Reaction Of Peroxide Research Articles

1,2‐Dichloroethane‐Assisted Defluorinative Ring‐Opening Reaction of DABCO and Polyfluoroalkyl Peroxides: Synthesis of Fluorinated N‐Ethyl Piperazines

Comprehensive SummaryA catalyst‐free and additive‐free ring‐opening reaction of polyfluoroalkyl peroxides, triethylenediamine (DABCO), and 1,2‐dichloroethane (DCE) has been developed for the defluorinative synthesis of structurally diverse piperazines featuring a fluoroenone framework and a N‐chloroethyl‐substituent with high Z‐stereoselectivity. The success of this three‐component reaction is attributed to the in situ generation of an active 1‐(2‐chloroethyl)‐1,4‐diazabicyclo[2.2.2]octan‐1‐ium (DABCO·DCE) salt, which judiciously acts as a formal N‐(2‐chloroethyl)piperazine equivalent in the defluorinative coupling with less‐studied aliphatic fluorinated substances. Impressively, this reaction accomplishes multi‐activation of robust C(sp3)‐F, C(sp3)‐Cl, C(sp3)‐O, and C(sp3)‐N bonds in a one‐pot process, offering a practical platform for the late‐stage functionalization of complex molecules. Furthermore, the resulting products can not only serve as versatile building blocks for the synthesis of fluorinated heterocycles, but also undergo C—Cl bond displacement transformations with N‐, O‐, and S‐nucleophiles.

Metal and Coordinating Atoms Synergistically Achieve High Activity and Stability in Single-Atom Catalysts within the Framework of TM-N3X for the Oxygen Evolution Reaction of Lithium Peroxide.

A critical challenge in the advancement of lithium-oxygen batteries (LOBs) is the difficulty in decomposing lithium peroxide, leading to high charge overpotentials and poor cycling stability. Single-atom catalysts (SACs), known for their ultrahigh catalytic activity in various electrochemical reactions, are expected to enhance the kinetics of the oxygen evolution reaction (OER) for LOBs. Herein, 24 SACs within the framework of TM-N3X have been designed and optimized for the OER of lithium peroxide. First-principles calculations reveal that the doped non-metal atom (X = B, C, O, or P) significantly contributes to the structural stability of the SACs while the metal atom (TM = Ru, Os, Rh, Ir, Pd, or Pt) significantly influences the catalytic activity of the SACs. Upon evaluation of their stability and catalytic activity, the Pt-N3B and Pd-N3B catalysts have been identified as promising candidates for the OER of lithium peroxide, with theoretical charge overpotentials of 0.19 and 0.18 V, respectively. This work provides new guidance for the design of efficient SACs for LOBs and inspires a fundamental understanding of the underlying structure-activity relationship.

Influenza and non-influenza ARVI in children. A relationship between cytokine profile, parameters of the “lipid peroxidation – antioxidant defense system” as well as clinical and laboratory indicators

Influenza and acute respiratory viral infections (ARVI) impose a substantial damage to the population health in the Russian Federation due to their seasonal circulation and predominantly affect young children. A very few data on the cytokine profile, the nonspecific LPO — AOD system and their relationships with clinical characteristics in such diseases in preschool children are available. The aim of this study was to assess the cytokine profile, LPO — AOD system parameters and their relationship with the clinical and laboratory characteristics of diseases in preschool children with influenza and other ARVI. 86 preschool children (3–6 years old) were examined: with an established diagnosis of influenza (n = 31), non-influenza ARVI (n = 28), apparently healthy children (control group (n = 27). All pediatric samples were analyzed by enzyme-linked immunosorbent assay assessing blood serum concentrations of C-reactive protein and cytokines IL-1β, IL-4, IL-6, IL-8, TNFα, IFNα, IFNγ. Spectrophotometric, fluorometric and enzyme immunoassay methods to assess the state of the “LPO — AOD” system were used. In the group of children with influenza vs other ARVI, a higher incidence of intoxication syndrome was revealed. Cytokine profile in children from both clinical groups compared with control cohort was featured with higher indicators of both pro-inflammatory and anti-inflammatory origin. Children with non-influenza ARVI, had increased magnitude of LPO final products in the nonspecific LPO — AOD system along with lowered concentration of fat-soluble vitamins, general antioxidant activity, GSH level, and SOD activity. In the group with influenza, the level of primary and final lipid peroxidation products was increased, whereas that of for retinol,α-tocopherol, and total antioxidant activity was decreased paralleled with higher GSSG and SOD levels. Numerous correlations were noted in the group of children with ARVI: IL-1β/ketones, IL-6/ketones, IL-8/ketones, TNFα/ketones, IL-4/ketones, IFNg/shortness of breath, IFNα/cough, double bonds/fever, double bonds/AST, SO/intoxication, retinol/fever, GSSG/cough. The influenza group differed in the following relationships: IL-4/ketones, IL-4/fever, IFNα/ketones, CDs/AST. It can be concluded that in preschool children with ARVI and influenza, changes in the cytokine profile are accompanied by increased pro- and anti-inflammatory cytokine levels, increased intensity of lipid peroxidation reactions along with reduced magnitude of antioxidant factors. In the group with ARVI, there was a relationship between the final toxic products of lipid peroxidation — Schiff bases — and the intoxication index, as well as the presence of protective mechanisms in the form of connections between interferons and disease clinical manifestations. The group with influenza was distinguished by the presence of protective relations, which may have a beneficial effect in the context of developing pathological process. The data obtained will help expand the understanding of the pathogenetic mechanisms related to immune reactivity and nonspecific lipid peroxidation reactions in preschool patients and formulate appropriate measures for correction.

