Peroxide Compounds Research Articles

Thermal and radiation effects on the cross-linking and mechanical properties of HNBR elastomers

This study investigates the enhancement of the properties of mixtures based on hydrogenated butadiene nitrile rubber (HNBR) under thermal, radiation and thermo-radiation effects by introducing into them the composition of chlorine-containing triazine and peroxide compounds (HCPX and ABTST) into the composition. It has been shown that radiation-chemical cross-linking and the formation of effective chemical cross-links in HNBR depend both on the absorbed dose of radiation and on the addition of vulcanizing agents. It has been established that the activity of hexachloroparaxylene (HCPX), dicumyl peroxide (DP) and triazine (ABTST) is not the same; the content of the gel increases markedly with increasing absorbed dose. A higher crosslinking density is observed for images subjected to thermo-radiation crosslinking. The change in the molecular structure of HNBR, observed both during heating and irradiation, has the same nature. It has been shown that the physical and mechanical properties of saturated radiation and thermal vulcanizates are practically inferior to thermo-radiation ones in strength.

Wipe Disinfection of Reusable Elastomeric Half-Mask Respirators for Health Care Use.

During shortages, elastomeric half-mask respirators (EHMRs) are an alternative to reusing N95 filtering facepiece respirators but require between-use disinfection. The objectives of this study were to (a) measure microbial reductions on EHMR surfaces under laboratory conditions by a standardized procedure using wipes impregnated with health care disinfectants and to (b) measure microbial reductions on EHMRs disinfected by volunteer health care providers. We inoculated EHMR (Honeywell model RU8500) surfaces with Pseudomonas aeruginosa, Bacillus atrophaeus spores, and bacteriophages MS2 and Φ6, and disinfected them using two wipes with hydrogen peroxide (HP), alcohols, and quaternary ammonium compounds (QACs). Then, we randomized 54 volunteer subjects into three groups (Group 1: two wipes with instructions, Group 2: five wipes with instructions, Group 3: no instructions or set number of wipes) and used 0.5% HP wipes without precleaning on EHMRs inoculated with Raoultella terrigena and MS2. The laboratory study demonstrated that all organisms achieved at least 4 log10 median reductions (HP>QAC/alcohol>QAC>QAC/saline). Pseudomonas was highly susceptible to HP and QAC/alcohol and Φ6 to all disinfectants. MS2 reduction was highest using HP and lowest using QAC/saline. Bacillus was least susceptible. The volunteer study showed a 3 to 4 log10 average reductions of bacteria and virus; Raoultella reductions were greater than MS2, with variability within and between subjects. Conclusions: HP disinfectant wipes used in laboratory and by volunteers reduce bacteria and viruses on EHMRs by 3 to 4 log10 on average. Commercially available hospital disinfectant wipes reduce bacteria and viruses on EHMRs and can fill the need for between-use disinfection. HP and combination QAC/alcohol have the greatest efficacy under our test conditions.

