Scavenging Activity Research Articles

Enzymatic synthesis of self-adhesive zein to impart durable hydrophobicity with antioxidant activity to cotton fabrics

In this study, dopamine (DA) was used as the acyl receptor to modify zein through transglutaminase (TGase)-mediated reaction, producing self-adhesive zein (zein-DA complex). The structure of zein-DA complex was characterized by Fourier transform infrared spectrum (FT-IR), 1H nuclear magnetic resonance spectrum (1H NMR), and circular dichroism spectrum (CD), revealing the successful grafting of catechol structure of DA to zein. The results of SDS-PAGE demonstrated that zein-DA complex exhibited great ability of self-polymerization. The zein-DA complex absorbed on the cotton fabric surface imparted hydrophobicity with a water contact angle value (WCA) of 121.34 ± 1.14° to the fabrics. After 5 washing cycles, the WCA still remained 100.28 ± 4.83°, which indicated the fabrics obtained relatively durable hydrophobicity due to the self-adhesion of zein-DA complex. The results of FT-IR, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and color reaction tests manifested that much more protein attached on the surface of cotton fabric treated with zein-DA complex after washing compared with that with zein, which verified that the zein-DA complex had strong adhesion properties. Due to the introduction of DA, the relative DPPH free radical scavenging activity of cotton treated with zein-DA complex reached 43.60 ± 0.28 %, which was obviously higher than cotton treated with zein. The functionalized fabrics with zein-DA complex had both hydrophobicity and antioxidant activities.

Expression of concern: "Okra seeds proteins: Amino acid profile, free radical scavenging activities and inhibition of diabetes and hypertensive converting enzymes indices" [Measurement: Food, Volume 11, September 2023, 100101]

Expression of concern: "Okra seeds proteins: Amino acid profile, free radical scavenging activities and inhibition of diabetes and hypertensive converting enzymes indices" [Measurement: Food, Volume 11, September 2023, 100101]

Preparation and characterization of Ag@MOF-eugenol/ poly (lactic acid) composite films for zucchini preservation

The rising demand for premium quality fruits and vegetables has resulted in an increased necessity for the advancement in active food packaging. This study aimed to develop eugenol-loaded Ag@MOF/poly(lactic acid) (Ag@MOF-EU/PLA) composite films to assess their efficacy in preserving zucchini. The results revealed that Ag@MOF-EU can be uniformly distributed within the PLA matrix, which significantly enhanced the tensile strength, hydrophobicity, and UV-blocking capacity of PLA films, and at the same time had no significant effect on the thermal properties and WVP of the PLA films. Moreover, the resulting Ag@MOF-EU/PLA films exhibited no cytotoxicity. In a food simulant (50 % ethanol), the release behavior of the EU demonstrated a sustained release over 20 days. Furthermore, Ag@MOF-EU/PLA had an enhanced antimicrobial activity and DPPH scavenging activity, compared to PLA films. The preservation experiment involving zucchini elucidated that the Ag@MOF-EU/PLA composite film could extend the shelf life of zucchini by maintaining color, reducing weight loss, delaying the decline in firmness, and inhibiting the growth of total viable colonies. These findings indicated that the Ag@MOF-EU/PLA films developed within the scope of this research possess the potential to serve as effective food-active packaging materials.

Synthesis, Characterization, Biological Evaluation, DFT, and Molecular Docking Study of a Co(II) Complex Derived from ON Donor Bidentate Schiff Base Ligand

