Evaluation of the potential of annatto seed powder to reduce the formation of heterocyclic amines in charcoal-grilled and pan-fried beef patties.

Various strategies are being explored to reduce the formation of undesirable compounds during the thermal processing of foods. This study investigates the impact of incorporating annatto seed powder (Bixa orellana L.) into beef patties to reduce the formation of heterocyclic amines (HAs) during charcoal-grilling and pan-frying. A three-level full factorial design was used to assess the effect of both annatto seed powder concentration and cooking times on HAs formation. The results showed that HA formation increased with longer cooking times and decreased with higher concentrations of annatto seed powder. A significant reduction in HA content was observed in both charcoal-grilled and pan-fried beef patties when annatto seed powder was added, with a particularly notable 91 % reduction at the 1 % addition level. These findings demonstrate that the addition of annatto seed powder is a highly effective strategy for reducing HA formation in beef patties. CHEMICAL COMPOUNDS STUDIED IN THIS ARTICLE: 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) (PubChem CID: 62275); 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) (PubChem CID: 104739); 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx) (PubChem CID: 104855); 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (PubChem CID: 1530); 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) (PubChem CID: 5284474); 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) (PubChem CID: 5284476); 2-amino-9H-pyrido[2,3-b]indole (AαC) (PubChem CID: 62805); 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAαC) (PubChem CID: 62244); Bixin (PubChem CID: 5281226).

Triethylammonium Salts of Dicoumarol: Synthesis, Characterization, Human Antiglioblastoma, Antimicrobial and Antioxidant Studies.

The most typical primary brain tumor, glioblastoma multiforme (GBM), has a dismal prognosis. They are removed through arduous, potentially fatal operations. The primary cause of tumor recurrence following surgery is glioblastoma stem cells (GSCs). In order to combat the recurrent glioblastoma malignant cells, medications have been developed. Chemotherapies now in use are expensive and encounter resistance. To combat inherent and developed resistance, new and powerful chemotherapeutics are being synthesized. In this regard, dicoumarols were deprotonated by triethylamine to produce corresponding salts which are reported and used for the first time for human antiglioblastoma activity. Spectroscopic characterizations like 1H and 13C-NMR were carried out. The cytotoxicity of normal human astrocytes (NHA) and human glioblastoma cells (A172 and LN229) were both examined in terms of dose and time dependence. The range of the IC50 value for all the deprotonated derivatives against A172 was found to be 2.81-0.24 µM, whereas the range against LN229 was found to be 2.50-0.85 µM. According to cytotoxicity results, malignant cell death was seen in GBM cells treated with triethylamine salts of dicoumarols compared to the control group, which suggested that salts may cause apoptosis in GBM cells. Antimicrobial and antifungal activities were also investigated for all the triethylamine salts of dicoumarols suggesting that salt formation enhances antimicrobial potentials manyfolds compared to the standard drug used. Free radical activities were also investigated using DPPH free radicals.

Easy and green synthesis of nano-ZnO and nano-TiO2 for efficient photocatalytic degradation of organic pollutants.

As the textile industry expands, more industrial waste effluents are released into natural water streams, prompting the research and development of innovative materials for the remediation of environmental issues. In this research, a direct precipitation and hydrolysis method were used to synthesize ZnO and TiO2 nanoparticles, respectively that were utilized to investigate the photocatalytic activity of Congo Red (CR) dye. Afterward, the crystallite size was computed from the data of the X-ray diffractometer (XRD), and utilizing several models (Scherrer equation, LSLMSE, Monshi-Scherrer equation, Williamson-Hall model, Size-strain plot method, Halder-Wagner model, Sahadat-Scherrer model). Among these models, the size-strain plot model yields the most accurate crystal size (45.31 nm) for ZnO nanoparticles and the Halder-Wagner model (2.44 nm) for TiO2 nanoparticles. Scanning Electron Microscope exhibited the spherical shape of nanoparticles (ZnO, and TiO2) with particle size (less than 151 nm). The absorption spectrum from Fourier transform infrared (FTIR) spectroscopy confirmed the formation of nanoparticles (ZnO, and TiO2). Thereafter, the photocatalytic activity of the ZnO-TiO2 nanocomposite was evaluated by using Congo Red (CR) dye under different process variables, such as catalyst dose, time, initial dye concentration, pH, radical scavenging ability, and reusability. The best degradation (90 %) was recorded at 180 min time intervals using a 0.2 g catalyst dose with a 20 ppm CR concentration at pH 9.

