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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]

[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]

Given their high safety, environmental friendliness and low cost, aqueous zinc-ion batteries (AZIBs) have the potential for high-performance energy storage. However, issues with the structural stability and electrochemical kinetics during discharge/charge limit the development of AZIBs. In this study, vanadium oxide electrodes with organic molecular intercalation were designed based on intercalating 11 kinds of charged organic carboxylic acid ligands between 2D layers to regulate the interlayer spacing. The negatively charged carboxylic acid group can neutralize Zn2+, reduce electrostatic repulsion and enhance electrochemical kinetics. The intercalated organic molecules increased the interlayer spacing. Among them, the 0.028EDTA · 0.28NH4+ · V2O5 · 0.069H2O was employed as the cathode with a high specific capacity (464.6 mAh g−1 at 0.5 A g−1) and excellent rate performance (324.4 mAh g−1 at 10 A g−1). Even at a current density of 20 A g−1, the specific capacity after 2000 charge/discharge cycles was 215.2 mAh g−1 (capacity retention of 78%). The results of this study demonstrate that modulation of the electrostatic repulsion and interlayer spacing through the intercalation of organic ligands can enhance the properties of vanadium-based materials. [ABSTRACT FROM AUTHOR]

Sixty-four phenols grouped as nitrated, bromo, amino, methyl, chloro-phenols, and cresols, and thirty-eight organic acids grouped as mono-carboxylic and dicarboxylic are analyzed in forty-two fog samples collected in the Alsace region between 2015 and 2021 to check their atmospheric behavior. Fogwater samples are collected using the Caltech Active Strand Cloudwater Collector (CASCC2), extracted using liquid–liquid extraction (LLE) on a solid cartridge (XTR Chromabond), and then analyzed using gas chromatography coupled with mass spectrometry (GC-MS). The results show the high capability of phenols and acids to be scavenged by fogwater due to their high solubility. Nitro-phenols and mono-carboxylic acids have the highest contributions to the total phenolic and acidic concentrations, respectively. 2,5-dinitrophenol, 3-methyl-4-nitrophenol, 4-nitrophenol, and 3,4-dinitrophenol have the highest concentration, originating mainly from vehicular emissions and some photochemical reactions. The top three mono-carboxylic acids are hexadecenoic acid (C16), eicosanoic acid (C18), and dodecanoic acid (C12), whereas succinic acid, suberic acid, sebacic acid, and oxalic acid are the most concentrated dicarboxylic acids, originated either from atmospheric oxidation (mainly secondary organic aerosols (SOAs)) or vehicular transport. Pearson's correlations show positive correlations between organic acids and previously analyzed metals (p < 0.05), between mono- and dicarboxylic acids (p < 0.001), and between the analyzed acidic compounds (p < 0.001), whereas no correlations are observed with previously analyzed inorganic ions. Total phenolic and acidic fractions are found to be much higher than those observed for pesticides, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) measured at the same region due to their higher scavenging by fogwater. [ABSTRACT FROM AUTHOR]

The decomposition mechanisms of Fe(EDTA)− and Fe(EDTMP)− complexes, widely used in various industrial applications, were investigated through a theoretical approach. Despite their structural similarities, the phosphonic acid and carboxylic acid groups in these complexes lead to vastly different decomposition behaviors. Fe(EDTA)−, stabilized by delocalized π bonds in carboxylic acid groups, exhibited higher stability than that of Fe(EDTMP)−, which has only σ bonds in phosphonic acid groups. Interaction Region Indicator (IRI) analysis revealed that the steric hindrance of Fe(EDTMP)− was stronger than that of Fe(EDTA)−. Ab initio molecular dynamics simulations revealed that Fe(EDTMP)− undergoes rapid decomposition due to the ease of breaking P-C bonds and the repulsion between phosphonic acid groups. In contrast, Fe(EDTA)− decomposes more slowly. These findings suggest the incorporation of phosphonic acid groups for easier degradation pathways when designing organic acid molecules. Understanding these mechanisms provides a basis for developing strategies for wastewater treatment in industrial settings. [ABSTRACT FROM AUTHOR]

Tailoring the properties of cellulose aerogel beads was investigated in the present study by using weak organic acids as coagulants. Three different weak acids were specifically chosen, acetic acid, lactic acid and citric acid. For comparative studies, a strong acid, hydrochloric acid was examined. The production of aerogel beads by conventional dropping technique was controlled and optimized for weak acids. Aerogels were characterized by density analyses, scanning electron microscopy, nitrogen adsorption–desorption analysis, X‐ray powder diffractometry and IR spectroscopy. In common, all the aerogel beads showed interconnected nanofibrillar network, high specific surface area, high pore volume, high porosity and meso‐ and macroporous structure. In particular, when the weakest acid (acetic acid) was used as coagulant in the regeneration bath, the lowest shrinkage was observed. As a result, the cellulose aerogel beads produced from acetic acid showed the highest values of specific surface area (423 m2 g−1) and pore volume (3.6 cm3 g−1). The porous structure can be tuned by the choice of regeneration bath, which has either strong acid or a high concentration of weak acid. The aerogel beads were pure and showed cellulose II crystallinity. Hence this study paves an alternative path way to tailor the properties of cellulose aerogel beads. [ABSTRACT FROM AUTHOR]

