Oxygen Radical Absorbance Capacity Assay Research Articles

Antioxidant capacity of edaravone, quercetin, and myricetin involving probabilistic fluctuations using eosin-Y and eosin-B as fluorescent probes in the ORAC assay

The oxygen radical absorbance capacity (ORAC) assay measures the antioxidant activity of the antioxidants through competitive consumption of peroxyl radicals relative to a fluorescent probe. This study evaluated fluorescein (FLH), eosin Y, and eosin B in ORAC assays using quantum computations. In ORAC-FLH assays, trolox (TRO) and ascorbic acid (ASC) showed fluorescence decay kinetics with a lag time, blocking initial reactions in the quenching cascade. Eosins were more reactive towards peroxyl radicals, making TRO assessment infeasible in ORAC-eosin assays. Quercetin and myricetin exhibited sigmoidal curve drifts proportional to squared and 3/2-ordered incubation times, indicating probabilistic fluorescence decay. Edaravone (EDA) weakly inhibited initial reactions, with accelerated quenching over time. In ORAC-eosin assays, flavonoids and EDA showed indistinguishable behavior due to high eosin reactivity. ORAC-FLH did not significantly assess BHT, though a dose-dependent change in half-life was noted. This study suggests broad applications for ORAC-eosin assays and potential for future comparative research.

Synthesis, crystal structures, DFT calculations, and oxygen radical absorbance capacity of 5-arylidene-thiazolidine-2,4-dione derivatives

A new green methodology has been developed for the synthesis of a series of substituted 5-arylidene-2,4-thiazolidinediones (ATZDs) 3a-q through Knoevenagel condensation, using barium hydroxide as an efficient heterogeneous catalyst. All compounds were characterized by ¹H NMR, ¹³C NMR, and HRMS spectroscopy. Additionally, seven compounds were analyzed by X-ray diffraction (XRD). Furthermore, some selected TZD derivatives were screened for their antioxidant activity using oxygen radical absorbance capacity (ORAC) assays. The results showed that five compounds exhibited excellent antioxidant properties, with ORAC values ranging from 4.73 TE to 6.31 TE, surpassing the reference antioxidants ferulic acid (3.70 TE) and melatonin (2.45 TE). Computational investigations based on the DFT method revealed that these compounds exert their antioxidant activity primarily through the HAT mechanism, preferentially from the OH bond rather than the NH bond. This study highlights the advantages of this methodology, providing products of high purity, with good yields and short reaction times, and proposes 5-arylidene-thiazolidine-2,4-dione derivatives as promising antioxidants.

Bioprospecting of novel and biologically active compounds and enzymes from a new fungal biobank for industrial biotechnology

Here, we present methods for screening any newly isolated microbial biobank for enzymes, antioxidants, and additional secondary metabolites. Bioactive compounds and enzymes produced by fungi have many applications in industry as valuable leads for pharmaceuticals, nutraceuticals, and potential strains for industrial biotechnology. In this study, fungi collected from Irish habitats were purified and identified by sequencing Internal Transcribed Spacer (ITS) ribosomal DNA regions. Reducing sugars released because of enzyme hydrolysis was used to estimate the relative enzyme activity for carboxymethyl cellulase, pectinase, β-xylanase, arabinoxylanase, mannanase, and galacto-mannanase in the fungal extracts and was normalized against the crude protein content to express relative enzyme activity/milligram. The best enzyme producers were as follows: F1 Clonostachys rosea demonstrated 351.63 U/mg β-xylanase and 645.50 U/mg arabinoxylanase activity; F2 Penicillium expansum had 25 U/mg cellulase and 112.5 U/mg pectinase activity; F3 Fusarium avenaceum had 139.36 U/mg arabinoxylanase, 52.33 U/mg galacto-mannanase, and 45 U/mg mannanase activity; and F9 Trichoderma koningii had 372.15 U/mg β-xylanase and 655.18 U/mg arabinoxylanase activity. In addition to enzyme activity, these strains also exhibited antioxidant activity when tested in Oxygen radical absorbance capacity (ORAC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric ion reducing antioxidant power (FRAP) assays, with activity expressed as μmol Trolox equivalents (TE) per gram of dried fungal extract. In results from the ORAC assay, F1 C. rosea reported 655,669 µmol TE/g; F2 P. expansum had 636,889 µmol TE/g; and F3 F. avenaceum had 4,488,035 µmol TE/g. High DPPH activity was observed for F1 C. rosea at 12,572 µmol TE/g, F3 F. avenaceum at 22,646 µmol TE/g, and F9 T. koningii at 22,558 µmol TE/g. F1 C. rosea, F3: F. avenaceum, and F9 T. koningii also reported high FRAP activity at 36,019 µmol TE/g, 69,325 µmol TE/g, and 25,812 µmol TE/g, respectively. In terms of secondary metabolites, the main compounds detected for the isolates were F1 C. rosea produced benzoic acid, 3-pyridinepropionic acid, and cyclo(-Gly-Phe); F2 P. expansum produced Cyclo(-Gly-Phe) and prenitremone A; F3 F. avenaceum produced cyclo(-Leu-Leu) and p-anisaldehyde; and F9 T. koningii produced cyclo(-Gly-Phe), canescin, citreoviridin X, and cyclopaldic acid. These selected isolates indicate that Irish fungi are a potential source of enzymes and novel biologically active compounds useful in industrial biotechnology and bioproduction supporting sustainability and responsible environmental management.

