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Enzymatic cleavage of C─F bonds in per- and polyfluoroalkyl substances (PFAS) is largely unknown but avidly sought to promote systems biology for PFAS bioremediation. Here, we report the reductive defluorination of α, β-unsaturated per- and polyfluorocarboxylic acids by Acetobacterium spp. The microbial defluorination products were structurally confirmed and showed regiospecificity and stereospecificity, consistent with their formation by enzymatic reactions. A comparison of defluorination activities among several Acetobacterium species indicated that a functional fluoride exporter was required for the detoxification of the released fluoride. Results from both in vivo inhibition tests and in silico enzyme modeling suggested the involvement of enzymes of the flavin-based electron-bifurcating caffeate reduction pathway [caffeoyl-CoA reductase (CarABCDE)] in the reductive defluorination. This is a report on specific microorganisms carrying out enzymatic reductive defluorination of PFAS, which could be linked to electron-bifurcating reductases that are environmentally widespread.

The photochemical dynamics of the acetic acid and trifluoro-acetic acid dimers in hexane are studied using time-resolved infrared absorption spectroscopy and ab initio electronic structure calculations. The different hydrogen bond strengths of the two systems lead to changes in the character of the accessed excited states and in the timescales of the initial structural rearrangement that define the early time dynamics following UV excitation. The much stronger hydrogen bonding in the acetic acid dimer stabilizes the system against dissociation. Ground state recovery is mediated by a structural buckling around the hydrogen bond itself with no evidence for excited state proton transfer processes that are usually considered to drive ultrafast relaxation processes in hydrogen bonded systems. The buckling of the ring leads to relaxation through two conical intersections and the eventual reformation of the electronic and vibrational ground states on a few picosecond timescale. In trifluoro-acetic acid, the weaker hydrogen bonding interaction means that the dimer dissociates under similar irradiation conditions. The surrounding solvent cage restricts the full separation of the monomer components, meaning that the dimer is reformed and returns to the ground state structure via a similar buckled structure but over a much longer, ∼100 ps, timescale. [ABSTRACT FROM AUTHOR]

Ammonium and carboxylic moieties play a central role in proton-mediated processes of molecular recognition, charge transfer or chemical change in (bio)materials. Whereas both chemical groups constitute acid–base pairs in organic salt-bridge structures, they may as well host excess protons in acidic environments. The binding of excess protons often precedes proton transfer reactions and it is therefore of fundamental interest, though challenging from a quantum chemical perspective. As a benchmark for this process, we investigate proton storage in the amphoteric compound 5-aminovaleric acid (AV), within an intramolecular proton bond shared by its primary amine and carboxylic acid terminal groups. Infrared ion spectroscopy is combined with ab initio Molecular Dynamics (AIMD) calculations to expose and rationalize the spectral signatures of protonated AV and its deuterated isotopologues. The dynamic character of the proton bond confers a fluxional structure to the molecular framework, leading to wide-ranging bands in the vibrational spectrum. These features are reproduced with remarkable accuracy by AIMD computations, which serves to lay out microscopic insights into the excess proton binding scenario. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) is a two-dimensional, mechanically strong, and chemically tunable material for separations. Elucidating GO–ion–water interactions at the molecular scale is highly important for predictive understanding of separation systems. However, direct observations of the nanometer region by GO surfaces under operando conditions are not trivial. Therefore, thin films of GO at the air/water interface can be used as model systems. With this approach, we study the effects of alkali metal ions on water organization near graphene oxide films at the air/water interface using vibrational sum frequency generation (SFG) spectroscopy. We also use an arachidic acid Langmuir monolayer as a benchmark for a pure carboxylic acid surface. Theoretical modeling of the concentration-dependent sum frequency signal from graphene oxide and arachidic acid surfaces reveals that the adsorption of monovalent ions is mainly controlled by the carboxylic acid groups on graphene oxide. An in-depth analysis of sum frequency spectra reveals at least three distinct water populations with different hydrogen bonding strengths. The origin of each population can be identified from concentration dependent variations of their SFG signal. Interestingly, an interfacial water structure seemed mostly insensitive to the character of the alkali cation, in contrast to similar studies conducted at the silica/water interface. However, we observed an ion-specific effect with lithium, whose strong hydration prevented direct interactions with the graphene oxide film. [ABSTRACT FROM AUTHOR]

DNA-encoded library technology grants access to nearly infinite opportunities to explore the chemical structure space for drug discovery. Successful navigation depends on the design and synthesis of libraries with appropriate physicochemical properties (PCPs) and structural diversity while aligning with practical considerations. To this end, we analyze combinatorial library design constraints including the number of chemistry cycles, bond construction strategies, and building block (BB) class selection in pursuit of ideal library designs. We compare two-cycle library designs (amino acid + carboxylic acid, primary amine + carboxylic acid) in the context of PCPs and chemical space coverage, given different BB selection strategies and constraints. We find that broad availability of amines and acids is essential for enabling the widest exploration of chemical space. Surprisingly, cost is not a driving factor, and virtually, the same chemical space can be explored with budget BBs.

The total oxidizable precursor (TOP) assay has been extensively used for detecting PFAS pollutants that do not have analytical standards. It uses hydroxyl radicals (HO•) from the heat activation of persulfate under alkaline pH to convert H-containing precursors to perfluoroalkyl carboxylates (PFCAs) for target analysis. However, the current TOP assay oxidation method does not apply to emerging PFAS because (i) many structures do not contain C-H bonds for HO• attack and (ii) the transformation products are not necessarily PFCAs. In this study, we explored the use of classic acidic persulfate digestion, which generates sulfate radicals (SO4-•), to extend the capability of the TOP assay. We examined the oxidation of Nafion-related ether sulfonates that contain C-H or -COO-, characterized the oxidation products, and quantified the F atom balance. The SO4-• oxidation greatly expanded the scope of oxidizable precursors. The transformation was initiated by decarboxylation, followed by various spontaneous steps, such as HF elimination and ester hydrolysis. We further compared the oxidation of legacy fluorotelomers using SO4-• versus HO•. The results suggest novel product distribution patterns, depending on the functional group and oxidant dose. The general trends and strategies were also validated by analyzing a mixture of 100000- or 10000-fold diluted aqueous film-forming foam (containing various fluorotelomer surfactants and organics) and a spiked Nafion precursor. Therefore, (1) the combined use of SO4-• and HO• oxidation, (2) the expanded list of standard chemicals, and (3) further elucidation of SO4-• oxidation mechanisms will provide more critical information to probe emerging PFAS pollutants.