In this reported work, bioscoured and bleached cotton fabrics were treated with three different polycarboxylic acids, i.e., malic acid, citric acid, and 1,2,3,4-butane tetracarboxylic acids. The presence of carboxylic acids on the fabric surface as well as the changes in the crystalinity index was determined by Fourier transform Infrared spectroscopy and X-ray diffraction analysis. The carboxylic acids treated fabrics were analyzed for their physico-mechanical as well as comfort properties such as tensile strength, elongation, stiffness, air permeability, abrasion resistance, drape, water absorption, and wicking. The results inferred that the polycarboxylic acid-treated cotton showed improved drapability, wrinkle recovery, and strength up to 7% concentration; afterward, it started deteriorating. Weight loss due to abrasion was found to decrease with the addition of crosslinkers. A minor improvement in wicking and wetting properties was also noticed. [ABSTRACT FROM AUTHOR]

Due to the varying connectivity of Zr6 cluster and unlimited carboxylic acid‐based organic linkers, zirconium‐based metal‐organic frameworks (Zr‐MOFs) exhibit the most abundant structural diversity. However, Zr‐MOFs possessing more than one kind of Zr6 clusters in a single structure have not yet been reported. Herein, four new pentacarboxylic acids are synthesized to prepare Zr‐MOFs, HIAM‐4051 to HIAM‐4054. As a result, due to the different lengths of linkers, two novel underlying nets (typ and cqh) are found in these four MOFs with coexisting 4‐ and 9‐connected Zr6 clusters. Furthermore, by changing the acceptor groups in the linker skeleton, the emission of results Zr‐MOFs can be customized from blue, yellow–green to red. The nano‐sized HIAM‐4053‐NS exhibits high sensitivity and efficient adsorption for tetracycline hydrochloride with 0.22 µm detection limit and ≈0.6 g g−1 removal capacity. To the best of the knowledge, this work is the first example of constructing Zr‐MOFs using pentacarboxylic acids as organic linkers and the first report of Zr‐MOFs with coexisted Zr6 connectivities in a single MOF matrix. This study provides a novel insight for the construction of Zr‐MOFs with unprecedented structures, which will not only enrich the structure diversity but also offer more opportunity to extend the applications of Zr‐MOFs. [ABSTRACT FROM AUTHOR]

Accurate and reliable quantification of organic acids with carboxylic acid functional groups in complex biological samples remains a major analytical challenge in clinical chemistry. Issues such as spontaneous decarboxylation during ionization, poor chromatographic resolution, and retention on a reverse-phase column hinder sensitivity, specificity, and reproducibility in multiple-reaction monitoring (MRM)-based LC–MS assays. We report a targeted metabolomics method using phenylenediamine derivatization for quantifying carboxylic acid-containing metabolites (CCMs). This method achieves accurate and sensitive quantification in various biological matrices, with recovery rates from 90% to 105% and CVs ≤ 10%. It shows linearity from 0.1 ng/mL to 10 µg/mL with linear regression coefficients of 0.99 and LODs as low as 0.01 ng/mL. The library included a wide variety of structurally variant CCMs such as amino acids/conjugates, short- to medium-chain organic acids, di/tri-carboxylic acids/conjugates, fatty acids, and some ring-containing CCMs. Comparing CCM profiles of pancreatic cancer cells to normal pancreatic cells identified potential biomarkers and their correlation with key metabolic pathways. This method enables sensitive, specific, and high-throughput quantification of CCMs from small samples, supporting a wide range of applications in basic, clinical, and translational research. [ABSTRACT FROM AUTHOR]

Prostate cancer is frequently diagnosed and the leading cause of death in men worldwide. Prostate-specific antigen (PSA) blood tests and biopsies are the primary methods for diagnosing prostate cancer; however, their accuracy is less than 50%. Therefore, there is a need to develop diagnostic tests that minimize patient discomfort during examination and adequate biomarkers that are more accurate, sensitive, and specific for the detection of prostate cancer. This study investigated the application of metabolomics to identify biomarkers in prostate cancer biofluids. In addition, changes in prostate cancer metabolite levels induced by chrysin, a natural anticancer compound, were evaluated and compared with those in non-treated prostate cancer cells. Gas chromatography-mass spectrometry (GC-MS)-based metabolomic profiling was performed to investigate the differences in metabolic alterations among prostate cancer, normal prostate, and chrysin-treated prostate cancer cells. Pairwise comparisons of the extracellular fluid metabolomes were performed using principal component analysis (PCA), partial least squares–discriminant analysis (PLS-DA), and Student's t-test. The results revealed significantly different patterns among the metabolite groups, including alcohols, amino acids, carboxylic acids, organic acids, sugars, and urea. The RWPE-1- and chrysin-treated PC-3 (PC-3 Chr) cell groups showed similar tendencies for 23 metabolites, while the groups showed significant differences from the PC-3 group. Most amino acids showed higher concentrations in PC-3 cells than in the normal cell line RWPE-1 cells and PC-3 Chr cells. Our results revealed that GC-MS might be an effective diagnostic tool to detect prostate cancer and contribute to finding new tumor markers for prostate cancer as the basis for new ideas. [ABSTRACT FROM AUTHOR]

