Hydroxyl Research Articles

Double-stranded binuclear helical complexes of 5,5’-bisdiazo-dipyrromethane with Zn(II): synthesis, structures, photophysical properties, and DFT calculations

The reaction of two 5,5΄-bisdiazo-dipyrromethane compounds (H2L1 and H2L2 ) with ZnCl2 afford two Zn(II) complexes (Zn2 L 2 1 and Zn2 L 2 2 ). The X-ray crystallographic studies revealed that both complexes were double-stranded binuclear helicates. Each Zn(II) ion was coordinated to four nitrogen atoms of two azopyrrole units from two ligands in a distorted tetrahedral geometry. Due to the existence of the hydroxyl groups, the Zn2 L 2 2 complex self-assembled into a two-fold interpenetrating grid structure through O-H…O and N-H…O hydrogen bonds. Zn2 L 2 1 and Zn2 L 2 2 displayed intense absorptions at 439 and 446 nm and shoulder peaks at 486 and 497 nm, respectively. Both complexes were also weakly fluorescent with a fluorescence band at 602 nm. DFT calculations revealed that the hydroxyl group can destabilize the frontier molecular orbitals and decrease the energy gap (ΔE), and finally caused Zn2 L 2 2 higher HOMO and LUMO orbital levels, smaller energy gap (ΔE), and longer λmax absorption than Zn2 L 2 1 .

Hydrothermal Synthesis of ZnO Nanoflowers: Exploring the Relationship between Morphology, Defects, and Photocatalytic Activity

Two forms of flower-like ZnO nanostructures were synthesized using hydrothermal methods at various growth times/temperatures and zinc precursors. The morphology, structure, chemical composition, and optical properties of these ZnO nanoflowers were studied using a scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD), X-ray photoelectrons spectroscopy (XPS), Raman spectroscopy, and UV–Vis spectroscopy. The SEM images revealed two forms of flower-like nanostructures, namely lotus- and tulip-like flower ZnO nanostructures. The XPS analysis revealed the oxidation state of the Zn and O elements, as well as the presence of OH groups on the surface of the lotus-like flower ZnO nanostructure. The XRD results revealed less crystallinity of the lotus-like ZnO nanoflowers (NFs) compared with the tulip-like ZnO NFs. The XRD results revealed the presence of Zn (OH)2 in the ZnO NFs. The Raman results confirmed less crystallinity of the lotus-like ZnO NFs. The estimated optical bandgap was 2.92 and 3.0 eV for the tulip- and lotus-like ZnO NFs, respectively. The tulip-like ZnO NFs showed superior photocatalytic degradation of methylene blue dye, verified via UV–Vis radiation, compared with the lotus-like ZnO NFs, which show the impact of the structure defects and OH- impurities on the photocatalytic performance of ZnO nanoflowers.

Chitosan-polyethersulfone mixed matrix composite membranes utilizing amine and non-amine hafnium-MOFs for enhanced CO2 separation

Exploring the realm of advanced membranes with customizable separation capabilities holds great promise in CO2 separation. A particularly exciting path is the utilization of mixed matrix membranes (MMMs) to surpass the performance of commonly used polymeric membranes. In recent times, there has been a surge of interest in hafnium (Hf) metal–organic frameworks (MOFs) due to their multiple potential sites for CO2 adsorption. These MOFs feature four bridging hydroxyl groups (μ3-OH) positioned at the corners of the tetrahedral cavity, electronegative linker moieties, and Bronsted acid sites arising from undercoordinated metals. In this study, we synthesized task-specific UiO-66(Hf) and UiO-66-NH2(Hf) MOFs and integrated them into a chitosan (CS) matrix to explore their effects on CO2 separation performance of MMMs. Comprehensive analyses using various analytical techniques were conducted on synthesized MOFs and MMMs. At an optimal loading of 5 wt% of UiO-66-NH2(Hf) under humid conditions, the MMMs demonstrated a remarkable 408 % increment in CO2 permeance and a 113 % improvement in CO2/N2 selectivity compared to unfilled CS membranes. Notably, the UiO-66-NH2(Hf) MOF, enriched with amino ligands, exhibited superior dispersibility and enhanced CO2 separation ability compared to the UiO-66(Hf) MOF within the CS matrix. These findings not only approach the 2008 Robeson upper bound curve but also demonstrate consistency in the CO2 separation performance for over 120 hours of exposure at elevated temperatures (85°C) and a feed pressure of 2.21 bar under humid conditions. These challenging conditions, mirroring real-world applications, highlight the stability of the synthesized MMMs as efficient gas separation technologies.