The combination of allantoin, bisabolol, D-panthenol and dipotassium glycyrrhizinate mitigates UVB-induced PGE2 synthesis by keratinocytes.

Erythema, characterized by the redness of the skin, is a common skin reaction triggered by various endogenous and exogenous factors. This response is often a result of the activation of underlying inflammatory mechanisms within the skin. The objective of this study is to investigate the potential benefits of applying a combination of skincare ingredients, namely allantoin, bisabolol, D-panthenol and dipotassium glycyrrhizinate (AB5D), in the modulation of inflammatory factors associated with erythema. Additionally, the study aims to elucidate the mechanisms by which these ingredients exert their combined actions to alleviate erythema-associated inflammation. Human epidermal keratinocytes were exposed to UVB and subsequently treated with AB5D. Transcriptomics profiling was performed to analyse the dose-response effect of AB5D treatment on keratinocytes. The quantitation of inflammatory mediators, including PGE2, IL-1α, IL-6, IL-8, IL-1RA and TNFα, was performed on cultured media. Additionally, the oxygen radical absorbance capacity (ORAC) assay was carried out to evaluate the total antioxidant capacity of both individual ingredients and the AB5D combination. To assess the in-vitro antioxidant effects of AB5D against UVB-induced oxidative stress in hTERT keratinocytes, real-time quantitation of mitochondrial superoxide was measured through live-cell imaging. The application of AB5D to UVB-exposed keratinocytes downregulated gene sets associated with inflammatory responses, highlighting the anti-inflammatory properties of AB5D. Specifically, AB5D effectively reduced the production of PGE2, leading to the downregulation of inflammatory cytokines. Moreover, our findings indicate that AB5D exhibits antioxidative capabilities, functioning as both an antioxidant agent and a regulator of antioxidant enzyme expression to counteract the detrimental effects of cellular oxidative stress. We demonstrated that AB5D can reduce UVB-induced PGE2, IL-1α, IL-6, IL-8, IL-1RA and TNFα as well as mitochondrial superoxide. These findings suggest that AB5D may alleviate erythema by modulating inflammation via PGE2 and through antioxidation mechanisms.

Chemical profile and biological activities of Lysiphyllum binatum (Blanco) de Wit.

Lysiphyllum binatum (Blanco) de Wit in the Fabaceae family, despite its traditional medicinal uses, has not been the subject of prior scientific inquiry into its chemical and biological profile. The dichloromethane and MeOH extracts of its roots exhibited notably similar antioxidant activity, while the dichloromethane extract of the vine stems showed aromatase inhibition. This study aimed to identify the bioactive components responsible for these activities. Chemical investigation of the roots led to the isolation of six new metabolites, named lysiphans A-F (1-6), along with eight known compounds (7-14). The vine stem yielded lysiphan C (3) and compound 7, as well as five known isolates (15-19). The structures of these metabolites were determined through NMR spectral analysis, HRESIMS, quantum chemical calculations of NMR and ECD spectra, and Mosher's modifications to establish their absolute configurations. The biogenetic relationships between the new compounds were proposed. Several of the isolates were evaluated for their antioxidant, anti-aromatase, and cytotoxic properties. Lysiphan B (2) exhibited significant antioxidant activity, with an IC50 value of 28.8 ± 0.4μM in the diphenyl picrylhydrazyl radical (DPPH) assay, 3.5 ± 0.2μM in the xanthine/xanthine oxidase (XXO) assay, and 1.5 ± 0.0 ORAC units in oxygen radical absorbance capacity (ORAC) assay. Additionally, compounds 12, 13, and 16 exhibited very strong aromatase inhibitory activity with IC50 values of 0.3 ± 0.2, 4.7 ± 0.1, and 0.9 ± 0.2µM, respectively. Compound 16 also demonstrated strong ORAC activity of 1.9 ± 0.1 ORAC units.