AbstractThe utilization of biologically active metal complexes in medicine is gaining recognition as an alternative approach to traditional biologically active organic molecules, which often exhibit undesirable side effects. This study focuses on the synthesis and characterization of a Co(II) complex derived from the (E)‐2‐((2‐hydroxybenzylidene)amino)‐5‐methylbenzonitrile ligand system (HL) and cobalt(II) acetate tetrahydrate in a dichloromethane/methanol solution. A comprehensive characterization strategy was employed, involving proton and carbon nuclear magnetic resonance, infrared, electronic spectra, PXRD, SEM‐EDX, and mass spectroscopies, as well as elemental analysis (CHN and Co), TGA, and molar conductance, to confirm the chemical structures of the ligand and its complex. The infrared spectral data revealed the ligand as a bidentate ligand, chelating the Co(II) ion through the oxygen and nitrogen atoms of the phenolate and imine groups. Additionally, PXRD and SEM analyses indicated crystalline and amorphous properties for the ligand and complex, respectively. Assessment of antimicrobial potential using a modified disc diffusion method, with streptomycin as the positive control, demonstrated the complex's enhanced antibacterial activity compared to the ligand against all tested bacteria, showing a concentration‐dependent response. Similarly, antioxidant studies revealed promising results, with the complex exhibiting superior DPPH radical scavenging activity (IC50 values: ligand 64.5 μg.mL−1, complex 43.1 μg.mL−1). Theoretical analysis through DFT calculations and molecular docking provided insights into the electronic properties and binding affinity of the ligand and complex, supporting the experimental findings and affirming the biological activities exhibited by the compounds. Overall, this research showcases the synthesis, characterization, and biological evaluation of a promising Co(II) complex, highlighting its potential as an effective antimicrobial and antioxidant agent.

Holistic exploration of silver nanoparticles synthesized from Carthamus oxycantha leaf extracts: Characterization and assessment of antioxidant, anti-α-amylase, and anti-cholinesterase activities using comprehensive statistical methods

In the burgeoning field of nanotechnology, plant-mediated nanoparticles (NPs) have attracted significant attention due to their small size, favorable chemical properties, and eco-friendly nature. We utilized Carthamus oxycantha leaf extract to synthesize silver nanoparticles (AgNPs) and evaluate their potential as antioxidants and inhibitors of acetylcholinesterase (AChE) and alpha-amylase (α-amylase). The AgNPs were characterized using advanced techniques. The UV–Vis spectrum recorded at 410 nm, with an absorbance of 2.3 a.u., confirmed the presence of AgNPs. Fourier transform infrared spectroscopy (FT-IR) indicated that functional groups from the extract were attached to the AgNP surface, aiding in their formation and stabilization. X-ray diffraction analysis (XRD) revealed four major peaks at 37, 43, 64, and 77, confirming AgNP synthesis. Scanning electron microscopy (SEM) showed that 80 % of the AgNPs were spherical, measuring 25–50 nm, while energy dispersive X-ray (EDX) analysis indicated that silver constituted 83 % of the material. The AgNPs demonstrated significant scavenging activity: 59.3 % with ABTS, 67.2 % with ammonium molybdate, 60.35 % with DPPH, 65.2 % with ferric chloride, and 55.2 % with H2O2. Both α-amylase and AChE were inhibited by AgNPs, exhibiting uncompetitive inhibition characteristics. For glucophage, Km decreased from 143 to 75 µg, and Vmax decreased from 45 % to 72 % as concentrations increased from 50 to 150 µg. The Km of AgNPs decreased from 25 to 17 µg, and Vmax decreased from 16 % to 37 %. The extract showed noncompetitive inhibition against α-amylase, while AgNPs caused noncompetitive inhibition in AChE. These findings highlight the potential of AgNPs as therapeutic agents for managing oxidative stress and enzyme-related disorders, paving the way for future research and applications in medicinal chemistry.

Phytochemistry, and Antioxidant Potential of Aqueous Extract of Terminalia chebula Fruit from the Coal-Affected Forests of Bokaro District, Jharkhand