ВІТАМІН С: СТРУКТУРА, БІОХІМІЧНЕ ЗНАЧЕННЯ, МЕТОДИ ВИЗНАЧЕННЯ

The role of vitamin C for the functioning of the human body is outlined. The antioxidant properties of vitamin C are thought to be a key factor in neutralizing free radicals and peroxide compounds, protecting cells from oxidative stress. It also replenishes other antioxidants, such as vitamins E and glutathione. It is a cofactor for enzymes involved in collagen synthesis. It is necessary for the normal functioning of the skin, bones, cartilage, tooth enamel and blood vessels. Due to the loss of the ability to independently produce ascorbic acid, people are completely dependent on the intake of vitamin C from food. The main food forms of vitamin C are L-ascorbic, D-ascorbic and dehydroascorbic acids. The content of vitamin C in vegetables and fruits and the norms of its consumption were analyzed. Vitamin C is an essential component of all green plants and the lowest daily human need for it (40 mg) can be obtained by eating any set of vegetables and fruits every day. Among the plants that are common in Europe, the highest content of the vitamin is inherent in rose hips and black currants. A relatively high content of ascorbic acid is found in strawberries, citrus fruits and various vegetables, in particular, in potatoes. The determination of vitamin C in food systems is a complex problem due to the oxidation of ascorbic acid, even at the sample preparation stage. The stability of L-ascorbic acid in aqueous solutions can be affected by a number of factors, including exposure to light rays, temperature increases, changes in pH, and the presence of oxygen and metal ions. Along with classical titrimetric methods, researchers use spectrophotometry, electrochemical and chromatographic methods, the advantages of which are high sensitivity, selectivity, expressiveness, and the possibility of automation. The property of L-ascorbic acid to participate in redox reactions is the basis of titrimetric methods, including iodometric titration (IODINE), dichlorophenol-indophenol titration (DCIP), titration with N-bromosuccinimide (NBS). Spectrophotometric studies are carried out at 530 nm using potassium permanganate as a chromogenic reagent. Electrochemical determination of vitamin C is carried out using mercury, gold, platinum and glass carbon electrodes. Ultra-efficient liquid chromatography (UPLC) and high-performance liquid chromatography (HPLC) are used. The UPLC method is believed to be faster, more sensitive, consumes less eluent, and is more environmentally friendly than the HPLC method The main reason for the deviation of the results and errors is the existence of vitamin C in natural objects in several forms with different activity and chemical resistance.

A New Approach for CRISPR/Cas9 Editing and Selection of Pathogen-Resistant Plant Cells of Wine Grape cv. 'Merlot'.

Grape is one of the most economically significant berry crops. Owing to the biological characteristics of grapes, such as the long juvenile period (5-8 years), high degree of genome heterozygosity, and the frequent occurrence of inbreeding depression, homozygosity during crossbreeding leads to loss of varietal characteristics and viability. CRISPR/Cas editing has become the tool of choice for improving elite technical grape varieties. This study provides the first evidence of a decrease in the total fraction of phenolic compounds and an increase in the concentration of peroxide compounds in grape callus cells upon the addition of chitosan to the culture medium. These previously unreported metabolic features of the grape response to chitosan have been described and used for the first time to increase the probability of selecting plant cells with MLO7 knockout characterised by an oxidative burst in response to the presence of a pathogen modulated by chitosan in the high-metabolite black grape variety 'Merlot'. This was achieved by using a CRISPR/Cas9 editing vector construction with the peroxide sensor HyPer as a reporter. This research represents the first CRISPR/Cas9 editing of 'Merlot', one of the most economically important elite technical grape varieties.

Formation of Uranyl Peroxide Compounds via Dissolution of Studtite, [(UO2)(O2)(H2O)2](H2O)2, in Ionic Liquids.

Four uranyl peroxide compounds with novel structures were formed following the dissolution of studtite, [(UO2)(O2)(H2O)2](H2O)2, in imidazolium-based ionic liquids. The compounds were characterized using single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), Raman and infrared (IR) spectroscopy, and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). The ionic liquids used in the experiments were 1-ethyl-3-methylimidazolium (EMIm) diethyl phosphate, EMIm ethyl sulfate, and EMIm acetate. Each of the four uranyl peroxide compounds contain components from the ionic liquids as terminal ligands on uranyl peroxide molecular units, bridging ligands in uranyl peroxide sheet structures, or charge balancing cations located in the interstitial space. The studtite dissolved in and reacted with the ionic liquids, producing unique crystal structures depending on the anionic component of the ionic liquid, the temperature at which the synthesis was performed, and the introduction of additional ionic species into the solution. This is the first report of studtite dissolving in and reacting with ionic liquids to form uranyl peroxide compounds, which has the potential to vastly increase the number of synthetic routes for the formation of uranyl peroxide clusters and uranyl peroxide cage clusters.

Chemical Diversity, Pharmacology, Synthesis and Detection of Naturally Occurring Peroxides.

Natural occurring peroxides are interesting bioprospecting targets due to their molecular structural diversity and the wide range of pharmacological activities. In this systematic review, a total of 123 peroxide compounds were analysed from 99 published papers with the compounds distributed in 31 plants, 18 animals and 41 microorganisms living in land and water ecosystems. The peroxide moiety exists as both cyclic and acyclic entities and can include 1,2-dioxolanes, 1,2-dioxane rings and common secondary metabolites with a peroxo group. These peroxides possessed diverse bioactivities including anticancer, antimalarial, antimicrobial, anti-inflammatory, neuroprotective, adipogenic suppressor, antituberculosis, anti-melanogenic and anti-coagulant agents. Biosynthetic pathways and mechanisms of most endoperoxides have not been well established. Method development in peroxide detection has been a challenging task requiring multidisciplinary investigation and exploration on peroxy-containing secondary metabolites are necessary.