This publication highlights the latest advancements in the field of energy and nutrient recovery from organics rich municipal and industrial waste and wastewater. Energy and carbon rich waste streams are multifaceted, including municipal solid waste, industrial waste, agricultural by-products and residues, beached or residual seaweed biomass from post-harvest processing, and food waste, and are valuable resources to overcome current limitations with sustainable feedstock supply chains for biorefining approaches. The emphasis will be on the most recent scientific progress in the area, including the development of new and innovative technologies, such as microbial processes and the role of biofilms for the degradation of organic pollutants in wastewater, as well as the production of biofuels and value-added products from organic waste and wastewater streams. The carboxylate platform, which employs microbiomes to produce mixed carboxylic acids through methane-arrested anaerobic digestion, is the focus as a new conversion technology. Nutrient recycling from conventional waste streams such as wastewater and digestate, and the energetic valorization of such streams will also be discussed. The selected technologies significantly contribute to advanced waste and wastewater treatment and support the recovery and utilization of carboxylic acids as the basis to produce many useful and valuable products, including food and feed preservatives, human and animal health supplements, solvents, plasticizers, lubricants, and even biofuels such as sustainable aviation fuel.One-sentence summaryMultifaceted waste streams as the basis for resource recovery are essential to achieve environmental sustainability in a circular economy, and require the development of next-generation waste treatment technologies leveraging a highly adaptive mixed microbial community approach to produce new biochemicals, biomaterials, and biofuels from carbon-rich organic waste streams.

This account describes the latest developments on 3d-metal-catalyzed single-electron-transfer (SET)-induced strategies that use carboxylic acids and their synthetic equivalents as substrates. In general, 3d-metal-promoted SET-mediated transformations of free carboxylic acids proceed readily via the formation of carboxylate radicals, whilst those of carboxylic acid equivalents, bearing an N-donor substituent, proceed via the formation of α-carbo radicals. The advantages of these strategies combine the low-cost of carboxylic acid starting materials and 3d metal catalysts with the possibility of realizing structurally diverse ranges of compounds in an atom- and step-economic manner. Developments primarily achieved by our group and a few by other researchers on this topic are discussed in this account. 1 Introduction 2 Mechanistic Considerations of 3d-Metal-Catalyzed SET-Mediated Transformations 3 Developments Based on SET-Mediated Transformations of Carboxylic Acids 4 Developments Based on SET-Mediated Transformations of Carboxylic Acid Equivalents 5 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

Here, we report the NiCo2 O4-nanoparticle-catalyzed dehydrogenative direct oxidation of primary alcohols to carboxylic acid in the presence of KOH under microwave irradiation in the absence of any oxidant in good to excellent yields (75–99%) within a short reaction time (5–10 min). The polycrystalline cubic spinel phase of NiCo2 O4 nanoparticles (NPs) with an average size of 25 nm were synthesized by the co-precipitation method and analyzed properly by using powder X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy measurements. The NiCo2 O4 NPs were stable under the reaction conditions and reused for up to eight cycles without appreciable loss in the yield of benzoic acid. According to mechanistic insight, the KOH acts as a second oxygen source and is essential for the synthesis of carboxylic acid from alcohols. The hydrogen gas was found to be the only byproduct of this method detected by chemical reactions. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Boronate esters are highly valued in synthetic and pharmaceutical industries for their versatility in creating C—C and C—X bonds. They also find applications as catalysts in chemical transformations as well as stimuli‐responsive materials in materials science. Some alkyl boronates themselves also show promising applications in medicinal chemistry. In the past few decades, chemists have been devoted to developing new methods or new starting materials for synthesizing boronate esters. Carboxylic acids and their derivatives are privileged chemical entities due to their readily availability or natural abundance, structural diversity, and chemical stability. Hence, the transformation of carboxylic acid and their derivatives to alkyl/aryl boronate esters has seen its fast development in the past decade. This review summarized the state‐to‐art development of decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives to aryl and alkyl boronate esters. Key Scientists: The decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives started only in the past decade. In 2016, the decarbonylative borylation of carboxylic esters and amides was reported by Zhuangzhi Shi and Magnus Reuping's groups. Then, in 2017, studies on the decarboxylative borylation of redox‐active esters such as NHPI esters started to receive increasing attention by Aggarwal, Baran, Fu, Glorius, and Li's groups. From 2018 to 2023, large numbers of studies on the decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives using transition‐metal‐catalyst, organo‐catalyst, or under photochemical or electrochemical conditions emerged. Due to space limitations, only pictures of scientists who have contributed more than two works in this area are shown herein. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Boronate esters are highly valued in synthetic and pharmaceutical industries for their versatility in creating C—C and C—X bonds. They also find applications as catalysts in chemical transformations as well as stimuli‐responsive materials in materials science. Some alkyl boronates themselves also show promising applications in medicinal chemistry. In the past few decades, chemists have been devoted to developing new methods or new starting materials for synthesizing boronate esters. Carboxylic acids and their derivatives are privileged chemical entities due to their readily availability or natural abundance, structural diversity, and chemical stability. Hence, the transformation of carboxylic acid and their derivatives to alkyl/aryl boronate esters has seen its fast development in the past decade. This review summarized the state‐to‐art development of decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives to aryl and alkyl boronate esters. Key Scientists: The decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives started only in the past decade. In 2016, the decarbonylative borylation of carboxylic esters and amides was reported by Zhuangzhi Shi and Magnus Reuping's groups. Then, in 2017, studies on the decarboxylative borylation of redox‐active esters such as NHPI esters started to receive increasing attention by Aggarwal, Baran, Fu, Glorius, and Li's groups. From 2018 to 2023, large numbers of studies on the decarboxylative and decarbonylative borylation of carboxylic acids and their derivatives using transition‐metal‐catalyst, organo‐catalyst, or under photochemical or electrochemical conditions emerged. Due to space limitations, only pictures of scientists who have contributed more than two works in this area are shown herein. [ABSTRACT FROM AUTHOR]

This study demonstrates the catalytic conversion of real plastic waste-extracted phthalate plasticizers into benzoic acid (BA), via a one-pot hydrolysis–decarboxylation process based on inexpensive Cu2O and H-beta zeolite, in water as a safe and environmentally benign solvent. As a result of the excellent product selectivity in both reactions, BA was obtained in quantitative yields (>99%). Esterification of the purified carboxylic acid resulted in the production of an alternative benzoate plasticizer, with a total process yield up to 94%. [ABSTRACT FROM AUTHOR]