Postoperative Intimal Hyperplasia: Review from My Research.

Postoperative intimal hyperplasia is the major cause of the vein graft occlusion. It is very important to establish an animal model for the start of research. After my vascular surgery residency in Japan, I started my research work on postoperative intimal hyperplasia at the University of Wisconsin-Madison. My research showed that endothelial injury and monocyte infiltration is the key for postoperative intimal hyperplasia, which is very similar to Ross' pathogenesis of atherosclerosis as an inflammatory disease. Focusing on postoperative intimal hyperplasia as an inflammatory disease, especially on tumor necrosis factor-α, FR-167653 (tumor necrosis factor-α suppressive agent, inhibitor of p 38 mitogen-activated protein kinase; Fujisawa Pharmaceutical Co., Ltd., Japan) is found to suppress postoperative intimal hyperplasia in a rat model by reducing serum monocyte chemoattractant protein-1 levels. However, FR-167653 is not commercially available today. Because endothelial injury is the first step of postoperative intimal hyperplasia, I investigated whether the free radical scavenger, edaravone (Radicut, Mitsubishi Tanabe Pharma Co., Japan), which alleviates the endothelial injury in vitro , can also suppress postoperative intimal hyperplasia. Moreover, the free radical scavenger edaravone (Radicut®, Mitsubishi Tanabe Pharma Co.) is also found to suppress postoperative intimal hyperplasia, by alleviating endothelial injury. In clinical settings, it is very important to detect postoperative intimal hyperplasia before its establishment. Hepatocyte growth factor is not only a hepatic growth factor but also a vascular endothelial growth factor. Recently, serum hepatocyte growth factor level was found to be a candidate biomarker for postoperative intimal hyperplasia in our rat model.

24R005A and 24R005B: Novel radical scavengers of DPPH obtained from Streptomyces sp. cultured in a fish powder medium.

We have successfully isolated two novel compounds, 24R005A (1, C13H14O4) and 24R005B (2, C13H13ClO4), from Streptomyces sp. 24R005, using fish (anchovy) powder as a medium. In this study, we evaluated the use of fish (anchovy) powder as a fermentation material for producing bioactive compounds. Spectroscopic analyses revealed that the two compounds share a common skeletal structure. However, each compound contains unique branched side chains. Furthermore, compounds 1 and 2 exhibit moderate radical-scavenging activity for 1,1-diphenyl-2-picrylhydrazyl (DPPH), with ED50 values of 200 and 130 µM, respectively.

Intracellular Protective Functions and Therapeutical Potential of Trehalose.

Trehalose is a naturally occurring, non-reducing saccharide widely distributed in nature. Over the years, research on trehalose has revealed that this initially thought simple storage molecule is a multifunctional and multitasking compound protecting cells against various stress factors. This review presents data on the role of trehalose in maintaining cellular homeostasis under stress conditions and in the virulence of bacteria and fungi. Numerous studies have demonstrated that trehalose acts in the cell as an osmoprotectant, chemical chaperone, free radical scavenger, carbon source, virulence factor, and metabolic regulator. The increasingly researched medical and therapeutic applications of trehalose are also discussed.

Gadolinium Doping Modulates the Enzyme-like Activity and Radical-Scavenging Properties of CeO2 Nanoparticles.