Effect of Peroxide Compounds on Biodegradable Blends Based on Poly(butylene adipate-co-terephthalate)/Plasticized Cellulose Acetate

Effect of Peroxide Compounds on Biodegradable Blends Based on Poly(butylene adipate-<i>co</i>-terephthalate)/Plasticized Cellulose Acetate

Design and synthesis of visible light-activatable photocaged peroxides for optical control of ROS-mediated cellular signaling

We designed and synthesized two novel photocaged peroxide compounds, N5TBHP and N6TBHP, featuring nitrogen-containing fused ring coumarin skeletons. Notably, a tetrahydroquinoline fused coumarin derivative, N6TBHP demonstrated significantly higher photocleavage efficiency under visible light at 455 nm compared to N5TBHP, which contains an indoline fused coumarin. This process effectively releases the oxidative stress inducer tert-butylhydroperoxide (TBHP). Additionally, N6TBHP exhibits high resistance to glutathione (GSH), and its UV spectral analysis suggests enhanced intracellular stability due to reduced reactivity with GSH through self-assembly. Furthermore, N6TBHP can release an optimal amount of TBHP into cells under visible light irradiation with minimal cell damage. These properties position N6TBHP as a promising tool for advancing research in intracellular redox signaling.

Obtaining unsaturated polyester resins using products of recycled polyethylene terephthalate solvolysis

A technique for obtaining an unsaturated polyester resin based on recycled polyethylene terephthalate has been developed. The process of curing an unsaturated polyester resin under the action of styrene, a peroxide compound (Butanox 50M) and an accelerator (cobalt ortoate) has been studied. The physical and mechanical properties of polymeric materials based on the developed resin have been studied, it was found that their strength depends on the mass fraction of recycled polyethylene terephthalate in the oligoether polyol used in the synthesis.

In vitro activity of Western Australian honeys and Manuka honey against clinically important yeasts.

With the steady rise in antifungal resistance amongst clinically important yeasts, antifungal drug discovery remains of the utmost importance. To determine the potential of some honeys as alternative antifungal agents, we quantified the antifungal activity of 12 Western Australian honey samples, two Manuka honey samples and an artificial honey against 10 yeast isolates including clinical and reference strains. Results showed that the tested honeys varied in activity, and yeasts species also differed in susceptibility, with minimum inhibitory concentrations (MICs) determined by broth microdilution ranging from 8% to >44% w/v honey. Honeys with the highest overall activity were derived from Blackbutt (Eucalyptus patens), Jarrah (E. marginata), and Karri (E. diversicolor). The optical density of each MIC microtitre plate was determined after incubation and showed that at relatively low concentrations of honey the growth of all yeasts was enhanced compared to the untreated control, whereas at and above approximately 12% w/v, honeys exerted a dose-dependent growth inhibitory effect, the extent of which varied by honey type. Time-kill studies with 64% w/v honey showed that all eight of the natural honeys tested had greater fungicidal activity than the comparator artificial honey. Our findings suggest that the specific nectar-derived phytochemicals present within each honey play an important role in antifungal activity, and support the notion that activity is due to a combination of factors including osmotic activity, hydrogen peroxide and phytochemical compounds. These data indicate that honey is worthy of further investigation as a potential therapeutic agent for superficial yeast infections.