Study on the Synergistic Mechanism of Photodynamic Therapy Combined With Ferroptosis Inducer to Induce Ferroptosis in Cholangiocarcinoma.

Photodynamic therapy (PDT) induced lipid peroxidation reaction can lead to necrosis and apoptosis of extrahepatic cholangiocarcinoma (ECC) cells, reducing the tumor load. However, the depth of action of PDT is shallow, and its therapy efficacy is weak, making it difficult to achieve eradication even with multiple treatments. This study aims to investigate the mechanism and main pathways of ferroptosis in cholangiocarcinoma under Hematoporphyrin-mediated photodynamic therapy, and to compare the effects of different ferroptosis inducers on photodynamic therapy-induced ferroptosis in cholangiocarcinoma. To provide an experimental basis for selecting appropriate ferroptosis-inducing agents and synergizing with photodynamic therapy during the clinical perioperative period. The Cell Counting Kit-8 (CCK-8) was used to examine the cytotoxicity of cholangiocarcinoma cells following PDT. Flow cytometry was used to detect apoptotic cell percentage and cell cycle changes to assess the enhanced photodynamic production of reactive oxygen species (ROS) by different ferroptosis inducers, confocal imaging was used to de-assay ROS content. Western blot analysis was employed to detect the expression of GPX4 、FSP1、ASCL4 and SLC7A11. Furthermore, a fluorescence spectrophotometric assay was used to quantify the alterations in lipid peroxides (MDA, LPO, GSH, and Fe2+). The combination of PDT with Lenvatinib or Erastin resulted in increased ROS levels, and decreased GSH content, tumor cells were inhibited in the G2 phase, and the proportion of apoptotic cells increased. Additionally, GPX4, FSP1, and SLC7A11 protein expression decreased, whereas ASCL4 increased This was accompanied by heightened levels of Fe2+, LPO, and MDA. Induction of the ferroptosis pathway was observed to enhance the therapeutic efficacy of PDT. Our findings suggest that Erastin or Lenvatinib can enhance the induction of ferroptosis in cholangiocarcinoma cells by photodynamic therapy by increasing intracellular ROS and inhibiting intracellular antioxidant pathways.

Biodegradable hydroxylase polyols production from epoxidized palm oleic acid

Recently, the trend of using renewable sources has great attention in the production of polyol chemicals via the epoxidation method. Palm-based polyols produced from the epoxidation and hydroxylation methods usually have low hydroxyl values (below 200 mg KOH/g). This study aimed to synthesize the hydroxylase polyols with a higher hydroxyl value from the renewable source palm oil. The epoxidized palm oleic acid was synthesized using the in situ performic acid, which is obtained from the reaction of formic acid and hydrogen peroxide. The Taguchi method was executed to optimize the epoxidation process for the maximum production of epoxidized oleic acid. Then, optimized epoxidized palm oleic acid was hydroxylated to produce polyols. In addition, the effect of process parameters on the polyol yields was also studied. At the optimum process parameters, the response of relative conversion to oxirane (RCO) with the determination of oxirane oxygen content (OOC) was found at the maximum value of 82%. According to the results, the maximum hydroxyl value produced was 339 mg KOH/g. A kinetic study revealed that the oxirane cleavage by methanol is a second-order reaction whereas the formation of epoxidized palm oleic acid is a first-order reaction.