Determination of antioxidant capacity and phenolic content of haskap berries (Lonicera caerulea L.) by attenuated total reflectance-Fourier transformed-infrared spectroscopy

The total phenolic content (TPC) and antioxidant capacity (TAC) of haskap berries cultivated in various locations across Alberta were analyzed using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The Folin–Ciocalteu assay was used to determine TPC, while TAC was quantified by 2,2-diphenyl-1-picrylhydrazl radicals (DPPH) assay and oxygen radical absorbance capacity (ORAC) assay. Three tenfold cross-validated partial least-squares regression (PLSR) models and three fivefold cross-validated deep learning models were developed separately based on FT-IR spectra collected from 22 haskap berry samples and their corresponding reference values determined through Folin-Ciocalteu, DPPH, and ORAC assays. The deep learning models (R2 = 0.95, 0.93, and 0.90 for Folin-Ciocalteu, DPPH, and ORAC assays, respectively) demonstrated better prediction capability compared to the PLSR models (R2 = 0.74, 0.72, and 0.66 for Folin-Ciocalteu, DPPH, and ORAC assays, respectively). In addition, PLS loading plots indicated that phenolic contents and polysaccharides in haskap berries could contribute to their antioxidant capacity. Using ATR-FTIR to estimate the TPC and TAC of fruits offers a rapid alternative to the conventional chemical assays.

Phytochemical Characterization of the Aerial Parts of Teucrium nuchense K. Koch: An Endemic Species of Caucasian Flora

Background: The genus Teucrium L. is frequently employed in traditional medicine, primarily for addressing disorders of the digestive and respiratory systems. Biological investigations focused on essential oils have substantiated their antibacterial, antioxidant, anti-tumor, anti-diabetic, and anti-rheumatic properties. Objective: The aim of the study was to assess the chemical composition and biological activities of the aerial parts of the endemic species Teucrium nuchense K. Koch. Methods: The chemical composition of the essential oil was analyzed using gas chromatography-mass spectrometry (GC-MS). The antioxidant activity was evaluated through the Oxygen Radical Absorbance Capacity (ORAC) assay and tested on normal skin fibroblasts (WS-1). Additionally, the antiinflammatory efficacy was assessed by monitoring nitric oxide production. The total phenolic content in the aqueous, methanolic, and chloroformic extracts was quantified using the Folin-Ciocalteu reagent. Individual compounds were isolated using preparative high-performance liquid chromatography. Their identification was accomplished using high-resolution mass spectrometry (HRMS) with an ESI-Q-TOF detector in conjunction with nuclear magnetic resonance (NMR) spectroscopy. Results: The essential oil yield was 0.32 ml/kg. Caryophyllene oxide, constituting 15.19 %, and 1- octen-3-ol, constituting 8.75%, emerged as the primary components in the essential oil. Oxygenated sesquiterpenes dominated the terpenic compounds, representing 25.1 % of the essential oil. The aqueous and methanolic extracts displayed a notable phenolic content, with percentages of 27 ± 2 % and 35 ± 0.1 %, respectively. Both the aqueous and methanolic extracts demonstrated robust antioxidant activity in the ORAC test and in vitro assessments using WS-1 cells. The methanolic extract, at a concentration of 160 μg/ml, inhibited NO formation by 90 %, without toxicity in RAW 264.7. Individual compounds, teucrioside from the phenylethanoid glycoside class, two neo-clerodane diterpenes, teucrin A, and 6-alpha-hydroxyteuscordine, were isolated. Conclusion: The essential oil extracted from the aerial parts of Teucrium nuchense is characterized by the presence of caryophyllene oxide and 1-octen-3-ol. The methanolic extract exhibits notable antioxidant as well as anti-inflammatory properties, whereas the aqueous extract demonstrates high antioxidant activity. Additionally, three compounds of teucrioside, teucrin A, and 6-α- hydroxyteuscordine have been isolated and characterized.

