Acid Chloride Research Articles

Antimicrobial effects of chlorhexidine gel associated with hyaluronic acid or cetylpyridinium chloride in a multispecies biofilm

Chlorhexidine (CHX) and cetylpyridinium chloride (CPC) are commonly used as mouthwashes due to their antimicrobial effect. More recently, hyaluronic acid (HA) has also been associated to oral health products aiming to improve their anti-inflammatory and antimicrobial effects. This study aimed to evaluate the effect of three different CHX-based commercially available products on the subgingival microbial composition and metabolic activity using a multispecies biofilm model. A biofilm model composed of 33 bacterial species with 7 days of maturation on a Calgary plate device was used. The multispecies biofilm was treated with CHX 0.2% (positive control), CHX 0.2% + CPC (test 1), CHX 0.2% + HA 1% (test 2), and culture medium (negative control). The metabolic activity of the multispecies biofilm was measured using a spectrophotometric assay and the microbial composition by checkerboard DNA-DNA hybridization. The studied groups were compared using ANOVA and post hoc Bonferroni tests. The significance level was established at 5%. The CHX+CPC gel was more effective than the other treatments in reducing proportions of red complex species and increasing bacterial species associated with periodontal health (p<0.05). A reduction of approximately 54% was observed in the microbial metabolic activity of biofilms treated with CHX and CHX + CPC, and 26% in biofilms treated with CHX+HA. The CHX+CPC gel seems to have a superior antibacterial potential when compared to a gel containing CHX only, or CHX+HA, in an in vitro multispecies biofilm model.

Technical and Economic Feasibility Investigation for the Treatment of Microplastic-Contaminated Marine Sediments Through an Environmentally Sustainable Separation Process

This work provides a comprehensive study of a density separation treatment through sucrose solution for the removal of microplastics (MPs) from marine sediments. The theoretical determination of flotation velocities for 1.0 mm diameter spherical MPs with a density of 1.3 g/cm3 at various solution temperatures and sucrose contents was performed. An optimal velocity of 1.03 m/h was observed with a 70% sucrose solution at 50 °C. The validation of theoretical velocities was carried out through experimental tests at optimal operating conditions for polypropylene (PP), high-density polyethylene (HDPE), polylactic acid (PLA), and polyvinyl chloride (PVC) as target MPs. The results showed an experimental floating velocity slightly lower than the theoretical predictions for PP, HDPE, and PLA. PVC, instead, characterized by a higher density than the separation solution, showed a settling velocity 42% lower than the theoretical one. Further tests were performed to assess the solid-to-liquid (S/L) ratio effect on MPs’ separation efficiency. The results showed an optimal S/L of 75 kg/m3 with 80% PVC removal and total PP, HDPE, and PLA removal. Finally, the design and cost optimization of a longitudinal settling tank were proposed for the pilot/real-scale treatment. The observed outcomes provided in-depth details useful for the development of an environmentally sustainable treatment for the preservation of marine areas.

Structural investigations of benzoyl fluoride and the benzoacyl cation of low-melting compounds and reactive intermediates.

Acyl fluorides and acyl cations represent typical reactive intermediates in organic reactions, such as Friedel-Crafts acylation. However, the comparatively stable phenyl-substituted compounds have not been fully characterized yet, offering a promising backbone. Attempts to isolate the benzoacylium cation have only been carried out starting from the acyl chloride with weaker chloride-based Lewis acids. Therefore, only adducts of 1,4-stabilized acyl cations could be obtained. Due to the low melting point of benzoyl fluoride, together with its volitality and sensitivity toward hydrolysis, the structures of the acyl fluoride and its acylium cation have not been determined. Herein, we report the first crystal structure of benzoyl fluoride, C7H5FO or PhCOF (monoclinic P21/n, Z = 8) and the benzoacylium undecafluorodiarsenate, C7H5O+·As2F11- or [PhCO]+[As2F11]- (monoclinic P21/n, Z = 4). The compounds were characterized by low-temperature vibrational spectroscopy and single-crystal X-ray analysis, and are discussed together with quantum chemical calculations. In addition, their specific π-interactions were elucidated.