Candida albicans pathways that protect against organic peroxides and lipid peroxidation.

Human fungal pathogens must survive diverse reactive oxygen species (ROS) produced by host immune cells that can oxidize a range of cellular molecules including proteins, lipids, and DNA. Formation of lipid radicals can be especially damaging, as it leads to a chain reaction of lipid peroxidation that causes widespread damage to the plasma membrane. Most previous studies on antioxidant pathways in fungal pathogens have been conducted with hydrogen peroxide, so the pathways used to combat organic peroxides and lipid peroxidation are not well understood. The most well-known peroxidase in Candida albicans, catalase, can only act on hydrogen peroxide. We therefore characterized a family of four glutathione peroxidases (GPxs) that were predicted to play an important role in reducing organic peroxides. One of the GPxs, Gpx3 is also known to activate the Cap1 transcription factor that plays the major role in inducing antioxidant genes in response to ROS. Surprisingly, we found that the only measurable role of the GPxs is activation of Cap1 and did not find a significant role for GPxs in the direct detoxification of peroxides. Furthermore, a CAP1 deletion mutant strain was highly sensitive to organic peroxides and oxidized lipids, indicating an important role for antioxidant genes upregulated by Cap1 in protecting cells from organic peroxides. We identified GLR1 (Glutathione reductase), a gene upregulated by Cap1, as important for protecting cells from oxidized lipids, implicating glutathione utilizing enzymes in the protection against lipid peroxidation. Furthermore, an RNA-sequencing study in C. albicans showed upregulation of a diverse set of antioxidant genes and protein damage pathways in response to organic peroxides. Overall, our results identify novel mechanisms by which C. albicans responds to oxidative stress resistance which open new avenues for understanding how fungal pathogens resist ROS in the host.

Electrochemical Formation and Removal of Homogeneous Cu Catalysts

Transition metal ions and their complexes play a crucial role in homogeneous catalysis. These catalysts are pivotal for the production of, for example, fine chemicals and pharmaceuticals. Nevertheless, due to the homogeneous nature of these catalysts, their extraction and removal from the crude reaction mixture is cumbersome. Here, we propose an alternative approach where metal‐based homogeneous catalysts are generated electrochemically from a metallic anode (Cu), followed by their use without current and finally again electrochemically deposited on the cathode. The generated Cu ions were used as catalysts in three different reactions of lauroyl peroxide: one ligand‐free (coupling with dienes), one without ligand but with a heteroatom containing substrate (coupling with toluidine and styrene) and one in the presence of 1,10‐phen as ligand (coupling with indazole). In the first two cases, performance of the electrochemically generated catalysts was similar to those reported in literature for classically prepared homogeneous catalysts, while in the last case a new reaction was observed. After reaction, the homogeneous copper catalyst could be efficiently removed electrochemically: 99% of the copper could be removed for the ligand‐free reaction, 97% for the amine coupling, while 89% of copper could be removed for the reaction containing N‐heterocycle and 1,10‐phenanthroline.

From agricultural waste to value: Integrated chemo and biocatalytic biorefinery processes to produce 2-furoic acid

The integration of biocatalysis in biorefineries can lead to synergies for raw material valorization. Enzymes must perform efficient and selective reactions when using crude effluents (to avoid costly downstream units). Herein, this is showcased with the synthesis of 2-furoic acid, starting from rice husk (agricultural waste), via a sequential organic-acid catalyzed pretreatment – to afford xylose and cellulose and lignin –, followed by the microwave-assisted acidic xylose dehydration to furfural, in situ extraction in ethyl acetate, and the final biocatalytic selective oxidation of furfural to 2-furoic acid (2-FA). To validate the concept, a xylose-rich hydrolysate (∼ 15 g xylose L−1) obtained from rice husk (RH) was used, achieving a furfural yield of 70 % in a biphasic system (water – ethyl acetate). The obtained furfural extracted in the ethyl acetate was subsequently oxidized to 2-furoic acid via an organic peroxide reaction mediated by Candida antarctica lipase B (CALB), with an overall yield of 90 %, and, with a yield of 41.72 % based on the initial xylose in biomass. Notably, 20 mg/mL CALB could tolerate up to 400 mM of furfural under optimum conditions of 40 °C, 48 h. The recyclability of the biocatalyst was investigated, enabling an efficient reuse of four consecutive cycles.

