Azino-bis(3-ethylbenzothiazoline)-6-sulfonate Research Articles

Variations in Proline Content, Polyamine Profiles, and Antioxidant Capacities among Different Provenances of European Beech (Fagus sylvatica L.).

International provenance trials are a hot topic in forestry, and in light of climate change, the search for more resilient beech provenances and their assisted migration is one of the challenges of climate-smart forestry. The main aim of the study was to determine intraspecific variability in European beech (Fagus sylvatica L.) among 11 beech provenances according to total antioxidant capacities estimated by various assays, such as DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid), FRAP (ferric reducing antioxidant power) assay, and radical scavenging capacity against nitric oxide (RSC-NO assays), as well as osmolyte content, primarily individual polyamines (putrescine, spermidine, and spermine), and free proline content. Polyamine amounts were quantified by using HPLC coupled with fluorescent detection after dansylation pretreatment. The highest values for radical scavenger capacity assays (ABTS, DPPH, and FRAP) were measured in the German provenances DE47 and DE49. Also, the highest NO inhibition capacity was found in the provenance DE49, while the highest content of proline (PRO), total phenolic content (TPC), and total flavonoid content (TFC) was recorded in DE47. The Austrian AT56 and German provenance DE49 were most abundant in total polyamines. This research underlines the importance of the application of common antioxidant assays as well as osmolyte quantification as a criterion for the selection of climate-ready beech provenances for sustainable forest management.

The antimicrobial activity of Hypericum perforatum L. flower extract against food pathogens and its non-enzymatic antioxidant activity

Foodborne pathogens pose a significant hazard to food safety. Most cases of foodborne illnesses are caused by bacterial pathogens that have infiltrated the food chain at some point, from farm to kitchen. According to the World Health Organization (WHO), approximately one-third of individuals in developed countries are affected by foodborne pathogens each year. Although there are studies on Hypericum perforatum L. in the literature, research in Turkey remains limited. Therefore, the aim is to contribute to the literature by studying H. perforatum samples from the Yaraş region of Muğla province in Turkey. This study specifically aims to investigate the antimicrobial activities against foodborne pathogens and the antioxidant activity of H. perforatum in Muğla. The in vitro antimicrobial activities of flower components from plants grown in Mugla were evaluated using the disc diffusion method and broth dilution test. Additionally, the extracts underwent ABTS (2,2'-azinobis-(3-ethyl benzothiazoline-6-sulfonic acid)) free-radical testing to evaluate their antioxidant activity. The extract exhibited a maximum inhibition zone of 16 mm against Staphylococcus aureus and Listeria monocytogenes. Notably, S. aureus and L. monocytogenes demonstrated the lowest sensitivity to H. perforatum methanol extract (1625 µg/mL). The methanol extract displayed moderate antioxidant activity, with a 53% ABTS radical scavenging capacity. Consequently, the extracts of H. perforatum exhibited both antimicrobial and antioxidant potential.

Enhanced chlorination of diclofenac using ABTS as electron shuttle: Performance, mechanism and applicability

Chlorination, one of the most common oxidation strategies, performed limited degradation capacity towards many emerging organic contaminants under neutral pH conditions. In this study, 2,2′-azinobis(3-ethylbenzothiazoline)-6-sulfonate (ABTS) was discovered to possess an outstanding activation property towards free available chlorine (FAC) during the chlorination of diclofenac (DCF) among pH 6.0–9.5. ABTS radical (ABTS•+) primarily accounted for the elimination of DCF in the ABTS/FAC system, although hydroxyl radicals, reactive chlorine species, and singlet oxygen were also generated via the self-decomposition of FAC. ABTS acted as the electron shuttle to degrade DCF in the ABTS/FAC system, where ABTS was firstly oxidized by FAC to ABTS•+ via single electron transfer, and followed by the elimination of DCF with the generated ABTS•+. Eight DCF degradation intermediates were identified by LC/Q-TOF/MS, and four DCF degradation pathways were proposed. Real water bodies, humic acid, and the coexistent anions of Cl−, HCO3−, NO3−, and SO42− performed negligible influence on DCF removal in ABTS/FAC system. ABTS/FAC system was much superior to sole chlorination in terms of toxicity reduction and anti-interference capacity. Overall, this study innovatively introduced ABTS as the electron shuttle to enhance the oxidative capacity of FAC under neutral pH conditions and provided a new insight that the ABTS-like organic/synthetic components might play an important role in degrading emerging organic contaminants by chlorination in water treatment.