Kinetics of galena leaching in nitric acid and sodium chloride solutions for potential lead recovery

ABSTRACT The kinetics of galena dissolution in nitric acid (HNO3) solutions in the presence of sodium chloride was examined by batch leaching process. Results obtained revealed that the concentration of HNO3, stirring speed, leaching temperature, solid/liquid (S/L) ratio, and particle size were the parameters of greatest impact. The result revealed that the leaching rate increased with increase in HNO3 concentration, stirring rate, and leaching temperature; while it decreased with rise in S/L ratio and particle size. The experimental results fitted into the product layer diffusion model while the rate-controlling step was found to be chemical reaction. Activation energy (Ea) of the leaching process was estimated to be 29.65 kJ/mol. The residue analysed by XRD showed the presence of cotunnite.

Synthesis of Telechelic Isotactic Polypropylenes for Circular Polypropylene-like Materials via Chain Transfer Polymerization.

While synthesizing circular polymers with telechelic polyolefin building blocks recently emerged as a promising strategy for addressing conventional polyethylenes' sustainability challenges, the lack of telechelic iPP (tPP) with sufficient difunctional purity for polycondensation has been limiting the development of circular polypropylenes with iPP-like structures and properties. Here we described a combined approach of coordinative chain transfer polymerization and transition-metal-catalyzed quenching reaction with various acyl chlorides, affording tPPs with a high difunctional ratio (up to ∼99%) and broad end functional group scope. The steric effect of polymeryl-Zn species and the role of Pd catalyst were revealed by DFT. This method also solved the low difunctional ratio challenge for telechelic polyethylenes. Ester-linked iPPs with iPP-like structure and thermomechanical properties and PE/iPP multiblock copolymers were synthesized by the resulting tPPs.

Ultrasound-Assisted Determination of Selenium in Organic Rice Using Deep Eutectic Solvents Coupled with Inductively Coupled Plasma Mass Spectrometry

As the focus on green chemistry intensifies, researchers are progressively looking to incorporate biodegradable and environmentally friendly solvents. Given the prevalent use of inorganic solvents in conventional methods for detecting selenium content, this study utilized a mixture design approach to create four deep eutectic solvents (DESs). The elements of the DESs consisted of six different compounds: guanidine hydrochloride, fructose, glycerol, citric acid, proline, and choline chloride. The synthesized deep eutectic solvents (DESs) exhibited a uniform and transparent appearance. The ideal ratios for each DES were established based on their density and viscosity measurements, leading to the formulations of DES1 (34% guanidine hydrochloride, 21% fructose, 45% water), DES2 (23% guanidine hydrochloride, 32% glycerol, 45% water), DES3 (27.5% citric acid, 27.5% proline, 45% water), and DES4 (30% choline chloride, 25% citric acid, 45% water). The characterization of the deep eutectic solvents (DESs) was performed using nuclear magnetic resonance (NMR) spectroscopy and infrared (IR) spectroscopy, which confirmed the molecular formation of each DES. Following this, the DESs were applied as extraction solvents in a process involving ultrasonic-assisted microextraction (UAE) combined with inductively coupled plasma mass spectrometry (ICP-MS) to assess the selenium levels in selenium-rich rice. The results were benchmarked against traditional microwave-assisted acid digestion (TM-AD), revealing selenium recovery rates ranging from 85.5% to 106.7%. These results indicate that UAE is an effective method for extracting selenium from selenium-rich rice, thereby establishing a solid data foundation for the environmentally friendly analysis of selenium content in rice.

Functional differentiation of human dental pulp stem cells into neuron-like cells exhibiting electrophysiological activity