Identification and quantification of the antioxidants in Ginkgo biloba leaf.

The antioxidant activity of Ginkgo biloba leaf (GBL) extract is closely related to its efficacy against various diseases; however, the antioxidant activities of the specific constituents of GBL remain unclear. In this study, 194 GBL constituents were identified using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry, including 97 flavonoids, 37 terpenoids, 29 lignans, 19 carboxylic acids, 5 alkylphenolic acids, 5 alkylphenols, and 2 other compounds. The cleavage rules of the main constituents of GBL were dissected in detail. The 36 GBL constituents with high antioxidant activity were subsequently discovered using the oxygen radical absorbance capacity assay, including 30 flavonoids and six carboxylic acids. Finally, an HPLC analysis method was established to determine the content of the nine major antioxidants in the three batches of GBL. Among them, kaempferol 3-O-β-D-(6″-p-coumaroyl) glucopyranosyl-(1-2)-α-L-rhamnopyranoside, kaempferol-3-O-rutinoside, and rutin exhibited high antioxidant activity and were found in significant amounts in GBL, with concentrations greater than 0.7mg/g. These results provide an important reference for the development of pharmaceuticals and health products containing GBL.

Chemical profile, antioxidant and anti-Alzheimer activity of leaves and flowers of Markhamia lutea cultivated in Egypt: in vitro and in silico studies

BackgroundNowadays Alzheimer’s disease and its treatment methods are global concerns. Patients with this disease have poor prognosis and need supportive treatment. The antioxidant activity, anti-acetylcholinesterase (anti-AChE), anti-butyryl cholinesterase (anti-BChE) and Aβ-amyloid-42 inhibition activities of the ethanolic extracts of both leaves and flowers (LEE and FEE) of Markhamia lutea were assessed. The antioxidant activity of LEE and FEE was evaluated using 2,2-diphenyl-1-picryl-hydrazyl-hydrate, oxygen radical absorbance capacity and ferrozine iron metal chelation assays. Additionally, their total flavonoids and total phenolics were determined. The phytochemicals of LEE were analysed using LC–MS/Q-TOF in both positive and negative modes. Also, molecular docking was done for phytochemicals identified in LEE.ResultLEE exhibited higher antioxidant and anti-Alzheimer activities in all techniques due to its high flavonoids content. LEE showed better activity than donepezil in case of anti-butyryl cholinesterase than both donepezil and rivastigmine in case of Aβ-amyloid-42 inhibition. A total of 62 compounds were tentatively identified using Ultra-performance Liquid Chromatography-Electrospray Ionization-Quadrupole Time-of-Flight Mass Spectrometry (UHPLC–ESI–TOF–MS), viz. 35 flavonoids, 11 phenolic acids, 2 terpenoids, 2 phenylpropanoids derivatives, 7 polyphenols, 3 coumarins and 2 organic acids. The molecular docking of some constituents showed that isorhamnetin-O-rutinoside, sissotrin, 3,5,7-trihydroxy-4'-methoxyflavone (diosmetin), rosmarinic acid, kaempferol hexoside, kampferol-7-neohesperoside, acacetin, taxifolin and apigenin-O-hexoside exert a promising activity as anti-Alzheimer drugs.ConclusionThe LEE of Markhamia lutea contains secondary metabolites that is promising to act as natural antioxidants, acetylcholinesterase, butyryl cholinesterase and Aβ-amyloid-42 inhibition inhibitors, which can aid in the treatment of Alzheimer’s.Graphical

Green synthesis of silver nanoparticles using food supplement from Avena sativa L., and their antioxidant, antiglycation, and anti-aging activities: In vitro and in silico studies