Carbonate-carbonate coupling on platinum surface promotes electrochemical water oxidation to hydrogen peroxide

Water electro-oxidation to form H2O2 is an important way to produce H2O2 which is widely applied in industry. However, its mechanism is under debate and HO(ads), hydroxyl group adsorbed onto the surface of the electrode, is regarded as an important intermediate. Herein, we study the mechanism of water oxidation to H2O2 at Pt electrode using in-situ Raman spectroscopy and differential electrochemical mass spectroscopy and find peroxide bond mainly originated from the coupling of two CO32- via a C2O62- intermediate. By quantifying the 18O isotope in the product, we find that 93% of H2O2 was formed via the CO32- coupling route and 7% of H2O2 is from OH(ads)-CO3•− route. The OH(ads)-OH(ads) coupling route has a negligible contribution. The comparison of various electrodes shows that the strong adsorption of CO3(ads) at the electrode surface is essential. Combining with a commercial cathode catalyst to produce H2O2 during oxygen reduction, we assemble a flow cell in which the cathode and anode simultaneously produce H2O2. It shows a Faradaic efficiency of 150% of H2O2 at 1 A cm−2 with a cell voltage of 2.3 V.

Unveiling the Potential of Phytocannabinoids: Exploring Marijuana’s Lesser-Known Constituents for Neurological Disorders

Cannabis sativa is known for producing over 120 distinct phytocannabinoids, with Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) being the most prominent, primarily in their acidic forms. Beyond Δ9-THC and CBD, a wide array of lesser-known phytocannabinoids, along with terpenes, flavonoids, and alkaloids, demonstrate diverse pharmacological activities, interacting with the endocannabinoid system (eCB) and other biological pathways. These compounds, characterized by phenolic structures and hydroxyl groups, possess lipophilic properties, allowing them to cross the blood–brain barrier (BBB) effectively. Notably, their antioxidant, anti-inflammatory, and neuro-modulatory effects position them as promising agents in treating neurodegenerative disorders. While research has extensively examined the neuropsychiatric and neuroprotective effects of Δ9-THC, other minor phytocannabinoids remain underexplored. Due to the well-established neuroprotective potential of CBD, there is growing interest in the therapeutic benefits of non-psychotropic minor phytocannabinoids (NMPs) in brain disorders. This review highlights the emerging research on these lesser-known compounds and their neuroprotective potential. It offers insights into their therapeutic applications across various major neurological conditions.

Molecular Dynamics Study of Hydrogen Bond Structure and Tensile Strength for Hydrated Amorphous Cellulose.

Molecular dynamics (MD) simulations were conducted to investigate the hydrogen-bond (H-bond) structure and its impact on the tensile strength of hydrated amorphous cellulose. The study identifies a stable intramolecular H-bond between the hydroxyl group at position 3 and the ether oxygen at position 5 (OH3···O5). Intermolecularly, the hydroxyl groups at positions 2 (OH2) and 6 (OH6) form stable H-bonds. Young's modulus, maximum tensile strength, and corresponding strain were calculated as functions of moisture content, while the H-bond network, water cluster formation, and cellulose chain orientation during tensile simulations were analyzed to elucidate mechanical properties. The substitution effect of cellulose on Young's modulus is also examined, revealing that the substitution of OH3 for a hydrophobic group minimally affects Young's modulus, but substitutions at OH2 and OH6 significantly reduce tensile strength due to their roles as key intermolecular H-bond donor sites.

Nanomodified bamboo (Phyllostachys aurea) biomass: its adsorbent features in the removal of dyes from water under high salinity conditions.