Background and aimHuman dental pulp stem cells (hDPSCs) constitute a promising alternative for central nervous system (CNS) cell therapy. Unlike other human stem cells, hDPSCs can be differentiated, without genetic modification, to neural cells that secrete neuroprotective factors. However, a better understanding of their real capacity to give rise to functional neurons and integrate into synaptic networks is still needed. For that, ex vivo differentiation protocols must be refined, especially to avoid the use of fetal animal serum. The aim of our study is to improve existing differentiation protocols of hDPSCs into neuron-like cells.MethodsWe compared the effects of the (1) absence or presence of fetal serum during the initial expansion phase as a step prior to switching cultures to neurodifferentiation media. We (2) improved hDPSC neurodifferentiation by adding retinoic acid (RA) and potassium chloride (KCl) pulses for 21 or 60 days and characterized the results by immunofluorescence, digital morphometric analysis, RT-qPCR and electrophysiology.ResultsWe found that neural markers like Nestin, GFAP, S100β and p75NTR were expressed differently in neurodifferentiated hDPSC cultures depending on the presence or absence of serum during the initial cell expansion phase. In addition, hDPSCs previously grown as spheroids in serum-free medium exhibited in vitro expression of neuronal markers such as doublecortin (DCX), neuronal nuclear antigen (NeuN), Ankyrin-G and MAP2 after neurodifferentiation. Presynaptic vGLUT2, Synapsin-I, and excitatory glutamatergic and inhibitory GABAergic postsynaptic scaffold proteins and receptor subunits were also present in these neurodifferentiated hDPSCs. Treatment with KCl and RA increased the amount of both voltage-gated Na+ and K+ channel subunits in neurodifferentiated hDPSCs at the transcript level. Consistently, these cells displayed voltage-dependent K+ and TTX-sensitive Na+ currents as well as spontaneous electrophysiological activity and repetitive neuronal action potentials with a full baseline potential recovery.ConclusionOur study demonstrates that hDPSCs can be differentiated to neuronal-like cells that display functional excitability and thus evidence the potential of these easily accessible human stem cells for nerve tissue engineering. These results highlight the importance of choosing an appropriate culture protocol to successfully neurodifferentiate hDPSCs.

Simultaneous removal of nitrate, carbamazepine, and copper by fulvic acid and ferric chloride composite modified ceramsite assembled fixed biofilter reactor: Performance and microbial community response.

The complex pollution and nutrient-poor characteristics of surface waters result in the limited ability of conventional reactors to remove pollutants. In this study, a novel modified ceramsite material, modified with trivalent iron (Fe(III)) and fulvic acid (FA) to form ceramsite@Fe(III)@FA (HC), was used for the first time as a biocarrier to immobilize strain Cupriavidus sp. W12, constructing a biofilter to enhance nitrate (NO3--N) removal in micro-polluted water. HC could accelerate electron transfer, significantly enhancing the denitrification capacity of the biofilter. When HRT was 6, pH was 7, and C/N was 2.5, the removal efficiency of NO3--N could reach 97.0%. Efficient removal of carbamazepine (CBZ) and copper (Cu2+) was achieved through adsorption by HC and precipitate. Calcium ions (Ca2+) removal (74.2%) was achieved through the microbial-induced carbonate precipitation (MICP) process. In addition, with the addition of CBZ and Cu2+, the biofilter maintained a stable microbial community and consistent expression of relevant functional genes. This research offers new perspectives on the efficient removal of complex pollutants in surface water treatment.

The Synthesis, Crystal Structure, Modification, and Cytotoxic Activity of α-Hydroxy-Alkylphosphonates.

A series of α-hydroxy-alkylphosphonates and α-hydroxy-alkylphosphine oxides were synthesized by the Pudovik reaction of acetaldehyde and acetone with dialkyl phosphites or diarylphosphine oxides. The additions were performed in three different ways: in liquid phase using triethylamine as the catalyst (1), on the surface of Al2O3/KF solid catalyst (2), or by a MW-assisted Na2CO3-catalyzed procedure (3). In most of the cases, our methods were more efficient and more robust than those applied in the literature. Two of the α-hydroxy-alkylphosphonates were subjected to single-crystal X-ray analysis, suggesting a dimeric and a chain supramolecular buildup in their respective crystals. Four α-hydroxy-alkylphosphonates and one α-hydroxy-ethylphosphine oxide were reacted with different acid chlorides to afford ten α-acyloxyphosphonates. Diethyl α-hydroxy-ethylphosphonate was transformed to the methanesulfonyloxy derivative that was useful in the Michaelis-Arbuzov reaction with triethyl phosphite and ethyl diphenylphosphinite to afford tetraethyl ethylidenebisphosphonate and diethyl α-(diphenylphosphinoyl)-ethylphosphonate, respectively. The α-hydroxyphosphonates and α-hydroxyphosphine oxides prepared were subjected to bioactivity studies, and the compounds tested exhibited limited cytotoxic effects on U266 cells with modest reductions in viability at a concentration of 100 μM.