This study investigates the ethnobotanical significance, phytochemical composition, and antioxidant potential of the aqueous extract of Terminalia chebula fruit, collected from the coal-affected forests of Bokaro District, Jharkhand. Using DPPH and NBT assays, the antioxidant activity of the extract was evaluated at various concentrations (50, 100, 250, and 500 µg/mL). The DPPH assay revealed a dose-dependent increase in radical scavenging activity, with Terminalia chebula achieving 82.3% inhibition at 500 µg/mL. In comparison, ascorbic acid, a standard antioxidant, exhibited higher inhibition rates, reaching 95.0% at the same concentration. Similarly, the NBT assay demonstrated that the extract inhibited superoxide radicals, with 78.9% inhibition at 500 µg/mL, while ascorbic acid achieved 94.4% inhibition. The phytochemical analysis indicates a rich composition of phenolic compounds, flavonoids, and tannins in the extract, which are likely responsible for its antioxidant properties. These findings support the traditional medicinal uses of Terminalia chebula, particularly in managing oxidative stress-related conditions. Overall, the study highlights the significant antioxidant potential of Terminalia chebula fruit extract, suggesting its possible applications in functional foods and natural health products. Future research should focus on isolating specific bioactive compounds and exploring their synergistic effects to fully understand the therapeutic potential of this valuable ethnobotanical resource.

Phytochemical Analysis, Cytotoxic, Antioxidant, and Anti-coccidian Activities of Vitis vinifera Leaves Grown in Saudi Arabia

Background: Natural products are essential for medicinal purposes in developing countries. Traditional and contemporary medicine utilized plant products as alternative treatments for parasitic diseases. Objectives: The purpose of the investigation is to analyze and assess the bioactive compounds in Vitis vinifera leaf extracts, as well as their effect on coccidiosis. Materials and methods: Several analytical techniques were utilized, such as infrared spectroscopy (IR) and gas chromatography-mass spectrometry (GC-MS). Additionally, we assessed the total phenol, tannin, flavonoid examination, and cytotoxicity of the plant extracts using an MTT assay and UV-visible spectrophotometry (UV-Vis). Moreover, the samples’ levels of antioxidant activity (measured with DPPH and ABTS) were analyzed. Results: The leaf extract's GC-MS study identified many bioactive elements linked to plant secondary metabolites. Further, the total phenol, tannin, and flavonoid were 160.217 ± 0.652, 65.872 ± 0.263, and 34.0463 ± 0.545 (mg TAE/g DW), respectively. It also contains these extracts with a high antioxidant and DPPH radical scavenging activity. This reflects the number of bioactive chemicals that are present in these extracts. Conclusions: The findings of this research discuss techniques in phytochemical analysis of Vitis vinifera leaf extracts and the identification of biologically active components that support and justify the utilization of grape leaves in folk medicine in developing countries.

Reactivity of (3‐(4‐Fluorophenyl)oxyran‐2‐yl)(naphthalene‐2‐yl)methanone Toward Some Nucleophiles for Preparing Promising Agents with Antimicrobial and Antioxidant Activities

Abstract(3‐(4‐Fluorophenyl)oxyran‐2‐yl)(naphthalene‐2‐yl)methanone 2 was prepared from the reaction of 3‐(4‐fluorophenyl)‐1‐(naphthalen‐2‐yl)prop‐2‐en‐1‐one (1) with hydrogen peroxide and reacted with different nucleophiles such as hydrazine hydrate, phenyl hydrazine, thiosemicarbazide to give 4‐hydroxy‐1H‐pyrazole derivatives 3a,b‐4. Also, compound 2 was treated with hydroxylamine hydrochloride to give the substituted 2,3‐dihydroisoxazole 5. Similarly, compound 2 was treated with carbon disulfide, phenyl isothiocyanate, and phenyl isocyanate to give the corresponding compounds 6–8. Various spectroscopic techniques and elemental analysis were used to determine the molecular structures of the new derivatives. All the new analogs were screened against five human pathogenic microbial strains: Escherichia coli and Pseudomonas aeruginosa as Gram‐negative bacteria, Bacillus subtilis and Staphylococcus aureus as Gram‐positive bacteria and the yeast Candida albicans using agar diffusion method. Compound 4 exhibited moderate antimicrobial activity against all the tested microorganisms compared to positive control ciprofloxacin and fluconazole. On the other hand, the free radical scavenging activity of the new compounds using DPPH assay protocol revealed that most of the compounds have a weak reducing activity. Moreover, compounds 4 and 8 were docked against 1KZN protein (DNA gyrase), 3FYV and 5V5Z showing the ability to interact with key amino acid residues and the potential to act as inhibitors.