Food supplement of Avena sativa L. dry extract (AsDE) is produced with green leaves of wild oats and it is commonly used in patients with cognitive disorders and muscle deficits. These symptoms and pathologies can be promoted and/or aggravated by oxidative stress and protein glycation. In order to prevent or treat these disorders, new formulations that could enhance and benefit AsDE have been developed and the formation of metallic nanoparticles by green synthesis has shown to be an alternative. Thus, this study aimed to prepare silver nanoparticles (AgNPs) by green synthesis using AsDE and characterize these AgNPs. Besides, it aimed to evaluate in vitro antioxidant and antiglycation activities of AsDE and AgNPS, and analyze in vitro and in silico inhibitory action on aging enzymes (collagenase, elastase, and tyrosinase). UV–visible spectroscopy, Zeta potential and scanning transmission electron microscopy were used to characterize AgNPs. Antioxidant activity was determined by DPPH free radical scavenging, ferric ion reducing power (FRAP), lipid peroxidation inhibition, ABTS radical scavenging, and oxygen radical absorption capacity (ORAC). Molecular docking analyses were performed to evaluate interactions between the major compounds of AsDE and aging enzymes or DNA. Antioxidant tests demonstrated antioxidant activity of 19.67 % for AsDE and 42.98 % for AgNPs in DPPH test; and 115.67 µM Trolox Equivalent (TE)/g for AsDE and 554.33 µM TE/g for AgNPs in FRAP test. In addition, AsDE and AgNPs inhibited 25.40 % and 11.33 % of lipid peroxidation, respectively, and presented 255.22 µM TE/g for AsDE and 317.44 µM TE/g for AgNPs in ABTS test. AsDE and AgNPs exhibited antioxidant potential observed in ORAC assay. In addition, AsDE presented inhibitory action on collagenase, elastase and tyrosinase activities (78.23 %, 68.14 % and 62.27 % inhibition, respectively). Antiglycation tests demonstrated that bovine serum albumin exposed to ribose and treated with AsDE at 0.5 mg/mL exhibited the highest percentage of free amino groups (45.21 %), while samples treated with AgNPs showed 35.41 % free amino groups. On the other hand, AgNPs exhibited the highest percentage of inhibition of advanced glycation end-products formation (85.75 %), which did not differ from aminoguanidine, a known antiglycation agent. Besides, relative electrophoretic mobility assay demonstrated that samples treated with AsDE at 0.1 mg/mL or AgNPs showed antiglycation activity comparable to aminoguanidine. The in silico assays showed interactions between the major compounds of AsDE and aging enzymes or DNA. Therefore, results represent an important indicator for the development and discovery of new nanostructured pharmaceutical and cosmetic formulations using plants and their bioactive compounds.

Antioxidant capacity and peptidomic analysis of in vitro digested Camelina sativa L. Crantz and Cynara cardunculus co-products

In recent decades, the food system has been faced with the significant problem of increasing food waste. Therefore, the feed industry, supported by scientific research, is attempting to valorise the use of discarded biomass as co-products for the livestock sector, in line with EU objectives. In parallel, the search for functional products that can ensure animal health and performances is a common fundamental goal for both animal husbandry and feeding. In this context, camelina cake (CAMC), cardoon cake (CC) and cardoon meal (CM), due valuable nutritional profile, represent prospective alternatives. Therefore, the aim of this work was to investigate the antioxidant activity of CAMC, CC and CM following in vitro digestion using 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), Ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays. Total phenolic content (TPC) and angiotensin converting enzyme (ACE) inhibitory activity, actively involved in modulating antioxidant properties, were also studied. Further, a peptidomic analysis was adopted to substantiate the presence of bioactive peptides after in vitro digestion. The results obtained confirmed an interesting nutritional profile of CAMC, CC and CM and relevant antioxidant and ACE inhibitory activities. In particular, considering antioxidant profile, CM and CC revealed a significantly higher (10969.80 ± 18.93 mg TE/100 g and 10451.40 ± 149.17 mg TE/100 g, respectively; p < 0.05) ABTS value than CAMC (9511.18 ± 315.29 mg TE/100 g); a trend also confirmed with the FRAP assay (306.74 ± 5.68 mg FeSO4/100 g; 272.84 ± 11.02 mg FeSO4/100 g; 103.84 ± 3.27 mg FeSO4/100 g, for CC, CM and CAMC, respectively). Similar results were obtained for TPC, demonstrating the involvement of phenols in modulating antioxidant activity. Finally, CAMC was found to have a higher ACE inhibitory activity (40.34 ± 10.11%) than the other matrices. Furthermore, potentially bioactive peptides associated with ACE inhibitory, anti-hypertensive, anti-cancer, antimicrobial, antiviral, antithrombotic, DPP-IV inhibitory and PEP-inhibitory activities were identified in CAMC. This profile was broader than that of CC and CM. The presence of such peptides corroborates the antioxidant and ACE profile of the sample. Although the data obtained report the important antioxidant profile of CAMC, CC, and CM and support their possible use, future investigations, particularly in vivo trials will be critical to evaluate and further investigate their effects on the health and performance of farm animals.