Leymus chinensis is a dominant halophytic grass in alkalized grasslands of Northeast China. To explore the alkali-tolerance mechanism of L. chinensis, we applied a widely targeted metabolomic approach to analyze metabolic responses of its root exudates, root tissues and leaves under alkali-stress conditions. L. chinensis extensively secreted organic acids, phenolic acids, free fatty acids and other substances having -COOH or phosphate groups when grown under alkali-stress conditions. The buffering capacity of these secreted substances promoted pH regulation in the rhizosphere during responses to alkali stress. L. chinensis leaves exhibited enhanced accumulations of free fatty acids, lipids, amino acids, organic acids, phenolic acids and alkaloids, which play important roles in maintaining cell membrane stability, regulating osmotic pressure and providing substrates for the alkali-stress responses of roots. The accumulations of numerous flavonoids, saccharides and alcohols were extensively enhanced in the roots of L. chinensis, but rarely enhanced in the leaves, under alkali-stress conditions. Enhanced accumulations of flavonoids, saccharides and alcohols increased the removal of reactive oxygen species and alleviated oxygen damage caused by alkali stress. In this study, we revealed the metabolic response mechanisms of L. chinensis under alkali-stress conditions, emphasizing important roles for the accumulation and secretion of organic acids, amino acids, fatty acids and other substances in alkali tolerance. [ABSTRACT FROM AUTHOR]

• Carboxylic acids (CAs) have powerful antimicrobial properties, specially at low pH. • Owing to their safety record, CAs are used by industry to assure safe food consumption. • The use of some CAs as antiseptics is done but still in a limited form. • CAs can be more explored as anti-infectious agents. Carboxylic organic acids are intermediates of central carbon metabolic pathways (e.g. acetic, propionic, citric, and lactic acid) long known to have potent antimicrobial potential, mainly at acidic pHs. The food industry has been leveraging those properties for years, using many of these acids as preservatives to inhibit the growth of pathogenic and/or spoilage fungal and bacterial species. A few of these molecules (the most prominent being acetic acid) have been used as antiseptics since Hippocratic medicine, mainly to treat infected wounds in patients with burns. With the growth of antibiotic therapy, the use of carboxylic acids (and other chemical antiseptics) in clinical settings lost relevance; however, with the continuous emergence of multi-antibiotic/antifungal resistant strains, the search for alternatives has intensified. This prospective article raises awareness of the potential of carboxylic acids to control infections in clinical settings, considering not only their previous exploitation in this context (which we overview) but also the positive experience of their safe use in food preservation. At a time of great concern with antimicrobial resistance and the slow arrival of new antimicrobial therapeutics to the market, further exploration of organic acids as anti-infective molecules may pave the way to more sustainable prophylactic and therapeutic approaches. [ABSTRACT FROM AUTHOR]

This article presents a study on the tert-butylation reaction of amino acids, carboxylic acids, and alcohols using bis(trifluoromethanesulfonyl)imide (Tf2NH) as a reagent. The study found that this method resulted in faster reactions and higher yields compared to conventional methods. The authors suggest that this information could be valuable to synthetic organic chemists as an alternative to using perchloric acid, as it offers safer conversions and improved reaction rates and yields. [Extracted from the article]

This study was investigated the relationship between Holstein bulls' fertility with some biomarkers (amino، fatty، and organic acids) and semen characteristics. The study included exploring the relationship among the fertility of Holstein bulls، several biomarkers، and semen characteristics in straws (20-25 straws/bull) preserved for three years. The cows were artificially inseminated (9-10 cows/bull) from semen. Based on the fertility rate، the bulls were divided into three groups، the first bulls of medium fertility (˂65%)، the second of good fertility (65-79%)، and the third of high fertility (>80%). The semen characteristics were evaluated، and the concentration of some amino acids and organic fatty acids was measured in the seminal plasma of bulls using gas chromatography and HPLC. The results revealed significant differences in the fertility rate among the different groups of bulls in favor of the highly fertile bulls. The results did not show any differences in most of the characteristics of the semen، except for a significant increase in the percentage of live sperm in good bulls compared to highly fertile ones. There were no significant differences for all the concentrations of carboxylic and most amino and fatty acids concentrations، except for an increase in the concentration of glycine acid (P˂0.05) and a decrease in the concentration of omega 9 (P˂0.05) in the highly fertile bulls compared to the medium fertile ones. In conclusion، glycine and omega-9 in the seminal plasma of bulls can be regarded as biomarkers of their fertility and the level of carboxylic acids (volatile fatty acids) can be adopted as an indicator of semen quality or energy level in the diet. [ABSTRACT FROM AUTHOR]