Functional Properties and Components of Koenigia alpina Extract.

Koenigia alpina (All.) T.M.Schust. & Reveal (alpine knotweed) is a perennial herb belonging to the Polygonaceae family. Several studies have examined Polygonaceae species' potential applications as cosmeceutical materials; however, the potential of K. alpina as a cosmeceutical has not yet been studied. Hydrogen peroxide (H2O2) and lipopolysaccharide were used to induce an inflammatory response in RAW 264.7 cells. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radicals and H2O2 were used to evaluate the free-radical scavenging activity of K. alpina extract and its protective effect against reactive oxygen species (ROS)-induced cell damage. The whitening, antiaging, and cell proliferation/migration effects of the extracts were evaluated via tyrosinase inhibition, collagenase/elastase inhibition, and wound healing assays, respectively. The anti-inflammatory effect was confirmed by evaluating nitric oxide (NO) production in RAW 264.7 cells. High-performance liquid chromatography (HPLC), UV, and MS/MS were used to determine the main components of the extract and fractions. The ethyl acetate (EA) fraction and its aglycone fraction showed very high free-radical scavenging activities (47.5 and 47.1µg/mL, respectively). The extract/fractions also showed significant tyrosinase inhibition (IC50 = 0.38mg/mL in EA fraction), collagenase inhibition (IC50 = 0.21mg/mL in EA fraction), and elastase inhibition (IC50 = 0.57mg/mL in aglycone fraction). NO production in lipopolysaccharide-induced RAW 264.7 cells was inhibited by the extract/fractions. The extract also promoted the closure of scratch wounds in HaCaT cells. The K. alpina extract/fractions contained cardamonin, quercetin, and quercitrin. K. alpina extracts/fractions showed antioxidant, antiaging, whitening, and anti-inflammatory activities, suggesting they may have potential as antiaging cosmeceuticals.

Octenylsuccinated alginate as a delivery agent for encapsulation of bergamot essential oil: Preparation, functional properties and release behavior

This study evaluate the effect of succinylation of sodium alginate (ALG) by octenyl succinic anhydride (OSA) and its effect on the bergamot essential oil (BEO)-loaded ALG beads. The physico-chemical, antioxidant, antibacterial, and in vitro release properties of BEO-loaded ALG beads were assessed. The presence of BEO in alginate beads was assessd using Fourier transform-infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and differential scanning calorimetry (DSC) experiments. The higher amount of BEO in modified alginate beads at higher degree of substitution (DS) has been confirmed. Accordingly, it was discovered that the DS has notable effects on encapsulation efficiency (EE), loading capacity (LC) of beads, so that the values of EE and LC were about 31–75 % and 19–45 %, respectively, when the DS value of ALG was 0.00–0.022. Besides, BEO-loaded beads prepared using high DS, exhibited higher total phenolic compound (TPC = 21.101 mg garlic acid/g brad), good antioxidant activity (DPPH radical scavenging activity ≈ 69 %) and antibacterial properties (against E. coli and S. aureus). In vitro release analysis showed the initial fast release followed by a slow-release. OSA modification slowed down the release rate of bergamot essential oil from alginate beads. Also, the release of BEO from the beads followed Fickian diffusion.