Curcumin-Loaded Liposomes in Gel Protect the Skin of Mice against Oxidative Stress from Photodamage Induced by UV Irradiation.

Prolonged exposure to ultraviolet (UV) irradiation can cause oxidative stress in the skin, accompanied by rapid immunosuppressive effects, resulting in a peroxidation reaction throughout the body. Curcumin (Cur), as the bioactive compound of turmeric, is a natural polyphenol with potent antioxidant properties but is often overlooked due to its poor solubility and low bioavailability. In this study, curcumin-loaded liposomes in a sodium alginate gel complex preparation were designed to improve the bioavailability of curcumin and to study its preventive effect on photodamage. Cur-loaded liposomes (Cur-L), Cur-loaded gel (Cur-G) based on an alginate matrix, and curcumin-loaded liposomes in gel (Cur-LG) were prepared, and their antioxidant effects and drug diffusion abilities were evaluated. The antioxidant capacity of Cur, Cur-L, Cur-G, and Cur-LG was also studied in a mouse model of photodamage. Cur had the highest antioxidant activity at about 4 mg/mL. Cur-LG at this concentration showed antioxidant effects during 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) and H2O2 experiments. During the UV light damage test, Cur-LG demonstrated the ability to effectively neutralize free radicals generated as a result of lipid peroxidation in the skin, serum, and liver, thereby enhancing the overall activity of superoxide dismutase (SOD). In conclusion, using Cur-LG may protect against epidermal and cellular abnormalities induced by UV irradiation.

Abiotic chlorination of organic matter in the soil environment: A simulation study

Chlorination of organic matter occurs naturally and is an important part of the chlorine cycle. To investigate the likelihood that inorganic oxidants, (Fe(NO3)3, H2O2, and hydroxyl radicals (·OH), frequently present in soil environments, could promote the synthesis of chlorinated organic matter in the soil environment, litterfall, humus, and soil (0–20 cm) were collected and used in laboratory based simulation experiments. Results indicate that these inorganic oxidants might promote the synthesis of chlorinated organic matter, but their impact varied due to varying suitable reaction circumstances. Litterfall was the most sensitive to chlorination, likely caused by the presence of abundant amounts of labile organic matter, and the chlorination process was limited by its Cl− level. Hydroxyl radicals showed a dual effect (producing or degrading chlorinated organic matter) on the three materials assessed, which was controlled by both ·OH concentration and the stability of organic matter, and the dual effect was evident in order of litterfall > humus > soil. The Fe(NO3)3-mediated chlorination of organic matter was only significant in litterfall due to its labile organic matter composition, while the peroxidative reaction caused by H2O2 in the producing chlorinated organic matter was only obvious in soil, most likely due to the presence of metals, facilitating the process. Combined this study sheds light on the chlorine cycle by verifying that inorganic oxidants might mediate abiotic chlorination of organic matter in a natural soil environment.

Operando X-Ray Fluorescence Analysis of Dynamic Cerium Radical Quencher Motion Perpendicular to MEA

