive's antioxidant activity under different storage conditions. The results showed that room temperature (RT) accelerated the accumulation of reactive oxygen species, though phenolics, organosulfur compounds, activities of antioxidant enzymes, and scavenging activity toward hydroxyl radical (OH) and superoxide anion (O2−) were observed to be enhanced in chives stored at RT. In contrast, AsA content, DPPH (1,1-diphenyl-1-picrylhydrazyl) scavenging and FRAP (ferric reducing antioxidant power) activity of the chive were increased by LT on day 5. Furthermore, S-alk(en)ylcysteine sulfoxides (CSOs) showed OH scavenging and weak DPPH scavenging but had no O2− scavenging and FRAP capacity. Volatile organosulfur compounds showed no antioxidant activities. Conclusively, the data demonstrated that AsA was largely responsible for DPPH scavenging and FRAP activity of the chive, while phenolic compounds, especially vanillic acid and p-hydroxybenzoic acid, were primarily responsible for OH and O2− scavenging activity.

Carbonyl Oxide Stabilization from Trans Alkene and Terpene Ozonolysis.

The pressure dependence of carbonyl oxide (Criegee intermediate) stabilization can be measured via H2SO4 detection using chemical ionization mass spectrometry. By selectively scavenging OH radicals in a flow reactor containing an alkene, O3, and SO2, we measure an H2SO4 ratio related to the Criegee intermediate stabilization, and by performing experiments at multiple pressures, we constrain the pressure dependence of the stabilization. Here, we present results from a set of monoterpenes as well as isoprene, along with previously published results from tetramethylethylene and a sequence of symmetrical trans alkenes. We are able to reproduce the observations with a physically sensible set of parameters related to standard pressure falloff functions, providing both a consistent picture of the reaction dynamics and a method to describe the pressure stabilization following ozonolysis of all alkenes under a wide range of atmospheric conditions.

Metabolite profiling and antioxidant capacity of natural Ophiocordyceps gracilis and its cultures using LC-MS/MS-based metabolomics: Comparison with Ophiocordyceps sinensis.

Ophiocordyceps gracilis is an entomopathogenic fungus and a precious traditional Chinese medicine with similar medicinal properties to Ophiocordyceps sinensis. However, information on the metabolite profiles of natural O. gracilis and its cultures is lacking, which limits their utilization. The metabolic variations and antioxidant activities of O. gracilis cultures and natural O. gracilis were analyzed to evaluate the nutritional and medicinal value of O. gracilis and its cultures. The metabolite profiles of O. gracilis cultures (fruiting bodies and aerial mycelia), natural O. gracilis, and natural O. sinensis were compared by LC-MS/MS coupled with multivariate data analysis. Furthermore, their antioxidant activities were evaluated based on their DPPH• , ABTS•+ , and • OH scavenging abilities. A total of 612 metabolites were identified, and the metabolic compositions of the four Cordyceps samples were similar, with differences observed in the levels of some metabolites. There were 126 differential metabolites between natural O. gracilis and natural O. sinensis, among which fatty acids, carbohydrates, and secondary metabolites are predominant in natural O. gracilis. Furthermore, 116 differential metabolites between O. gracilis cultures and natural Cordyceps were identified, with generally higher levels in O. gracilis cultures than in natural Cordyceps. O. gracilis cultivated fruiting bodies exhibited the strongest antioxidant capacity among Cordyceps samples. Additionally, 46 primary and 24 secondary differential metabolites contribute to antioxidant activities. This study provides a reference for the application of natural O. gracilis and its cultures in functional food and medicine from the perspective of metabolites and antioxidant capacity.

Effect of Capsaicin and Dihydrocapsaicin in Capsicum on Myofibrillar Protein in Duck Meat.