Alkaline treatment for targeted lignin breakdown in rice straw: Maximizing phenolic content and product characterization

Lignin is a significant renewable source for the production of phenolics and aromatic compounds for use as functional materials. Rice straw (RS), a lignocellulosic biomass was given alkaline treatment, to breakdown lignin into methoxyphenols and heterocyclic compounds, leaving behind carbohydrate rich residue. Process parameters such as NaOH (M), time (min) and liquid to solid (L:S) ratio (mL/g) were optimized using Response Surface Methodology (RSM) to enhance the extraction of phenolics. The maximum phenolic content (13.98 mg/g RS) was obtained after treatment with 3 M NaOH for 30 min with L: S ratio of 20:1 mL/g at 121°C. GC-MS revealed the presence of 14 compounds, primarily methoxyphenols like acetosyringone (32.44 %), 2-methoxy-4-vinyl phenol (23.71 %), vanillin (1.25 %) and 2, 6-dimethoxyphenol (1.49 %). Additionally, a significant proportion of a heterocyclic compound, 2, 3-dihydrobenzofuran (31.72 %), was also present. The extract exhibited considerable levels of 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (IC50 (half-maximal inhibitory concentration) = 0.45 mg/mL) radical scavenging activity, which was comparable to ascorbic and gallic acids. With substantial conversion (60.17 %) of rice straw lignin to phenols and simultaneous recovery of both cellulose (45.7 %) and hemicellulose (14.6 %), this process can be useful in biorefining of lignocellulosic biomass to phenolic chemicals for application in food and pharmaceutical industry.

Synthesis, Molecular Docking Studies and Biological Evaluation of Thiazolyl Hydrazone Derivatives of Chromone-3-carbaldehyde as Potent Anti-Oxidant and Anti-Inflammatory Agents.

A series of 15 thiazolyl hydrazone derivatives of chromone-3- carbaldehyde have been designed and synthesized by the cyclization of thiosemicarbazone derivatives of chromone-3-carbaldehydes with 4'-substituted-2-bromo acetophenones. All these derivatives were evaluated for antioxidant activity by their direct scavenging activity objects to reactive oxygen species such as DPPH, and nitric oxide, as well as in vitro antiinflammatory activity by a protein denaturation method. Most of these synthesized compounds have shown significant antioxidant activity, among which the compounds 5b, 5c, 5e, 5g, and 5j showed very good antioxidant activities in comparison with the standard ascorbic acid. The in vitro anti-inflammatory activity revealed that the compounds 5b, 5g, and 5h possessed significant activity compared to standard diclofenac sodium. Additionally, molecular docking studies of these molecules using ovalbumin as the protein showed remarkable interactions with its active site residues, and the results indicated that the binding mode of these compounds closely resembled that of the reference compound, diclofenac sodium. Thus, these compounds represent an attractive template for the evaluation of new antiinflammatory and antioxidant agents and might be useful for exploring new therapeutic tools.

Maximizing polyphenol yield: ultrasound-assisted extraction and antimicrobial potential of mango peel

This study investigated the ultrasound-assisted extraction (UAE) techniques used to enhance the polyphenols and antioxidants of mango peel extract (MPE). Additionally, it explored the bacteriostatic activity of MPE against various microorganisms. The UAE method was optimized using response surface methodology (RSM) at different times, temperatures, and ratios, with optimal conditions found to be 35 minutes, 45 °C, and a 1:35 ratio. The optimized yield results for total polyphenol content (TPC) were 17.33 ± 1.57 mg GAE/g, total flavonoid content (TFC) was 12.14 ± 0.29 mg QE/g, and radical scavenging activity (RSA) was 72.11 ± 2.19%. These response models were extremely significant with p-values less than 0.05. MPE showed selective effectiveness against Bacillus cereus, Geobacillus stearothermophilus, and Escherichia coli (E. coli). The results highlight the potential of mango peel as a sustainable source of bioactive compounds, contributing to waste reduction in the food industry and the development of natural antimicrobial agents. This study contributes to further research on the application of MPE in processed foods.

