P-hydroxybenzoic Acid Research Articles

Synthesis, crystal structures, characterizations and antibacterial activities for four lithium(I)-based metal organic frameworks

Lithium(I)-based compounds are extensively utilized across various domains, however, their structural characteristics remain inadequately explored, which has hindered further development and application of their functionalities. Thus, the exploration of their structural intricacies is crucial for unlocking their full potential and paving the way for innovative applications in diverse fields. In this study, four Li(I)-based metal organic frameworks (MOFs), namely, [Li4(BNZ)4(H2O)4]n (1), [Li(HBNZ)]n (2), [Li(BNZ)(DPRO)]n (3), [Li2(MBNZ)2(DPRO)2]n (4), are synthesized through hydrothermal method, and structurally characterized by single crystal X-ray diffraction, powder X-ray diffraction, and IR, where BNZ, HBNZ, MBNZ and DPRO are benzoic acid, 4-hydroxybenzoic acid, 3-methoxybenzoic acid and d-proline, respectively. Crystallographic analysis reveals that all these complexes are two-dimensional layered architectures, of which 3 and 4 display a similar wave-like square grids network. The crystal structures of the complexes 1–4 are stabilized by one or more kinds of NH···O, CH···O, OH···O, CH···π, π-π interactions, and the intermolecular interactions and thermal stabilities of these complexes were also analyzed by Hirshfeld surface and thermogravimetric analysis, respectively. Moreover, these complexes show the great photoluminescence properties and antibacterial activities, exhibiting remarkable potential applications in both material and pharmaceutical science, and the necessity for continued research to promise a paradigm shift in the design and application of advanced materials.

Phenolic Compounds, Fatty Acid Contents, and Antibacterial Properties of Ozonated and Non-Ozonated Tobacco Seed Oils

ABSTRACT In this study, the fatty acid content, phenolic compounds, and antimicrobial activity of seed oils from Ege Özbaş (EO), Sarıbağlar 407 (S407) and Akhisar 98 (A98) tobacco plants grown in the Aegean region were investigated. The ozonation process altered fatty acid and phenolic compound compositions and affected antimicrobial activities against Gram-positive and Gram-negative bacteria in the oils. Tobacco seed oils (TSOs) were extracted via cold pressing (CP) and Soxhlet extraction (SE). Fatty acids and phenolic compounds were analyzed using GC-FID and LC-MS/MS, respectively. Non-ozonated oils averaged 73% linoleic acid, 13% oleic acid, 9% palmitic acid, and 3% stearic acid, while ozonated oils contained 41% linoleic acid, 18% oleic acid, 22% palmitic acid, and 11% stearic acid. The presence of 33 phenolic compounds was investigated and 22 common phenolic compounds were detected in both ozonated and non-ozonated TSOs, including gallic acid, protocatechuic acid, chlorogenic acid, 3-hydroxybenzoic acid, (-)-epicatechin, 2,5-dihydroxybenzoic acid, caffeic acid, verbascoside, luteolin-7-glucoside, hesperidin, and rosmarinic acid. The increased antimicrobial activity of fatty acids and phenolic compounds following ozonation suggests the potential for developing creams to treat skin diseases and wounds caused by antibiotic-resistant pathogens, and to reduce the effects of aging skin wrinkles.

Profiling metabolites and exploring metabolism of parabens in human urine using non-target screening and molecular networking

Parabens are widely used as preservatives in food, pharmaceuticals, and cosmetics due to their excellent antimicrobial activities, cost-effectiveness, and stability. Previous studies have demonstrated their harmful potential and ubiquity in the environment and human tissues. This study revealed profiles of parabens and their metabolites in urine samples from a general population of different ages in China using non-target screening. Metabolism of parabens in human bodies was further explored through the identified metabolites in combination of molecular networking. A total of 34 paraben compounds were screened in the urine samples. In addition to 3 identified confidence level 1 (CL1) parent parabens, 3 CL2 compounds were also identified, namely 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and ethylparaben sulfate. Furthermore, 6 CL3 compounds were tentatively identified, five of which were sulfonated and sulfated metabolites of parabens. The remaining 22 were CL4 features without certain chemical structures. Hazardousness assessment suggested toxic potential of the identified metabolites. Distribution of the parabens and metabolites in the urines showed age-dependent differences. Sulfonation and sulfation were potentially significant metabolic pathways of the parabens in human bodies. This study provides a new insight into understanding metabolism of parabens in human bodies and potential risks of human exposure to parabens.