Eco-friendly sensing of hexavalent chromium ions via copper-doped carbon quantum dots: a fluorescent probe for water safety

The hydrothermal synthesis is presented of copper-doped carbon dots (Cu-CDs) from citric acid, urea, and copper chloride, resulting in blue-fluorescent particles with stable emission at 438 nm when excited at 340 nm. Through comprehensive spectroscopic and microscopic characterization (FTIR, XPS, UV, and HRTEM), the Cu-CDs demonstrated remarkable stability across varying pH levels, ionic strengths, temperatures, and UV exposure. Notably, Cu-CDs exhibit ultra-sensitive and selective detection of hexavalent chromium [Cr(VI)] ions in aqueous environments driven by fluorescence quenching. The system showed a robust linear response to Cr(VI) in the 0–80 µM range, with an impressive limit of detection (LOD) of 0.186 µM, significantly lower than the WHO’s permissible limit of 0.96 µM. These findings position Cu-CDs as an effective tool for environmental monitoring and water safety applications.Graphical

Synthesis and properties of a new environmentally friendly bicyclic imidazoline quaternary ammonium salt as a corrosion inhibitor of carbon steel

Abstract A new corrosion inhibitor, environment-friendly bicyclic imidazoline quaternary ammonium salt (DL-IM), was synthesized using DL-aspartic acid, hydroxyethyl ethylenediamine, and benzyl chloride as the main raw materials. The amidation, cyclization, and quaternization reactions were carried out at 140 °C for 4 h, 220 °C for 3 h, and 70 °C for 3 h, respectively. The structure of DL-IM was characterized by infrared spectroscopy and nuclear magnetic hydrogen spectroscopy. The corrosion experiments of carbon steel sheets (American Petroleum Institute, API 5CT N80, primarily used in well drilling operations to protect the wellbore), protected with or without DL-IM, demonstrated that DL-IM had a good anti-corrosion performance (with the inhibition efficiency and corrosion rate of 97.13% and 0.6528 mm/a, respectively) in the 1 M HCl solution at 60 °C. DL-IM was a kind of cathodic protection-type corrosion inhibitor confirmed by Tafel curves. The analysis of adsorption kinetics by quantum chemical simulations demonstrated that the imidazoline ring in the DL-IM molecule can form covalent bonds with the empty d-orbitals of Fe through charge sharing. Moreover, the dipole moment of DL-IM is 1.3931 D (1 D = 3.34×10-30 C·m), suggesting a good hydrophobicity of DL-IM. Therefore, the adsorption film formed by DL-IM on the surface of N80 can effectively isolate the corrosive medium from N80. Thus, successful synthesis of DL-IM provides a new insight into the design and synthesis of the environment-friendly corrosion inhibitor with stronger corrosion inhibition effect.

Benzoxazinone Derivatives as Antiplatelet: Synthesis, Molecular Docking, and Bleeding Time Evaluation

Background The recurrence of atherosclerosis is still a global problem. Unfortunately, the drugs currently being used are reported to have resistance. Purpose To prevent the recurrence of atherosclerosis disease, this study developed benzoxazinone derivatives as an antiplatelet agent: 2-phenyl-3,1-benzoxazine-4-one (BZ1) and 2-(4′-chlorophenyl)-3,1-benzoxazin-4-one (BZ2). Methods The target compounds were synthesized through acyl nucleophilic substitution from acyl chloride and anthranilic acid using a base catalyst in triethylamine. This compound was then given to mice at three different doses to perform bleeding-time and clotting-time tests, using acetosal as a comparison. In silico, the binding energy between the test compound and the cyclooxygenase 1 enzyme was tested using Molegro Virtual Docker version 5.5 (MVD 5.5). The pharmacokinetic parameters were predicted using pharmacokinetics and chemistry through space mapping (pkCSM). Results The synthesis provided 83% yield. The biological assay at a dose of 20 mg/kg body weight (BW) BZ1 showed a higher bleeding time (361 s) than acetosal (324 s), whereas BZ2 was lower (179 s). The molecular analysis revealed that the compound had higher activity than aspirin. The absorption, distribution, metabolism, excretion, and toxicity (ADMET) showed that the compound posed high intestinal absorption. Conclusion This research concluded that both of the synthesized compounds have the potential and prospective to be developed as antiplatelet agents.