The effluent generated by textile industries is among the most polluting to the environment. Dyes such as methylene blue (MB) and indigo blue (IB) are used in cotton dyeing. This work proposes to evaluate the potential of in natura (BIN) and nanomodified (BNP) bamboo (Phyllostachys aurea) biomass as biosorbents for the removal of MB and IB dyes in an aqueous medium under high salinity conditions. These materials were characterized by Fourier transform infrared (FTIR) and X-ray (XRD) spectroscopies and scanning electron microscopy (SEM) to investigate their morphology and interaction with the dyes and the nanoparticles. The FTIR spectra revealed the existence of hydroxyl and carbonyl groups, ethers, phenols, and aromatic compounds, indicating the presence of a lignocellulosic structure. XRD and SEM analyses confirmed the effectiveness of the nanocomposite synthesis process. The dyes were quantified by ultraviolet-visible spectroscopy (UV/Vis). The material's pH at the point of zero charge (pHPZC) was 5.52 (BIN) and 4.84 (BNP), and the best IB and MB sorption pH were 3.0 and 9.0 for BNP, respectively, employing 30min of contact time. The material sorption capacity (Qexp) was assessed using batch procedures, in which 100-1000mg/L dye concentrations were tested with a 0.5g/L adsorbent dose. The dye's Qexp for BIN and BNP was 25.41 ± 0.58 and 23.42 ± 0.07mg/g (MB) and 84.26 ± 1.1 and 130.81 ± 0.20mg/g (IB), respectively. The kinetic model that best fit BNP experimental data was the pseudo-2nd-order with r2 = 0.99868 (MB) and r2 = 0.99873 (IB), and Freundlich, D-R, and Temkin isotherms best fit the dye sorption data. The bamboo nanomodification facilitates the biosorbent removal from the medium after sorption, enabling large-scale studies and industrial applications-the investigated materials provided promising adsorption features for removing contaminant dyes in saline water.

Preparation and Catalytic Properties of Gold Single-Atomand Cluster Catalysts Utilizing Nanoparticulate Mg-Al Layered Double Hydroxides.

Au single atoms and clusters were stabilized on Mg-Al layered double hydroxide nanoparticles (LDH NPs), and the obtained Au@LDH NPs were supported on SiO2 and CeO2. After hydrogen reduction, Au single atoms were found together with Au clusters on LDH/SiO2. In contrast to Au single-atomcatalysts which are deposited in metal vacancies of oxide supports, the LDH NPs stabilize small Au species despite the absence of metal vacancies. The obtained Au(0)@LDH/SiO2 catalyzed aerobic oxidation of alcohols, and Au single atoms maintained after the reaction. Given that only Au NPs were observed on bulk LDH, the abundant surface OH group of LDH NPs would contribute to stabilize Au, resulting in higher activity than Au/LDH-bulk. After calcination to transform LDH to mixed metal oxide (MMO), the obtained Au(0)@MMO/SiO2 also exhibited high catalytic activity. Moreover, Au(0)@LDH/CeO2 exhibited higher activity and excellent selectivity for hydrogenation of 4-nitrostyrene to 4-aminostyrene than conventional Au catalysts such as Au/CeO2 and Au/TiO2 even though onlyAu NPs were present. We demonstrated that Au size can be minimized using LDH NPs, exhibiting in high catalytic performance. The basic surface OH groups of LDH would be also beneficialfor deprotonation of alcohols and heterolytic H2dissociation in the catalytic reactions.

De novo Drug Design and Repurposing to suppress Liver Cancer via VEGF-R1 Mechanism: Comprehensive Molecular Docking, MolecularDynamics Simulations and ADME Estimation