Microwave-assisted extraction of mucilage from juá: Characterization and antioxidant activity.

Microwave-assisted extraction of mucilage from juá was investigated using response surface methodology. The optimal conditions for extraction were a power of 300W, an extraction time of 240s, a pH of 8.0, and a water/sample ratio of 1/6, which achieved a 26.43% yield. The monosaccharide composition and antioxidant activity of the mucilage from juá fruits from different regions of Caatinga were investigated. The fruits from Agreste Paraibano showed the highest mucilage extraction yield (18.64%) compared to that of fruits from Mata Paraibana (MP) (12.37%), Borborema (BB) (11.47%), and Sertão Paraibano (8.31%) (p<0.05). Glucose (32.8%-50.8%) and arabinose (19.3%-32.9%) were the main monosaccharides found in juá mucilage. The mucilage from fruits in the MP presented the highest antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl and oxygen radical absorbance capacity assays. Our results demonstrated the potential for the future exploration and application of juá mucilage in the food industry. PRACTICAL APPLICATION: Juá (Ziziphus joazeiro Mart.) mucilage contains phenolic compounds and antioxidant activity, and its extraction by MAE is efficient, as it contributed to a higher yield.

Flow-based bioconjugation of coumarin phosphatidylethanolamine probes: Optimised synthesis and membrane molecular dynamics studies

A series of phosphatidylethanolamine fluorescent probes head-labelled with 3-carboxycoumarin was prepared by an improved bioconjugation approach through continuous flow synthesis. The established procedure, supported by a design of experiment (DoE) set-up, resulted in a significant reduction in the reaction time compared to the conventional batch method, in addition to a minor yield increase. The characterization of these probes was enhanced by an in-depth molecular dynamics (MD) study of the behaviour of a representative probe of this family, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine labelled with 3-carboxycoumarin (POPE-COUM), in bilayers of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine (SLPC) 2:1, mimicking the composition of the egg yolk lecithin membranes recently used experimentally by our group to study POPE-COUM as a biomarker of the oxidation state and integrity of large unilamellar vesicles (LUVs). The MD simulations revealed that the coumarin group is oriented towards the bilayer interior, leading to a relatively internal location, in agreement with what is observed in the nitrobenzoxadiazole fluorophore of commercial head-labelled NBD-PE probes. This behaviour is consistent with the previously stated hypothesis that POPE-COUM is entirely located within the LUVs structure. Hence, the delay on the oxidation of the probe in the oxygen radical absorbance capacity (ORAC) assays performed is related with the inaccessibility of the probe until alteration of the LUV structure occurs. Furthermore, our simulations show that POPE-COUM exerts very little global and local perturbation on the host bilayer, as evaluated by key properties of the unlabelled lipids. Together, our findings establish PE-COUM as suitable fluorescent lipid analogue probes.

Use of Botanical Ingredients: Nice Opportunities to Avoid Premature Oxidation of NABLABs by Increasing Their ORAC Values Strongly Impacted by Dealcoholization or Pasteurization

Even when fresh, non-alcoholic, and low-alcoholic beers (NABLABs) exhibit significant staling defects due to premature oxidation. In this study, the antioxidant power of eleven fresh commercial NABLABs was assessed by means of three different assays: the oxygen radical absorbance capacity (ORAC), the linoleic acid-induced oxidation (TINH), and the indicator time test (ITT). Only the first two assays, both involving radicalar degradations initiated by AAPH, were found to correlate with each other. NABLABs displayed lower ORAC values than conventional beers (on average, 6127 μmol eq. Trolox/L), except for three samples made with special-colored malts or dry-hopped. Dealcoholization was the step with the greatest impact on the ORAC value (up to a 95% loss) and on flavan-3-ols, sotolon, and polyfunctional thiols, while pasteurization strongly affected color, TBA, and Strecker aldehydes. ORAC assays applied to hop, alternative cereals, and various botanical ingredients indicated that mashing with red sorghum, dry hopping/spicing, and wood maturation could bring the antioxidant power of a NABLAB close to those of conventional beers. With an ORAC value not reached by any other tested botanical ingredient (5234 µmol eq. Trolox/g), African Vernonia amygdalina leaves (traditionally used for Rwandan Ikigage beers) emerged here as the best candidate.