Synthesis, characterization and anticorrosion performance of a new corrosion inhibitor based on cobalt- phenanthroline- p-hydroxybenzoic acid ternary complex

In this paper, a new corrosion inhibitor based on cobalt- phenanthroline- p-hydroxybenzoic acid ternary complex was synthesized. Its anti-corrosion effects on carbon steel in 0.5 M HCl were investigated by weight-loss measurements, electrochemical tests, surface analyses, and quantum chemical calculations. The results indicated that the Co-phen-phba ternary complex exhibits excellent anti-corrosion efficiencies of ∼97 % at 298 K and ∼86 % at 328 K. The excellent anti-corrosion performance of Co-phen-phba ternary complex could be attributed to the combination of inorganic and organic corrosion inhibitors. Theoretical calculations established the correlation between the structure and the anti-corrosion effect of corrosion inhibitor.

Assessment of antioxidant, antidiabetic, and antimicrobial properties of hybrid mushroom strains derived through intergeneric hybridization between Pleurotus sajor-caju and Calocybe indica

Our present study aims to evaluate the biological activities of the six hybrid mushrooms (APS) obtained through the protoplast fusion technique between two mushrooms Calocybe indica and Pleurotus sajor-caju, in our previous study. Antioxidant activity of hybridized mushroom samples was determined by the free radical scavenging method, using DPPH radical, Superoxide radical, and Hydroxyl radical. Additionally, all the mushroom extract has shown a good amount of total phenolic content, and total flavonoid content and also has potent Ferric reducing antioxidant power. The Total phenolic content, Total flavonoid content, and Ferric reducing antioxidant power were estimated. Six constituents: gallic acid, catechin, protocatechuic acid, p-hydroxybenzoic acid, p-coumaric acid, and cinnamic acid were identified by UHPLC. The MIC values, zone of inhibition, growth kinetic, and scanning electron microscopy (SEM) were performed to establish the antimicrobial efficacy. The tested samples exhibited antimicrobial activity against selected microorganisms Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis, Pseudomonas aeruginosa. A clear morphological change was observed under SEM when Bacillus subtilis and Pseudomonas aeruginosa were treated with APS-4 and APS-3 mushroom extracts. The ability to inhibit carbohydrate hydrolyzing enzymes such as α-amylase and α-galactosidase has also been studied to explore antidiabetic properties. The inhibitory activity of α-glucosidase was APS-4 reflected a very prominent result with the lowest IC50 value i.e.,118.058 ± 1.515, APS-2 and APS-6 showed almost similar IC50 values. α – galactosidase inhibitory activity of APS-4 and APS-6 exhibit better results than other strains.

Metabolic profiling and antioxidant activity of fenugreek seeds cultivars ‘Giza 2’ and ‘Giza 30’ compared to other geographically-related seeds

This study addresses a comparative comprehensive metabolic profiling of two Egyptian cultivars of fenugreek (Trigonella foenum-graecum L.) seeds ‘Giza 2’ and ‘Giza 30’ via RP-HPLC-DAD-QTOF-MS and MS/MS. Briefly, 126 metabolites were detected in the samples under investigation, being classified into hydroxybenzoic acids (8), hydroxycinnamic acids (7), flavonoids (49 with a predominancy of flavones in particular apigenin derivatives), coumarins (1), furostanol saponins (17), alkaloids (2), amino acids (11), peptides (2), jasmonates (6), nucleosides (30), organic acids (16), terpenoids (1), and sugars (3). In addition, the total phenolic content and antioxidant activity were determined and compared with other geographically related seeds (chickpea Giza-1, sesame Giza-32, and linseed, Giza-10), showing slight differences among them but higher values than the other geographically related seeds that were segregated from them upon chemometric analysis. This is the first comprehensive metabolic profiling of these cultivars, presenting an initial account of some metabolites found in Fabaceae, such as apigenin di C pentoside, with a significant occurrence of biologically active furostanol saponins. It gives a prospect of fenugreeks richness of bioactive metabolites as an essential functional food that could add value to the food and nutraceutical industries' sustainability.