Determination of the antioxidant and enzyme-inhibiting activities and evaluation of selected terpenes' ADMET properties: in vitro and in silico approaches

The in vitro antioxidant capacity of eugenol, eucalyptol, linalool, and carvacrol was performed using six test systems: phosphomolybdenum, DPPH (2,2′-diphenyl-1-picrylhydrazyl radical), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate), CUPRAC (cupric ion reducing antioxidant capacity), FRAP (Ferric reducing ability of plasma), and metal chelating effect. Their inhibitory activities on cholinesterases, α-amylase, α-glucosidase, and tyrosinase were assessed as well. Molecular docking helped to explain the obtained outcomes while in silico ADMET (absorption, distribution, metabolism, excretion, and toxicity) prediction served for assessing the physicochemical and pharmacokinetic profiles. Our findings showed that the examined terpenes have promising antioxidative activity with eugenol and carvacrol displaying the highest efficiency. Linalool presented the highest anti-AChE and anti-tyrosinase activities (7.931 ± 0.034 mg GALAE/g and 58.707 ± 5.120 mg KAE/g, respectively). Eucalyptol exhibited the strongest anti-BChE activity (2.704 ± 0.025 mg GALAE/g), while carvacrol exhibited the highest rates for α-glucosidase and α-amylase inhibition (1.414 ± 0.042 and 1.023 ± 0.054 mM ACAE/g, respectively). Molecular docking revealed that all compounds interacted in varied ways with the five enzymes’ active sites. Excellent binding profiles and greatest inhibitory activity to AChE (−7.4 kcal/mol), α-glucosidase (−6.5 kcal/mol), and α-amylase (−6.5 kcal/mol) was attributed to carvacrol. As regards to tyrosinase, eugenol (−6.2 kcal/mol) was the potent one whereas carvacrol and eugenol (−6.5 kcal/mol for both) strongly interacted with BChE. Furthermore, in silico ADMET-related physicochemical and pharmacokinetic properties revealed good profiles. To sum up, here we demonstrate the powerful antioxidant potency and enzymatic inhibitory effects of the four terpenes which may enable the discovery of lead compounds that are extremely potent antioxidants and enzyme inhibitors.

A Comparative GC/MS Analysis of Citrus Essential Oils: Unveiling the Potential Benefits of Herb-Drug Interactions in Preventing Paracetamol-Induced Hepatotoxicity.

Our study aimed to test the potential of Citrus oils in protecting against paracetamol (PAR)-induced hepatotoxicity. The essential oils of Pineapple sweet orange (OO), Murcott mandarin (MO), Red grapefruit (GO), and Oval kumquat (KO) were investigated using gas chromatography coupled with mass spectrometry (GC/MS). Twenty-seven compounds were identified, with monoterpene hydrocarbons being abundant class. d-Limonene had the highest percentage (92.98 %, 92.82 %, 89.75 %, and 94.46 % in OO, MO, GO, and KO, respectively). Hierarchical cluster analysis (HCA) and principal components analysis (PCA) revealed that octanal, linalool, germacrene D, and d-limonene were the principal discriminatory metabolites that segregated the samples into three distinct clusters. In vitro antioxidant capacities were ranged from 1.2-12.27, 1.79-5.91, and 235.05-585.28 μM Trolox eq/mg oil for 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic (ABTS), ferric-reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC), respectively. In vivo, citrus oils exhibited a significant reduction in alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and nitric oxide (NO). Additionally, there was an increase in glutathione reductase (GSH), and the liver architecture was nearly normal. Molecular docking revealed that d-limonene exhibited a good inhibitory interaction with cytochrome P450 (CYP450) isoforms 1A2, 3A4, and 2E1, with binding energies of -6.17, -4.51, and -5.61 kcal/mol, respectively.

In vitro production of steroidal saponin, total phenols and antioxidant activity in callus suspension culture of Paris polyphylla Smith: an important Himalayan medicinal plant.