Their unique physicochemical properties and multi-enzymatic activity make CeO2 nanoparticles (CeO2 NPs) the most promising active component of the next generation of theranostic drugs. When doped with gadolinium ions, CeO2 NPs constitute a new type of contrast agent for magnetic resonance imaging, possessing improved biocatalytic properties and a high level of biocompatibility. The present study is focused on an in-depth analysis of the enzyme-like properties of gadolinium-doped CeO2 NPs (CeO2:Gd NPs) and their antioxidant activity against superoxide anion radicals, hydrogen peroxide, and alkylperoxyl radicals. Using an anion-exchange method, CeO2:Gd NPs (~5 nm) with various Gd-doping levels (10 mol.% or 20 mol.%) were synthesized. The radical-scavenging properties and biomimetic activities (namely SOD- and peroxidase-like activities) of CeO2:Gd NPs were assessed using a chemiluminescent method with selective chemical probes: luminol, lucigenin, and L-012 (a highly sensitive luminol analogue). In particular, gadolinium doping has been shown to enhance the radical-scavenging properties of CeO2 NPs. Unexpectedly, both bare CeO2 NPs and CeO2:Gd NPs did not exhibit SOD-like activity, acting as pro-oxidants and contributing to the generation of reactive oxygen species. Gadolinium doping caused an increase in the pro-oxidant properties of nanoscale CeO2. At the same time, CeO2:Gd NPs did not significantly inhibit the intrinsic activity of the natural enzyme superoxide dismutase, and CeO2:Gd NPs conjugated with SOD demonstrated SOD-like activity. In contrast to SOD-like properties, peroxidase-like activity was observed for both bare CeO2 NPs and CeO2:Gd NPs. This type of enzyme-like activity was found to be pH-dependent. In a neutral medium (pH = 7.4), nanoscale CeO2 acted as a prooxidant enzyme (peroxidase), while in an alkaline medium (pH = 8.6), it lost its catalytic properties; thus, it cannot be regarded as a nanozyme. Both gadolinium doping and conjugation with a natural enzyme were shown to modulate the interaction of CeO2 NPs with the key components of redox homeostasis.

Oxidative Stress Response Mechanisms Sustain the Antibacterial and Antioxidant Activity of Quercus ilex.

The development of new natural antibiotics is considered as the heart of several investigations in the nutraceutical field. In this work, leaves of Quercus ilex L. treated by tropospheric ozone (O3) and nitrogen (N) deposition, exhibited a clear antimicrobial efficacy against five multi-drug resistant (MDR) bacterial strains (two gram-positive and three gram-negative). Under controlled conditions, it was studied how simulated N deposition influences the response to O3 and the antibacterial and antioxidant activity, and antioxidant performance. The extraction was performed by ultra-pure acetone using two different steps. A higher antioxidant activity was measured in the presence of interaction between O3 and N treatments on Quercus leaves. At the same time, all organic extracts tested have shown bacteriostatic activity against all the tested strains with a MIC comprised between 9 and 4 micrograms/mL, and a higher antioxidant efficacy shown by spectrophotometric assay. Stronger antimicrobial activity was found in the samples treated with O3, whereas N-treated plants exhibited an intermediate antibacterial performance. This performance is related to the stimulation of the non-enzymatic antioxidant system induced by the oxidative stress, which results in an increase in the production of antimicrobial bioactive compounds.

Spray-Drying Microencapsulation of Bauhinia ungulata L. var. obtusifolia Aqueous Extract Containing Phenolic Compounds: A Comparative Study Using Different Wall Materials.

Species belonging to the Bauhinia genus, usually known as "pata-de-vaca", are popularly used to treat diabetes. Bauhinia ungulata var. obtusifolia (Ducke) Vaz is among them, of which the leaves are used as a tea for medicinal purposes in the Amazon region. A microencapsulation study of lyophilized aqueous extract from Bauhinia ungulata leaves, which contain phenolic compounds, using five different wall materials (maltodextrin DE 4-7, maltodextrin DE 11-14; ß-cyclodextrin; pectin and sodium carboxymethylcellulose) is described in this paper. The microstructure, particle size distribution, thermal behavior, yield, and encapsulation efficiency were investigated and compared using different techniques. Using high-performance liquid chromatography, phenolics, and flavonoids were detected and quantified in the microparticles. The microparticles obtained with a yield and phenolics encapsulation efficiency ranging within 60-83% and 35-57%, respectively, showed a particle size distribution between 1.15 and 5.54 µm, spherical morphology, and a wrinkled surface. Among them, those prepared with sodium carboxymethylcellulose or pectin proved to be the most thermally stable. They had the highest flavonoid content (23.07 and 21.73 mg RUTE/g Extract) and total antioxidant activity by both the DPPH (376.55 and 367.86 µM TEq/g Extract) and ABTS (1085.72 and 1062.32 µM TEq/g Extract) assays. The chromatographic analyses allowed for quantification of the following substances retained by the microparticles, chlorogenic acid (1.74-1.98 mg/g Extract), p-coumaric acid (0.06-0.08 mg/g Extract), rutin (11.2-12.9 mg/g Extract), and isoquercitrin (0.49-0.53 mg/g Extract), compounds which considered to responsible for the antidiabetic property attributed to the species.