Efficacy of Three Antimicrobials Against two SARS-COV-2 Surrogates, Bovine Coronavirus and Human Coronavirus OC43, on Hard or Soft Nonporous Materials

The efficacy of three antimicrobials was evaluated against two severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surrogates – bovine coronavirus (BCoV) and human coronavirus (HCoV) OC43 – on hard and soft nonporous materials. Three antimicrobials with three different active ingredients (chlorine, hydrogen peroxide, and quaternary ammonium compound + alcohol) were studied. Initially, a neutralization method was optimized for each antimicrobial. Then, we determined their efficacy against BCoV and HCoV OC43 in both suspension and on surfaces made with polyethylene terephthalate (PET) plastic and vinyl upholstery fabric. All tests were conducted under ambient environmental conditions with a soil load of 5% fetal bovine serum. After a 2-min exposure, all three antimicrobials achieved a >3.0 log10 reduction in viral titers in suspension. All three also reduced virus infectivity on both surface materials below the detection limit (0.6 log10 TCID50/carrier). Treatments in which the reduction in virus titer was <3.0 log10 were attributed to a decreased dynamic range on the carrier during drying prior to disinfection. The carrier data revealed that both surrogates were inactivated more rapidly (p <0.05) on vinyl or under conditions of high relative humidity. Three classes of antimicrobials were efficacious against both SARS-CoV-2 surrogate viruses, with BCoV demonstrating slightly less sensitivity compared to HCoV OC43. These findings also illustrate the importance of (1) optimizing the neutralization method and (2) considering relative humidity as a key factor for efficacy testing.

Prospects for the use of sulfur-containing pteridines in toxic liver damage

The presented material describes the results of the purposeful search for the novel hepatoprotective agents among synthetic sulfur-containing pteridines. The studied compounds were obtained using previously described synthetic procedures. SwissADME and ProTox-II services, as well as a docking study were used to predict the compounds` pharmacokinetics, drug-likeness and toxicity. The effects of sulfur-containing pteridines on lipid peroxidation in vitro and GSH/GSSG levels in vivo were studied for evaluation of their hepatoprotective potential. In silico procedures allowed us to exclude the compounds with inappropriate ADME parameters and high predicted toxicity. Molecular docking of the obtained compounds towards the active site of CYP-enzyme allowed us to clarify the specifics of ligand-enzyme interactions and predict cytochrome-inhibiting activity of the studied agents. The antioxidant activity of the studied compounds was evaluated in vitro using the linoleic acid peroxidation model. It has been found that sulfur-containing pteridines inhibit the peroxidation of linoleic acid. The structure – antioxidant activity relationships were evaluated and discussed as well. Additionally, it has been estimated that antioxidant properties of the studied pteridines directly correlate with their hydrophilicity and number of functional groups with exchangeable proton in molecules. In vivo studies showed that some of the studied sulfur-containing pteridines reduced severity of the hepatotoxic effects caused by the administration of carbon tetrachloride. (3-(7-Hydroxy-4-oxo-2-thioxo-1,2,3,4-tetrahydropteridin-6-yl)propanoyl)alanine has been identified as the most active hepatoprotective agent. The above mentioned compound significantly increases the content of GSH and decreases the level of GSSG compared with non-treated experimental pathology, which reliably affirms its hepatoprotective activity. The hepatoprotective activity of the studied compounds is likely associated with their ability to increase the level of GSH, inhibit lipid peroxidation and decrease prooxidant compounds levels. The obtained results attest the reasonability of further search for hepatoprotective agents among sulfur-containing pteridine derivatives.

Exploring Acne Treatments: From Pathophysiological Mechanisms to Emerging Therapies.

Acne vulgaris is a common dermatological condition that can present across different ages but predominantly affects adolescents and young adults. Characterized by various lesion types, the pathogenesis of acne is complex, involving genetic, hormonal, microbial, and inflammatory factors. This review comprehensively addresses current and emerging acne management strategies, emphasizing both topical and systemic treatments, procedural therapies, and dietary modifications. Key topical agents include retinoids, benzoyl peroxide, antibiotics, and other specialized compounds. Systemic options like antibiotics, hormonal therapies, and retinoids offer significant therapeutic benefits, particularly for moderate to severe cases. Procedural treatments such as laser devices, photodynamic therapy, chemical peels, and intralesional injections present viable alternatives for reducing acne symptoms and scarring. Emerging therapies focus on novel biologics, bacteriophages, probiotics, and peptides, providing promising future options. This review underscores the importance of personalized approaches to treatment due to the multifaceted nature of acne, highlighting the potential of innovative therapies for improving patient outcomes.