Spice and its extracts have gained widespread utilization as natural and eco-friendly additives, imparting enhancements in flavor, color, and antioxidative attributes to meat-based products. This work aims to study the effect mechanism of capsaicin (CA) and dihydrocapsaicin (DI) in capsicum (chili pepper) on the structure and function of myofibrillar proteins (MPs) in duck meat during thermal treatment. The results showed that at a CA-DI to MP ratio of 1:500 (g/g) following a 12 min heat treatment, the carbonyl content of MPs in duck meat decreased by 48.30%, and the sulfhydryl content increased by 53.42%. When the concentration was 1:500 (CA-DI, g/g) after 24 min of heat treatment, the •OH and DPPH radical scavenging rates were highest at 59.5% and 94.0%, respectively. And the initial denaturation temperature of MPs was the highest at 96.62 °C, and the thermal absorption was lowest at 200.24 J g-1. At the parameter, the smallest particle size and size distribution range of MP were 190 nm (9.51%). Furthermore, the interplay between CA-DI and MPs contributed to a reduction in the protein particle size and intrinsic fluorescence. In summary, the combination of CA-DI and MPs played a crucial role in inducing protein unfolding and disintegration.

An effective antioxidant to mitigate reperfusion injury by tailoring CeO2 electronic structure on layered double hydroxide nanosheets

Highly effective antioxidants are needed to attenuate ischemia/reperfusion-induced reactive oxygen species (ROS) and inflammation as a way to alleviate the secondary injury of brain tissue from reperfusion. Herein, we propose the utilization of a two-dimensional (2D) layered double hydroxide (LDH) to optimize the activity of integrated CeO2, hence modifying the electron structure and density of Ce active sites. Through modulation of the surface-to-volume ratio of Ce active sites and Ce3+/(Ce3+ + Ce4+) of the integrated CeO2, the composite-type CeO2@LDH (C-CL) reduces the reaction barrier in the rate-limiting step (from *H2O2 to *O2) for H2O2 decomposition. As a result, in vitro experiments demonstrate that C-CL exhibits 1.6 times higher superoxide dismutase (SOD)-like activity than CeO2, with a remarkable •OH scavenging rate of 86.8%. Moreover, C-CL effectively simulates catalase (CAT)-like activity with Michaelis-Menten constant (Km) value of 18.63 mM, which facilitates H2O2 decomposition. Meanwhile, in vivo experiments reveal that C-CL treatment significantly reduces the infarct area from 36.4% to 4.1% after reperfusion therapy, accompanied by a decrease in neurological deficit score from 4.4 to 0.6. In conclusion, C-CL exhibits immense potential for mitigating reperfusion injury in ischemic stroke. Therefore, this strategy provides a new insight for designing high-performance antioxidants to treat ROS-related diseases, by modulating the density of active sites and altering the electronic state of antioxidants based on 2D materials.

Structure characterization and antioxidant activity of abalone visceral peptides-selenium in vitro

Peptide-selenium chelate is widely regarded as one of the best selenium supplements for relieving selenium deficiency. In this study, abalone visceral peptides (AVP) was used to prepare a new type of peptides-selenium chelate to develop an organic selenium supplement with antioxidant activity. AVP prepared by alcalase exhibited the highest selenium-chelating ability. UV–visible spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy and other structural analysis showed that selenium was mainly bound to the functional groups of –NH, –OH, –CH, CC, CO, and CN bonds on AVP. The formation of AVP-selenium chelate enhanced thermal stability and generated a new crystal structure. The ABTS•+ and •OH scavenging activities of AVP-selenium chelate were increased after in vitro digestion than that of AVP. Conclusively, this study analyzed the chelating mechanism of AVP and selenium from a structural perspective, which would provide a theoretical basis for the development of new selenium supplements.

Biological Activity of Genus Hypericum Sect. Hypericum Species-H. tetrapterum, H. maculatum subsp. immaculatum, H. triquetrifolium.

St. John's wort (Hypericum perforatum, Hypericaceae) has long been used in traditional medicine as a potent remedy, while many other species of this genus have not been thoroughly investigated. The study aimed to detect the biological activity, including antioxidant, antihyperglycemic, anticholinergic, antimicrobial and monoaminoxidase inhibitory potential, of water-alcoholic extracts of three species autochthonous for Serbia and Greece from plant genus Hypericum (section Hypericum-H. tetrapterum, H. maculatum ssp. immaculatum and H. triquetrifolium), followed by phytochemical profiling. The highest amount of phenolics was recorded in H. maculatum subsp. immaculatum extract, while the highest abundance of flavonoids was characteristic of H. tetrapterum extract. Hypericin and hyperforin, quercetin, and its flavonoid, rutin, were present in all of the evaluated species. The evaluated species were good scavengers of DPPH, OH and NO radicals, as well as potent reducers of ferric ions in FRAP assay. Furthermore, the evaluated species were shown as potent inhibitors of monoaminoxidase A and α-glucosidase and modest inhibitors of acetylcholinesterase, monoaminoxidase B and α-amylase. No anti-Candida activity was recorded, but the extracts were effective against MRSA Staphylococcus aureus and Enterococcus sp., as well as against Proteus mirabilis. The obtained results strongly highlight the need for further in vivo studies in order to better define the potential of the medicinal application of the studied species.