The Gram-negative, strictly anaerobic bacterium Megasphaera elsdenii was first isolated from the rumen in 1953 and is common in the mammalian gastrointestinal tract. Its ability to use either lactate or glucose as its major energy sources for growth has been well documented, although it can also ferment amino acids into ammonia and branched-chain fatty acids, which are growth factors for other bacteria. The ruminal abundance of M. elsdenii usually increases in animals fed grain-based diets due to its ability to use lactate (the product of rapid ruminal sugar fermentation), especially at a low ruminal pH (<5.5). M. elsdenii has been proposed as a potential dietary probiotic to prevent ruminal acidosis in feedlot cattle and high-producing dairy cows. However, this bacterium has also been associated with milk fat depression (MFD) in dairy cows, although proving a causative role has remained elusive. This review summarizes the unique physiology of this intriguing bacterium and its functional role in the ruminal community as well as its role in the health and productivity of the host animal. In addition to its effects in the rumen, the ability of M. elsdenii to produce C2–C7 carboxylic acids—potential precursors for industrial fuel and chemical production—is examined. [ABSTRACT FROM AUTHOR]

‒ The root exudation of the low molecular weight components of susceptible and resistant to Fusarium root rot barley plants was studied. Barley with different resistance to root rot differed not only in the amount of various components in their root exudates but also in their composition. The presence of F. culmorum in the roots of barley of both genotypes was accompanied by an increase in the total amount of exudates and by the changes in the composition and the ratio of various groups of components as compared to the control. In response to the fungus, a significant increase in the amount of low molecular weight organic acids, amino acids and auxins was detected in the root exudates of the susceptible barley, while in the root exudates of the resistant barley a significant increase in the amount of sugars and aromatic carboxylic acids was observed. [ABSTRACT FROM AUTHOR]

A non-absorbable therapeutic candidate for the treatment of hyperammonemia has been identified and characterized. Conventional approaches to reducing ammonia concentration in the blood and colon include acidifying the colon, inhibiting the bacterial production of ammonia, and activation of the urea cycle. Addressing gaps in the literature around therapeutic ammonia adsorption, this study established assays for ammonia uptake from both NH4OH and NH4Cl solutions as well as interference and selectivity for potassium absorption. Performance was characterized for a large number and variety of materials, spanning zeolites, ion-exchange resins, metallopolymers, metal–organic frameworks (MOFs), and polymeric carboxylic acids. The latter class showed low potassium capacity (poly(acrylic acid): 10 mg/g, poly(maleic-co-acrylic acid): 4 mg/g) and a therapeutically relevant depression of pH in buffered simulated intestinal fluid (SIF) (poly(acrylic acid): −2.01 and poly(maleic-co-acrylic acid): −3.23) compared to lactulose (−3.46), an approved therapeutic for hyperammonemia that works by acidifying the colon. In the polymeric organic acids evaluated, pH depression correlated well with pKa and acid site density. Additionally, this class of candidates should avoid the undesirable side effects of lactulose, such as the potential for hyperglycemia in diabetic patients and incompatible use with galactosemic patients. [ABSTRACT FROM AUTHOR]

One of the fundamental issues in modern pharmacy is the expansion of the range of medications based on plant-derived raw materials with specific targeted effects. An example of such a plant is the woolly-flowered milkvetch (Astragalus dasyanthus Pall.). This perennial herbaceous medicinal plant belongs to the Fabaceae family and is listed in the Red Book of Europe. Astragalus dasyanthus Pall. is cultivated for pharmaceutical purposes. The herb of a plant exhibits sedative, cardiotonic, hypotensive, and diuretic effects, as well as hepatoprotective and antioxidant properties. The herb of Astragalus dasyanthus Pall. contains polysaccharides (arabinose, bassorin), flavonoids (quercetin, kaempferol), glycyrrhizin, starch, and triterpenoid saponins, which contribute to the broad spectrum of the plant’s pharmacological activity. Continuing the investigation of this plant, it is advisable to study the qualitative and quantitative composition of organic and fatty acids. By the HPLC method, the following organic acids were identified and determined quantitative content: tartaric (8.68 mg/g), citric (7.69 mg/g), oxalic (6.90 mg/g), succinic (5.01 mg/g), isocitric (1.30 mg/g), and malic (0.49 mg/g). The saturated and unsaturated fatty acids were determined by the GC/MS method. The Astragalus dasyanthus Pall. herb contained seven fatty acids. High concentrations of fatty acids such as pentadecanoic acid (4.16 mg/g), linoleic acid (1.73 mg/g), and stearic acid (1.14 mg/g) predominate in woolly-flowered milkvetch. The character of many processes in which these organic and fatty acids take part may be associated with the medicinal properties of this plant pursuant to its use in medicine and, therefore, may contribute to the insight into its therapeutic properties. [ABSTRACT FROM AUTHOR]