Receptor-Mediated and Receptor-Independent Actions of Melatonin in Vertebrates.

Melatonin (N-acetyl-5-methoxytryptamine) is an indolamine that is synthesized from tryptophan in the pineal glands of vertebrates through four enzymatic reactions. Melatonin is a quite unique bioactive substance, characterized by a combination of both receptor-mediated and receptor-independent actions, which promote the diverse effects of melatonin. One of the main functions of melatonin, via its membrane receptors, is to regulate the circadian or seasonal rhythm. In mammals, light information, which controls melatonin synthesis, is received in the eye, and transmitted to the pineal gland, via the suprachiasmatic nucleus, where the central clock is located. Alternatively, in many vertebrates other than mammals, the pineal gland cells, which are involved in melatonin synthesis and secretion and in the circadian clock, directly receive light. Recently, it has been reported that melatonin possesses several metabolic functions, which involve bone and glucose, in addition to regulating the circadian rhythm. Melatonin improves bone strength by inhibiting osteoclast activity. It is also known to maintain brain activity during sleep by increasing glucose uptake at night, in an insulin-independent manner. Moreover, as a non-receptor-mediated action, melatonin has antioxidant properties. Melatonin has been proven to be a potent free radical scavenger and a broad-spectrum antioxidant, even protecting organisms against radiation from space. Melatonin is a ubiquitously distributed molecule and is found in bacteria, unicellular organisms, fungi, and plants. It is hypothesized that melatonin initially functioned as an antioxidant, then, in vertebrates, it combined this role with the ability to regulate rhythm and metabolism, via its receptors.

Edaravone counteracts redox and metabolic disruptions in an emerging zebrafish model of sporadic ALS.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which the death of motor neurons leads to loss of muscle function. Additionally, cognitive and circadian disruptions are common in ALS patients, contributing to disease progression and burden. Most ALS cases are sporadic, and environmental exposures contribute to their aetiology. However, animal models of these sporadic ALS cases are scarce. The small vertebrate zebrafish is a leading organism to model neurodegenerative diseases; previous studies have proposed bisphenol A (BPA) or ß-methylamino-l-alanine (BMAA) exposure to model sporadic ALS in zebrafish, damaging motor neurons and altering motor responses. Here we characterise the face and predictive validity of sporadic ALS models, showing their potential for the mechanistic study of ALS drugs. We phenotypically characterise the BPA and BMAA-induced models, going beyond motor activity and motor axon morphology, to include circadian, redox, proteostasis, and metabolomic phenotypes, and assessing their predictive validity for ALS modelling. BPA or BMAA exposure induced concentration-dependent activity impairments. Also, exposure to BPA but not BMAA induced motor axonopathy and circadian alterations in zebrafish larvae. Our further study of the BPA model revealed loss of habituation to repetitive startles, increased oxidative damage, endoplasmic reticulum (ER) stress, and metabolome abnormalities. The BPA-induced model shows predictive validity, since the approved ALS drug edaravone counteracted BPA-induced motor phenotypes, ER stress, and metabolic disruptions. Overall, BPA exposure is a promising model of ALS-related redox and ER imbalances, contributing to fulfil an unmet need for validated sporadic ALS models.

Identifying eleven new ferroptosis inhibitors as neuroprotective agents from FDA-approved drugs.

With increasing evidence that ferroptosis is associated with diverse neurological disorders, targeting ferroptosis offers a promising avenue for developing effective pharmaceutical agents for neuroprotection. In this study, we identified ferroptosis inhibitors as neuroprotective agents from US Food and Drug Administration (FDA)-approved drugs. 1176 drugs have been screened against erastin-induced ferroptosis in HT22 cells, resulting in 89 ferroptosis inhibitors. Among them, 26 drugs showed significant activity with EC50 below10 µM. The most active ferroptosis inhibitor is lumateperone tosylate at nanomolar level. 11 drugs as ferroptosis inhibitors were not reported previously. Further mechanistic studies revealed that their mechanisms of actions involve free radical scavenging, Fe2+ chelation, and 15-lipoxygenase inhibition. Notably, the active properties of some drugs were firstly revealed here. These ferroptosis inhibitors increase the chemical diversity of ferroptosis inhibitors, and offer new therapeutic possibilities for the treatments of related neurological diseases.