Paris polyphylla Smith (Melanthiaceae) family, which is native to the Himalayan region, has received a lot of attention recently due to its extensive history of usage in traditional medicine. The production of steroidal saponin from callus suspension cultures of P. polyphylla was observed in the current study. The current study attempted to develop a P. polyphylla plant callus suspension culture through optimization of cultivation technique for callus suspension, quantification of total phenolic components and estimation of the extract's antioxidant activity. A light-yellow callus was formed within six weeks of cultivating rhizomes on Murashige and Skoog (MS) media supplemented with Thidiazuron (TDZ). Furthermore, the effect of TDZ, Methyl Jasmonate (MeJA), and Yeast Extract (YE) on callus growth, steroidal saponin (dioscin and diosgenin), total phenolic content, total flavonoids, total tannin, and total antioxidant activity was also measured. The medium containing 0.5 μM TDZ depicted the maximum callus biomass (2.98 g fresh weight). Significantly high phenolic and tannin content was observed in the MS medium containing 50 μM MeJA, whereas, no significant increase was observed in total tannin production in any treatment. Three in vitro assays, DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis (3-ethylbenzothiazoline- 6-sulfonic acid)) and FRAP (ferric ion reducing antioxidant potential) and FC (Folin-Ciocalteu), were used to assess antioxidant potential of callus. Maximum antioxidant analysis reported in 1.0 μM TDZ (6.89 mM AAE/100 g) containing medium followed by 50 μM MeJA (6.44 mM AAE/100g). The HPLC analysis showed a high presence of dioscin and diosgenin (5.43% and 21.09%, respectively) compared to the wild sample (2.56% and 15.05%, respectively). According to the results, callus produced on media supplemented with 50 μM MeJA have significant phenolic contents and elevated antioxidant activity; nevertheless, callus growth was greater in the presence of 0.5 μM TDZ. The findings of the current study have commercial implications since greater biomass production will result in active phytochemicals that the pharmaceutical and nutraceutical sectors are in need desperately.

Comparison of Composition, Free-Radical-Scavenging Capacity, and Antibiosis of Fresh and Dry Leave Aqueous Extract from Michelia shiluensis.

Numerous plants of medicinal value grow on Hainan Island (China). Given the lack of knowledge on the phytochemical and pharmacological properties of Michelia shiluensis Chun and Y. F. Wu (M. shiluensis), the application of natural antioxidants and antimicrobials in the food industry has attracted increasing interest. This study aimed to compare the chemical composition, free-radical-scavenging capacity, and antibiosis of aqueous extracts of the fresh and dried leaves of M. shiluensis. The aqueous extract of the leaves of M. shiluensis was obtained using steam distillation, and its chemical components were separated and identified via gas chromatography-mass spectrometry (GC-MS). The free-radical-scavenging capacity and antibiosis were determined. Further, 28 and 20 compounds were isolated from the fresh leaf aqueous extract of M. shiluensis (MSFLAE) and dried leaf aqueous extract of M. shiluensis (MSDLAE), respectively. The free-radical-scavenging capacity of MSFLAE and MSDLAE was determined by the 2,2-diphenyl-1 picrylhydrazyl (DPPH) method, which was 43.43% and 38.74%, respectively. The scavenging capacity of MSFLAE and MSDLAE determined by the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonate (ABTS)) method was 46.90% and 25.99%, respectively. The iron ion reduction capacity of MSFLAE and MSDLAE was determined by the ferric-reducing antioxidant power (FRAP) method as 94.7 and 62.9 μmol Fe2⁺/L, respectively. This indicated that the two leaf aqueous extracts had a certain free-radical-scavenging capacity, and the capacity of MSFLAE was higher than that of MSDLAE. The antibiosis of the two leaf aqueous extracts on the three foodborne pathogenic bacteria was low, but the antimicrobial effects on Gram-positive bacteria were better than those on Gram-negative bacteria. The antibiosis of MSFLAE on Escherichia coli and Staphylococcus aureus was greater than that of MSDLAE. Finally, MSFLAE and MSDLAE both had certain free-radical-scavenging capacities and antibiosis, confirming that the use of this plant in the research and development of natural antioxidants and antibacterial agents was reasonable. Plant aqueous extracts are an essential source of related phytochemistry and have immense pharmacological potential.

Rapid spectrophotometric determination of peroxydisulfate in water via oxidative coloration of 2,2′azino-bis(3-ethylbenzothiazoline)-6-sulfonate (ABTS) using ferrous ion as catalyst