The document "Green Chemistry" published by the Royal Society of Chemistry features cutting-edge research on sustainable chemistry practices. The contents include critical reviews on topics such as microbial lignin valorization and catalytic hydrodeoxygenation, as well as tutorial reviews on plastic chemical recycling and the role of reticular chemistry in photoenzymatic reactions. The journal also presents communications on various topics like hypervalent iodine chemistry and N-heterocycle synthesis, along with papers on sustainable ligand biofunctionalization and solid-liquid separation of lignocellulosic sugars. [Extracted from the article]

Conventional transition metal-catalyzed carbonylative reactions are a powerful tool for the direct incorporation of electrophilic reagents, CO, and nucleophilic reagents into high-value-added products. Although these metal-catalyzed carbonylation strategies can efficiently synthesize carbonylated compounds, metal-free systems remain an attractive direction in carbonylative reactions. Inspired by the achievements in metal-free radical carbonylation, herein we describe a photochemical method for the carbonylation of aryl sulfonium salts using photoexcitation of electron donor–acceptor (EDA) complexes. This strategy is metal-free and widely applicable, enabling ready access to a wide range of aryl carboxylic acid derivatives in a simplified manner. Notably, by choosing different amines, the reaction intermediates can be captured and then quenched stepwise. It has the potential to be a direct green alternative to conventional carbonylation methods for the synthesis of aryl carboxylic acid derivatives. [ABSTRACT FROM AUTHOR]

Formic acid (HCOOH) is a promising source of hydrogen energy that can be used to produce hydrogen in a more economical and ecological way. Formic acid is a simple carboxylic acid with a high hydrogen concentration and is generally stable, making it useful as a hydrogen transporter. Catalytic dehydrogenation is usually used to extract hydrogen from formic acid; this process releases hydrogen gas and yields carbon dioxide as a byproduct. Comparing this technology to conventional hydrogen generation methods, there are several benefits, such as the utilization of the formic acid handling infrastructure already in place and the possibility of a simpler integration into different energy systems. Notwithstanding, several obstacles persist, including enhancing the effectiveness of the dehydrogenation procedure and reducing the ecological consequences of the correlated carbon dioxide discharges. Catalysts, reaction conditions, and carbon collection and utilization methodologies are all being researched further. The development of Ru and Cu‐based catalysts for the catalytic breakdown of HCOOH into CO2 and H2 is the main topic of this account. Herein, the focus is on the kinetic studies of HCOOH dehydrogenation, encompassing mechanistic investigations that consider intermediate studies and DFT calculations. [ABSTRACT FROM AUTHOR]

A zinc‐catalyzed C(sp2)−N dehydrative cross‐coupling between carboxylic acids and NH‐sulfoximines to afford N‐aroylated sulfoximines under mild reaction conditions is described. Various NH‐sulfoximines were coupled with readily available carboxylic acids to provide the corresponding N‐aroylated sulfoximines in good to excellent yields. [ABSTRACT FROM AUTHOR]

The Chemical Communications journal, published by The Royal Society of Chemistry, features a variety of articles on advancements in chemistry. Topics covered include organelle-targeting fluorescent probes, photodynamic therapy, hydrogen production, and battery technologies. The journal aims to connect the global chemistry community and foster scientific progress through original research and discoveries. [Extracted from the article]

We report a one-pot synthesis of aryl carboxylic acids utilizing HCOOH as a CO surrogate with low Pd-catalyst loading. This operationally simple and scalable method does not require use of a high-pressure reactor, two-chamber reaction vessel, phosphine ligand, or base and proceeds in a relatively short amount of time at ambient temperature. Notably, halides, including iodo and bromo groups, and nitro groups remain intact under these mild reaction conditions. This methodology has been successfully applied to synthesizing 13C-labeled aryl carboxylic acids with satisfactory yields. [ABSTRACT FROM AUTHOR]

We developed a semiconductor photocatalyst, Pd–Pt alloy nanoparticle-loaded, Al-doped SrTiO3 (PdPt/STO:Al), for photoreduction of unsaturated carboxylic acids. Due to the cooperative STO:Al surface and Pd–Pt alloy nanoparticles, the catalyst dispersed in water provided highly redox-selective photoreduction against oxidative degradation of starting materials/products and against reductive evolution of H2, where minimal glycolic acid worked as an efficient electron-donating fuel. [ABSTRACT FROM AUTHOR]

A highly effective and selective ortho -directed hydrogen isotope exchange process for aryl carboxylic acids has been achieved by using an iridium(I) N-heterocyclic carbene/phosphine complex under mild and neutral conditions. Good levels of deuterium incorporation have been delivered across a wide array of examples, including a number of biologically active drug compounds. [ABSTRACT FROM AUTHOR]

A meso -BODIPY-type photoremovable protecting group for carboxyl group is developed. BODIPYs are well-known for brilliant color, favorable to reaction monitoring and purification. meso -BODIPY esters are achieved via esterification in 44–89% yields, while deprotection is fulfilled under irradiation of blue LED bulb in the presence of photocatalyst and organic hydrogen donor in 43–95% yields. This method is applicable to a variety of acids, such as aromatic, heteroaromatic, alkyl, α,β-unsaturated carboxylic acids, etc. Our BODIPY-deprotective condition is almost neutral that both methyl and tert -butyl esters are compatible. [ABSTRACT FROM AUTHOR]

The palatability of 15 carboxylic and other organic acids (ascorbic, citric, sorbic, malic, oxalic, acetic, glycolic, α- and γ-aminobutyric acids) and their derivatives (Na+ and K+ salts, 0.1 M) was compared for five species of cichlid fish (Cichlidae): Nile tilapia Oreochromis niloticus, Mozambique tilapia O. mossambicus, golden mbuna Melanochromis auratus, lemon cichlid Neolamprologus leleupi, and tailbar cichlid Vieja hartwegi. Citric and oxalic acids, Na+-ascorbate, K+-sorbate, K+-citrate, and ammonium oxalate have an attractive or indifferent taste for fish; ascorbic and sorbic acids, Na+-citrate, and Na+-malate have a repulsive or indifferent taste. Malic acid has an attractive taste for tailbar cichlid, a repulsive taste for Mozambique tilapia, and an indifferent taste for other cichlids. Acetic acid and isomers of aminobutyric acid are indifferent in taste for all fish. The taste attractiveness of organic acids may differ in comparison with their salts. The attractiveness of salts is higher than that of the corresponding acids in ten of 28 cases, lower in four cases, and the same in 14 cases. The transformation of ascorbic and sorbic acids into Na+ and K+ salts is accompanied by an increase in palatability for most cichlids, while that of malic acid transformation into Na+-malate in half of the studied species. Citric acid and its Na+ and K+ salts have similar palatability for most fish. Oxalic acid, compared to ammonium oxalate, has a higher palatability for lemon cichlid, a lower palatability for Mozambique tilapia, and the same palatability for the other three fish species. There are no differences between the consumption of food pellets with aminobutyric acid isomers and that with acetic and glycolic (hydroxyacetic) acid for all cichlids. The feeding behavior demonstrated by cichlids during orosensory testing of pellets is similar: the fish make a small number of rejections and repeated grasps of the food pellets, and the duration of their retention in the oral cavity is similar. [ABSTRACT FROM AUTHOR]