Comparison of piperine content, antimicrobial and antioxidant activity of Piper chaba root and stem

Piper chaba (locally known as “Choi Jhal”) is used traditionally as spices and folk medicine in different parts of Bangladesh. One of the most important bioactive compounds in this plant is piperine. In this study, the amount of piperine in P. chaba root and stem was investigated and the optimal solvent for piperine extraction at room temperature was also studied. High performance liquid chromatography (HPLC) was operated using a reverse phase column where methanol and water (70:30) were used as mobile phase. The detection was performed using photo diode array (PID) detector at a wavelength of 345 nm. The standard piperine showed linearity between 0.005 % and 0.04 % and the correlation co-efficient found for the linearity was 0.9933. The percentage of relative standard deviation (RSD) for both retention time and peak area were less than 2.0 %. The theoretical plate number (N) > 3000 and a tailing factor (T) < 1.5 were found in the acceptable range. The recovery percentage (%) of standard piperine was 99.16 %. Low value of co-efficient of variation and standard deviation are recognized for high precision of the method. The highest amount of piperine was found in root extracted with methanol (MR) amounting to 1.75 % in the root powder. The maximum amount of piperine in the stem was 1.59 % when extracted with methanol (MS). The piperine quantification in other extract like n-hexane root (HR), ethyl acetate root (ER), n-hexane stem (HS), ethyl acetate stem (ES) were 0.76 %, 1.69 %, 0.33 % and 1.46 % respectively. Methanol has given the highest yield of piperine compared to ethyl acetate and n-hexane for both root and stem. The developed method was simple, rapid, economic and validated in terms precision, accuracy and recovery. This selective method is found to be repeatable, accurate and successfully utilized for the Piper extract in marketed and pharmaceutical samples with well chromatographic conditions. The ethyl acetate extract of root and stem showed promising DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical scavenging activity with an IC50 value of 39.62 ± 0.95 μg/mL and 43.85 ± 1.50 μg/mL respectively. The study reports potential antibacterial activity and antifungal activity of P. chaba root and stem extracts. These outcomes revealed that different extracts of P. chaba may be used as natural preservatives.

Efficacy of Radical‐Scavenging Activity in Novel Diorganotin(IV) Complexes of Schiff Bases of Salicylaldehyde

AbstractBiopotent hybrid diorganotin(IV) complexes, derived from salicylaldehyde Schiff bases having general formula R2SnL, where LH = (OH)C6H4HC: NCR′(R″)CHR‴OH] [where R = Me or Bu], were logically designed, generated, and characterized using spectroscopic techniques, single‐crystal X‐ray investigations, and DFT studies. Different diorganotin(IV) complexes were synthesized because of interaction between diorganotin(IV) dichloride and sodium salts of Schiff bases of salicylaldehyde ligand in anhydrous refluxing THF at 1:1 and 1:2 molar ratio (Product A and B). The chelating property of Schiff bases replaces organo group from diorganotin(IV) dichloride. It creates an O2SnL type of complex when diorganotin(IV) dichloride and ligand interact in 1:2 ratio, which is this study's most fascinating aspect. The characterization of these complexes is aided by physicochemical and spectroscopic investigations, including IR and NMR (1H, 13C, and 119Sn). Single‐crystal X‐ray investigations, mass spectrum studies, and DFT investigations suggest the dimeric structure of these compounds. These diorganotin(IV) complexes have a dimeric structure containing hexacoordinated central tin atom. Two µ2─O atoms bridge the gap between two Sn(IV) atoms in the dimeric dimethyltin(IV) complexes. The DPPH assay results for radical scavenging activity and IC50 values demonstrate the antioxidative potential of diorganotin(IV).

Preparation and characterization of cysteine-rich collagen peptide and its antagonistic effect on microplastic induced damage to HK-2 cells