Carbon flow from roots to rhizobacterial networks: Grafting effects

Plants recruit microorganisms from bulk soil by secreting easily available organic carbon into the rhizosphere. Grafting often increases the disease resistance of agricultural plants by modifying this carbon flow from roots into rhizosphere and by recruiting active microorganisms that suppress pathogens. Here, we continuously labeled grafted and ungrafted watermelon plants in a 13CO2 atmosphere to identify the active microorganisms assimilating root exudates. Multi-omics associated technologies (amplicon sequencing, metagenomics and metabolomics) combined with 13C tracing were used to examine the carbon flows, microbial utilization and transformation in the rhizosphere. The number of potentially active bacterial species recruited in the rhizosphere of grafted plants and utilizing root exudates was four times more than in ungrafted plants. These potentially active species matched to metagenome-assembled-genomes (MAGs) mainly belonging to Sphingomonas in the rhizosphere of ungrafted plants, and to Sphingomonas, Chitinophaga, Dyadobacter and Pseudoxanthomonas in the rhizosphere of grafted plants. Sphingomonas possesses the functional potential to metabolize a plant self-toxic substance, namely 4-hydroxybenzoic acid. Furthermore, grafting shaped the complex metabolic interactions and changed the original metabolic dependence between the potentially active bacterial species. Grafting plants diversified belowground carbon flows, activating a greater number of beneficial microbes.

Cytotoxic, antioxidant, and enzyme inhibitory activities of Centaurea stapfiana extracts and their HPLC-ESI-QTOF-MS profiles: Insights into an unexplored Centaurea species

The members of the genus Centaurea have a great interest in pharmaceutical and nutraceutical fields due to their biological potential. Based on this information, we aimed to evaluate the biological properties (antioxidant, enzyme inhibition and cytotoxicity) and chemical profile of the extract of Centaurea stapfiana, an unstudied species. The highest total phenolic content was found in the ethanol/water extract with 32.17 mg GAE/g. A total of 102 of them were identified by HPLC-ESI-QTOF-MS analysis. These compounds were mainly hydroxybenzoic acid and hydroxycinnamic acid as well as flavonoids. In the antioxidant tests, the ethanol/water extract had the best free radical scavenging and reducing ability. However, in the enzyme inhibition test, the ethanol extract was the most active. The extracts were also tested on two tumour cell lines (RAW 264.7 and HepG2) and one non-tumour cell line (S17). The ethanol extract showed the promising effect on HepG2 (cell viability: 28.6 % at 50 g/ml). Furthermore, we examined the interactions between the compounds and enzymatic and cellular targets. A good interaction was found between quercetin-3-xylosyl-(1- > 6)-glucoside and iNOS. In summary, our results suggest that C. stapfiana can be considered as a versatile raw material for the development of health-promoting applications in the pharmaceutical and cosmeceutical fields.

Pepper root exudate alleviates cucumber root-knot nematode infection by recruiting a rhizobacterium

Root-knot nematodes (Meloidogyne spp.) have garnered significant attention from researchers due to their substantial damage to crops and worldwide distribution. However, controlling this nematode disease is challenging which results from limited chemical pesticides and biocontrol agents effective against them. Here, we demonstrate that pepper-rotation markedly reduces Meloidogyne incognita infection in cucumber and diminishes the presence of p-hydroxybenzoic acid in the soil, a compound known to exacerbate M. incognita infection. Pepper-rotation also structures the rhizobacterial community, leading to the colonization of two Pseudarthrobacter oxydans strains (RH60 and RH97) in the cucumber rhizosphere, facilitated by palmitic acid enrichment in pepper root exudates. Furthermore, both strains exhibit high nematocidal activity against M. incognita, and possess the ability to biosynthesize indoleacetic acid and biodegrade p-hydroxybenzoic acid. RH60 and RH97 additionally induce systemic resistance in cucumber plants and promote their growth. These data suggest that pepper root-exudate palmitic acid alleviates M. incognita infection by recruiting beneficial P. oxydans in the cucumber rhizosphere. Our analyses identify a novel chemical component in root exudates and uncover its pivotal role in crop rotation for disease attenuation, providing intriguing insights into the keystone function of root exudates in plant protection against root-knot nematode infection.