Aims: The aim is to halt the progression of liver cancer [Hepatocellular carcinoma] by suppressing the VEGF-R1 receptor using Myricetin and its de novo-designed analogues. Background: VEGF/VEGFR autocrine signalling promotes the growth, progression, and metastasis of Hepatocellular carcinoma, making the development of molecularly targeted therapies highly feasible. Invasive and metastatic behaviours in various cancers, including hepatocellular carcinoma [HCC], are closely monitored through the use of VEGF signalling pathway inhibitors. Specifically in HCC, VEGFR-1 facilitates the invasive capabilities of cancer cells primarily by triggering the epithelial-mesenchymal transition [EMT] process. VEGFR-1 significantly influences the activity of proteolytic enzymes that are critical for the invasive behaviour of HCC cells. Notably, a novel mechanism has been discovered where VEGFR-1 activation leads to the upregulation of MMP-9, thereby enhancing the invasiveness of HCC cells. The scientists, in their study, have elaborated on the various antiangiogenic agents developed for the treatment of HCC. They have highlighted clinical trials that explore the efficacy of these treatments, which include the application of monoclonal antibodies and small-molecule kinase inhibitors designed to target specific pathways involved in tumour angiogenesis and growth. Objective: Creating a pharmaceutical chemistry table regarding ‘’Structure-Activity Relationship of New Compounds on anticancer’’. To do so, Myricetin and its de novo designed structured variants were used in molecular docking, molecular dynamics, cluster analyses, and 1H NMR estimation to specifically understand and enhance the mechanism of suppressing the VEGF-R1 receptor. Method: Proper ligand [Myricetin and its analogues] and receptor [VEGF-R1] preparations, and optimizations were done using the density functional theory [DFT]/B3LYP function along with the 6-31G[d,p] basis set principle in the latest software programs such as Gaussian 09, Gauss View 6.0 and Avogadro. Then using PyRx and Autodock Vina 1.1.2., many molecular docking trials were achieved with 100 posed simulations in each run. An extensive cluster analysis was performed to identify the most optimal docking poses with the highest accumulation and most favourable binding interactions, ensuring the accuracy of the study. The docking configurations that exhibited the most precise and advantageous binding energies were chosen as initial structured data for subsequent Molecular Dynamics [MD] simulations for each drug candidate. To verify the molecular docking results, MD runs were achieved in our supercomputers and the trajectory analyses were made. The data confirmed what was found in molecular docking results, verifying the high efficiency of the druggable molecules’ inhibition towards VEGF-R1. Result: Amine-derivatized Myricetin has a significantly high docking score [-10.56 kcal/mol] and great inhibition constant compared to pristine Myricetin [-4.77 kcal/mol] itself while Fluorinederivatized Myricetin [-6.45 kcal/mol] has an affinity towards VEGF-R1 between the first two molecules. Thus, the structure-activity relationship concerning pharmaceutical chemistry aspects of all the molecules studied, yielded us a great insight into what Myricetin’s organic structure possesses towards inhibiting the progression of Liver Cancer. Also, ADME studies showed that both Amine and Fluorined-derivatized Myricetin molecules are good drug candidates. Conclusion: This study highlighted the significant potential of Myricetin as an anti-cancer drug when modified with specific functional groups. Through comprehensive in silico computational analyses, our research group enhanced Myricetin's inhibitory capabilities by derivatizing its Hydroxyl group with Amine and Fluorine, resulting in improved docking scores and inhibition constants. The findings from molecular docking and molecular dynamics simulations provide a promising foundation for future in vitro and in vivo investigations of this molecule as a potential drug in cancer research.

Physiological and biomolecular interventions in the bio-decolorization of Methylene blue dye by Salvinia molesta D. Mitch

Methylene blue, a cationic dye as a pollutant is discharged from industrial effluent into aquatic bodies. The dye is biomagnified through the food chain and is detrimental to the sustainability of aquatic flora. Despite of number of physico-chemical techniques of dye removal, the use of aquatic flora for bio-adsorption is encouraged. Thus, we used Salvinia molesta D. Mitch in bio-reduction of methylene blue on concentrations of 0, 10, 20, and 30 mg L−1 through 5 days with biosorption kinetics. The dye removal was concentration-dependent, maximized at 2 days with 30 mg L−1 which altered the relative growth rate (44%) of plants. Biosorption recorded 71% capacity at optimum pH (8.0), 24 h reducing major bond energies of amide, hydroxyl groups, etc. Bioaccumulation of dye changed potassium content (446%) under maximum dye concentration modifying tissues for dye sequestration. Reactive oxygen species were altered on dye reduction by oxidase (33%) with redox homeostasis by enzymes. Plants altered the metabolism with over accumulation of polyamines (51%), abscisic acids (448%), and phosphoenolpyruvate carboxylase (83%) on dye reduction. Thus, this study is rationalized with a sustainable approach where aquatic ecosystems can be decontaminated from dye toxicity with the exercise of bioresources like Salvinia molesta D. Mitch as herein.