Bay Laurel of Northern Morocco: A Comprehensive Analysis of Its Phytochemical Profile, Mineralogical Composition, and Antioxidant Potential

Laurus nobilis, sometimes referred to as laurel, has been used for medicinal and culinary purposes for a very long time. The main subjects of this study are the phytochemical composition, mineralogical profile, and potential antioxidant properties of Laurus nobilis in Tangier, Northern Morocco. For phytochemical analysis of methanolic extracts, high-performance liquid chromatography (HPLC-UV-MS) was used, and Fourier transformation infrared spectroscopy (FT-IR) was used to identify each individual component. Minerals were studied by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and wavelength dispersive X-ray fluorescence (WD-XRF). Total tannin, flavonoid, and phenolic amounts were quantified using aqueous and methanolic extracts. The antioxidant properties were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) assays. Research has revealed a complex array of phytochemicals, including tannins, flavonoids, and phenolic acids. Mineral analysis has revealed the existence of vital components that are beneficial to health. Comparing the methanolic extract to the water extract, it demonstrated higher levels of phenols, flavonoids, and tannins as well as stronger antioxidant activity, indicating greater health benefits. This comprehensive study highlights the importance of Laurus nobilis from Northern Morocco as a reliable botanic resource with potential pharmaceutical, nutritional, and cosmetic uses.

Development of Thai-taste maoberry (Antidesma bunius (L.) Spreng.) vegan sorbet from fruit of different maturities with added inulin: Physicochemical and antioxidant properties

Maoberry (Antidesma bunius (L.) Spreng.) is a tropical fruit popularly consumed with Thai-style chili sugar flakes containing sugar, salt, and chili to enhance its flavour, and reduce its sour and bitter taste. The present work aimed to develop a Thai-taste maoberry vegan sorbet using maoberries at different stages of maturity with added inulin, and to evaluate its physicochemical properties, total phenolic and total flavonoid contents, and antioxidant capacities. Results showed that the three different stages of maoberry maturity caused significant changes on pH, total soluble solids, mixture viscosity, overrun, and firmness of the sorbets. The antioxidant activities assessed using ferric-reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 3-ethylbenzthiazoline-6-sulphonic acid (ABTS), radical cation decolourisation, and oxygen radical absorbance capacity (ORAC) assays indicated similar trends. Black maoberry sorbet exhibited total flavonoid contents and FRAP values almost twice those of red maoberry sorbet. However, adding inulin significantly increased the melting rate of the product (p &lt; 0.05), but improved the mixture viscosity and overrun, which are important attributes of sorbets.

Evidence of the Relationship between the Oxygen Radical Absorbance Capacity (ORAC) and the Potential Exposure of White Wines to Atypical Aging (ATA).

Atypical aging (ATA) is a well-known wine defect that leads to unacceptable off-odors of wet mop, soap, waxy, furniture varnish, and dish rag. The main compound that is responsible for these undesired scents, 2-aminoacetophenone (AAP), results from the oxidative degradation of 3-indole acetic acid. This study aimed to investigate different technological factors for a possible effect on the oxygen radical absorption capacity (ORAC) and ATA development in white wine. Oxygenation during fermentation did not result in a significant effect on the development of ORAC or ATA development. Instead, the addition of ascorbic acid after vinification led to increased ORAC and decreased AAP formation. The first evidence of a tendency toward a correlation between ORAC and potential ATA development was found, with r = 0.365. This study showed the potential of the ORAC assay for an early assessment of the possible formation of ATA during wine storage.

Influence of Nutrient Deprivation on the Antioxidant Capacity and Chemical Profile of Two Diatoms from Genus Chaetoceros.

The limited availability of phosphate, nitrogen and silicon in the growth media affects the growth, cellular processes, and metabolism of diatoms. Silicon deficiency primarily affects diatom morphology, while phosphate deficiency reduces the production of nucleic acids and phospholipids. Differences in pigment and protein composition are mainly due to nitrogen deficiency. In this study, Chaetoceros socialis and Chaetoceros costatus were cultured under phosphate, nitrogen, and silicon deprivation conditions. The diatom biomass was collected during the stationary growth phase and extracted with 70% ethanol under ultrasonication. The chemical profiles of the extracts were analyzed by high-performance liquid chromatography with high-resolution mass spectrometry with electrospray ionisation (UHPLC-ESI-HRMS), while the antioxidant capacity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbance capacity (ORAC) assays. Pigments, fatty acids, sterols, and derivatives were detected in both species. The total phenolic content in the extracts ranged from 46.25 ± 1.08 to 89.38 ± 6.21 mg of gallic acid equivalent (GAE)/L and from 29.58 ± 1.08 to 54.17 ± 1.18 mg GAE/L. for C. costatus and C. socialis, respectively. Antioxidant activity was higher in C. costatus extracts, especially those obtained from nitrogen-deprived media. The results of this study contribute to the existing knowledge and the ongoing efforts to overcome application and commercialization barriers of microalgae for wide-ranging potential in different industries.