Potential and Simulation of Functional Compounds Recovery from Clitoria ternatea L. Extract during The Commercial Sterility Process

The butterfly pea flower (Clitoria ternatea L.) is a flower that is identical to blue to purple petals and contains various phytochemical compounds. Heat processing in butterfly pea flower extract can reduce its nutritional and sensory properties, which is indicated by a decrease in each quality parameter, namely color intensity, total anthocyanins, red flavylium cation, purple quinonoidal base, blue anionic quinonoidal base, ferrulic acid, caffeic acid, p-hydroxybenzoic acid, procatechuic acid, gallic acid, vanillic acid, vanillin, procyanidin hexamer III, and delphinidin-3-glucosse. The thermal process can deactivate bacterial spores to maintain the quality of butterfly pea flower extract. This paper will review steps that can be used as a reference for researchers or industry to optimize commercial sterilization processes using heating process kinetics. The method studied to be adopted in this article is based on the heating process kinetics of each quality parameter (k and D values) combined towards temperature (Z value). The combination of temperature and time to optimize the process is determined by referring to the D and Z values. To optimize the heating process, the sterilization heater needs to be evaluated and the kinetics of the thermal process for each quality parameter need to be prescribed. This thermal process design will contribute greatly to the functional food business with commercial sterilization standards that aim to claim functional compounds at certain concentrations after processing.

Anti-neuroinflammatory potential of hydroxybenzoic ester derivatives: In silico insight and in vitro validation

This study explores the anti-neuroinflammatory and antioxidant potential of 42 hydroxybenzoic acid esters and three parent acids. Molecular docking simulations targeted key proteins involved in the lipopolysaccharide (LPS) signaling pathway to identify lead compounds for synthesis and in vitro evaluation. Among the screened esters, the most promising candidates demonstrated antioxidant activity comparable to vitamin C in ABTS and DPPH assays. Additionally, these esters significantly reduced the production of reactive oxygen species (ROS) and nitric oxide (NO) in H2O2- and LPS-stimulated BV2 microglial cells, indicating their ability to attenuate neuroinflammation. Further testing in SH-SY5Y neuronal cells exposed to microglia-derived supernatants confirmed the neuroprotective effects of these esters, reducing microglia-mediated neurotoxicity. These results suggest that hydroxybenzoic acid ester derivatives are promising candidates for mitigating microglia-driven neuroinflammation and protecting neurons, offering potential therapeutic applications for neurodegenerative diseases.

Bioassay-guided fractionation and biological activities of antimycin A and 4-hydroxybenzoic acid isolated from Nocardiopsis sp. strain LC-9

Bioassay-guided fractionation and biological activities of antimycin A and 4-hydroxybenzoic acid isolated from Nocardiopsis sp. strain LC-9

Microwave pre-treatment of niger (Guizotia abyssinica) seeds: Impact on stability, physicochemical characteristics, bioactive and fatty acid profiles of extracted oil

The study explored the impact of microwave pre-treatment (MPT) at different powers (360, 540 and 720 W) and exposure times (2, 4, 6 and 8 min) on the qualitative characteristics of niger seed oil (NgO). The changes in physicochemical characteristics, oxidative stability index (OSI), phenolic constituents, Maillard products, tocopherols, pigments and phytosterols in NgO were elucidated after MPT of seeds. The NgO yield increased from 33.19 % to 38.76 % and OSI augmented from 2.69 to 3.93 h upon MPT at 540 W and 720 W for 8 min, respectively. The tocopherols and phytosterols levels augmented upon MPT at 540 W for 4 and 6 min, respectively while declined by further elevating power (720 W) and exposure time (8 min). The total hydroxycinnamic (27.41 mg/kg) and hydroxybenzoic (1.48 mg/kg) acids and total flavonoids (115.83 mg/kg) were highest upon MPT at 720 W for 6 min while viscosity (56.71 mPa.s), chlorophylls (0.12 mg/kg), carotenoids (0.85 mg/kg) and 5-hydroxymethylfurfural (1.38 mg/kg) were highest upon MPT at 720 W for 8 min. In conclusion, the MPT promoted the release of bioactive compounds and lowered the generation of harmful oxidative by-products. The results highlight the potential of MPT in enhancing quality attributes of NgO for use in the food, cosmetics, and pharmaceutical industries.