In this study, a rapid, sensitive and reliable spectrophotometric method for peroxydisulfate (PDS) determination in water was established. The proposed spectrophotometric method was based on the oxidation of 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) to form stable and green-colored ABTS radical (ABTS•+) by ferrous ion (Fe(II))-catalyzed PDS. The formed ABTS•+ performed well linear relationship with PDS concentration (R2 > 0.999) in the range of 0–60 μM at four wavelengths of 415, 650, 732, and 820 nm under optimized conditions. The proposed Fe(II)-ABTS spectrophotometric method was highly sensitive with the absorptivity of 3.595 × 104 M−1 cm−1, 1.530 × 104 M−1 cm−1, 1.945 × 104 M−1 cm−1 and 1.768 × 104 M−1 cm−1 at four detection peaks of 415, 650, 732 and 820 nm, respectively. Additionally, the proposed Fe(II)-ABTS spectrophotometric method possessed well anti-interference capacity to common natural water constituents and was reliable to determine PDS concentration in water. What’s more, the proposed Fe(II)-ABTS spectrophotometric method was successfully applied in monitoring the change of PDS concentration during the degradation of diclofenac in heat-activated PDS process. In a word, the proposed Fe(II)-ABTS spectrophotometric method could be employed as a promising approach for the rapid and accurate measurement of PDS in water, and this study provided a new perspective for the measurement of PDS by the visible spectrophotometry.

Effect of Marinating Temperature of Atlantic Herring on Meat Ripening, Peptide Fractions Proportion, and Antioxidant Activity of Meat and Brine

The temperature has a significant effect on cathepsin activity, but the effect of temperature on the ripening of marinades, and the formation of protein hydrolysis products, is less studied than other technological factors. The results of this study showed that herring marinated at 2 °C showed a higher mass yield, but lower non-protein nitrogen (NPN), peptides, and free amino acid fraction content, than after marinating at 7 and 12 °C. The higher temperature increased the free amino acid content the most, and decreased the hardness, as measured via sensory assessment, of the marinated meat. This was confirmed by the hardness measurement in the texture profile analysis. The highest activity of cathepsins D and B in the meat was found at 7 °C, while cathepsin L was found at 2 °C. Increasing the temperature by 10 °C increased the diffusion/loss of nitrogenous substances from the meat to the brine by 36%. The meat and brine showed high antioxidant activity, which depended on the marinating temperature, and originated mainly from the 5–10 or <5 kDa fraction. The meat had a higher ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonate) activity than the brine, opposite to the DPPH (2,2-diphenyl-1-picrylhydrazyl radical) activity, while the FRAP (Ferric Reducing Antioxidant Power) capacity was similar for meat and brine. The fractionation of the meat and brine extracts increased the antioxidant potential of FRAP and ABTS only for the brine. The most hydrophobic peptides were released during marinating at 7 °C. The meat and brine were dominated by 2–4 kDa peptides, followed by 4–6 and 0.5–2 kDa. The higher temperature favored a higher proportion of <4 kDa than >4 kDa peptides in the brine.

Alterations in the phytochemical composition and antioxidant activity of Ligustrum robustum according to continuous wet‐ and dry‐heat treatment

Small-leaved Kuding tea (SLKDT) obtained from Ligustrum robustum is a traditional tea substitute in southern China and has a range of physiological effects. However, the changes in its phytochemical composition after various heat treatments are not reported yet. Thus, the phytochemical composition and antioxidant activities of fresh leaves of SLKDT (LrF1) and SLKDT after high-temperature wet-heat treatment (LrF2) and wet- and dry-heat treatments (LrF3) were assessed using liquid chromatography-mass spectrometry, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities and lipid peroxidation inhibition activity of LrF1 and LrF3 were investigated. The results indicated that the phytochemical composition of LrF1, LrF2, and LrF3 was significantly different. Overall, 258 and 83 differential constituents, respectively, were obtained in LrF1 versus LrF2 and LrF2 versus LrF3. The differential constituents mainly included amino acids and their derivatives, nucleosides, flavonoids, terpenoids, simple phenylpropanoids, and coumarins. After heat treatment, SLKDT exhibited obvious changes in sensory characteristics and physiological properties, which may be related to the changes in the levels of amino acids, linalool, beta-geraniol, myricetin, naringin, fraxetin, and isoacteoside. Moreover, the antioxidant activities significantly changed after heat treatment of SLKDT. Overall, our study demonstrated that heat treatment can alter the phytochemical composition of SLKDT, thus affecting its sensory properties and physiological properties. PRACTICAL APPLICATION: This study preliminarily assessed the changes in the composition of small-leaved Kuding tea (SLKDT) after various heat treatments and revealed that the composition of SLKDT tea can be adjusted by various heat and temperature treatments.

Study of Essential Oil Isolated from Achiote (Bixa orellana) Leaves: Chemical Composition, Enantiomeric Distribution and Antimicrobial, Antioxidant and Anticholinesterase Activities.