Sinapic acid (SA) is a naturally occurring carboxylic acid found in citrus fruits and cereals. Recent studies have shown that SA has potential anti-seizure properties due to its anti-inflammatory, antioxidant, and anti-apoptotic effects. The present study investigated the neuroprotective role of SA at two different dosages in a pentylenetetrazol (PTZ)-induced acute seizure model. Mice were divided into six groups: normal control, PTZ, SA (20 mg/kg), SA (20 mg/kg) + PTZ, SA (40 mg/kg), and SA (40 mg/kg) + PTZ. SA was orally administered for 21 days, followed by a convulsive dose of intraperitoneal PTZ (50 mg/kg). Seizures were estimated via the Racine scale, and animals were behaviorally tested using the Y-maze. Brain tissues were used to assess the levels of GABA, glutamate, oxidative stress markers, calcium, calcineurin, (Nod)-like receptor protein-3 (NLRP3), interleukin (IL)-1β, apoptosis-associated speck-like protein (ASC), Bcl-2–associated death protein (Bad) and Bcl-2. Molecular docking of SA using a multistep in silico protocol was also performed. The results showed that SA alleviated oxidative stress, restored the GABA/glutamate balance and calcium/calcineurin signaling, downregulated NLRP3 and apoptosis, and improved recognition and ambulatory activity in PTZ-treated mice. In silico results also revealed that SA strongly interacts with the target proteins NLRP3 and ASC. Overall, the results suggest that SA is a promising antiseizure agent and that both doses of SA are comparable, with 40 mg/kg SA being superior in normalizing glutathione, calcium and IL-1β, in addition to calcineurin, NLRP3, ASC and Bad. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are used in the production of PTFE based coatings for cookware. In this study, emission of PFAS and further volatile organic compounds (VOC) from kitchenware articles were investigated. First, method development for thermal extraction of baking trays, frying pans and baking mats at 250 °C was done by testing three different extraction devices. A thermal desorption oven showed the best blank and highest recoveries of PFAS analytes (70–101% for 12 perfluorocarboxylic acids (PFCAs), 2 fluorotelomer alcohls (FTOHs), 3 per- and polyfluoroether carboxylic acids (PFECAs), 1 polyfluoroether (PFE)). Second, 18 cookware samples, a PTFE micro powder and 2 lab made coating strips have been investigated. No PFAS were detected in 12 samples (limits of detection: 1–13 ng/dm2). PFCAs (C5–C23) were detected in a baking tray in amounts up to 34 ng/dm2. A baking mat contained 3 ng/dm2 PFOA. FTOHs were not detected in the samples. A PFECA (bC7O2) and its hydride (bC6O2H PFE) were detected in one coating intended for use in frying pans. The hydrides of the PFECA mixture, b(C3O1)nC3 PFECA (Krytox 157FSH), were detected in five baking trays. The PFAS target analytes were not detectable in the five investigated frying pans. Analysing further VOC in the emissions of coatings, 175 compounds could be identified, including alkanes, alkenes, aromatic substances, esters, aldehydes, ketones, ethers, alcohols, carboxylic acids, siloxanes and sulphur, nitrogen, as well as chlorine containing compounds (< 10 µg/dm2). The identified substances cannot be connected to the basic coating polymer of the kitchenware articles, which were PTFE and PES. All samples have undergone a threefold thermal extraction. No substances could be detected in the second and third consecutive extraction, which means that a removal and no new formation of the investigated PFAS as well as the further VOC at 250 °C has occurred. [ABSTRACT FROM AUTHOR]

The study examined the interactions between a deep eutectic solvent (DES) containing choline chloride (ChCl) along with ethylene glycol (EG) in a molar ratio of 1:3, and three carboxylic acids: acetic acid, propanoic acid and butanoic acid. The structural stability, electrical characteristics and dynamic behavior of these DES-carboxylic acid systems were investigated utilizing techniques like density functional theory (DFT), natural bond orbital (NBO) analysis and molecular dynamics (MD) simulations. The results showed that the addition of carboxylic acids in the DES framework had a substantial impact on the distribution of electrons and the interactions between molecules in the system. More specifically, the presence of longer alkyl chains in the acids caused a more significant disturbance in the hydrogen- bond network of the DES. This was observed through alterations in the electron localization function (ELF) and noncovalent interaction (NCI) investigations. The results yielded useful insights into the design and implementation of DESs, including improving their stability and reactivity through targeted acid interactions. Interactions between a DES with carboxylic acids have been studied using computational calculations. Addition of carboxylic acids on the DES framework had a substantial impact on the distribution of electrons and the interactions between molecules in the system. This was observed through alterations in the electron localization function and non-covalent interaction investigations. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl substances (PFAS) as a large group of synthetic compounds widely contaminated the environment and lead to health problems. However, the correlation between PFAS exposure, bone health parameters and osteoporosis remains controversial. Therefore, we conducted a systematic review and meta-analysis of published literature to evaluate the effects of PFAS on human bone health. All observational studies were collected up to 2 December 2023. A total of 2096 articles were retrieved. Of these, 21 articles investigated the association between PFAS exposure and human bone health. However, only 10 studies were included in the final meta-analysis. Doubling of serum perfluorooctanoic acid (PFOA) (β = -0.11, 95% confidence interval (CI): −0.18, −0.05) and perfluorooctane sulfonic acid (PFOS) (β = -0.06, 95% CI: −0.11, −0.01) levels showed significant negative correlations with total body less head bone mineral density (TBLH-BMD). Subgrouping showed that only perfluorohexane sulfonate (PFHxS) (odds ratio [OR] = 1.37, 95% CI: 1.12, 1.68) was correlated with osteoporosis. [ABSTRACT FROM AUTHOR]