Study of plasma metabolic markers in unexplained recurrent spontaneous abortion based on non-target metabolomics approach

Objective: To screen plasma metabolic markers in patients with unexplained recurrent spontaneous abortion (URSA) by non-target metabolomics approach. Methods: From September 2022 to May 2023, the plasma of 23 URSA pregnant women with threatened abortion who visited the outpatient clinic of Gansu Provincial Maternity and Child-care Hospital in the first trimester (URSA group) was collected, and the plasma of 22 healthy pregnant women in the first trimester who underwent prenatal examination during the same period (normal control group) was collected. Plasma metabolomics was analyzed by ultra performance liquid chromatography (UPLC) coupled with mass spectrometry (MS), fold change analysis, principal component analysis and partial least square discriminant analysis were applied to screen for differential metabolites, and the metabolites and their pathways associated with URSA were screened using receiver operating characteristic (ROC) curve and pathway enrichment analysis. Results: There were no significant differences in age, body mass index and gestational weeks between URSA and normal control group(all P<0.05). Metabolomics analysis using UPLC-MS showed that a total of 526 metabolites were detected from plasma, of which 33 were found to be differential metabolites associated with URSA based on the screening standards. Six potential metabolites with large area under the curve (AUC) were identified by ROC curve analysis, including phosphatidylethanolamine (AUC=0.972, 95%CI: 0.920-1.000), santene hydrate (AUC=0.902, 95%CI: 0.786-0.982), L-leucine (AUC=0.884, 95%CI: 0.772-0.960), cembrene (AUC=0.881, 95%CI: 0.758-0.956), caffeine (AUC=0.875, 95%CI: 0.756-0.962), and 4-hydroxybenzoic acid propyl ester (AUC=0.864, 95%CI: 0.732-0.946). The AUC for the combined diagnosis of URSA by the six metabolites was 0.983 (95%CI: 0.929-1.000). Pathway enrichment analysis of the differential metabolites showed that the pathogenesis of URSA was associated with a variety of metabolic pathways including caffeine metabolism, glycerophospholipid metabolism, and unsaturated fatty acid biosynthesis. Conclusion: The plasma metabolic profiles of pregnant women with normal pregnancies versus URSA differ in early pregnancy, and six potential metabolites such as phosphatidylethanolamine, santene hydrate, L-leucine, cembrene, caffeine, 4-hydroxybenzoic acid propyl ester, and their metabolic pathways may be involved in the pathogenesis of URSA.

Aromatic Polymethacrylates from Lignin-Based Feedstock: Synthesis, Thermal Properties, Life-Cycle Assessment and Toxicity.

There is currently a great need for rigid, high-performance and processable bio-based polymers and plastics as alternatives to the fossil-based materials used today. Here, we report on the straightforward synthesis and polymerization of lignin-derived methacrylate monomers based on the methyl esters of syringic, vanillic, and 4-hydroxybenzoic acid, respectively. The corresponding homopolymethacrylates exhibit high glass transition temperatures (Tgs) at 106, 128, and 197°C, respectively. Rheological properties and thermal stability up to at least 277 °C indicate that these polymers are melt-processable. In addition, copolymers with methyl methacrylate are prepared to further vary and tune the polymer properties. An integrated ex-ante and prospective life-cycle assessment of key environmental impact parameters indicates similar or only slightly higher values compared to well-established fossil-based methyl methacrylate. Moreover, the toxicity towards human HeLa cell lines compares well with that of poly(methyl methacrylate). Hence, the potential availability of lignin-derived acids, combined with the straightforward and potentially upscalable monomer synthesis, make these rigid polymers appealing alternatives towards bio-based high-Tgthermoplastic materials with low toxicity.