Detailed investigation of photocatalyzed degradation of dibutyl phthalate (DBP), an endocrine disrupter, in the presence of α-FeOOH (goethite) and different carboxylic acids is the focus of this study. To get a better insight into the efficiency of the degradation, the influence of different parameters, such as concentration of total Fe and Fe(II), dissolved oxygen, DBP concentration, pH and salinity is investigated. The reaction mechanism consists of several interrelationship steps. The first step is the chemical reaction of carboxylic acid groups of the organic acids with hydroxyl groups of the α-FeOOH and a charge transfer upon illumination generating Fe(II). The second step is the release of Fe(II) into the solution followed by H2O2 oxidation to form highly photoactive hydroxyl complex of iron(III) and ˙OH. Simultaneously, the superoxide radical O2˙− and hydroperoxyl radical is formed in acidic solutions in presence of carboxylic acids as well. This mechanism explains the genesis of different reactive species oxidizing DBP. From the variety of the studied carboxylic acids (oxalic, citric, salicylic, pyruvic, maleic, and fumaric), oxalic acid is the best Fe-ligand for the photoreductive dissolution of goethite. Concentrations of the total amount of Fe and its dissociated forms Fe(II) as well as oxygen and hydroxyl radicals play a fundamental role in efficiency of DBP degradation. The photodegradation of DBP with goethite and the use of suitable carboxylic acids under optimized reaction conditions could be an efficient process for decontamination of polluted waters. [ABSTRACT FROM AUTHOR]

Organic acid‐base species in the dissolved organic carbon pool have been shown to make an important contribution (i.e., organic alkalinity; OrgAlk) to the total alkalinity (TA) in many coastal systems. This study documents an intensive investigation of OrgAlk characteristics in the river‐to‐coast transition zones of six southeast Chinese rivers. OrgAlk, mainly originating from river input, accounted for an important proportion of TA (0.3%–12%) in six estuaries. Carboxylic acid groups were commonly present in all estuaries. Notable differences in the TA values (1–18 μmol kg−1) determined by several established TA measurement approaches were identified in estuaries where organic acids with pKa <5.2 were abundant. The most widely used open‐cell titration method, in comparison with closed‐cell titration and single‐step titration, is the best approach to incorporate OrgAlk in titrated TA when the pKa values of organic acids were >5 in the study estuaries. Across our study sites, OrgAlk might modify H+ concentrations by 3%–69% (i.e., pH by 0.01–0.78) and aragonite saturation states by 1%–72%, indicating that OrgAlk can play a significant role in the coastal carbonate buffering system. It is essential to improve current TA measurement approaches to more accurately represent OrgAlk in the coastal system and assess impacts of OrgAlk on coastal carbonate chemistry. Plain Language Summary: Organic acid‐base species have been shown to make an important contribution (i.e., organic alkalinity; OrgAlk) to total alkalinity (TA) in the coastal systems. However, the established aquatic TA model generally does not consider OrgAlk as a significant term. In this study, we assessed the influence of OrgAlk on TA measurements and the role it plays in the carbonate buffering system in six southeastern Chinese estuaries. Some of the established TA measurement approaches could not fully incorporate OrgAlk according to the definition of TA, resulting in differences in the TA values determined by different TA measurement approaches in the study estuaries, where large quantities of organic acids with pKa <5.2 were present. OrgAlk was estimated to affect H+ concentration and aragonite saturation state considerably across our study sites, thus playing an important role in the coastal carbonate buffering system. Improving the current TA measurement approaches to better include OrgAlk in the TA model is greatly needed to avoid misinterpretation of key carbonate system indicators. This requires a comprehensive understanding of the characteristics of organic acid‐base species and their cycling across coastal systems. Key Points: Organic alkalinity can greatly affect seawater acidity and the carbonate system in six southeast Chinese estuariesOrganic acids with low‐pKa values caused significant uncertainties in different total alkalinity measurement approaches in southeastern Chinese estuariesRiver input is a major source of organic alkalinity in the study estuaries [ABSTRACT FROM AUTHOR]

Electrocarboxylation reaction, which employs organic electrosynthesis to achieve the utilization of CO2 as a carboxylative reagent, provides a powerful and efficient tool for the preparation of organic carboxylic acid. In some electrocarboxylation reactions, CO2 also acts as a promoter to facilitate the desired reaction. This concept mainly highlights recent CO2‐promoted electrocarboxylation reactions via CO2⋅− intermediate or transiently protective carboxylation of active intermediate with CO2. [ABSTRACT FROM AUTHOR]