Bixa orellana is a native and cultivated species of Ecuador commonly known as achiote (annatto), this species is very versatile with a wide variety of uses and applications of its leaves, fruits and seeds. In this study, the chemical composition, enantiomeric distribution and biological activity of essential oil isolated from the leaves of Bixa orellana were determined. Hydrodistillation was used to isolate the essential oil. Gas chromatography coupled with mass spectrometry was used to determine the qualitative composition, a gas chromatograph equipped with a flame ionization detector was used to determine quantitative composition and gas chromatography on an enantioselective column was used to determine enantiomeric distribution. Antibacterial activity was determined using the broth microdilution method, for which we used three Gram-positive cocci bacteria, a Gram-positive bacilli bacterium and three Gram-negative bacilli bacteria. 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic (ABTS) acid radical cation and 2,2-diphenyl-1-picrylhydryl (DPPH) free radical were used as reagents for determining the antioxidant activity of the essential oil. The spectrophotometric method was used to analyze acetylcholinesterase inhibitory effect of the essential oil. The yield of leaves in essential oil was 0.13 ± 0.01% (v/w). A total of 56 chemical compounds, which represent 99.25% of the total composition, were identified in the essential oil. Sesquiterpene hydrocarbons were the most representative group in number of compounds and relative abundance with 31 compounds and 69.06%, respectively. The principal constituents were found to germacrene D (17.87 ± 1.20%), bicyclogermacrene (14.27 ± 0.97%), caryophyllene < (E)- > (8.56 ± 1.24%) and pinene <α-> (6.34 ± 0.13%). Six pairs of enantiomers were identified in the essential oil of Bixa orellana. The essential oil presented strong activity against the Enterococcus faecium (ATCC 27270) with an MIC of 250 μg/mL and weak activity against Enterococcus faecalis (ATCC 19433) and Staphylococcus aureus (ATCC 25923) with an MIC of 1000 μg/mL. The antioxidant activity of the essential oil was strong according to ABTS methods with a SC50 of 61.49 ± 0.04 µg/mL and was moderate in DPPH with a SC50 of 224.24 ± 6,4 µg/mL. Additionally, the essential oil reported moderate anticholinesterase activity with an IC50 of 39.45 ± 1.06 µg/mL.

Capsaicin toxicity to the yeast Saccharomyces cerevisiae is not due to oxidative stress but to disruption of membrane structure

Capsaicin (CAP) is a common food constituent, conferring a pungent taste to red peppers of the genus Capsicum. It has bactericidal and fungicidal activity. The study was aimed to test the hypothesis of whether oxidative stress mediates the toxicity of CAP to the baker's yeast Saccharomyces cerevisiae as a model yeast. CAP showed good antioxidant properties (1.30 and 1.10 mol Trolox equivalents/mol in the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate (ABTS) radical scavenging assay and the Ferric Reducing Antioxidant Power assay, respectively). However, its autoxidation generated hydrogen peroxide. CAP inhibited the growth of S. cerevisiae at concentrations ≥100 μM. Yeast mutants deficient in superoxide dismutase 1 or catalase T were more sensitive to CAP than wild-type yeast. CAP did not augment the ROS level in yeast cells. Standard antioxidants (N-acetylcysteine and ascorbate) did not protect significantly against CAP-induced yeast growth inhibition. Thus, oxidative stress does not mediate the CAP's inhibition of yeast growth. CAP did not decrease mitochondrial membrane potential of the yeast but induced a concentration-dependent decrease in membrane fluidity. These results indicate that the disturbance of membrane properties is the apparent cause of CAP toxicity to the yeast.

Probiotic properties of Lactobacillus paraplantarum LS-5 and its effect on antioxidant activity of fermented sauerkraut

This study aimed to investigate the safety and probiotic properties of Lactobacillus paraplantarum LS-5 isolated from traditional northeastern sauerkraut, and to assess the antioxidant capacity of different solvent extracts (ethanol, water, and hot water) of L. paraplantarum LS-5-inoculated sauerkraut. L. paraplantarum LS-5 was shown to have various probiotic characteristics, such as good survival ability under artificial gastrointestinal conditions, antagonistic activity of various pathogens, non-biogenic amines, antibiotic susceptibility, and non-hemolytic. The 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonate (ABTS) radical scavenging activity of the L. paraplantarum LS-5-inoculated sauerkraut alcohol extract (71.13%) was significantly higher than water extract (59.59%) (p < 0.05). The ferric reducing antioxidant power (FRAP) of sauerkraut alcohol extract (614.93 Trolox μmol L−1) exhibited a slightly stronger ability compared to water extract (388.53 Trolox μmol L−1) and the heated sauerkraut water extract (383.20 Trolox μmol L−1) at extract concentrations of 5.0 mg mL−1. Its 1, 1-diphenyl1-2-picrylhydrazyl (DPPH) radical scavenging activity was also stronger. It was found by principal component analysis (PCA) and Pearson that the DPPH radical-scavenging activities of sauerkraut extracts were significantly correlated with the content of polyphenols and flavonoids (p < 0.05). Unlike kimchi, Northeastern sauerkraut is consumed mainly by heating, so this study could contribute to understanding the antioxidant capacity of different solvent extracts of sauerkraut, and before and after heating water extracts.