Accumulation of Parabens, Their Metabolites, and Halogenated Byproducts in Migratory Birds of Prey: A Comparative Study in Texas and North Carolina, USA.

Parabens are alkyl esters of p-hydroxybenzoic acid that are commonly used as preservatives in personal care products such as cosmetics. Recent studies have revealed the presence of parabens in surface and tap water because of their use as disinfection products; however, little is known about their occurrence in biological samples and their bioaccumulation potential, particularly in raptor birds known as sentinels for pollutant detection. We examined the occurrence and tissue distribution of parabens, their metabolites, and halogenated byproducts in the liver, kidney, brain, and muscle of birds of prey from Texas and North Carolina (USA). Methylparaben (MeP), propylparaben (PrP), and butylparaben (BuP) were detected in more than 50% of all tissues examined, with the kidney exhibiting the highest concentration of MeP (0.65-6.84 ng/g wet wt). Para-hydroxybenzoic acid (PHBA), a primary metabolite, had the highest detection frequency (>50%) and a high accumulation range in the liver, of 4.64 to 12.55 ng/g. The chlorinated compounds chloromethylparaben and chloroethylparaben were found in over half of the tissues, of which dichloromethylparaben (2.20-3.99 ng/g) and dichloroethylparaben (1.01-5.95 ng/g) in the kidney exhibited the highest concentrations. The dibrominated derivatives dibromideethylparaben (Br2EtP) was detected in more than 50% of samples, particularly in muscle and brain. Concentrations in the range of 0.14 to 17.38 ng/g of Br2EtP were detected in the kidney. Dibromidepropylparaben (Br2PrP) was not frequently detected, but concentrations ranged from 0.09 to 21.70 ng/g in muscle. The accumulations of total amounts (sum) of parent parabens (∑P), metabolites (∑M), and halogenated byproducts (∑H) in different species were not significantly different, but their distribution in tissues differed among the species. Positive correlations were observed among MeP, PrP, BuP, and PHBA in the liver, suggesting similar origins and metabolic pathways. Environ Toxicol Chem 2024;43:2365-2376. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Thermodynamic characteristics of multi-component crystals: Experimental evaluation, prediction and relationship with crystal parameters

In this study, we have analyzed the thermodynamic formation functions for four multi-component crystals based on the solubility data in the range of 293.15–313.15 K. The investigation was performed for the cocrystals of fluconazole (FLZ) with 4-hydroxybenzoic (4OHBA) and vanillic (VA) acids, and salts of fenbendazole (FNB) with maleic (Mal) and oxalic (Ox) acids. A database on the thermodynamic parameters of the multi-component molecular crystals (Gibbs free energy, enthalpy, and entropy) obtained in this study and borrowed from the literature was created. These parameters were determined using the experimental data on the solubility of the individual components and the product of the solubilities of the multi-component crystals at 298.15 K. A regression model was proposed to estimate the solubility product of the two-component crystals using the intrinsic solubility of the individual components as an independent variable. A detailed analysis of the database disclosed the relationship between the entropy term and the molecular volume of the multi-component crystal formation.

Engineering the Rhizosphere Microbiome with Plant Growth Promoting Bacteria for Modulation of the Plant Metabolome.

Plant-growth-promoting bacteria (PGPB) have beneficial effects on plants. They can promote growth and enhance plant defense against abiotic stress and disease, and these effects are associated with changes in the plant metabolite profile. The research problem addressed in this study was the impact of inoculation with PGPB on the metabolite profile of Salicornia europaea L. across controlled and field conditions. Salicornia europaea seeds, inoculated with Brevibacterium casei EB3 and Pseudomonas oryzihabitans RL18, were grown in controlled laboratory experiments and in a natural field setting. The metabolite composition of the aboveground tissues was analyzed using GC-MS and UHPLC-MS. PGPB inoculation promoted a reconfiguration in plant metabolism in both environments. Under controlled laboratory conditions, inoculation contributed to increased biomass production and the reinforcement of immune responses by significantly increasing the levels of unsaturated fatty acids, sugars, citric acid, acetic acid, chlorogenic acids, and quercetin. In field conditions, the inoculated plants exhibited a distinct phytochemical profile, with increased glucose, fructose, and phenolic compounds, especially hydroxybenzoic acid, quercetin, and apigenin, alongside decreased unsaturated fatty acids, suggesting higher stress levels. The metabolic response shifted from growth enhancement to stress resistance in the latter context. As a common pattern to both laboratory and field conditions, biopriming induced metabolic reprogramming towards the expression of apigenin, quercetin, formononetin, caffeic acid, and caffeoylquinic acid, metabolites that enhance the plant's tolerance to abiotic and biotic stress. This study unveils the intricate metabolic adaptations of Salicornia europaea under controlled and field conditions, highlighting PGPB's potential to redesign the metabolite profile of the plant. Elevated-stress-related metabolites may fortify plant defense mechanisms, laying the groundwork for stress-resistant crop development through PGPB-based inoculants, especially in saline agriculture.