Several raw materials have been used as partial supplements or entire replacements for the main ingredients of kombucha to improve the biological properties of the resulting kombucha beverage. This study used pineapple peels and cores (PPC), byproducts of pineapple processing, as alternative raw materials instead of sugar for kombucha production. Kombuchas were produced from fusions of black tea and PPC at different ratios, and their chemical profiles and biological properties, including antioxidant and antimicrobial activities, were determined and compared with the control kombucha without PPC supplementation. The results showed that PPC contained high amounts of beneficial substances, including sugars, polyphenols, organic acids, vitamins, and minerals. An analysis of the microbial community in a kombucha SCOBY (Symbiotic Cultures of Bacteria and Yeasts) using next-generation sequencing revealed that Acetobacter and Komagataeibacter were the most predominant acetic acid bacteria. Furthermore, Dekkera and Bacillus were also the prominent yeast and bacteria in the kombucha SCOBY. A comparative analysis was performed for kombucha products fermented using black tea and a fusion of black tea and PPC, and the results revealed that the kombucha made from the black tea and PPC infusion exhibited a higher total phenolic content and antioxidant activity than the control kombucha. The antimicrobial properties of the kombucha products made from black tea and the PPC infusion were also greater than those of the control. Several volatile compounds that contributed to the flavor, aroma, and beneficial health properties, such as esters, carboxylic acids, phenols, alcohols, aldehydes, and ketones, were detected in kombucha products made from a fusion of black tea and PPC. This study shows that PPC exhibits high potential as a supplement to the raw material infusion used with black tea for functional kombucha production. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed tandem reaction of 7-oxabenzonorbornadienes with organic carboxylic acids that provides cis-1,2-dihydro-l-naphthyl derivatives in moderate to good yields in a highly diastereoselective manner is described. A possible reaction mechanism involving syn acylation followed by insertion and diastereoselective ring-opening with 7-oxabenzonorbornadienes is proposed to account for the reaction. [ABSTRACT FROM AUTHOR]

The chemical components of the family Gesneriaceae are complex and diverse. The compounds isolated from the plants of this family mainly include flavonoids, phenylethanoid glycosides, terpenoids, anthraquinones, organic carboxylic acids, and steroids. Gesneriaceae have a wide range of pharmacological activities, including antioxidant, antibacterial, anti-tumor, enzyme inhibition and activation, cytotoxicity, and anti-Alzheimer activities. In this study, the chemical components and pharmacological activities of Gesneriaceae in recent years were summarized to provide a reference for future studies. [ABSTRACT FROM AUTHOR]

Carboxyl groups are frequently found in both natural products with proven bioactivities and small functional molecules with significant synthetic applications. Carboxylic acids are therefore one class of the most critical and easily accessible catalysts in organic synthesis. Herein, a brief overview of chiral carboxylic acid‐catalyzed asymmetric reactions is provided. Typical reactions and mechanisms are systematically discussed. We also provide our own perspectives on the future development within this research field based on our comprehensive understanding of the carboxylic acid‐promoted organocatalytic reactions. [ABSTRACT FROM AUTHOR]

Organic acids and their salts are used as additives in aquafeeds, as their participation in some metabolic pathways and energy generation in organisms increases the nutritional value. Benzoic acid (BA; C6H5‐COOH), a white crystalline substance with a chemical structure that contains carboxylic acid attached to a benzene ring, is naturally found in plant and animal tissues. It is one of the most used organic acids due to its antifungal properties, and it acts as a preservative for a variety of human consumption products. Additionally, it demonstrates health and growth benefits when included in feeds by modifying the energy metabolism, microbiota, and intestinal tract morphology. Information on BA inclusion in aquatic food is rare, and such information for Pacific white shrimp Penaeus vannamei is nonexistent. This study evaluated the effects on growth, survival, feed conversion ratio, energy content, and health status (through lipid quantification in the hepatopancreas, histological examination, and salinity stress tests) of Pacific white shrimp juveniles by including BA at different concentrations (0.0, 1.0, 1.5, and 2.0 g/kg) in a commercial feed. Diets with BA inclusion produced significant differences in the hepatosomatic index, hepatopancreas lipid content, and histopathological index value (reflecting damage to the hepatopancreas and antennal gland atrophy) at all BA concentrations. The lowest survival obtained was 94.44% at a BA concentration of 1.0 g/kg. The feed conversion ratio was in accordance with the range established by the Food and Agriculture Organization of the United Nations except for values obtained at 0 g/kg. Calorimetric analysis and BA detection in muscle revealed no significant differences between concentrations. Due to the results obtained in this study, the evaluated inclusions of BA are not recommended for use in juvenile Pacific white shrimp diets. [ABSTRACT FROM AUTHOR]