ABTS/TAC Methodology: Main Milestones and Recent Applications

ABTS (2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid) is a widely used compound for determining the total antioxidant capacity (TAC) of plant extracts, food, clinical fluids, etc. This photometric assay is based on the reduction by the presence of antioxidant compounds of a well-known metastable radical (ABTS•+) which can be formed via several different approaches and be used in many different determination methodologies such as automated photometric measures in microplates, clinical robots, valuable titrations, and previous liquid chromatographic separation. Another interesting aspect is that, in some cases, the ABTS/TAC method permits sequential hydrophilic and lipophilic antioxidant activity determinations, obtaining total antioxidant activity values through the summatory data of both types of antioxidants. In this work, we present a review of several aspects of the ABTS/TAC, highlighting the major achievements that have made this method so widely used, e.g., ABTS radical formation in hydrophilic or lipophilic reaction media, measurement strategies, automatization, and adaptation to high-throughput systems, as well as the pros and cons. Moreover, some recent examples of ABTS/TAC method applications in plant, human, and animal samples are discussed.

Biological active compounds and biological activities of the foam used in the traditional kerebiç dessert

In the present work, foam and water extracts were obtained from Gypsophila root, which forms the foam part of the dessert known as kerebiç. The bioactive compounds of samples were analysed with Fourier transform infrared (FT-IR) and high-performance liquid chromatography (HPLC). To determine their antioxidant properties, ferric-reducing antioxidant power (FRAP) method, cupric-reducing antioxidant capacity (CUPRAC) method, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate (ABTS) method, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method, and total antioxidant activity method were performed. The pUC18 plasmid DNA was used to investigate the effect of the samples on the deoxyribonucleic acid (DNA). In addition, the inhibitory properties of the samples against key enzymes (acetyl and butyryl-cholinesterases) involved in the pathogenesis of diseases were investigated. Based on the results of FT-IR analysis, terpenes and sugars were detected in the extracts. Based on the HPLC results, glucose, fructose, maleic acid, acetic acid, acetoin, and 2,3 butanediol were detected in the extracts. Antioxidant results showed that extracts had similar and moderate activities as compared to the standard antioxidants. It was observed that the extracts preserved the stable structure of pUC18 plasmid DNA, but could not remove the scavenging effect of peroxide. In addition, it was determined that the extracts showed a stronger inhibitory effect on acetylcholinesterase (AChE) and butyryl-cholinesterases (BChE) than galantamine, which was used as the control.

Synthetic Mono-Carbonyl Curcumin Analogues Attenuate Oxidative Stress in Mouse Models.

Alzheimer’s disease is the commonest form of dementia associated with short-term memory loss and impaired cognition and, worldwide, it is a growing health issue. A number of therapeutic strategies have been studied to design and develop an effective anti-Alzheimer drug. Curcumin has a wide spectrum of biological properties. In this regard, the antioxidant potentials of mono-carbonyl curcumin analogues (h1–h5) were investigated using in vitro antioxidant assays and hippocampal-based in vivo mouse models such as light–dark box, hole board, and Y-maze tests. In the in vitro assay, mono-carbonyl curcumin analogues h2 and h3 with methoxy and chloro-substituents, respectively, showed promising 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azinobis-3-ethylbenzothiazo-line-6-sulfonate (ABTS) free radical scavenging activities. In the in vivo studies, scopolamine administration significantly (p < 0.001) induced oxidative stress and memory impairment in mice, in comparison to the normal control group. The pretreatment with mono-carbonyl curcumin analogues, specifically h2 and h3, significantly decreased (123.71 ± 15.23 s (p < 0.001), n = 8; 156.53 ± 14.13 s (p < 0.001), n = 8) the duration of time spent in the light chamber and significantly enhanced (253.95 ± 19.05 s (p < 0.001), n = 8, and 239.57 ± 9.98 s (p < 0.001), n = 8) the time spent in the dark compartment in the light–dark box arena. The numbers of hole pokings were significantly (p < 0.001, n = 8) enhanced in the hole board test and substantially increased the percent spontaneous alternation performance (SAP %) in the Y-maze mouse models in comparison to the stress control group. In the biomarker analysis, the significant reduction in the lipid peroxidation (MDA) level and enhanced catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH) activities in the brain hippocampus reveal their antioxidant and memory enhancing potentials. However, further research is needed to find out the appropriate mechanism of reducing oxidative stress in pathological models.