Synergistic mixture of the Dactyloctenium aegyptium extract and KI as an environment friendly and highly efficient corrosion inhibitor for steel in 0.5 M HCl

To prevent steel from corroding in HCl solution, a cost-effective inhibitor of Dactyloctenium aegyptium and KI is presented. UV–Vis, infrared spectroscopy, and scanning electron microscopy analysis are used to undertake a comprehensive experimental evaluation of the inhibitors and their interactions with the steel. The optimum concentration of the Dactyloctenium aegyptium extract (DAE) with the maximum corrosion protection efficacy is found via electrochemical measurements. The bioactive constituents of the DAE such as Tricin, Vanillic acid, p-hydroxybenzaldehyde, and p-hydroxybenzoic acid conferred a maximum inhibition efficiency of 95.7 % at 800 ppm. The inhibitory activity of its ethanolic extract increased with increasing concentration. Further various adsorption isotherm models including Langmuir, Temkin and Frendluich were used to understand the adsorption of the DAE on the metal surface. The DFT based investigations show that the active constituents of the DAE are highly polarized, soluble in aqueous solution and adsorb on the steel surface efficiently.

Exploring the adsorption of 4,4’-[oxalylbis(imino)]bis(2-hydroxybenzoic acid) layer at steel/biogasoline interface by the combined electrical-optical-simulation approach

Reactions at the steel/biogasoline interface trigger the adsorption of 4,4’-[Oxalylbis(imino)]bis(2-hydroxybenzoic Acid) (ODA) layer on the steel surface, thereby activating a mechanism that inhibited the early reactions. Exploring the conditionally deposited ODA layer requires a combined approach, including electrical, optical, and simulation techniques to track the film development and coating characteristics over time, and with the assistance of atomic force microscopy, quantum chemistry (DFT), and molecular dynamics (MD) simulations to reveal the adsorption mechanism of the ODA layer at steel/biogasoline interface. The four experimental ODA concentrations were conducted, related to the simulated un-coverage, undersaturated-, saturated-, and oversaturated-coverage model of the adsorbate on the adsorbent. The EC-RS data examines surface compositions and their distribution, coating/solution interface, and coating/substrate adhesion by, respectively, Raman spectroscopy (RS), electrochemical impedance spectroscopy (EIS), and current density—potential (I-V) scan. Namely, RS pointed out that an organic layer was established when ODA was added to the simulated biogasoline. EIS results revealed insulator behaviors of the ODA layer at the solid–liquid interface, limiting the charge transfer between the steel substrate and the biogasoline. I-V results showed an increase in surface current density and a decrease in surface polarization resistance of the coating with the rise in ODA concentration. The AFM morphology profile verified the degradation of the sample’s surface when exposed to biogasoline and the minimization of surface damage by ODA addition through adsorption. The simulation findings revealed that the adsorption of ODA on steel preferred physisorption, reaching the most stable state at a specified temperature and ODA concentration. The adsorption mechanism follows the Generalized Langmuir isotherm. The adsorbate (ODA molecules) can produce a transition phase with the steel substrate surface, which modifies the surface thermodynamic characteristics. The combined electro-optical-simulation technique can be applied to investigate various surface phenomena (reactions, catalyzes, adsorption). It especially helps to understand the protective mechanism of inhibitors in different media.