Polymer electrolyte fuel cells (PEFCs) are required to have a durability of over 50,000 hours. One of the degradation factors is chemical degradation of perfluorosulfonic acid (PFSA) electrolyte membrane. The reaction of hydrogen peroxide with iron impurities produces hydroxyl radicals that break the chemical bonds in the PFSA membrane. Cerium ions are added to electrolyte membranes to absorb these radicals and act as a radical quencher, contributing to improved membrane durability.1 However, cerium ions have been shown to move in both the planar and through-plane directions under fuel cell operating conditions.2,3 The spatial scale of migration in the membrane planar direction is large, and therefore the time scale is also large, where analysis of end-of-life samples has been reported. On the other hand, the observation of the movement in the membrane direction is not easy because the thickness of the electrolyte membrane is 10 micrometers, and it is estimated to be significantly different between the post-disassembly condition and the operating condition. Therefore, it is necessary to establish operando measurement technique for cerium ion concentration with high spatial and temporal resolution in the direction perpendicular to the membrane. We developed an operando X-ray fluorescence spectroscopy technique using a combination of high-energy X-rays and a focused microbeam, and analyzed the behavior of cerium concentration change under current-applied conditions.4 The distribution behavior of cerium ions in the membrane is significantly different depending on the current and humidity. In a high-humidity environment, the ions move in the membrane in the vertical direction in about 1 second. Therefore, in this study, we developed a method to continuously measure the cerium ion concentration in the membrane on a sub-second scale and were able to estimate the effective cerium diffusion coefficient. It was also found that cerium ions migrate to the cathode layer under current-applied conditions. This behavior is accelerated in low humidity environments. This is because the diffusion coefficient of cerium ions is smaller at lower humidity and the back-diffusion flux is smaller.This work is based on results obtained from the project commissioned by the New Energy and Industrial Technology Development Organization (NEDO) of Japan.[1] E. Endoh, ECS Trans., 16, 1229–1240 (2008).[2] Y. Lai, K. M. Rahmoeller, J. H. Hurst, R. S. Kukreja, M. Atwan, A. J. Maslyn,C. S. Gittleman, J. Electrochem. Soc., 165, F3217-F3229(2018).[3] S.M. Stewart, D. Spernjak, R. Borup, A. Datye, F. Garzon, ECS Electrochem. Lett., 3, F19-F22 (2014).[4] Y. Orikasa, A. Takezawa, K. Amemiya, Y. Tsuji, T. Asaoka, M. Ohki, O. Sekizawa, K. Nitta, ECS Trans., 109 109 (2022).

Potential of Soursop Leaf Extract as an Antioxidant in MCF-7 Cells

The frequency of breast cancer tends to increase. Malondialdehyde (MDA) is a marker of oxidative stress as an end product from the chain reaction of lipid peroxidation. The use of traditional medicine soursopleaf (Annona muricata L.) has been reported for a long time because of its bioactivity as an antioxidant. This study analyzes the relationship between MDA levels and glutathione enzymes in MCF-7 cells given the methanol extract of soursop leaves. The methanol extract of soursop leaves was carried out by infusion method. The methanol extract of soursop leaves was given to cancer cells at several doses with an incubation of 24 hours. The cytotoxic test was carried out using the MTT method. Measurement of MDA levels was carried out using the thiobarbituric acid reactive substance (TBARS/TBA) reactivity test method. GSH measurements used the colorimetric method. The results showed that the ethanol extracts of soursop leaves have cytotoxic activity in the MCF-7 breast cancer cell line with IC50 values of 23.96 ppm. Ethanol extract of soursop leaves increased levels of MDA inhibition and GSH level. Soursop leaf extract could increase MDA inhibition GSH level in human breast cancer cells MCF-7.

Phase engineering boosting heterogeneous interface effect in RuO2/MnO2 catalysts for acidic oxygen evolution reaction

Oxygen evolution reaction (OER) of ruthenium dioxide (RuO2) in acidic media usually faces the problem of poor stability caused by excessive oxidation and dissolution. To address this issue, the present work prepares heterojunction catalysts by introducing RuO2 into manganese dioxide (MnO2) with different crystal types. The obtained RuO2/MnO2-γ exhibited excellent acid OER activity (η = 220 mV at 10 mA·cm−2) and could operate stably for 80 h. Mainly because the Ru-O-Mn bonds generated at the RuO2/MnO2-γ heterointerface fine-tune the charge environment of RuO2. The formation of this particular interface can enable MnO2-γ to produce more reactive oxygen defects, which promotes the transfer of electrons. At the same time, it can also minimize the peroxidation reaction and structural collapse of RuO2 under acidic conditions, thereby suppressing the Lattice Oxygen Mechanism (LOM) to improve stability. Density functional theory (DFT) results show that RuO2/MnO2-γ lowers the energy barrier for the *O to *OOH conversion. This research findings provides a new perspective for elucidating the role of the regulated electronic environment arising from heterogeneous interfaces.