Structural modification of poppy-pollen protein as a natural antioxidant, emulsifier and carrier in spray-drying of O/W-emulsion: Physicochemical and oxidative stabilization

This study was aimed to investigate the efficiency of poppy-pollen (PP) protein and peptides as carrier for spray-drying encapsulation of grape-seed oil (GSO). The composition of amino acids, functional properties and bioactivity (scavenging of DPPH, ABTS, OH, and nitric-oxide radicals, reducing power, total antioxidant, TBARS levels in O/W-emulsion, and chelation of Fe2+ and Cu2+ ions) of PP-protein were affected by the enzymolysis time. Partial enzymolysis (30 min) led to improved solubility, protein surface activity and increased physical stability of GSO/W emulsion (relative to creaming, aggregation and flocculation) during storage. Also, spray-dried emulsions with this type of carrier (H−30) had the highest production yield (~67 %), solubility (~92 %), flowability, encapsulation efficiency (~96 %), reconstitution ability (least size and EE changes), physical and oxidative stability. The evaluation of the chemical structures (FTIR) indicated the formation of hydrogen bonds between the cis-alkene groups of fatty acids and the hydroxyl groups of the amide A and B regions, as well as the trapping of oil in the carrier matrix. SEM images illustrated the effect of native protein carriers (particles with smooth, dents, and hollow surfaces with surface pores), partially (wrinkled and reservoir-type), and strongly (irregular structures, sticky and amorphous agglomerates) hydrolyzed peptides on the morphology of oily-particles. The results of this research indicate the usability of partially hydrolyzed poppy-pollen protein as a source of natural antioxidant, emulsifier, and carrier in the production, stabilization, and encapsulation of oxidation-sensitive bioactive components and emulsions.

Preparation, characteristics, and antioxidant activities of carboxymethylated polysaccharides from Paeonia x suffruticosa petals

Two carboxymethylated polysaccharides (CPSP30, CPSP60) were obtained from the petals of Paeonia x suffruticosa Andrews (PSP30, PSP60, respectively) with different molecular weight. Chemical characterization, morphological properties and antioxidant activities of PSP and CPSP were determined. PSP were mainly composed of galactose, glucose, fructose and galacturonic with different molar percentages. CPSP were mainly composed of arabinose, galactose, glucose with different molar percentages. The signals of carboxymethyl groups were found in Fourier transform infrared spectroscopy (FT-IR) and 13C nuclear magnetic resonance (NMR) spectra. Scanning electron microscopy (SEM) indicated that the original polysaccharides had a smooth surface, while the modified polysaccharides had an irregular lamellar structure. Thermal analysis indicated that the modified polysaccharides (CPSP30, CPSP60) presented higher thermal stability than the original polysaccharides. All polysaccharides presented typical structures of non-crystalline compounds. Carboxymethylation did not destroy the triple-helical structures of the polysaccharides. With its lower molecular weight, CPSP30 had higher scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH), OH, and Fe2+ chelating ability than PSP30. The scavenging DPPH and OH abilities of both derivatives were higher than that of original polysaccharides. This study demonstrates that carboxymethylation improved the solubilities and antioxidant abilities of the original polysaccharides, thus enhancing their potential for application in food and pharmaceutical industry.

Olive pectin-chitosan nanocomplexes for improving stability and bioavailability of blueberry anthocyanins.