The essential metals Cu, Zn, and Fe are involved in many activities required for normal and stress responses in plants and their microbiomes. This paper focuses on how drought and microbial root colonization influence shoot and rhizosphere metabolites with metal-chelation properties. Wheat seedlings, with and without a pseudomonad microbiome, were grown with normal watering or under water-deficit conditions. At harvest, metal-chelating metabolites (amino acids, low molecular weight organic acids (LMWOAs), phenolic acids, and the wheat siderophore) were assessed in shoots and rhizosphere solutions. Shoots accumulated amino acids with drought, but metabolites changed little due to microbial colonization, whereas the active microbiome generally reduced the metabolites in the rhizosphere solutions, a possible factor in the biocontrol of pathogen growth. Geochemical modeling with the rhizosphere metabolites predicted Fe formed Fe–Ca–gluconates, Zn was mainly present as ions, and Cu was chelated with the siderophore 2′-deoxymugineic acid, LMWOAs, and amino acids. Thus, changes in shoot and rhizosphere metabolites caused by drought and microbial root colonization have potential impacts on plant vigor and metal bioavailability. [ABSTRACT FROM AUTHOR]

Pyrite has been used in photo-Fenton reactions for the degradation of pollutants, but the application of photo-Fenton processes with extra H2O2 in real water/wastewater treatment has still been limited by the economic cost of H2O2 and artificial light sources. Herein, citric acid (CA) and simulated/natural sunlight are used to develop a pyrite-based photo-Fenton system (pyrite–CA–light) in situ generating H2O2 through the enhanced activation of molecular oxygen. The degradation of pharmaceuticals and personal care products (PPCPs), especially acetaminophen (APAP) as the main target pollutant, in the pyrite–CA–light system was investigated. The effects of influencing factors such as various organic acids, APAP concentration, pH, pyrite dosage, CA concentration and co-existing anions (HCO3−, Cl−, NO3−, SO42− and H2PO4−) were examined. At a pyrite dosage of 0.1 g L−1, CA concentration of 0.6 mM and an initial pH of 6.0, the degradation efficiency of APAP (30 μM) was 99.1% within 30 min under the irradiation of xenon lamp (70 W, λ ≥ 350 nm). Almost the same high efficiency of APAP degradation (93.9%) in the system was achieved under natural sunlight irradiation (ca. 650 W m−2). The scavenging experiments revealed that the dominant active species for degrading APAP was hydroxyl radical (HO•). Moreover, a quantitative structural–activity relationship (QSAR) model for pseudo-first-order rate constants (kobs) was established with a high significance (R2 = 0.932, p = 0.001) by using three descriptors: octanol–water partition coefficient (logKow), dissociation constant (pKa) and highest occupied molecular orbital (HOMO). This work provides an innovative strategy of the photo-Fenton process for the degradation of PPCPs using natural minerals and ordinary carboxylic acid under sunlight. [ABSTRACT FROM AUTHOR]

Various widely applied compounds contain cyano‐groups, and this functional group serves as a chemical handle for a whole range of different reactions. We report a cyanide free chemoenzymatic cascade for nitrile synthesis. The reaction pathway starts with a reduction of carboxylic acid to aldehyde by carboxylate reductase enzymes (CARs) applied as living cell biocatalysts. The second – chemical – step includes in situ oxime formation with hydroxylamine. The final direct step from oxime to nitrile is catalyzed by aldoxime dehydratases (Oxds). With compatible combinations of a CAR and an Oxd, applied in one‐pot two‐step reactions, several aliphatic and aryl‐aliphatic target nitriles were obtained in more than 80% conversion. Phenylacetonitrile, for example, was prepared in 78% isolated yield. This chemoenzymatic route does not require cyanide salts, toxic metals, or undesired oxidants in contrast to entirely chemical procedures. [ABSTRACT FROM AUTHOR]

The synthesis of esters of some carboxylic acids was carried out by the oxidative esterification method. It was shown that the proposed method allows the selective esterification of carboxylic acids with hindered carboxyl groups. It was found that the synthesized esters have anti-aggregation activity at the level of acetylsalicylic acid. [ABSTRACT FROM AUTHOR]