Antioxidant Activity of Virgin Coconut Oil Emulsion Drink with The Addition of Cinnamon (Cinnamomum burmanii)

ABSTRACT The aims of this study were to analyse the antioxidant activity and to determine the maximum concentration of cinnamon extract that can improve sensory attributes of VCO emulsion drink. The research method used is a completely randomized design (CRD) with five concentrations of cinnamon extract, i.e., 0% (P1), 2% (P1), 4% (P2), 6% (P3), and 8% (P3). Each treatment was triplicated. The results showed that all treatments exhibited stable emulsion with 0% creaming index. VCO emulsion drink with cinnamon extract contained total phenol ranged from 19.88 mg GEA/100 g to 28.58 mg GEA/100 g, with increasing antioxidant activity, expressed as percentage of inhibition, where P1: 80.35%; P1: 85.59%; P2: 86.38%, P3: 87.43%, and P4: 88.54%, respectively. It was concluded that cinnamon extract could increase the antioxidant activity of VCO emulsion drinks. Increasing percentage of cinnamon extract can increase the total phenol content, hence increase the inhibitory power on the formation of peroxide compounds. The addition of 6% cinnamon is the maximum limit that can improve the panellists’ liking for the overall sensory attributes of the VCO emulsion drink. Keywords: Antioxidant activity; cinnamon; VCO emulsion

Storage stability of Asian seabass oil-in-water Pickering emulsion packed in pouches made from electrospun and solvent casted bilayer films from poly lactic acid/chitosan-gelatin blend containing epigallocatechin gallate

Bilayer pouches were fabricated with chitosan (CS)-fish gelatin (FG) mixture containing epigallocatechin gallate (EGCG) deposited over the poly lactic acid (PLA) film through solvent casting and electrospinning techniques. Pickering emulsions (PE) of Asian seabass depot fat oil stabilized by zein colloidal particles were packed in bilayer pouches and stored at 28 ± 2 °C. The PE packed in pouch containing EGCG had higher emulsion and oxidative stability after 30 days of storage as witnessed by the smaller droplet size and lower values of thiobarbituric acid reactive substances, peroxide, conjugated diene and volatile compounds in comparison with control (PE packed in monolayer PLA pouch) (P < 0.05). EGCG incorporated pouch retained more linoleic acid (C18:2 n-6) and linolenic acid (C18:3 n-9) in emulsion than PLA pouch. Therefore, pouch from bilayer PLA/CS-FG films comprising EGCG could serve as active packaging and extended the shelf life of Pickering emulsion.

Chronobiological approach to study microsymbiont catalase activity in female reproductive tract

Catalase is a heme-containing enzyme belonging to protection factors that destroys peroxide compounds. The presence of catalase activity is an important ability of microorganisms that allows them to be protected from unfavorable factors as well as adapt to macroorganism conditions. Catalase along with superoxide dismutase plays an important role in pathogen resistance to phagocyte oxygen-dependent bactericidal mechanisms. The aim of the study was to investigate microsymbiont catalase activity from female reproductive tract in normocenosis and candidiasis dysbiosis using the chronobiological approach. The study was conducted on clinical isolates, isolated from female reproductive tract microsymbiocenosis. The catalase activity was determined by spectrophotometry based on 24 hour-long hydrogen peroxide reduction with 3-hours interval in winter season. Dynamic hydrogen peroxide was assessed in 3–5 experiment replicates. In some Lactobacillus spp., catalase was found containing no heme group — pseudocatalase. Chronobiological approach allowed to reveal enzyme activity from all microsymbionts. The dominant and associative microbiota isolated from healthy females was characterized by circadian (24 hours) rhythms of catalase activity early in the morning — 5 a.m. (р 0.05). Hydrogen peroxide decomposes spontaneously or via non-enzymatic catalysts, and microorganisms cope with this situation under such conditions. In microsymbionts characteristic of female reproductive tract dysbiosis, and usually found in large numbers along with decreased Lactobacillus spp. ultradian rhythms with 12- and 8-hour harmonics of catalase activity with acrophase were recorded in the morning (8 a.m.) and evening hours (8 p.m.). The minimum values of enzyme production in all cultures were recorded at 12 p.m. and 5 p.m. Therefore, the contribution of the rhythm of the studied parameter at varying degree of vaginal sterility reflects the adaptive pathogen capabilities to the conditions of existence and can be the basis for studying related regulatory mechanisms. Mesor and amplitude phase stability are universal rhythmometric parameters used to evaluate patient’s condition independent of species assignment.