Blueberry anthocyanins (ANCs) are natural dietary bioactive colorants, but are unstable and easily degraded. To improve their stability, we constructed the nanocarriers for ANCs through an electrostatic self-assembly method, using chitosan (CS) and olive pectin (PC). Results showed that the CS-ANCs-PC nanocomplexes had nanoscale particle size (81.22±0.44nm), and an encapsulation efficiency of 91.97±0.33% at pH 3.0, 1:1:5 ratio (m/v) of CS: ANCs: PC. Fourier transform infrared and UV-visible spectra demonstrated that ANCs can be embedded into the CS-PC carrier through electrostatic interaction. CS-ANCs-PC with stacked spherical particle structure had good thermal stability by scanning electron microscope and thermogravimetric analysis. Compared with free anthocyanins, CS-ANCs-PC possessed better DPPH· and ·OH scavenging activities, stronger environmental stability, and better targeted release in vitro digestion. This study may provide an important fundamental basis for improving the stability of anthocyanins in the blueberry industry.

Kinetics and Mechanism of Ultrasonic Defluorination of Fluorotelomer Sulfonates.

Ultrasound degrades "legacy" per- and polyfluoroalkyl substances (PFAS) via thermolysis at the interface of cavitation bubbles. However, compared to "legacy" PFAS, polyfluoroalkyl substances have a lesser affinity to the interface and may react with •OH. To understand the effect of size on degradation kinetics and mechanism of polyfluoroalkyl substances, this work compared ultrasonic treatment (f = 354 kHz) of n:2 fluorotelomer sulfonates (FTSAs) of varying chain lengths (n = 4, 6, 8). Of the congeners tested, 4:2 fluorotelomer sulfonate (FtS) degraded the fastest in individual solutions and in mixtures. Sonolytic rate constants correlated to diffusion coefficients of FTSAs, indicating that diffuse short-chain FTSAs outcompete long-chain FTSAs to adsorb and react at the bubble interface. Interestingly, 4:2 and 8:2 FtS had different evolutions of fluoride-to-sulfate ratios, [F-]/[SO42-], over time. Initially, [F-]/[SO42-]4:2 FtS and [F-]/[SO42-]8:2 FtS were respectively higher and lower than theoretical ratios. This difference was attributed to the lower maximum surface excess of 8:2 FtS, hindering its ability to pack and, consequently, defluorinate at the interface. In the presence of an •OH scavenger, FTSAs had similar %F- release compared to no scavenger, whereas %SO42- release was drastically diminished. Therefore, thermolysis is the primary degradation pathway of FTSAs; •OH supplements SO42- formation. These results indicate that ultrasound directly cleaves C-F bonds within the fluoroalkyl chain. This work shows that ultrasound efficiently degrades FTSAs of various sizes and may potentially treat other classes of polyfluoroalkyl substances.

Phytochemical Screening of Ultrasonic Extracts of Salix Species and Molecular Docking Study of Salix-Derived Bioactive Compounds Targeting Pro-Inflammatory Cytokines.

Willow bark (Salix spp., Salicaceae) is a traditional analgesic and antirheumatic herbal medicine. The aim of this study was to evaluate and compare the phytochemical and antioxidant profiles of leaf and bark extracts of six species of the genus Salix obtained by ultrasound-assisted extraction (UAE) and to examine the inhibitory potential of target bioactive compounds against two inflammatory mediators, tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), through in silico molecular docking. The total phenolic and flavonoid content of the extracts was estimated using spectrophotometric methods and the antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and hydroxyl radical (•OH) scavenging assays. Chemical profiling of extracts was carried out using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Principal component analysis (PCA) was performed to differentiate the sample extracts based on their phytochemical profiles and amounts of target bioactive compounds. Chemical composition varied among the analyzed willow species and also among the plant organs of the same species. The major bioactive compounds of the extracts were salicin, chlorogenic acid, rutin and epicatechin. The extracts exhibited significant DPPH● and ●OH scavenging activities. Results of molecular docking revealed that chlorogenic acid had the highest binding affinity toward TNF-α and IL-6. UAE extracts represent valuable sources of antioxidant and anti-inflammatory compounds.

Synthesis, Computational Studies, Antioxidant and Anti-Inflammatory Bio-Evaluation of 2,5-Disubstituted-1,3,4-Oxadiazole Derivatives.