Fishing antioxidant 4-hydroxycoumarin derivatives: synthesis, characterization, and in vitro assessments.

Coumarins represent a diverse class of natural compounds whose importance in pharmaceutical and agri-food sectors has motivated multiple novel synthetic derivatives with broad applicability. The phenolic moiety in 4-hydroxycoumarins underscores their potential to modulate the equilibrium between free radicals and antioxidant species within biological systems. The aim of this work was to assess the antioxidant activity of 18 4-hydroxycoumarin coumarin derivatives, six of which are commercially available and the other 12 were synthesized and chemically characterized and described herein. The 4-hydroxycoumarins were prepared by a two steps synthetic strategy with satisfactory yields. Their antioxidant potential was evaluated through three in vitro methods, two free radical-scavenging assays (DPPH• and ABTS•+) and a metal chelating activity assay. Six synthetic coumarins (4a, 4g, 4h, 4i, 4k, 4l) had a scavenging capacity of DPPH• higher than butylated hydroxytoluene (BHT) (IC50 = 0.58 mmol/L) and compound 4a (4-hydroxy-6-methoxy-2 H-chromen-2-one) with an IC50 = 0.05 mmol/L outperformed both BHT and ascorbic acid (IC50 = 0.06 mmol/L). Nine hydroxycoumarins had a scavenging capacity against ABTS•+ greater (C3, 4a, 4c) or comparable (C1, C2, C4, C6, 4g, 4l) to Trolox (IC50 = 34.34 µmol/L). Meanwhile, the set had a modest ferrous chelation capacity, but most of them (C2, C5, C6, 4a, 4b, 4h, 4i, 4j, 4k, 4l) reached up to more than 20% chelating ability percentage. Collectively, this research work provides valuable structural insights that may determine the scavenging and metal chelating activity of 4-hydroxycoumarins. Notably, substitutions at the C6 position appeared to enhance scavenging potential, while the introduction of electron-withdrawing groups showed promise in augmenting chelation efficiency.

Decreased proteasome function increases oxidative stress in the early stage of pressure ulcer development.

The aging process in the elderly results in heightened skin fragility associated with various disorders, including pressure ulcers (PUs). Despite the high incidence of PUs in the elderly population, there is a limited body of research specifically examining the impact of aging on the development of pressure ulcers. Therefore, investigating age-related physiological abnormalities is essential to elucidate the pathogenesis of PUs. Ischemia-reperfusion (I/R) injury and the subsequent oxidative stress caused by reactive oxygen species (ROS) play essential roles in the early stage of PUs. In this study, we used a mouse model of proteasomal dysfunction with an age-related phenotype to examine the role of proteasome activity in cutaneous I/R injury in vivo. Decreased proteasome function did not affect the expression of inflammatory cytokines and adhesion molecules in the I/R area in transgenic mice; however, proteasome inhibition increased oxidative stress that was not attenuated by activation of the oxidative stress response mediated by NF-E2-related factor 2 (Nrf2). In dermal fibroblasts (FCs) subjected to hypoxia-reoxygenation (H/R), proteasome inhibition induced oxidative stress and ROS production, and Nrf2 activation did not adequately upregulate antioxidant enzyme expression, possibly leading to antioxidant/oxidant imbalance. The free radical scavenger edaravone had protective effects against I/R injury in vivo and decreased oxidative stress in FCs treated with a proteasome inhibitor and subjected to H/R in vitro. The results suggest that the age-related decline in proteasome activity promotes cutaneous I/R injury-induced oxidative stress, and free radical scavengers may exert protective effects by preventing oxidative stress in the early stage of PUs.

Update on Antioxidant Therapy with Edaravone: Expanding Applications in Neurodegenerative Diseases.