Consecutive Sonogashira–Suzuki–Michael Cyclization: Three-Component Synthesis of Phenanthridines and Benzo[c]chromenes

AbstractThe equistoichiometric three-component reaction of an acid chloride, an alkyne, and an ortho-amino- or ortho-hydroxyphenylboronic ester proceeds smoothly to give phenanthridines or benzo[c]chromenes, respectively, with good to quantitative yields in the sense of a Sonogashira–Suzuki–Michael cyclization sequence. In the coupling of ortho-amidophenylboronates, interestingly, after ring closure a subsequent an acyl migration occurs to give 6-(2-(acyloxy)vinyl)phenanthridines.

Optimized pure cellulose from rice straw using low alkali concentration for sustainable nanocellulose and nanohydrogel production with enhanced dye reduction.

Conversion of rice straw into nanocellulose offers a sustainable approach to agricultural waste management, yielding an industrially important product with potential applications. This work focuses on effectively extracting pure cellulose from both widely used Basmati and Parmal rice straw (BRS and PRS) using less alkali concentrations (3-5 % NaOH). The process was optimized via Box Behnken design at 90-150 °C temperatures for 90-150 min, which resulted in 88.8 ± 2.07 % cellulose for BRS and 89.10 ± 2.67 % for PRS. The cellulose was then processed into nanocellulose (BRSNC and PRSNC) through the combined approach of citric acid and ferric chloride hydrolysis. Various characterization techniques confirmed the removal of lignin and hemicellulose from the rice straws at different stages of hydrolysis. Nanocellulose was further transformed into nanohydrogel (BRSHG and PRSHG) using neem oil. In comparison to nanocellulose, the nanohydrogels exhibited remarkable dye reduction under UV light. The antimicrobial activity revealed superior efficacy of nanohydrogels against E. coli and S. aureus highlighting their potential in environmental remediation and antimicrobial applications.

Enhanced α-phase stability of formamidinium lead iodide with addition of 5-ammonium valeric acid chloride

The photoactive α-phase of formamidinium lead iodide (FAPbI3) is not thermodynamically stable at operating temperatures, but can be significantly improved by incorporating 5-ammonium valeric acid chloride into precursor solutions.

A Chiral Sensing Platform Based on a Starfish-Shaped AuCu Alloy for Chiral Analysis.

Designing alloys with intrinsic chirality for chiral analysis is an interesting subject, since most alloys are achiral. Here, a starfish-shaped AuCu alloy is facilely prepared through simultaneous reduction of chloroauric acid (HAuCl4) and copper chloride (CuCl2) by l-ascorbic acid (l-AA). The resultant AuCu alloy exhibits fascinating chirality due to the chiral lattice distortion generated in the alloy. More interestingly, the chirality of the AuCu alloy is exactly opposite to that of Au nanoparticles (AuNPs) and Cu nanoparticles (CuNPs) prepared through the reduction of HAuCl4 and CuCl2 by l-AA. Additionally, the AuCu alloy also has good electrical conductivity, and thus, it is used in the construction of the electrochemical chiral sensing platform for chiral analysis. The tryptophan (Trp) enantiomers can be discriminated with the AuCu alloy-based chiral sensing platform. Moreover, this chiral sensing platform can also be used for the detection of l-Trp in the concentration ranging from 10 nM to 10 mM with a limit of detection (LOD) of 3.12 nM.