The 1,3,4-oxadiazole derivatives Ox-6a-f have been synthesized by incorporating flurbiprofen moiety with the aim to explore the potential of target molecules to decrease the oxidative stress. The title compounds Ox-6a-f were prepared by simple reactions in which a flurbiprofen -COOH group was esterified with methanol in an acid-catalyzed medium, which was then reacted with hydrazine to afford the corresponding hydrazide. The acid hydrazide was then cyclized into 1,3,4-oxadiazole-2-thiol by reacting with CS2 in the presence of KOH. The title compounds Ox-6a-f were synthesized by the reaction of an -SH group with various alkyl/aryl chlorides, which involves an S-alkylation reaction. The structures of the synthesized Ox-6a-f derivatives were ascertained by spectroscopic data. The in silico molecular docking was performed against target proteins cyclooxygenase-2 COX-2 (PDBID 5KIR) and cyclooxygenase-1 COX-1 (PDBID 6Y3C) to determine the binding affinity of the synthesized compounds with these structures. It has been inferred that most of the synthesized compounds bind well with an active binding site of 5KIR compared to 6Y3C, and especially compound Ox-6f showed excellent binding affinity (7.70 kcal/mol) among all synthesized compounds Ox-6a-f. The molecular dynamic (MD) simulation has also been performed to check the stability of docking complexes of ligands with COX-2 by determining their root mean square deviation and root mean square fluctuation. Little fluctuation was observed in case of Ox-6f, which forms the most stable complex with COX-2. The comprehensive antioxidant potential of the synthesized compounds has been evaluated by determining their free radical scavenging activity, including DPPH, OH, nitric oxide (NO), and iron chelation assay. The derivative Ox-6f showed promising results with 80.23% radical scavenging potential at a dose of 100 µg/mL while ascorbic acid exhibited 87.72% inhibition at the same dose. The anti-inflammatory activity of the final products has also been performed, and inflammatory markers were assayed, such as a thiobarbituric acid-reducing substance, nitric oxide, interleukin-6 (IL-6), and COX-2. The derivatives Ox-6d and Ox-6f displayed higher anti-inflammatory activity, exhibiting 70.56% and 74.16% activity, respectively. The results were compared with standard ibuprofen, which showed 84.31% activity at the same dose, 200 µg/mL. The anti-inflammatory potential has been performed by following the carrageen-induced hind paw edema model, and results showed that derivative Ox-6f exhibited 79.83% reduction in edema volume compared to standard ibuprofen, which reduced 84.31% edema volume. As dry lab and wet lab results confirm each other, it has been deduced that derivative Ox-6f may serve as the lead structure to design potent compounds to address oxidative stress.

Enhanced photocatalytic activity of methylene blue using heterojunction Ag@TiO2 nanocomposite: Mechanistic and optimization study

The objective in this study is to investigate the adsorption-degradation of the methylene blue (MB) dye using a fabricated heterojunction Ag@TiO2 nanocomposite. The batch factors used in photo catalytic reactions were pH, UV-irradiation time, temperature, catalytic dosage, and concentration of MB. The results showed that 0.2 × 103 g·ml−1) of the catalytic dose caused the Ag@TiO2 adsorption to degrade by 96.67% with darks and UV exposure. Using the Langmuir-Hinshelwood model to determine the kinetic, the Ag@TiO2 displays a greater kinetic rate than TiO2 and silver nanoparticle (AgNPs). The photocatalytic degradation of MB, which is an endothermic reaction involving all catalysts, is shown by the thermodynamic parameter to have the positive value of enthalpy (ΔH°). The enthalpies observed were Ag@TiO2 (126.80 kJ·mol−1) < AgNPs (354.47 kJ·mol−1) < TiO2 (430.04 kJ·mol−1). Ascorbic acid (OH scavenger), 2-propanol (O2 scavenger), and ammonium oxalate (AO) (hole h+ scavenger) were employed to conduct the scavenger effects. The Ag@TiO2 demonstrated a reduction in MB degradation when combined with 2-propanol, and this clearly demonstrated that, in contrast to hydroxyl radicals (OH) and hole (h+) scavengers, superoxide radical anion (O2 scavenger) plays a significant role in MB degradation. Utilizing density functional theory (DFT) to elucidate the mechanism and B3LYP/6-311+G(d,p) level optimization, the degradation-adsorption process was explained. When the NN, CN or CC bonds were severed, the Fukui faction was demonstrated for nucleophilic, electrophilic, and radical attack.