The brain is susceptible to oxidative stress, which is associated with various neurological diseases. Edaravone (MCI-186, 3-methyl-1 pheny-2-pyrazolin-5-one), a free radical scavenger, has promising effects by quenching hydroxyl radicals (∙OH) and inhibiting both ∙OH-dependent and ∙OH-independent lipid peroxidation. Edaravone was initially developed in Japan as a neuroprotective agent for acute cerebral infarction and was later applied clinically to treat amyotrophic lateral sclerosis (ALS), a neurodegenerative disease. There is accumulating evidence for the therapeutic effects of edaravone in a wide range of diseases related to oxidative stress, including ischemic stroke, ALS, Alzheimer's disease, and placental ischemia. These neuroprotective effects have expanded the potential applications of edaravone. Data from experimental animal models support its safety for long-term use, implying broader applications in various neurodegenerative diseases. In this review, we explain the unique characteristics of edaravone, summarize recent findings for specific diseases, and discuss its prospects for future therapeutic applications.

Rapid screening and target-guided isolation of antioxidants from German chamomile by 2,2-diphenyl-1-picrylhydrazyl-ultra-high-performance liquid chromatography-mass spectrometry coupled with off-line two-dimensional high-speed countercurrent chromatography.

German chamomile is one of the most effective herbal elements used in anti-allergic products and as an antioxidant. Herein, the antioxidant activity of different extract fractions of German chamomile was initially evaluated using an off-line 2,2-diphenyl-1-picrylhydrazyl spectrophotometric assay. The ethyl acetate extract demonstrated the highest efficacy in scavenging free radicals. Based on this, a rapid screening and separation method using ultra-high-performance liquid chromatography combined with the 2,2-diphenyl-1-picrylhydrazyl assay was implemented to identify antioxidants in the ethyl acetate fraction of German chamomile flowers. Ten potential radical scavengers were tentatively screened from German chamomile using a target-guided isolating approach with off-line two-dimensional high-speed countercurrent chromatography and the structures of the compounds were analyzed and identified. Ultimately, 10 radical scavengers were obtained from the ethyl acetate extract with a purity quotient exceeding 90%. The results demonstrated the effectiveness and reproducibility of this method for isolating potential antioxidants from complex mixtures in a targeted manner. This strategy can be applied to the target-guided isolation of complex mixtures of natural products with broad K-values and similar structures.

An Integrated Approach to the Anti-Inflammatory, Antioxidant, and Genotoxic Potential of Portuguese Traditional Preparations from the Bark of Anacardium occidentale L.

Anacardium occidentale L. stem bark Traditional Herbal Preparations (AoBTHPs) are widely used in traditional medicine to treat inflammatory conditions, such as diabetes. The present study aims to evaluate the anti-inflammatory, antioxidant, and genotoxic potential of red and white Portuguese AoBTHPs. Using a carrageenan-induced rat paw edema model, a significant anti-edema effect was observed for all tested doses of white AoBTHP (40.2, 71.5, and 127.0 mg/kg) and the two highest doses of red AoB THP (71.5 and 127.0 mg/kg). The anti-edema effect of red AoBTHP's highest dose was much more effective than indomethacin 10 mg/kg, Trolox 30 mg/kg, and Tempol 30 mg/kg. In DPPH, FRAP, and TAC using the phosphomolybdenum method, both types of AoBTHPs showed similar antioxidant activity and no genotoxicity up to 5000 µg/plate in the Ames test. The LC-UV/DAD-ESI/MS fingerprint allowed the identification of gallic and protocatechuic acids as the two main marker compounds and the presence of catechin, epicatechin, epigallocatechin gallate, and ellagic acid in both AoBTHPs. The obtained results support the validation of red and white AoB and their THPs as anti-inflammatory agents and contribute to the possible development of promising new therapeutic options to treat inflammatory conditions.

TiN as Radical Scavenger in Fe─N─C Aerogel Oxygen Reduction Catalyst for Durable Fuel Cell.