Therapeutic overview of sudachitin.

Citrus fruits are extensively cultivated and eaten both raw and in refined forms. Citrus fruit peels are highly concentrated in polyphenolic substances. This makes them useful resources. Polymethoxyflavones (PMFs), found in citrus peels, belong to a specific subclass of flavonoids where most or all hydroxyl groups are methylated. PMFs have been documented to possess chemopreventive actions, anticancer, anti-inflammatory, and anti-atherosclerosis properties, as well as neuroprotective effects. Sudachitin, a PMF, is primarily found in Citrus sudachi. Japan's Tokushima prefecture is home to this famous fruit. In recent years, there has been a growing interest among researchers in exploring the potential health benefits of sudachitin, spurred by its presence in traditional diets and its association with various positive health outcomes. Studies conducted over the past decade have revealed promising effects of sudachitin in multiple health conditions, including cancer, skin disorders, inflammatory conditions, diabetes, obesity, and neurodegenerative disorders. Although these promising results exist, there is still a need for thorough preclinical and clinical research to confirm sudachitin's effectiveness in treating chronic conditions. This review seeks to summarize animal and cell studies exploring sudachitin's pharmacological properties and the potential molecular pathways underlying its therapeutic effects. Through this, we aim to clarify the clinical potential of sudachitin across various disorders, paving the way for future research and the development of sudachitin-based therapies.

Synergistic Modulation of Sn2+ Oxidation and Perovskite Crystallization Induced by 4-Hydroxypyridine for Stable Lead-Free Solar Cells.

Tin perovskites present promising alternatives to lead perovskites, offering comparable optoelectronic properties alongside environmentally friendly characteristics. However, the rapid crystallization and easy oxidation of Sn2+ lead to poor film quality, further constraining the device performance. Here, 4-hydroxypyridine (4-HP) is introduced into the tin perovskite precursor for fabrication of high-quality tin perovskite films. 4-HP could modulate the colloidal size of prenucleation perovskite clusters in the precursor, thus inducing fast nucleation and retarding the crystal growth rate of tin perovskite through the formation of chemical interaction between nitrogen of pyridine and Sn2+ ions. Furthermore, the hydroxyl group on the pyridine ring contributes to suppressing the oxidation of Sn2+. As a result, the power conversion efficiency (PCE) of the devices based on 4-HP increases up to 11.3%. The stability of the unencapsulated devices shows significant improvement, retaining 100% of their initial PCEs after 2000 h of storage in N2 with 50-100 ppm of O2. This research presents a novel approach to the synchronized regulation of tin perovskite crystallization and the suppression of Sn2+ oxidation.

Component analysis of Cucumis melo L. leaves and their antioxidant activity

Cucumis melo var. reticulatus Ser. (or netted melon ‘Earl’s Favourite’), a variety of Cucumis melo L., is widely cultivated in Shizuoka, Japan. However, the leaves and stems are discarded after harvest. Therefore, we investigated the chemical constituents of melon leaves to suggest potential applications. Air-dried melon leaves were extracted using methanol. The methanol extract was suspended in water and successively partitioned using n-hexane, ethyl acetate, and to yield each fraction. Eight flavone glycosides (1 − 8) and three terpenes (9 − 11) were obtained. The chemical structures of these compounds were determined via nuclear magnetic resonance and mass spectrometry. The antioxidant activity of compounds 1 − 8 was evaluated using a 2,2-diphenyl-1-picrylhydrazyl radical assay. All compounds showed radical-scavenging activity in the range of IC50, 24.2 − 129.5 μM, which depended on the number of hydroxyl groups on the benzene ring and ortho-substitution. Therefore, the leaves of C. melo may be considered valuable material for developing antioxidants.