Phenolic Profile and Antioxidant Potential of Aqueous Extracts of Selected Traditional Anti-cough Plants

The recent surge in attention towards plant-based antioxidants can be attributed to their perceived advantageous impact on human health. The present study assessed the phenolic profile, antioxidant potential, and free radical scavenging ability of hot aqueous leaf extracts obtained from Vernonia amygdalina, Piper guineense, and Gongronema latifolium. High-Performance Liquid Chromatography (HPLC) was used to examine phenolic profile. Antioxidant capacity was conducted using total flavonoid content (TFC), total phenol content (TPC), total antioxidant capacity (TAC), polyphenol oxidase (PPO) activity, while ferric reducing antioxidant potential (FRAP), nitric oxide (NO), hydroxyl (OH), and 2, 2-diphenyl-2-picrylhydrazyl (DPPH) were analysed for their radicals scavenging activities. G. latifolium displayed notable phenolic compounds, such as lunamarin (76.32mg/ml), ribalinidine (64.08 mg/ml), gallocatechin (48.58mg/ml), aglycone (41.69 mg/ml), flavonone (33.45mg/ml), and flavan-3-ol (30.49mg/ml). The plant extracts contained resveratol, kaempferol, and ribalinidine in a consistent manner across all samples. The findings suggest that the plants exhibits noteworthy antioxidant potential, with G. latifolium displaying the highest antioxidant capacity (96.18 ± 0.11µg/mL) and total phenolic content (28.50 ± 0.04 µg/mL). V. amgydalina showed highest polyphenol oxidase activity, at 7.14 ± 0.10 µg/mL G. latifolium as well showed high •NO scavenging radicals and FRAP activity, while exhibiting the least efficacy in •OH scavenging radicals. The results indicate that all three samples demonstrated a noteworthy increase in DPPH scavenging activity, which was statistically significant at p&lt;0.05 compared to standard. Results reveals that plant extracts showed significant phenolic compounds, antioxidant and free radicals property. These observations provides a rationale for the traditional use of these extracts in folk medicine for management and treatment of cough.&#x0D; Keywords. Gongronema latifoluim, Veronia amygdalina, Piper guineense, Phenolic profile, Antioxidant capacity, Free Radical, cough.

Physicochemical and functional properties of Pleurotus eryngii proteins with different molecular weight

Pleurotus eryngii, rich in polysaccharides and proteins, is precious commercial edible fungus with favorable nutrition. In this study, four kinds of Pleurotus eryngii proteins (PEPs) with different molecular weight (PEP: control, PEP-I: >100 kDa, PEP-II: 50–100 kDa, PEP-III: 10–50 kDa) were prepared by alkaline-solution and ultrafiltration method. The results revealed that PEP-I (82.5 °C) and PEP-III (81.9 °C) with high denaturation temperature. Glu, Asp, Leu, and Lys were the most enriched amino acids in PEPs. The SDS-PAGE results revealed that a low molecular weight fraction of 17 kDa was clearly obtained in the PEP-III. The secondary structure of PEPs was mainly β-turn and β-sheet, and account for 79.8–90.3% of the total content. Moreover, PEP-II and PEP-III had better solubility and emulsification compared to PEP-I and PEP. Finally, the antioxidant capacity of PEPs, especially PEP-II and PEP-III, shown significantly ·OH scavenging capacity and Fe2+ chelating force. The key findings suggested in this paper refer to the exploration of functional properties and antioxidant activity of Pleurotus eryngii protein. The PEP-III with low molecular weight is potentially advantageous as a protein alternative resource application in the food industry.