The aim of this study was to screen the phytochemicals and assess the antibacterial properties of crude extracts from Vernonia amygdalina leaves against specific pathogenic bacteria. Qualitative and qauntitave analysis was performed on both ethanol and ethyl acetate crude extracts using standardized techniques. The analysis revealed the presence of alkaloids, phenol, flavonoids, terpenoids, saponins, tannins, and cardiac glycosides in the ethanol extract, while saponins and glycosides were absent in the ethyl acetate extract. The quantities of phenols, flavonoids, and alkaloids were determined using Gallic acid, quercetin, and atropine assays, respectively. The ethanol extract contained 154.7 ± 3.6 (mg GAE/g) of total phenols, 33.3 ± 1.8 (mg QE/g) of flavonoids, and 2.4 ± 0.08 (mg AE) of alkaloids, whereas the ethyl acetate extract contained 93.7 ± 3.9 (mg GAE/g) of total phenols, 30.7 ± 8.3 (mg QE/g) of flavonoids, and 1.57 ± 0.3 (mg GAE/g) of alkaloids. This study identified 44 components in the ethanol crude extract and 10 components in the ethyl acetate crude extract. The presence of alkanes, alkenes, amines, carboxylic acids, and alcohols was confirmed by FT-IR analysis. Each crude extract was tested at concentrations of 500 mg/mL, 250 mg/mL, 125 mg/mL, and 62.5 mg/mL using the same method. A concentration of 0.001 mg/mL of Penicillin capsule standard drugs and dimethyl sulfoxide were used as positive and negative controls, respectively. Overall, the results of the study indicated that both crude extracts exhibited antibacterial activity at higher concentrations. [ABSTRACT FROM AUTHOR]

In this study, an efficient catalytic protocol using CuCoFe2O4@GO (CCF@GO) for the synthesis of amide bond (−CONH−) via direct coupling of carboxylic acids and N,N‐dialkylformamides is presented. The CCF@GO nanocatalyst has been synthesized via a single‐pot solvothermal method, by changing the proportions of copper and cobalt (1:1, 1:3, and 3:1). Catalyst screening, employing a model reaction with benzoic acid and dimethylformamide (DMF), revealed that the 1:1 proportion of CCF@GO catalyst exhibited excellent efficiency, achieving a high conversion (98%) towards amide formation. The enhanced catalytic efficiency observed in CCF@GO catalysts can be ascribed to the uniform distribution of active copper and cobalt species on the graphene oxide support, which possesses a high surface area. Optimization of the reaction was conducted by varying parameters such as temperature, solvent, catalyst loading, and oxidant. The prepared catalyst was characterized using various analytical techniques including XRD, FTIR, XPS, SEM, EDX mapping, and TEM. Furthermore, this heterogeneous nanocatalyst demonstrated recoverability using an external magnet and reused up to five times with just a modest loss of catalytic performance. [ABSTRACT FROM AUTHOR]

Five new lanthanide complexes {[Sm(H2L)(H2O)4(Cl)]⋅H2O⋅Cl}n (1), {[Eu(H2L)(H2O)4Cl]⋅Cl}n (2), {[La(H2L)(H2O)4Cl]⋅Cl}n (3), {[Pr(H2L)(H2O)4Cl]⋅Cl}n (4), {[Ce(H2L)(H2O)4Cl]⋅Cl}n (5) (H3L = 2‐hydroxy‐5‐(5‐(hydroxy‐λ2‐methoxy)‐1H‐benzo[d]imidazole‐5‐carboxylic acid) were successfully synthesized under solvothermal method. 1 exhibits a two‐dimensional (2D) network structure, whereas 2–5 feature one‐dimensional (1D) chain structure. The fluorescence investigations demonstrated that 1–5 could be the fluorescent sensor for nitrobenzene (NB) and Fe(III) ions with high selectivity, sensitivity, and low detection limits. Furthermore, 1–5 displayed the good adsorption to anionic dye Congo red (CR), and the adsorption capacities were 140.5, 206.5, 212.5, 111.5, and 211.5 mg·g−1, respectively. [ABSTRACT FROM AUTHOR]

Catalytic kinetic resolutions of racemic carboxylic acids are important methods for preparing chiral carboxylic acids in their optically active forms. While several effective methods for the catalytic kinetic resolution of chiral α‐tertiary carboxylic acids have been reported, the efficient kinetic resolution of α‐quaternary carboxylic acids remains a significant challenge. In this context, we aimed to develop methods for the kinetic resolution of α‐quaternary carboxylic acids. Our approach involves a BINOL‐derived chiral bifunctional sulfide‐catalyzed bromolactonization technique, which was developed by our research group. In this work, we report the kinetic resolution of α‐allyl‐α‐cinnamyl carboxylic acids bearing an α‐quaternary stereocenter via chemo‐ and stereoselective bromolactonizations. The use of a BINOL‐derived chiral bifunctional sulfide catalyst with a hydroxy group was key for the efficient kinetic resolution of racemic α‐allyl‐α‐cinnamyl carboxylic acids. [ABSTRACT FROM AUTHOR]

The influence of the monolayer order, defect density, and bilayer formation on the formation of binary self-assembled monolayers (SAMs) was investigated via the solution-phase displacement of 3-mercaptopropionic acid (MPA) by 1-decanethiol (DT). The ultrahigh vacuum scanning tunneling microscopy results confirm that well-ordered, pristine MPA SAMs are displaced at slower rates than MPA SAMs with less long-range order and greater defect density. Furthermore, MPA samples containing regions of an MPA bilayer displayed the slowest rates of displacement with DT. For pristine MPA samples and MPA samples with regions of an MPA bilayer, displacement with DT resulted in the formation of the low-density, lying down phase of DT. Our results suggest that the presence of an MPA bilayer, the result of hydrogen bonding between carboxylic acid groups in MPA, significantly lowers the rate of total displacement of MPA by DT compared to moderately defected MPA SAMs. These results highlight the importance of the structure, composition, and intermolecular forces, such as hydrogen bonding, when considering binary SAM formation via solution-phase displacement methods. [ABSTRACT FROM AUTHOR]