Cysteine (Cys) plays a significant role in the stability and antioxidant capacity of peptide. This study was to prepare Cys-rich collagen peptide and evaluate its preventive effect on microparticle (MPs)-induced HK-2 cell damage. The results showed that the Cys-rich peptides (AMP-C) were successfully prepared from collagen hydrolysate by plastein reaction in the presence of exogenous Cys. The scavenging activities of 2,2-Diphenyl-1-picrylhydrazyl and hydroxyl radical of AMP-C were significantly higher than those of original peptides without Cys. The fraction with molecular weight < 3 kDa (AMP-CA) significantly improved MPs-induced damage and apoptosis of HK-2 cells. Compared with the same fractions lacking Cys (AMP-A), AMP-CA showed better performance in reducing reactive oxygen species and increasing the total superoxide dismutase and glutathione peroxidase levels, which may be related to its down-regulation of Kelch-like ECH-associated protein 1 (Keap1) expression. In addition, AMP-CA showed strong effects on inhibiting interleukin-6, tumor necrosis factor-α, monocyte chemoattractant protein-1, kidney injury molecule-1, and nuclear factor kappa-B levels. Finally, 330 Cys-containing peptides were isolated from AMP-CA, among which Leucine-Glycine-Asparagine-Glycine-Cysteine-Proline (LGNGCP) showed the lowest binding energy with Keap1 protein. In conclusion, the Cys-rich collagen peptide with higher antioxidant activity was successfully prepared by plastein reaction, which alleviated the HK-2 cells damage induced by MPs through antioxidant and anti-inflammatory. Our findings suggested that Cys-rich collagen peptide might be used as a functional food to mitigate health hazards associated with MPs accumulation.

Antioxidant potential and stability of bovine liver peptides in fermented sausage (sucuk): A pathway to value-added functional meat products

The objective of the present study was to evaluate the stability of low-molecular-weight peptides after their incorporation into fermented sausages. Peptide fractions were produced from the bovine liver peptides (BLP) by enzymatic hydrolysis. Optimal conditions were identified as hydrolysis at 45 °C for 24 h, resulting in the generation of <3 kDa and <10 kDa peptide fractions exhibiting the highest antioxidant activity. The antioxidant potential of fermented sausages made from beef meat containing BLPs at 0.5% and 1% concentrations was assessed during manufacturing and storage. The initial antioxidant activity values of the sausages containing BLPs were higher than that of the control. Furthermore, the stability of the peptides in the sausages was demonstrated by their preserved antioxidant activity for 102 days. Peptides extracted from 1% of <10 kDa-peptide containing sausages possessed two-fold higher radical scavenging activity than control. The highest peptide concentration in the sausages containing 1% of <10 kDa-peptides (79.32±1.34–101.56±1.22 μg peptide/mg) was maintained from day 0 to day 102. The SDS-PAGE profile of myofibrillar proteins and peptide extracts revealed the degradation of proteins were delayed in <10 kDa of peptide added sausages, suggesting that the protein oxidation was slowed down. These results contribute to the advancement of peptide commercialization as functional ingredients in fermented food products. Furthermore, our research sheds light on the enduring impact of fermentation on the stability of the added peptides and the synergistic interactions between naturally produced peptides during fermentation and those introduced externally.

Phytochemical Analysis, Antioxidant Activity and Bioassay-Guided Isolation of Acetylcholinesterase and Butyrylcholinesterase Inhibitors from Horsfieldia polyspherula Bark (Myristicaceae).

Alzheimer's disease (AD) is a neurodegenerative condition brought on by aging and characterised by progressive decline in cognitive function and abnormalities in the central cholnergic system. β-amyloid deposits, neurofibril tangle aggregation, oxidative stress or reduced level of acetylcholine are a few causes that have been linked to AD. In this study, the bioassay-guided isolation from ethyl acetate (EtOAc) extract of Horsfieldia polyspherula bark led to the isolation of nine compounds namely, 16-phenylhexadecanoic acid (1), undecylbenzene (2), 3,4-dihydroxybenzoic acid (3), dodecanoic acid (4), tetradecanoic acid (5), pentadecanoic acid (6), 1-tridecene (7), stigmasterol (8) and trimyristin (9). Phytochemical analysis revealed the presence of flavonoids, steroids, lignin, alkaloids, phytosterol and triterpenoids. The DPPH scavenging activity of EtOAc extract was related to the phenolic content (116.67 ± 16.98 GAE mg/g) and other non-phenolics such as lower fatty acids. Meanwhile, the DPPH scavenging activity was found to be concentration-dependent and correlated with both flavonoid and phenolic content. Furthermore, EtOAc and methanol (MeOH) extracts of H. polyspherula bark showed significant inhibitory activity at 100 μg/mL on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), with EtOAc extract showing 77.2% and 64.1% inhibition and MeOH extract showing 37.5% and 39.2% inhibition, respectively. Additionally, the IC50 for BuChE and AChE of the EtOAc extract were found to be effective, with 15.41 ± 0.78 μg/mL and 7.67 ± 0.13 μg/mL, respectively. Compound 1 exhibited dual inhibition of 40.99 ± 1.99 μM (BuChE) and 46.83 ± 2.44 μM (AChE), while compounds 2 and 3 showed IC50 values above 200 μM. This study revealed that this plant shows a significant potential as anti-cholinesterase focusing on acetylcholinesterase (AchE) and butyrylcholinesterase (BuChE). This is the first report on Horsfieldia polyspherula and their biological activity.