Managing Encapsulated Oil Extract of Date Seed Waste for High Hydroxyl Radical Scavenging Assayed via Hybrid Photo-Mediated/Spectrofluorimetric Probing

This work addresses two research topics: the first concerns the specific/sensitive trapping of hydroxyl radicals (•OH), and the second concerns the efficacy of encapsulating natural antioxidants, potentially lengthening their preservation activity. For context, nano-titania was solar-irradiated to produce •OH, which was spectrofluorimetrically assessed, based on the selective aromatic hydroxylation of the non-fluorescent sodium terephthalate to 2-hydroxyterephthalate fluorophore. Fluorescence intensity is proportional to generated •OH. Thus, a simple/rapid indirect method was utilized to assess •OH precisely. Accordingly, novel photoluminescent system is outlined in order to assess the scavenging potentiality of •OH in date seed oil (DSO) in both its pure and encapsulated formulations (ECP–DSO), i.e., when fresh and 5 months after extraction and encapsulation, respectively. With the addition of 80 μg/mL DSO or ECP–DSO, the efficacy of •OH scavenging amounted to 25.12 and 63.39%, which increased to 68.65 and 92.72% when 200 μg/mL DSO or ECP–DSO, respectively, was added. Moreover, the IC50 of DSO and ECP–DSO is 136.6 and 62.1 µg/mL, respectively. Furthermore, DSO and ECP–DSO decreased the kinetics for producing •OH by ≈20 and 40%, respectively, relative to •OH generated in the absence of antioxidant. This demonstrates the benefits of encapsulation on the preservation activity of natural antioxidants, even after five months after extraction, in terms of its interesting activity when compared to synthetic antioxidants. The developed fluorimetric •OH probing upgrades antioxidant medicines, thus paving the way for theoretical/practical insights on mechanistic hydroxyl radical-damaging biology.

Structural characterization and antioxidant activity of pectic polysaccharides from Veronica peregrina L.

Pectins are a class of acidic polysaccharides with complex structures. Different pectin molecules are composed of different domains, which have an important impact on their biological activity. This study aimed to determine the structural features and the antioxidant activities of the pectic polysaccharides isolated from Veronica peregrina L. The polysaccharide was isolated from Veronica peregrina L by water extraction and fractionated by ion exchange chromatography and gel permeation chromatography. The structure features of the pectic polysaccharides were determined by Fourier transforminfrared spectroscopy (FT-IR) and Nuclear magnetic resonance (NMR). The antioxidant activities was evaluated by the DPPH, OH and ABTS radical scavenging ability. WVPP-A2b and WVPP-A3b, with molecular weights of 48.7 × 104 and 77.6 × 104 kDa, respectively, contained homogalacturonan (HG), rhamnogalacturonan I (RG-I), and rhamnogalacturonan II (RG-II) domains with a mass ratio of 2.08:2.64:1.00 and 3.87:4.65:1:00, respectively. The RG-I domain contained an arabinogalactan II backbone and arabinans consisting of t-Araf, (1→5)-α-Araf, and (1→3,5)-α-Araf. WVPP-A3b also contained short chains consisting of the [t-Araf-(1→5)-α-Araf-(1→] structural unit. WVPP-A3b showed stronger ability to scavenge DPPH, hydroxyl, and ABTS radicals, which was potentially associated with its high content of galacturonic acid and presence of the HG domain. The results provide information for enhancing knowledge of the structureactivity relationship of pectic polysaccharides from V. peregrina and their potential application in the healthcare food field.

Phenolic composition, antioxidant, and cytotoxic effects on HeLa and HepG2 cancer cell lines of Mespilus germanica grown in Turkey

This study screened flavonoids and phenolic acids, antioxidant and cytotoxic effects of Mespilus germanica leaf and fruit samples. The RP-HPLC-DAD analysis allowed the identification of hesperidin, epicatechin, epigallocatechin, benzoic, p-hydroxybenzoic, vanillic, protocatechuic, syringic, caffeic, ferulic, sinapic and p-coumaric acids in various extracts. Fruit alkaline-hydrolysable phenolic acids extract (BHPA), leaf bound phenolic acids from basic hydrolysis-2 extract (BPBH2) and leaf free flavan-3-ol extract exhibited the largest DPPH, OH and NO radicals scavenging activity, respectively. Leaf flavone extract showed strong cytotoxicity on the HepG2 cell line (IC50 = 36.49 ± 1.12 μg/mL) as well as good •OH scavenging and Fe2+ chelation activities. Additionally, leaf bound phenolic acids from acid hydrolysis-1 extract (BPAH1) demonstrated strong cytotoxicity on the HeLa cell line (IC50 = 36.24 ± 1.89 μg/mL). This study suggests Turkish medlar as a natural source of phenolic compounds with potential application in food and pharmaceutical industries as anticancer/antioxidant agents.