A Kinetic Approach to Oxygen Radical Absorbance Capacity (ORAC): Restoring Order to the Antioxidant Activity of Hydroxycinnamic Acids and Fruit Juices.

This study introduces a kinetic model that significantly improves the interpretation of the oxygen radical absorbance capacity (ORAC) assay. Our model accurately simulates and fits the bleaching kinetics of fluorescein in the presence of various antioxidants, achieving high correlation values (R2 > 0.99) with the experimental data. The fit to the experimental data is achieved by optimizing two rate constants, k5 and k6. The k5 value reflects the reactivity of antioxidants toward scavenging peroxyl radicals, whereas k6 measures the ability of antioxidants to regenerate oxidized fluorescein. These parameters (1) allow the detailed classification of cinnamic acids based on their structure-activity relationships, (2) provide insights into the interaction of alkoxyl radicals with fluorescein, and (3) account for the regeneration of fluorescein radicals by antioxidants. The application of the model to different antioxidants and fruit extracts reveals significant deviations from the results of traditional ORAC tests based on the area under the curve (AUC) approach. For example, lemon juice, rich in 'fast' antioxidants such as ascorbic acid, shows a high k5 value, in contrast to its low AUC values. This finding underscores the limitations of the AUC approach and highlights the advantages of our kinetic model in understanding antioxidative dynamics in food systems. This study presents a comprehensive, quantitative, mechanism-oriented approach to assessing antioxidant reactivity, demonstrating a significant improvement in ORAC assay applications.

Chemical and biological characterization of Melaleuca subulata (Cheel) Craven leaves’ volatile constituents supported by chemometric analysis and molecular docking

BackgroundThe genus Melaleuca (Myrtaceae) comprises dozens of essential oil (EO)-rich species that are appreciated worldwide for their various medicinal values. Additionally, they are renowned in traditional medicine for their antimicrobial, antifungal, and other skin-related activities. The current study investigated the chemical profile and skin-related activities of volatile constituents derived from M. subulata (Cheel) Craven (Synonym Callistemon subulatus) leaves cultivated in Egypt for the first time.MethodsThe volatile components were extracted using hydrodistillation (HD), headspace (HS), and supercritical fluid (SF). GC/MS and Kovat’s retention indices were implemented to identify the volatile compounds, while the variations among the components were assessed using Principal Component Analysis and Hierarchical Cluster Analysis. The radical scavenging activity was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC) and β-carotene assays. Moreover, the anti-aging effect was evaluated using anti-elastase, and anti-collagenase, while the antimicrobial potential was deduced from the agar diffusion and broth microdilution assays. Lastly, the molecular docking study was executed using C-docker protocol in Discovery Studio 4.5 to rationalize the binding affinity with targeted enzymes.ResultsThe SF extraction approach offered the highest EO yield, being 0.75%. According to the GC/MS analysis, monoterpene hydrocarbons were the most abundant volatile class in the HD oil sample (54.95%), with α-pinene being the most copious component (35.17%). On the contrary, the HS and SF volatile constituents were pioneered with oxygenated monoterpenes (72.01 and 36.41%) with eucalyptol and isopulegone being the most recognized components, representing 67.75 and 23.46%, respectively. The chemometric analysis showed segregate clustering of the three extraction methods with α-pinene, eucalyptol, and isopulegone serving as the main discriminating phytomarkers. Concerning the bioactivity context, both SF and HD-EOs exhibited antioxidant effects in terms of ORAC and β-carotene bleaching. The HD-EO displayed potent anti-tyrosinase activity, whereas the SF-EO exhibited significant anti-elastase properties. Moreover, SF-EO shows selective activity against gram-positive skin pathogens, especially S. aureus. Ultimately, molecular docking revealed binding scores for the volatile constituents; analogous to those of the docked reference drugs.ConclusionsM. subulata leaves constitute bioactive volatile components that may be indorsed as bioactive hits for managing skin aging and infection, though further in vivo studies are recommended.