Oxygen-18 Labeling Defines a Ferric Peroxide (Compound 0) Mechanism in the Oxidative Deformylation of Aldehydes by Cytochrome P450 2B4.

Most cytochrome P450 (P450) oxidations are considered to occur with the active oxidant being a perferryl oxygen (FeO3+, Compound I). However, a ferric peroxide (FeO2®, Compound 0) mechanism has been proposed, as well, particularly for aldehyde substrates. We investigated three of these systems, the oxidative deformylation of the model substrates citronellal, 2-phenylpropionaldehyde, and 2-methyl-2-phenylpropionaldehyde by rabbit P450 2B4, using 18O labeling. The formic acid product contained one 18O derived from 18O2, which is indicative of a dominant Compound 0 mechanism. The formic acid also contained only one 18O derived from H218O, which ruled out a Compound I mechanism. The possibility of a Baeyer-Villiger reaction was examined by using synthesized possible intermediates, but our data do not support its presence. Overall, these findings unambiguously demonstrate the role of the Compound 0 pathway in these aldehyde oxidative deformylation reactions.

МЕТОДЫ ОЦЕНКИ КАЧЕСТВА ДЕЗИНФЕКТАНТОВ НА ОСНОВЕ НУК

The article presents the history of discoveries of peroxide compounds. A brief description of peracetic acid is given. Regulatory documents governing methods for determining the active substance in disinfectants based on peracetic acid are presented. An analytical analysis of these methods for assessing the quality of disinfectants based on peracetic acid is conducted.

Socialization Of The Characteristics Of Oil That Is Used Repeatedly For The People Of Ranah Batahan District

In this activity, food safety outreach was carried out regarding the use of cooking oil for repeated frying. Cooking oil is a triglyceride compound which has a high boiling point. The use of cooking oil in society is often used repeatedly. This means that the chemical content in cooking oil can undergo oxidation and hydrolysis processes so that the quality of the oil becomes damaged. The formation of peroxide compounds means that oil will become a precursor to the formation of an unhealthy condition for those who consume it. Therefore, this socialization was carried out to increase public knowledge. The socialization activities were carried out during real work lecture activities for Andalas University students for the 2023 period. The socialization was carried out using the lecture and question and answer method. As a result of this activity, it is known that there has been an increase in community knowledge, which is indicated by the establishment of very good communication activities between the community and the real work lecture team from Andalas University. It is hoped that this activity will be carried out again with a different food safety topic.

Cavity-Modified Chemiluminescent Reaction of Dioxetane.

Chemiluminescence is a thermally activated chemical process that emits a photon of light by forming a fraction of products in the electronic excited state. A well-known example of this spectacular phenomenon is the emission of light in the firefly beetle, where the formation of a four-membered cyclic peroxide compound and subsequent dissociation produce a light-emitting product. The smallest cyclic peroxide, dioxetane, also exhibits chemiluminescence but with a low quantum yield as compared to that of firefly dioxetane. Employing the strong light-matter coupling has recently been found to be an alternative strategy to modify the chemical reactivity. In the presence of an optical cavity, the molecular degrees of freedom greatly mix with the cavity mode to form hybrid cavity-matter states called polaritons. These newly generated hybrid light-matter states manipulate the potential energy surfaces and significantly change the reaction dynamics. Here, we theoretically investigate the effects of a strong light-matter interaction on the chemiluminescent reaction of dioxetane using the extended Jaynes-Cummings model. The cavity couplings corresponding to the electronic and vibrational degrees of freedom have been included in the interaction Hamiltonian. We explore how the cavity alters the ground- and excited-state path energy barriers and reaction rates. Our results demonstrate that the formation of excited-state products in the dioxetane decomposition process can be either accelerated or suppressed, depending on the molecular orientation with respect to the cavity polarization.