Design and synthesis of novel antibacterial agents that targets the bacterial fatty acid pathway

Antibacterial resistance is a global threat that is rapidly overtaking every known drug which has been designed for curbing its spread rendering them ineffective. This emphasizes the urgent need for the development of novel agents with unique targets that would show no resistance when employed against bacterial pathogens, using Escherichia coli and Staphylococcus aureus as test bacterial strains. The FAS II pathway has now become a prime candidate for developing significant and novel antibacterials as Platensimycin, a newly discovered inhibitor of the pathway further validates it. Three compounds were synthesized from carboxylic acids derivatives known as Acyl chlorides whose –OH group has been replaced by a chlorine atom and whose general formula is represented as RCO-Cl and a primary amine having one alkyl group on the nitrogen atom giving rise to its formula as RNH2 and were subjected to spectroscopic analysis to confirm their chemical structure using NMR, TLC and LC-MS instruments. Biological assays involving the potency test of this synthesized compounds against bacteria confirmed any antibacterial activity as all three novel compounds showed inhibition activity even at the lowest concentration tested. The methyl CH3 groups as well as the various benzene substituted rings of the compounds showed to be contributors to their inhibition activity. Recrystallization of this novel compounds is recommended in the future as a means of purifying it as well as the application of minimal inhibitory concentration (MIC) assay to ensure that this antibacterial agents are selected effectively to improve treatment outcomes.

Synthesis of 2-(4-Methyl-Phenoxymethyl) Benzoic Acid; Cresol and its Metal Coordinate Complexes

A series of phenoxymethylbenzoic acid derivatives were synthesized by reacting p-cresol with phthalide. The resulting phenoxymethyl benzoic acid was converted into corresponding acid chloride by reacting with cyanuric chloride. These phenoxymethyl benzoyl chlorides were then reacted with various aminobenzenesulfonamides and synthesize d new sulfonamide derivatives. The targeted sulfonamides were subjected to structural characterization by contemporary spectroscopic techniques like UV-visible and FT-IR. The presence of a peak at 3400/cm confirmed the existence of amide functionality, and furthermore , the broad peak at1250/cm showed that the sulfone group is present in the molecule.

Escape of etiolated hypocotyls of cotton (Gossypium hirsutum) from the unilateral high intensity blue light after being pulled out from the soil.

Plant stems grow towards the incident light in response to unilateral blue light to optimize photosynthesis. However, our findings reveal that unilateral high-intensity blue light (HBL) triggers backlit lodging in etiolated cotton (Gossypium hirsutum ) hypocotyls when they are pulled approximately 1.5cm from the soil. Phenotypic analysis indicated that stomata on the lit side were open, while those on the shaded side were closed under unilateral HBL. To investigate the relationship between stomatal movement and backlit lodging, we applied abscisic acid (ABA), hydrogen peroxide (H2 O2 ), and lanthanum chloride (LaCl3 ) to the lit side, and cytokinins (6-BA) and ascorbic acid (ASA) to the shaded side. Results showed that all these treatments inhibited the backlit lodging phenomenon, specifically, ABA, H2 O2 , and LaCl3 reduced stomatal opening on the lit side, while 6-BA and ASA enhanced stomatal opening on the shade side. These results demonstrate that HBL-induced asymmetrical stomatal opening on the lit and shade side of hypocotyl supports the backlit lodging phenomenon. Notably, maize (Zea mays ), which lack stomata in the hypocotyl did not exhibit HBL-induced backlit lodging, whereas soybean (Glycine max ), which has stomata in its etiolated hypocotyl, displayed a similar phenotype to that of cotton. Additionally, while both red light and low-intensity blue light (LBL) can induce stomatal opening, they do not trigger the backlit lodging phenomenon. These findings suggest that backlit lodging is a unique HBL-dependent response, but the mechanism need further investigation.

Synthesis of a Novel Class of Some 1,3,5-Triazine Derivatives and their Anti-HIV Activity

Novel substituted s-triazine based derivatives were prepared by condensation of 2,4,6-trichloro-1,3,5-s-triazine with anisole, p-trifluoromethyl aniline and amino acid chloride, upon which the compounds were derivatized to their phenyl(thio)urea derivatives, and evaluated for their antiviral activity against human immunodefiency virus HIV-1 (IIIB) and HIV-2 (ROD). The structures of novel synthesized compounds have been established on the basis of 1H NMR, FTIR spectral data and elemental analysis.