Impact of Indole Inclusion in the Design of Multi-Tactical Metal-Binding Tetra-Aza Macrocycles that Target the Molecular Features of Neurodegeneration.

Numerous small molecules have been studied for their ability to counteract oxidative stress, a key contributor to neurodegenerative diseases such as Alzheimer's. Despite these efforts, the pharmacological properties and structure-activity relationships of these compounds remain insufficiently understood, yet they are critical in evaluating a drug molecule's therapeutic potential. A modified tetra-aza macrocycle has demonstrated strong antioxidant activity through various mechanisms; however, its limited permeability presents challenges for advanced formulation studies. To enhance permeability while preserving the beneficial reactivity of the parent molecule, two synthetic modifications involving indole functionality were explored and compared to modifications using methyl groups alone. New synthetic strategies were developed to produce the indole-containing molecules, which were characterized by 1D/2D NMR techniques. Isoelectric points, metal binding, and radical scavenging activity were determined to validate that the reactivity of the parent molecules was retained. The permeability of all molecules explored was improved. Protection against oxidative stress through activation of the Nrf2 pathway was demonstrated for molecules containing indoles in cellular models by measuring ROS levels upon treatment and mRNA levels of HO-1 and Nrf2. In contrast, no protection or Nrf2 activation was observed with the methylation of the O- or N atom. These results suggest that while alkylation improves permeability overall, concomitant antioxidant protection and positive permeability are achieved with the indole congeners alone.

Green synthesis of carbon dots nanoparticles from edible swiftlet nest and evaluation of their antioxidant activity

Edible swiftlet nest (ESN) confers various health benefits to humans, including immune system enhancement, anti-inflammatory properties, bone strengthening, and antioxidative effect. ESN is notably rich in protein and minerals, with its proteins serving as non-enzymatic antioxidants capable of binding free radicals. However, the antioxidant capacity of ESN is comparatively lower than that of other free radical scavengers, such as carbon dots nanoparticles (CNPs). CNPs features charged ligands on their surface that act as electron donors for free radical binding. The presence of the carbon chain forming proteins in ESN suggests their potential as the primary source for CNPs formation. The enhancement of hydroxyl groups and delocalized electrons is imperative for enhancing the antioxidant activity of ESN. This study aims to enhance the antioxidant activity of ESN by converting it into CNPs nanoparticles. The results demonstrated the effective synthesis of CNPs from the ESN solution using microwave methods. This was evidenced by XRD patterns indicating CNPs formation, and an average particle size of 4.86 nm as indicated by TEM analysis. The optimal microwave heating duration of 30 min yielded CNPs with a prominent emission spectrum peak at 425 nm and significantly high intensity. Absorbance data revealed the presence of C=C bonds, consistent with aromatic CNPs bonds observed in FTIR studies. CNPs possessed hydroxyl and carboxyl linkages, suggesting their potential as antioxidants. The percent inhibition results indicated that CNPs exhibited a substantial percentage (62.5%) at a concentration of 50 mg ml−1. The free radical scavenging activity of the CNPs significantly elevated compared to ESN.