The valorization of agroindustrial residues for second-generation biofuels has garnered attention due to the increasing demand for low-carbon fuels aligned with transportation sector decarbonization efforts. In this context, cassava processing residues, particularly cassava peel, remain largely unexplored but offer a cheap, abundant, and renewable feedstock that can be converted into hydrocarbon-rich biofuel. Thus, the originality of this study lies in investigating the selective conversion of cassava peel into renewable aromatic hydrocarbons through flash pyrolysis catalyzed by an environmentally friendly MFI-type zeolite synthesized from rice husk ash and diatomite residue. A micro-pyrolyzer interfaced with chromatographic separation and mass spectrometry detection was used to compare the composition of condensable volatile products from catalytic pyrolysis over HZSM-5 with those from catalyst-free pyrolysis. Cassava peel, characterized by high volatile matter content (84.3 %), low ash content (3.19 %), and reasonable energy content (15 MJ kg −1), yielded a high content of valuable platform chemicals, such as carboxylic acids and furans, when subjected to catalyst-free pyrolysis. The catalytic upgrading pyrolysis vapors over the environmentally friendly HZSM-5 catalyst yielded approximately 56.0 % industrially relevant aromatic hydrocarbons and 39.9 % light organic acids. Other strengths of using HZSM-5 in upgrading pyrolysis vapors were its low selectivity for naphthalenes, precursors for coke formation, and the production of hydrocarbons in the gasoline range. Thus, HZSM-5 was an efficient catalyst for promoting deoxygenation and improving hydrocarbon content, with high selectivity for valuable aromatic hydrocarbons. In conclusion, cassava peel showed favorable prospects for conversion into hydrocarbon-rich bio-oil, serving as a valuable precursor for low-carbon biofuels. [Display omitted] • Novel insights into valorization of cassava peel for hydrocarbon-rich bio-oil reported. • Catalytic upgrading of pyrolysis vapors over low-cost HZSM-5 using Py–GC/MS. • HZSM-5 synthesized from low-cost precursors promotes deoxygenation and hydrocarbons. • High selectivity for aromatic hydrocarbons (56 %) and light organic acids (40 %). • Catalytic pyrolysis demonstrated suitability for hydrocarbon-rich bio-oil from cassava peel. [ABSTRACT FROM AUTHOR]

Facile and precise regulation of the selective layer structure is challenging but highly crucial for the development of nanofiltration (NF) technology. In this work, we present an innovative strategy to modulate the polyamide physicochemical structure by introducing oleic acid (OA) into the organic boundary during interfacial polymerization (IP) process. As a naturally extracted product, OA is a kind of unsaturated fatty acid with a carboxylic head and a C17 alkyl chain tail. The presence of OA in organic phase allows to diminish the interfacial tension and accelerate the diffusion of piperazine (PIP) towards the organic boundary. Meanwhile, in situ reaction of OA with PIP during IP process yields organic particles that are embedded in the selective layer and alter its morphology. These two effects can result in opposite influence on membrane performance. Under the optimized OA dosage of 1 %, the MgSO 4 rejection boosted from 70.8 % to 97.4 % while maintaining a high pure water permeability up to 16.4 ± 0.1 L m−2 h−1 bar−1. This improvement is closely attributed to the augmented crosslinking degree and lessened MWCO/average pore size. In comparison to the control sample, the membrane surface changed from a smooth to a clustered morphology while the film thickness increased. This is mainly caused by the embedding of organic particles into the selection layer. This advancement provides a convenient and effective method for the design of high-performance NF membranes. [Display omitted] [ABSTRACT FROM AUTHOR]

Herein, we report a DMAP-catalysed Curtius rearrangement and intramolecular cyclisation cascade reaction of 2-substituted aryl carboxylic acids with organic azides for the first time. This protocol features simple operation, broad scope and metal-free conditions, furnishing a broad spectrum of biologically attractive heterocycles. The synthetic virtue of this reaction was demonstrated by gram-scale synthesis and applicability toward drug-like molecules. [ABSTRACT FROM AUTHOR]

Ultrareactive F-doped crystalline mesoporous aggregates of titanium dioxide nanoparticles have been synthesized by the acidic hydrolysis of a titanium precursor with different aqueous acidic solutions of organic acids, namely, ascorbic acid (AA), citric acid (CA), benzoic acid (BA) and salicylic acid (SA). The nanomaterials obtained were characterized by different techniques observing, in all cases, that they consist of crystalline mesoporous aggregates of anatase nanoparticles with ultrareactive {001} facets (promoted by F doping) and surface areas of up to ca. 75 m2 g−1. The present study has demonstrated that the use of the "green reagent" ascorbic acid generates titanium dioxide-based systems with superior activity compared with those obtained with other organic acids or HNO3 under the same experimental conditions. The anatase-based nanomaterials obtained when using ascorbic acid are able to photocatalytically degrade up to 92% of a concentrated solution of methylene blue (MB) in 15 min, and common emerging pollutants such as ciprofloxacin and naproxen (87% and 76% degradation, respectively) under UV light (300 W) in 15 min. The photocatalytic activity of the ascorbic acid-promoted systems appears to be associated with differences in the crystallinity of the system promoted by the presence of carbon species on the surface of the material, which are formed even after calcination. Finally, doping the anatase-based nanomaterials with palladium nanoparticles makes them effective heterogeneous catalysts with good to excellent halide conversions (between 60 and 99% for the formation of biphenyl derivatives), yields of up to 40% and a good degree of recyclability in Suzuki–Miyaura C–C coupling at short reaction times and very low loading of Pd. [ABSTRACT FROM AUTHOR]