Chemical and Biological Characterization of Metabolites from Silene viridiflora Using Mass Spectrometric and Cell-Based Assays.

A comprehensive metabolite profiling of the medicinal plant Silene viridiflora using an UHPLC-ESI-MS/MS method is described for the first time. A total of 71 compounds were identified and annotated, the most common of which were flavonoids, triterpene glycosides, and ecdysteroids. The three major compounds schaftoside, 26-hydroxyecdysone, and silviridoside can be chosen as the markers for the assessment of the quality of S. viridiflora preparations. The methanol extract and a variety of metabolites identified in S. viridiflora were screened for their cytotoxic and Wnt pathway-inhibiting activities against triple-negative breast cancer (TNBC), the deadliest form of cancer in women. 2-Deoxy-20-hydroxyecdysone with submicromolar IC50 was identified as a result. The structure-activity relationship derived from the data from the in vitro proliferation assay showed that the hydroxyl group present at position C-2 of steroid core reduces the ecdysteroids' cytotoxicity against cancer cells.

Thermal modification’s influence on the color of Tectona grandis L.f. sapwood to resemble heartwood

The commercial value of teak wood is associated with its heartwood, which has a naturally darker color than sapwood. To reduce this color disparity, thermal modification can be used to homogenize the color between sapwood and heartwood by minimizing color differences. This research aimed to assess the effectiveness of thermal modification in making the color of teak sapwood similar to that of heartwood. Thermal modification was carried out at 160, 180, 200, and 220 °C for 150 min. Thermal modification of teak sapwood at 180 °C ensured greater color similarity to the heartwood of a fast-growing 16-year-old plantation. The material darkened with increasing process temperature. There was a change in the content of soluble substances, and hot water extraction had greater correlations with hue angle, lightness, and yellowness. Thermal modification also reduced the number of hydroxyl groups and improved the wood’s thermal stability.

Polymeric phenylpropanoid derivatives crosslinked by hydroxyl fatty acids form the core structure of rape sporopollenin.

Sporopollenin, a critical innovation in the evolution of terrestrial plants, is the core building brick for the outer wall of land-plant spores and pollen. Despite its significance, the basic structure of sporopollenin remains elusive due to its extreme chemical inertness. In this study, we used ethanolamine to completely dissolve rape sporopollenin and successfully identified a total of 22 components, including fatty acids, p-coumaric acid, sterols and polymeric phenylpropanoid derivatives. After that, using NaOH treatment and partial dissolution, alongside Arabidopsis mutants analysis and spectroscopic methods, we determined that polymeric phenylpropanoid derivatives crosslinked by hydroxyl fatty acids serve as the core structure of sporopollenin. The free hydroxyl groups and carboxyl groups of the polymeric phenylpropanoid derivatives can be modified by other fatty acids (C16:0, C18:0 and C18:3) as well as alcohols/phenols (for example, naringenin, β-sitosterol), resulting in a structure that protects pollen from terrestrial stresses. This discovery provides a basis for further exploration of sporopollenin's role in plant reproduction and evolution.

Ph3P═O-Catalyzed Reductive Deoxygenation of Alcohols.

Reductive deoxygenation of alcohols is particularly challenging because of the high bond dissociation energy of the C-OH bond and the poor leaving ability of the hydroxyl group. Herein we describe a Ph3P═O-catalyzed reductive deoxygenation of benzyl alcohols with PhSiH3 under an air atmosphere within 30 min of reaction time. The use of catalytic loading of Ph3P═O enhances the practicality of this protocol.

Towards Photocrosslinkable Lyotropic Blends of Organosolv Lignin and Hydroxypropyl Cellulose for 3D Printing by Direct Ink Writing.