Co(II) fenamato, tolfenamato and niflumato complexes with neocuproine: Synthesis, crystal structure, spectral characterization and biological activity

Four novel cobalt(II) complexes with the non-steroidal anti-inflammatory drugs - fenamic acid derivatives have been synthesized and characterized. The complexes [Co(neo)(fen)2] (1) and [Co(neo)(tol)2] (2) were prepared by the reaction of fenamic (Hfen = 2-(phenylamino)benzoic acid) and tolfenamic acid (Htol = 2-[(3-chloro-2-methylphenyl)amino]benzoic acid), respectively with cobalt(II) chloride and neocuproine (neo = 2,9-dimethylphenantroline). However, the same procedure applied to niflumic acid (Hnif = 2-{[3-(trifluoromethyl)phenyl]amino}nicotinic acid) mixture has led to formation of [Co(neo)(nif)2(MeOH)]·MeOH (3A) and [CoCl(neo)(nif)(MeOH)] (3B). The crystal structure of all prepared compounds has been determined by single-crystal X-ray crystallography. Complexes 1 and 2 were further subjected to full spectral characterization (IR, UV-VIS, fluorescence) as well as biological activity studies. The radical scavenging activity against free model radicals ABTS (diammonium 2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonate) and DPPH (2,2-Diphenyl-1-picrylhydrazyl) revealed the selectivity of complexes against ABTS with higher scavenging activity observed for 2, while both compounds were ineffective towards DPPH. Furthermore, the interaction of molecules with Fish-sperm DNA revealed a moderately strong interaction based on combined intercalative and minor-groove binding mode. The interaction with human and bovine serum albumins determined by fluorescence quenching experiments revealed the binding constants within the optimal range proposed for effective drug binding.

Characteristics of new anthraquinone derivative-decolorizing versatile peroxidase produced by Bjerkandera adusta strain CCBAS 930

The aim of the study was to purify and characterize a peroxidase synthesized by the B. adusta strain CCBAS 930. Moreover, optimal pH and temperature, substrate specificity (2,2′-azino-bis(3-ethylben-zothiazoline-6-sulfonate (ABTS), veratryl alcohol (VA), guaiacol (GA), o-dianisidine, 2,6-dimetoxyphenol (2,6-DMP), 2-methoxy-1,4-benzohydroquinone (MBQH2), 2,6-Dimethoxy-1,4-benzohydroquinone (DBQH2)) and the influence of different ions (Al3+, Mn2+, Mg2+, Ca2+, Cu2+, Fe2+, Co2+, Ag2+, Cd2+, Hg2+, and K+ and organic solvents (ethanol, methanol, DMSO, ethyl acetate, n-hexane, diethyl ether, and dichloromethane) on VP/Ba activity were determined. The purified VP/Ba had an RZ value (A407/A280) of 1.85, 45 kDa and an N-terminal sequence VTXPGKVNVVENSA. The catalytic activity of VP/Ba measured by the oxidation of 2,6-DMP with/without Mn2+ was noted at optimum temperature values of 50 °C and 55 °C, respectively. After 24h incubation in different pH conditions (pH = 3.0–7.0), residual VP/Ba activity ranging from 30 to 50% with the optimum at pH = 5.5 (50%) was observed. All the seven substrates tested were oxidized by purified VP/Ba, but the oxidation ratio of 2,6-DMP, VA, GA, and o-dianisidine in the presence of Mn2+ was higher. The highest activity of VP/Ba was detected in the presence of 0.1 mM Al3+, Cu2+, Ca2+, and Mn2+ ions (126%–176%), while Ag2+, Hg2+, Ni+, and K+ at all the concentrations tested (5, 1, and 0.1 mM) significantly decreased its activity. Organic solvents e.g. ethanol, methanol, DMSO, ethyl acetate, n-hexane, diethyl ether, and dichloromethane, partially decreased the activities of VP/Ba measured without and with Mn2+, with residual activities ranging from 10.33% to 69.16% and from 50% to 68.75%, respectively.