Reaction of hydrogen peroxide with amorphous Ti–O surfaces

Amorphous Ti–O thin films were synthesized by reactive magnetron sputtering and their affinity to H2O2 was studied electrochemically. They exhibit a pronounced affinity to H2O2, with TiO0.6 outperforming TiO1.5 and TiO2. Cathodic currents in the range of −211 μA/cm2 suggest that TiO0.6 is highly electroactive to H2O2. Molecular dynamics simulations based on density functional theory revealed rapid dissociation of H2O2 into OH on Ti–O surfaces, leading to diffusion of OH, facilitating both oxidation and reduction processes. These OH groups predominantly dock onto bridge and atop sites, oxidizing the surfaces. Notably, stronger interactions observed for lower oxidation states give rise to higher cathodic currents. Additionally, the ability of amorphous Ti–O thin films to generate free H atoms implies a possible reduction mechanism, likely leading to the desorption of H2O. Hence, amorphous TiO0.6 is more suitable for detection and monitoring of H2O2 than higher oxidation states in their crystalline forms, e.g., rutile TiO2, known as a benchmark for such applications.

Hydrophobic-treated yolk-shell SnS2@CSs Z-scheme confinement reactor for solar-electro-driven hydrogen peroxide production in neutral media

The diffusion and adsorption properties of the O2/H2O corpuscles at active sites play a crucial role in the fast photo-electrocatalytic reaction of hydrogen peroxide (H2O2) production. Herein, SnS2 nanosheets with abundant interfacial boundaries and large specific areas are encapsulated into hollow mesoporous carbon spheres (CSs) with flexibility, producing a yolk-shell SnS2@CSs Z-scheme photocatalyst. The nanoconfined microenvironment of SnS2@CSs could enrich O2/H2O in catalyst cavities, which allows sufficient internal O2 transfer, improving the surface chemistry of catalytic O2 to O2− conversion and increasing reaction kinetics. By shaping the mixture of SnS2@CSs and polytetrafluoroethylene (PTFE) on carbon felt (CF) using the vacuum filtration method, the natural air-breathing gas diffusion photoelectrode (AGPE) was prepared, and it can achieve an accumulated concentration of H2O2 about 12 mM after a 10 h stability test from pure water at natural pH without using electrolyte and sacrificial agents. The H2O2 product is upgraded through one downstream route of conversion of H2O2 to sodium perborate. The improved H2O2 production performance could be ascribed to the combination of the confinement effect of SnS2@CSs and the rich triple phase interfaces with the continuous hydrophobic layer and hydrophilic layer to synergistically modulate the photoelectron catalytic microenvironment, which enhanced the transfer of O2 mass and offered a stronger affinity to oxygen bubbles. The strategy of combining the confined material with the air-breathing gas diffusion electrode equips a wide practical range of applications for the synthesis of high-yield hydrogen peroxide.

Benzoyl peroxide encapsulation in poly(urea‐formaldehyde) microcapsules for use in dental materials

AbstractNew self‐healing resin composites with tertiary amine microcapsules enhance the mechanical performance of dental restorations. However, a higher concentration of dibenzoyl peroxide (BPO) must be added to the composite to react with the core material when the microcapsules rupture, reducing the shelf life of dental materials due to their reactivity. As a result, one approach to reducing the amount of BPO dissolved in dental resin is to microencapsulate it. Thus, this manuscript described the encapsulation of BPO in poly(urea‐formaldehyde) (PUF) microcapsules (MC) and investigated its effect on the flexural strength of BisGMA/TEGDMA composites. To synthesize hollow MC, poly(acrylic acid) (PAA) was tested as a continuous phase viscosity modifier. The MC were then infiltrated with BPO dissolved in linseed oil as core materials. PAA in continuous phase increased MC diameter due to improved air bubble stability. BPO dissolved in linseed oil was successfully infiltrated into empty PUF MC, causing the MC shell wall to expand. The dental resin had adequate adhesion to the PUF shell, which ruptured under induced stress. Thus, the MC filled with BPO as a healing agent has the potential to reduce the amount of BPO that is typically dissolved in the monomeric phase of dental materials, which can increase the shelf life of self‐healing dental materials.Highlights The reactivity of dibenzoyl peroxide (BPO) affects resin stability in dental materials. When combined with tertiary amines, BPO acts as a healing agent in self‐healing composite materials. BPO dissolved in linseed oil can be infiltrated in PUF microcapsules and increase its size. Hollow microcapsules synthesized in a more viscous continuous phase have a larger diameter. Microencapsulated BPO is released during stress stimuli in dental resin.