Background: Recycled materials are a major research topics of the new era to relieve pressure on raw material extraction from our planet and reduce its pollution levels. This has helped us to reinvent our relationship with nature, and to commit ourselves to a sustainable economic and social reconstruction. An excellent option to add value to waste while protecting the environment is the synthesis of carbon nanostructures (CNSs) using a recycled material as a precursor. In this research, the synthesis and functionalization of CNSss in a single‐step chemical vapour deposition (CVD) process was carried out using a recycled precursor. The methanol fraction is waste from the distillation process in the production of alcoholic beverages. The synthesis temperatures were 750, 800 and 850 °C. Results: As a result, carbon nanotubes, carbon nanoribbons and carbon nanobeads with diameters <100 nm and widths <500 nm were obtained. The crystal size of CNSs decreased with increasing synthesis temperature, from 20 to 12 nm. RAMAN spectra revealed the high degree of graphitization and the presence of different types of nanostructures. Carbonyl (CO) and hydroxide (‐OH) stretching of the carboxylic acid were present in all samples. Conclusion: The results obtained shown that the CNSs synthetized are functionalized in a single‐step CVD process using the methanolic fraction as a precursor. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Eumelanin is a complex biopolymer that is ubiquitous in nature. Eumelanins are reported to exhibit extensive biochemical and functional properties. These properties attribute to the composition and structural organization of the molecules. Eumelanins are composed of Dihydroxy indole (DHI) and Dihydroxy indole 3 carboxylic acid (DHICA) units and their quinone forms. In spite of immense studies the structure of eumelanin is not completely elucidated. Molecular simulation studies had predicted oligomeric/tetrameric structure of eumelanin. Cephalopod ink eumelanins are used in treating several female reproductive disorders. Since estrogen receptors play a crucial role in female reproductive disorders, the present study aims at understanding the binding affinity of the predicted forms of eumelanin with estrogen receptors by docking and simulation analysis. It was observed that eumelanin has better binding affinity than other estrogen receptor ligands and the closed tetrameric structure of eumelanin showed better binding affinity to estrogen receptor α than β. [ABSTRACT FROM AUTHOR]

A pair of enantiomers is known to have different biological activities. Two catalysts with opposite chirality are nearly always required to deliver both enantiomeric products. In this work, chiral rhodium(III) cyclopentadienyl complexes are repurposed as efficient catalysts for enantiodivergent and atroposelective hydroamination of sterically hindered alkynes. Products with opposite chirality have been both obtained using the same or closely analogous chiral catalyst in good efficiency and excellent enantioselectivity, and the enantiodivergence was mainly enabled by an achiral carboxylic acid and its silver salt. Mechanistic studies revealed the origin of the enantiodivergence ascribable to the switch of the enantiodetermining step (alkyne insertion versus protonolysis) under acid control, which constitutes a previously unidentified working mode of enantiodivergence by leveraging two elementary steps. [ABSTRACT FROM AUTHOR]

Engineering nonribosomal peptide synthetases (NRPSs) has been a "holy grail" in synthetic biology due to their modular nature and limited understanding of catalytic mechanisms. Here, we reported a computational redesign of the "gate-keeper" adenylation domain of the model NRPS-like enzyme carboxylic acid reductases (CARs) by using approximate mechanism-based geometric criteria and the Rosetta energy score. Notably, MabCAR3 mutants ACA-1 and ACA-4 displayed a remarkable improvement in catalytic efficiency (kcat/KM) for 6-aminocaproic acid, up to 101-fold. Furthermore, G418K exhibited an 86-fold enhancement in substrate specificity for adipic acid compared to 6-aminocaproic acid. Our work provides not only promising biocatalysts for nylon monomer biosynthesis but also a strategy for efficient NRPSs engineering. [ABSTRACT FROM AUTHOR]

Carboxylic acids are attractive synthetic feedstocks with stable, non‐toxic, and inexpensive properties that can be easily obtained from natural sources or through synthesis. Carboxylic acids have long been considered environmentally friendly coupling agents in various organic transformations. In recent years, electrochemically mediated decarboxylation reactions of decarboxylic acids and their derivatives (NHPI) have emerged as effective new methods for constructing carbon‐carbon or carbon‐heterocarbon chemical bonds. Compared with transition metal and photochemistry‐mediated catalytic reactions, which do not require the addition of oxidants and strong bases, electrochemically‐mediated decarboxylative transformations are considered a sustainable strategy. In addition, various functional groups tolerate the electrochemical decarboxylation conversion strategy well. Here, we summarize the recent electrochemical decarboxylation reactions to better elucidate the advantages of electrochemical decarboxylation reactions. [ABSTRACT FROM AUTHOR]

Functional group interconversion is of great significance in organic synthesis. However, aerobic cleavage of C=N bonds to access carbonyl compounds still suffered from some limitations such as harsh reaction conditions, stoichiometric oxidants, poor substrate scope and use of toxic reagents. Herein, we report a catalyst‐free and photo‐induced aerobic cleavage of C=N bonds to afford diverse carbonyl compounds using oxygen from air as green oxidant. This mild methodology permits N‐tosylhydrazones converted into the corresponding carbonyl compounds including ketones, aldehydes and carboxylic acids, showing broad functional group tolerance and compatibility. Moreover, the gram‐scale reaction and post‐modification of complicated molecules proved the applicability and efficiency of this strategy. Finally, a plausible mechanism was proposed based on spectroscopic investigations and detailed mechanistic studies. [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTY STATEMENT\nHIGHLIGHTSIn this study, rice plants were co-exposed to selenium (Se) and silica (Si) under arsenic (As) stress to evaluate As accumulation in rice grains, associated cancer risk, and its impact on the types and numbers of grain metabolites. A total of 58 metabolites were identified, of which, 19 belong to sugars, and drastically altered during different treatments. Arsenic exposure significantly reduced monosaccharides, i.e., D-glucose (83%) >D-galactose (60%) >D-fructose (57%) >D-ribose (29%) but increased that monosaccharide units which have antioxidant properties (i.e. α-D-glucopyranoside and melibiose). However, the levels of D-galactose, fructose, and ribose were significantly increased during co-supplementation of selenite (SeIV) and Si under As stress. Other groups of rice grain metabolites, like sugar alcohols, organic acids, polyphenols, carboxylic acids, fatty acids, and phytosterols, were also significantly altered by As exposure and increased in grains of SeIV and Si supplemented rice compared to alone As exposure. In brief, rice growing in As-affected areas may have a low level of different metabolites. However, supplementation by selenite (SeIV) with Si not only increased metabolites and amylose/amylopectin ratio but also reduced ∼90% of As accumulation in grains. Thus, the use of SeIV with Si might be advantageous for the locals to provide a healthy diet of rice and limit As-induced cancer risk up to 10-fold.The effects of the integrated application of selenium and silica on metabolite levels and the distribution of metalloids such as arsenic, selenium, and silica from the bran layer to the inner starchy endosperm in rice grains under arsenic exposure have not been reported yet. Our study found that this combined treatment reduces arsenic accumulation in rice grains, thereby lowering cancer risk by limiting arsenic intake from a rice-based diet. Additionally, this approach improves grain quality, nutrient levels, and metabolite storage, offering a healthier rice option for those who reside in arsenic-affected areas.Vegetative growth was more in Si application while yield was high in selenite.Selenite supplementation increased the amylose and amylopectin ratio in grains.Number of sugar metabolites was increased under metalloid exposure.Arsenic reduced the D-glucose, D-galactose, D-fructose, and D-ribose in rice grains.Use of selenite and silica as fertilizer can produce low-GI rice.Vegetative growth was more in Si application while yield was high in selenite.Selenite supplementation increased the amylose and amylopectin ratio in grains.Number of sugar metabolites was increased under metalloid exposure.Arsenic reduced the D-glucose, D-galactose, D-fructose, and D-ribose in rice grains.Use of selenite and silica as fertilizer can produce low-GI rice. [ABSTRACT FROM AUTHOR]