In Vivo Antistress Effects of Synthetic Flavonoids in Mice: Behavioral and Biochemical Approach.

Natural flavonoids, in addition to some of their synthetic derivatives, are recognized for their remarkable medicinal properties. The present study was designed to investigate the in vitro antioxidant and in vivo antistress effect of synthetic flavonoids (flavones and flavonols) in mice, where stress was induced by injecting acetic acid and physically through swimming immobilization. Among the synthesized flavones (F1–F6) and flavonols (OF1–OF6), the mono para substituted methoxy containing F3 and OF3 exhibited maximum scavenging potential against DPPH (2,2-diphenyl-1-picrylhydrazyl) with IC50 of 31.46 ± 1.46 μg/mL and 25.54 ± 1.21 μg/mL, respectively. Minimum antioxidant potential was observed for F6 and OF6 with IC50 values of 174.24 ± 2.71 μg/mL and 122.33 ± 1.98 μg/mL, respectively, in comparison with tocopherol. The ABTS scavenging activity of all the synthesized flavones and flavonols were significantly higher than observed with DPPH assay, indicating their potency as good antioxidants and the effectiveness of ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) assay in evaluating antioxidant potentials of chemical substances. The flavonoids-treated animals showed a significant (* p < 0.05, ** p < 0.01 and *** p < 0.001, n = 8) reduction in the number of writhes and an increase in swimming endurance time. Stressful conditions changed plasma glucose, cholesterol and triglyceride levels, which were used as markers when evaluating stress in animal models. The level of these markers was nearly brought to normal when pre-treated with flavones and flavonols (10 mg/kg) for fifteen days in experimental animals. These compounds also considerably reduced the levels of lipid peroxidation (TBARS: Thiobarbituric acid reactive substances), which was significant (* p < 0.05, ** p < 0.01 and *** p < 0.001, n = 8) compared to the control group. A significant rise in the level of catalase and SOD (super oxide dismutase) was also observed in the treated groups. Diazepam (2 mg/kg) was used as the standard drug. Additionally, the flavonoids markedly altered the weight of the adrenal glands, spleen and brain in stress-induced mice. The findings of the study suggest that these flavonoids could be used as a remedy for stress and are capable of ameliorating diverse physiological and biochemical alterations associated with stressful conditions. However, further experiments are needed to confirm the observed potentials in other animal models, especially in those with a closer resemblance to humans. Toxicological evaluations are also equally important.

Biological Evaluation of 4-(1H-triazol-1-yl)benzoic Acid Hybrids as Antioxidant Agents: In Vitro Screening and DFT Study

Fourteen triazole benzoic acid hybrids were previously characterized. This work aimed to screen their in vitro antioxidant activity using different assays, i.e., DPPH (1,1-diphenyl-1-picrylhydrazyl), reducing the power capability, FRAP (ferric reducing antioxidants power) and ABTS (2,2′-azino-bis(3-ethylben zothiazoline-6-sulfonate) radical scavenging. The 14 compounds showed antioxidant properties in relation to standard BHA (butylated hydroxylanisole) and Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid). Higher antioxidant activity was observed by the parent (1) at a concentration of 100 µg/mL (89.95 ± 0.34 and 88.59 ± 0.13%) when tested by DPPH and ABTS methods in relation to BHA at 100 µg/mL (95.02 ± 0.74 and 96.18 ± 0.33%). The parent (2) demonstrated remarkable scavenging activity when tested by ABTS (62.00 ± 0.24%), however, 3 was less active (29.98 ± 0.13%). Compounds 5, 6, 9, and 11 exhibited good scavenging activity compared to 1. DFT studies were performed using the B3LYP/6-311++g (2d,2p) level of theory to evaluate different antioxidant descriptors for the targets. Three antioxidant mechanisms, i.e., hydrogen atom transfer (HAT), sequential electron transfer proton transfer (SETPT) and sequential proton loss electron transfer (SPLET) were suggested to describe the antioxidant properties of 1–14. Out of the 14 triazole benzoic acid hybrids, 5, 9, 6, and 11 showed some good theoretical results, which were in agreement with some experimental outcomes. Based on the computed (PA and ETE) and (BDE and IP) values in (SPLET) and (HAT and SETPT) mechanisms, respectively, compound 9 emerged has having good antioxidant activity.