In silico analysis of a heme-thiolate peroxidase gene discovered in an ectomycorrhizal fungus of Carpathian primeval forest: implications for biotechnological applications

In this work, we focus on the identification of novel fungal peroxygenase gene belonging to the peroxidase-peroxygenase superfamily. We applied a metagenomic approach on soil samples from primeval forest and appropriate bioinformatics tools for analysis of obtained genomic DNA sequence. Peroxidases are ubiquitous metalloenzymes that are able to reduce reactive peroxides, mainly hydrogen peroxide, into water, whereas several substrates can be concomitantly oxidized during their catalytic reaction. Our purpose was to collect unique peroxygenase sequence data originating from a preserved biotope for a robust phylogenetic reconstruction of a particular gene family coding for highly versatile heme-thiolate peroxidases that has peculiar yet undiscovered representatives among ectomycorrhizal fungi. We identified unique DNA sequence, 812 bp long, from ectomycorrhizal Suillus species coding for a heme-thiolate peroxidase with 1 typical intron that appears distinctive for Carpathian forests. After translation in corresponding protein sequence 251 amino acids long we could identify typical signatures of this peroxygenase. On the proximal side of heme we found the conserved P-C-P triad responsible for efficient ligation of heme iron thus influencing the reactivity of this peroxidase. On the distal side we recognized the E-H-D-X-S-L motif for interaction with a stabilizing magnesium ion. Maximum likelihood reconstruction of protein phylogeny revealed with a high bootstrap support the presence of a monophyletic HTP4 clade originating in numerous Suillus representatives. Together with sister clades of edible Boletus and poisonous Paxillus containing diverse peroxygenases these newly discovered heme catalyst can be considered for application of oxyfunctionalization of organic molecules.

Magnetically induced asymmetry and fuel-propulsion of lipid vesicles containing Fe3O4 micromotors

Artificial micro/nanomotors possess the capability to navigate intricate environments in accordance with a premeditated blueprint. Hybrid-propelled micromotors may present an efficacious approach in addressing scientific research quandaries. In this context, ferric oxide magnetic nanoparticles (Fe3O4 MNPs) are chosen as catalysts to be encapsulated within lipid vesicles (LVs) due to their superior quality and cost-effectiveness. The external magnetic field induces the aggregation of Fe3O4 MNPs within the LVs, resulting in the formation of an asymmetrical structure that promotes the catalytic reaction of hydrogen peroxide, producing oxygen to propel the movement of Fe3O4@LVs micromotors. The magnetic-fuel dual drive enables the Fe3O4@LVs micromotor to move 1.3 times faster than the LVs alone. Additionally, the magnetic field offers the advantage of controlling the direction of motor movement and facilitating retrieval for practical applications. This dual drive micromotor exhibits exceptional stability and reusability in aqueous solutions, underscoring its immense potential for future applications.

Conversion of Phorbol into Des-D-Ring Tricycle and Crotonianoid B via Peroxidation Reaction.

Phorbol (1) has a tetracyclic ABCD-ring and is readily isolable from a natural source. We previously synthesized 1 and 16 structurally related natural products using common ABC-ring intermediate 2. Here we report a new synthetic route to 2 using 1 as a starting material. Key features of the synthesis are chemoselective removal of the D-ring via cyclopropane opening, peroxidation, and retro-aldol reactions. The high utility of the peroxidation was further demonstrated in the first synthesis of crotonianoid B (9).

Degradation of methyl orange by the Fenton-like reaction of pyrite-activated hydrogen peroxide forming the Fe(III)/Fe(II) cycle

In this study, the typical azo dye methyl orange (MO) was degraded by pyrite (FeS2) activated by hydrogen peroxide (H2O2). When [MO] = 0.1 mM, [FeS2] = 2.0 g/L and [H2O2] = 22 mM, 96.4% MO was removed in 120 min and the TOC removal rate was higher than 50%. HO• was the primary radical responsible for MO degradation. In addition, the acid condition promoted the degradation of MO in the FeS2/H2O2 system. MO in tap water and river water was not effectively degraded, whereas acidification could weaken the inhibitory effect on the FeS2/H2O2 system to enable the degradation of MO in tap and river water. The OD600 indicated that the solution was environmentally friendly after the reaction, and three degradation pathways of MO were discussed. In summary, Fe(II) could be dissolved from FeS2, which activated H2O2 to generate Fe(III) and HO•. FeS2 could reduce Fe(III) into Fe(II), thus realizing the Fe(III)/(II) cycle and efficiently activating H2O2 to degrade MO.