Fe─N─C is the most promising alternative to platinum-based catalysts to lower the cost of proton-exchange-membrane fuel cell (PEMFC). However, the deficient durability of Fe─N─C has hindered their application. Herein, a TiN-doped Fe─N─C (Fe─N─C/TiN) is elaborately synthesized via the sol-gel method for the oxygen-reduction reaction (ORR) in PEMFC. The interpenetrating network composed by Fe─N─C and TiN can simultaneously eliminate the free radical intermediates while maintaining the high ORR activity. As a result, the H2O2 yields of Fe─N─C/TiN are suppressed below 4%, ≈4 times lower than the Fe─N─C, and the half-wave potential only lost 15 mV after 30 kilo-cycle accelerated durability test (ADT). In a H2─O2 fuel cell assembled with Fe─N─C/TiN, it presents 980 mA cm-2 current density at 0.6 V, 880 mW cm-2 peak power density, and only 17 mV voltage loss at 0.80 A cm-2 after 10 kilo-cycle ADT. The experiment and calculation results prove that the TiN has a strong adsorption interaction for the free radical intermediates (such as *OH, *OOH, etc.), and the radicals are scavenged subsequently. The rational integration of Fe single-atom, TiN radical scavenger, and highly porous network adequately utilize the intrinsic advantages of composite structure, enabling a durable and active Pt-metal-free catalyst for PEMFC.

Isolation of hitherto-uncultivated microorganisms- Application of radical scavengers.

The culture filtrates of the predominant bacterial strains isolated from soil samples have been shown to increase the microbial colony counts on agar plates used for the isolation of uncultured bacteria. One of the factors in the culture filtrates responsible for this increase was identified to be superoxide dismutase (SOD). The generation of reactive oxygen species (O2-, H2O2, and ・OH) was detected from conventional laboratory agar media. The use of agar media supplemented with radical scavengers (SOD, catalase, ascorbic acid, or rutin) effectively increased the colony counts and kinds of microbial strains that grew from soil samples. Taxonomical studies on these isolates revealed new taxa for phylum Actinomycetota; one family, three genera, and nine species were newly described. One of the strains, Patulibacter minatonensis KV-614T belonging to the new family Patulibacteraceae, was isolated on agar medium supplemented with SOD. P. minatonensis KV-614T represents a novel lineage within the phylum Actinomycetota. A polymerase chain reaction (PCR) study using specific primers for the detection of strains related to the genus Patulibacter, order Solirubrobacterales, showed a high distribution frequency, with detection in over 70% of the soil samples tested. These data suggest that the use of radical scavengers may facilitate the isolation of some hitherto-uncultivated microorganisms widely distributed in soil.

Hybrids of selective COX-2 inhibitors and active derivatives of edaravone as COX-2 selective NSAIDs with free radical scavenging activity: Design, synthesis and biological activities.

Novel hybrids of selective COX-2 inhibitors (coxibs) and active derivatives of free radical scavenger edaravone were designed to overcome the risk of cardiovascular events and stroke increased by NSAIDs (nonsteroidal anti-inflammatory drugs) in this study. All the hybrids were assayed for the COX-2 inhibitory and DPPH (2, 2-diphenyl-1-picrylhydrazyl) free radical scavenging activities in vitro. Finally, we found a series of hybrids with good inhibitory activity and selectivity of COX-2 and excellent free radical scavenging activity in vitro. The most promising compound 6a (WYZ90) exhibited very potent COX-2 inhibitory activity (COX-2, IC50 = 75 nM), weak COX-1 inhibitory activity (COX-1, IC50 = 5734 nM), better free radical scavenging activity (DPPH, IC50 = 19.9 µM) than edaravone, moderate drug-likeness and ADME properties in silico, acceptable pharmacokinetic properties (T1/2 = 4.16 h, 10 mg/kg, o.p.) and oral bioavailability (F% = 36.03 %) in mice. In addition, compound WYZ90 showed similar analgesic activity to the selective COX-2 inhibitor celecoxib in acetic acid-induced mice and better antioxidant activity in Fe2+-induced lipid peroxidation in mouse liver tissue homogenate than edaravone. In conclusion, this study provided a novel class of coxibs containing edaravone moiety as COX-2 selective NSAIDs with free radical scavenging activity and the candidate compound WYZ90 showed not only similar selective COX-2 inhibitory and analgesic activity to celecoxib but also better free radical scavenging and antioxidant activity than edaravone.