Polymer blends containing up to 70% organosolv lignin content and lyotropic cellulose derivatives have been established as "lignin inks" for direct ink writing of fully biobased 3D parts. However, a fast-crosslinking mechanism is needed to improve throughput and design space. In this paper, UV-photocrosslinkable organosolv lignin/hydroxypropyl cellulose inks are formulated through doping with common photocrosslinkers. The most potent photocrosslinkers for neat hydroxypropyl cellulose, lignin and their blends are determined through a series of DOEs. Hydroxypropyl cellulose is significantly more amenable to photocrosslinking than organosolv lignin. The optimal photocrosslinkable ink formulations are printable and exhibit up to 70% gel content, although thermal post-curing remains essential. Chemical, thermal, and mechanical investigations of the photocrosslinked 3D parts evidence efficient crosslinking of HPC through its hydroxyl groups, while lignin appears internally plasticized and/or degraded during inefficient photocrosslinking. Despite this, photocrosslinkable inks exhibit improved tensile properties, shape flexibility, and fidelity. The heterogeneous crosslinking and residual creep highlight the need to further activate lignin for homogeneous photocrosslinking in order to fully exploit the potential of lignin inks in DIW.

Optimizing Desmostachya bipinnata-derived platinum nanoparticles for enhanced antibacterial and biofilm reduction

This study presents the green synthesis and comprehensive characterization of platinum nanoparticles (PtNPs) using Desmostachya bipinnata (Db) extract, incorporated into two innovative mouthwash formulations (MW1 and MW2). UV–Vis spectroscopy confirmed the successful synthesis of PtNPs, with distinct absorption peaks between 250 and 600 nm. Fourier-transform infrared (FTIR) spectroscopy identified hydroxyl and carbonyl functional groups, critical for the bioreduction and stabilization of PtNPs. High-resolution transmission electron microscopy (HR-TEM) revealed uniformly dispersed, spherical nanoparticles with a size range of 10–20 nm, while dynamic light scattering (DLS) confirmed a hydrodynamic diameter of 10–30 nm and a low polydispersity index (PDI) of 0.238, indicating excellent stability. Both formulations exhibited robust antimicrobial, antibiofilm, and anti-plaque properties, with MW2 showing superior efficacy, particularly against Staphylococcus aureus and Escherichia coli, as well as a notable 70 % reduction in biofilm formation and a 60 % plaque reduction within 2 h of treatment. The study underscores the potential of Desmostachya bipinnata-derived PtNPs as a promising alternative to conventional mouthwash, offering enhanced antimicrobial efficacy, biofilm disruption, and plaque prevention, alongside excellent stability and biocompatibility for oral healthcare applications.

Empirical Approach to Quantifying Sensitivity in Different Chemical Ionization Techniques for Organonitrates and Nitroaromatics Constrained by Ion-Molecule Reaction and Transmission Efficiency.

Accurate identification and quantification of nitro-containing species are of great significance to understanding their chemical behaviors in the atmosphere. By optimizing the operational conditions of the H3O+ and NO+ ionization modes in a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) and evaluating the performance of an iodide chemical ionization mass spectrometer (I- CIMS), this study leveraged the individual advantages of each ionization mode to effectively detect a diverse array of nitroaromatics and organonitrates (ONs). The H3O+ ionization mode largely fulfilled the criteria for real-time monitoring of gas-phase alkyl-, aryl-, and hydroxy-nitrates, and nitrophenols, albeit its reduced sensitivity toward ONs due to extensive fragmentation. In contrast, the NO+ mode demonstrated enhanced sensitivity for ONs with less fragmentation than the H3O+ mode. The I- CIMS featured distinguished sensitivity toward oxidized compounds containing polar functional groups, particularly increasing with the incorporation of hydroxyl, carboxyl, or nitrate groups. Further, we developed a calibration-based semiquantitative framework to enhance the accuracy of sensitivity estimation, constrained by ion-molecule reaction, transmission efficiency, along with possible decomposition of ion-clusters, with uncertainties ranging from 21% to 41% for H3O+ and 21-43% for NO+. Given considerable discrepancies (up to 1 order of magnitude) between measured and predicted sensitivity in I- CIMS using previously reported log-linear fitting, a declustering voltage (dV50)-based categorization approach was introduced, leading to a 5-fold improvement in measurement accuracy and an overall uncertainty of I- CIMS in quantifying nitro-containing species varying from 27% to 60%.