Reaction of the ionic liquid [NEt3Me][Cl3] with white phosphorus (P4) gives, quantitatively, hexachlorophosphate [NEt3Me][PCl6]. This compound shows similar reactivity as PCl5, as confirmed for the reaction with phenol, carboxylic acids and ammonium chloride. At elevated temperature, [NEt3Me][PCl6] releases PCl3 and can therefore be used as a potential PCl3-storage material. [ABSTRACT FROM AUTHOR]

A robust, practical, and sustainable isomerization‐suppressed peptide bond formation via acyl sulfonamide, a twisted amide, is disclosed. Tosyl isocyanate and pentafluorobenzyl bromide were applied in combination to activate the peptide C‐terminus, which then reacted with an amine to yield an elongated peptide with high stereochemical purity. Careful analysis of NMR spectra of the active intermediate revealed the presence of an intramolecular hydrogen bond, suggesting that the hydrogen bond suppressed Cα‐epimerization during amidation. The isomerization suppression by the intramolecular hydrogen bond is expected to be effective even under high dilution conditions, making the present method a powerful tool for the synthesis of complex macrocyclic peptides. In addition to peptide synthesis, the developed synthetic entry to twisted amides can be applied to the investigation of transition metal‐catalyzed N−C bond activation. Moreover, the application to the N−C bond activation returned insight into peptide synthesis, leading to the use of sulfonamide as a protecting group of carboxylic acid that can be orthogonally removed in the presence of other conventional protecting groups. [ABSTRACT FROM AUTHOR]

As enzyme mimics, metal porphyrin complex catalysts have become increasingly powerful for facilitating alkyl radical transformations. This report describes an iron porphyrin/photoredox catalytic manifold that enables the heteroselective assembly of sp3-hybridized carbon frameworks from diverse aliphatic carboxylic acids. The double decarboxylative cross-coupling reaction features mild and redox-neutral conditions, good functional group tolerance, and high heteroselectivity. Due to their opposing redox characteristics, photoredox-mediated electron shuttling between carboxylic acids and NHPI esters provides ready access to distinct alkyl radicals in the absence of external oxidants or reductants. The iron porphyrin-catalyzed radical-sorting SH2, evidenced by mechanistic studies, is proposed to be responsible for the highly selective radical–radical heterocoupling. [ABSTRACT FROM AUTHOR]

Cyanidation reactions are an essential method for creating C─CN bonds. Traditional cyanidation reactions usually require the use of highly toxic and unstable cyanide sources, such as NaCN, KCN, CuCN, and TMSCN. K4[Fe(CN)6], a product of the coal chemical industry, has the advantages of high yield and low toxicity. It is a very environmentally friendly, safe, and stable cyanide source. Since 2004, K4[Fe(CN)6] has emerged as a viable alternative to conventional, highly toxic, and hazardous cyanide sources like NaCN and KCN in cyanidation reactions. Over the past two decades, significant progress has been made in studying green cyanidation reactions involving K4[Fe(CN)6]. This paper reviews the advancements in the study of cyanidation coupling reactions between substrates such as aryl halides, sulfonates, aryl carboxylic acids, aromatic aldehydes, acyl chlorides, phenols, benzyl alcohols, and aryl sulfonium salts with K4[Fe(CN)6]. [ABSTRACT FROM AUTHOR]

Photobromination of toluene derivatives using blue LED (454 nm) or UV LEDs (365, 385, 395 nm) with aqueous HBr and NaOCl·5H2O in trifluoromethyl benzene afforded the corresponding benzoic acids derivatives. The intermediates were (dibromomethyl)benzene derivatives, isolated in a nitrogen atmosphere. The dibromomethyl benzene derivatives afforded the corresponding aldehydes. After the reaction with HBr, the aqueous layer could be recovered and reused. [ABSTRACT FROM AUTHOR]

This study aims to delineate the synthesis of eugenol derivatives, starting with hydroxyl group protection and then the subsequent oxidation stages. Initially, eugenol underwent conversion into acetyleugenol and benzyleugenol during the protection phase. Subsequently, a kinetic oxidation of acetyleugenol with KMnO4 via GC-MS analysis resulted in the identification of four compounds. The kinetic investigation indicated the primary formation of diolacetyleugenol, succeeded by aldehyde eugenol, which further gets converted into its respective carboxylic acid. Additionally, acetyleugenol and benzyleugenol underwent oxidation with CrO3 , yielding the corresponding carboxylic acids. [ABSTRACT FROM AUTHOR]

[Display omitted] • Four functionalized terephthalic acid-based HOFs were prepared. • Their ultrahigh proton conductivities were explored and compared. • The conducting mechanisms were highlighted. Recently, the utilization of hydrogen-bonded organic frameworks (HOFs) with high crystallinity and inherent well-defined H-bonding networks in the field of proton conduction has received increasing attention, but obtaining HOFs with excellent water stability and prominent proton conductivity (σ) remains challenging. Herein, by employing functionalized terephthalic acids, 2,5-dihydroxyterephthalic acid, 2-hydroxyterephthalic acid, 2-nitro terephthalic acid, and terephthalic acid, respectively, four highly water-stable ionic HOFs (iHOFs), [(C 8 H 5 O 6)(Me 2 NH 2)]∙2H 2 O (iHOF 1), [(C 8 H 5 O 5)(Me 2 NH 2)] (iHOF 2), [(C 8 H 4 NO 6)(Me 2 NH 2)] (iHOF 3) and [(C 8 H 5 O 4)(Me 2 NH 2)] (iHOF 4) were efficiently prepared by a straightforward synthesis approach in DMF and H 2 O solutions. The alternating-current (AC) impedance testing in humid conditions revealed that all four iHOFs were temperature- and humidity-dependent σ, with the greatest value reaching 10-2 S·cm−1. As expected, the high density of free carboxylic acid groups, crystallization water, and protonated [Me 2 NH 2 ]+ units offer adequate protons and hydrophilic environments for effective proton transport. Furthermore, the σ values of these iHOFs with different functional groups were compared. It was discovered that it dropped in the following order under 100 °C and 98 % relative humidity (RH): σ iHOF 1 (1.72 × 10−2 S·cm−1) > σ iHOF 2 (4.03 × 10−3 S·cm−1) > σ iHOF 3 (1.46 × 10−3 S·cm−1) > σ iHOF 4 (4.86 × 10−4 S·cm−1). Finally, we investigated the causes of the above differences and the proton transport mechanism inside the framework using crystal structure data, water contact angle tests, and activation energy values. This study provides new motivation to develop highly proton-conductive materials. [ABSTRACT FROM AUTHOR]

Two new macrocyclic arenes H1 and H2 were conveniently synthesized by the one‐step reaction of carboxylic acid substituted octopus[3]arene. It was found that H1 was composed of three ethenoanthracene subunits with a rigid hexagonal structure and H2 contained two ethenoanthracene subunits and one anthracene subunit with a rigid house‐shaped structure. Among them, H2 exhibited strong blue fluorescence due to the existence of an anthracene subunit. Moreover, both H1 and H2 showed large and electron‐rich cavities, which enable them to effectively complex different nitrogen‐containing heterocyclic salt guests in solution and the solid state. It was further found that H2 exhibited stronger complexation towards the tested guests than H1 probably due to the stronger charge‐transfer interactions between H2 and the guests. [ABSTRACT FROM AUTHOR]

AbstractGFH009 is a potent and highly selective cyclin-dependent kinase 9 (CDK9) inhibitor currently under phase II clinical trials. In this study, we investigated the metabolism and disposition of GFH009 in Sprague-Dawley (SD) rats, as well as in vitro metabolism of CD-1 mouse, SD rat, beagle dog, cynomolgus monkey, and human.A radiolabelled study indicated that [14C]GFH009 was quickly and widely distributed throughout the body, but presented low levels in brain, testis, and epididymis after a single intravenous dose of 6 mg (100 µCi)/kg to SD rats.GFH009 undergoes systemic metabolic changes, primarily through O-demethylation, oxidation to carboxylic acid and N-dealkylation, cleavage off the methoxyisopropyl moiety being a minor pathway. These metabolic pathways were found to be mainly consistent both in vitro and in vivo.In SD rats, GFH009 was rapidly and completely eliminated, with faeces serving as the major excretion pathway and urine serving as the minor one. Besides, the major clearance pathway for GFH009 was excretion and the minor one was metabolism.GFH009 exhibits favourable drug metabolism and pharmacokinetics (DMPK) properties, which provides valuable insights into the disposition of GFH009 and can be used to guide future clinical studies.GFH009 is a potent and highly selective cyclin-dependent kinase 9 (CDK9) inhibitor currently under phase II clinical trials. In this study, we investigated the metabolism and disposition of GFH009 in Sprague-Dawley (SD) rats, as well as in vitro metabolism of CD-1 mouse, SD rat, beagle dog, cynomolgus monkey, and human.A radiolabelled study indicated that [14C]GFH009 was quickly and widely distributed throughout the body, but presented low levels in brain, testis, and epididymis after a single intravenous dose of 6 mg (100 µCi)/kg to SD rats.GFH009 undergoes systemic metabolic changes, primarily through O-demethylation, oxidation to carboxylic acid and N-dealkylation, cleavage off the methoxyisopropyl moiety being a minor pathway. These metabolic pathways were found to be mainly consistent both in vitro and in vivo.In SD rats, GFH009 was rapidly and completely eliminated, with faeces serving as the major excretion pathway and urine serving as the minor one. Besides, the major clearance pathway for GFH009 was excretion and the minor one was metabolism.GFH009 exhibits favourable drug metabolism and pharmacokinetics (DMPK) properties, which provides valuable insights into the disposition of GFH009 and can be used to guide future clinical studies. [ABSTRACT FROM AUTHOR]

This work studied the auxin-like activity of liquid and solid hydrochar from aboveground corn biomass prepared using hydrothermal carbonization (HTC). Understanding the action of organic compounds in regulating plant metabolism is important to develop strategies to improve plant growth and production. Bioassays were performed by testing liquid hydrochar concentrations in the range of 0.0557-5570.0 mg carbon L−1; and solid hydrochar (via extracted dissolved organic matter, DOM) in the range of 0.026-2600.0 mg carbon L−1, using seeds of Lactuca sativa. SEM, ATR-FTIR, and Py-GC/MS were applied to assess the effect of HTC on hydrochar production/composition. Liquid hydrochar presented an intense bioactivity, completely inhibiting the germination of testing seeds at higher concentrations. Liquid hydrochar also was considerably more bioactive. Py-GC/MS allowed the identification of the molecules involved in IAA-like effects: carboxylic acids (linear and aromatic) and amino acids. The concentration of more bioactive molecules, rather than their simple presence in the hydrochar fraction, determined the bio-stimulating effect, besides an excellent linear regression between the auxin-like effect and the concentration of active molecules. [ABSTRACT FROM AUTHOR]

This study aims to delineate the synthesis of eugenol derivatives, starting with hydroxyl group protection and then the subsequent oxidation stages. Initially, eugenol underwent conversion into acetyleugenol and benzyleugenol during the protection phase. Subsequently, a kinetic oxidation of acetyleugenol with KMnO4 via GC-MS analysis resulted in the identification of four compounds. The kinetic investigation indicated the primary formation of diolacetyleugenol, succeeded by aldehyde eugenol, which further gets converted into its respective carboxylic acid. Additionally, acetyleugenol and benzyleugenol underwent oxidation with CrO3 , yielding the corresponding carboxylic acids. [ABSTRACT FROM AUTHOR]

Adoption of multitarget, cost‐effective fixed‐dose medication combinations can help lower the pill load without increasing the risk of adverse events. In this study, three new 1:1 drug‐drug binary solid forms of panobinostat (PNB) and nonsteroidal anti‐inflammatory drugs (NSAIDs) were effectively synthesized by liquid‐assisted grinding and slow evaporation crystallization techniques. The obtained solid forms were extensively characterized by various analytical techniques. The structural investigation revealed that all molecular adducts formed salt with a comparable R42${\mathrm{R}}_4^2$(10) graph set pattern created by heteromeric interactions formed between PNB and corresponding salt formers. To determine the dissolving behavior of the newly developed adducts, solubility tests were performed at various pH levels (pH 1.2 and pH 7), and the results indicated that the solubility of all forms is increased at pH 7.0, particularly PNB.NIF has a solubility of 0.195 mg/mL, which is seven times higher than the parent drug. Furthermore, PXRD was used to assess the stability of the synthesized adduct at varied temperature and humidity levels and it was found that all the adducts are stable. Based on the findings, we hope that the newly found PNB drug‐drug binary adducts have possible potential to broaden the use of drug combinations without changing the chemical structures. [ABSTRACT FROM AUTHOR]