Malonic Acid Research Articles

Qualitative and Quantitative Metabolite Comparison of Korean Traditional Alcoholic Beverages: Takju, Yakju, and Traditional-Soju.

With increasing interest in Korean foods and beverages, Korean traditional alcoholic beverages need to be studied. To characterize Korean traditional alcoholic beverages, we analyzed the metabolites of Takju, Yakju, and Traditional-Soju using 48 commercial products. We performed non-targeted metabolite profiling using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) and identified 33 significantly discriminant metabolites, including nine organic acids, three amino acids, and seven fatty acids, in the three types of alcoholic beverage. Subsequently, we quantified the profiled metabolites in each product and compared their contents to identify alcoholic beverage type-specific metabolites. Thus, we figured out seven metabolites using receiver operating characteristic (ROC) curves. The results revealed that octadecanoic acid (limit of detection (LOD) to 168.72 mg/L), nonanoic acid (LOD to 112.54 mg/L), and octanoic acid (8.00 to 145.08 mg/L) in Takju; succinic acid (LOD to 1.90 mg/mL), heptanoic acid (LOD to 343.23 mg/L), and hexadecanoic acid (20.28 to 126.45 mg/L) in Yakju; and malonic acid (LOD to 19.13 mg/mL) in Traditional-Soju, with an area under the curve (AUC) > 0.7, are important metabolites that can distinguish the type of alcoholic beverage. Our results provide qualitative and quantitative metabolite information about Korean traditional alcoholic beverages that can be used by consumers and manufacturers.

Environmentally Friendly Leaching of Antimony from Mining Residues Using Deep Eutectic Solvents: Optimization and Sustainable Extraction Strategies

This paper focuses on the environmental leaching of antimony, a critical mineral, using deep eutectic solvents. Mining residues often contain embedded antimony, posing environmental risks. Deep eutectic solvents, known for being low in toxicity, cost-effective, and environmentally friendly, present a promising avenue for sustainable antimony extraction. The study focuses on optimizing the leaching process through experimental analysis by considering variables such as temperature, time, and percentage of solids. Different deep eutectic solvent (DES) compositions are being studied, including choline chloride with malonic acid, thiourea, and ethylene glycol in different molar ratios, to identify the most effective solvent system for antimony extraction. A sample, originally obtained from mining waste produced via the flotation of antimonite ore, was used to test these three types of DESs. By optimizing the leaching process by changing the ratio of solid and liquid components, as well as the amount of oxidizing agent up to 3 g, iodine, yields of up to 100% were achieved after leaching for 4 h at 100 °C. The aim of the study is to advance sustainable resource management by providing knowledge on an ecological and feasible method of extracting antimony from mine waste, leading to more conscious and efficient resource practices in the mining sector.

Efficient continuous synthesis of 2-[3-(trifluoromethyl)phenyl]malonic acid, a key intermediate of Triflumezopyrim, coupling with esterification-condensation-hydrolysis

Triflumezopyrim (TFM) is a novel mesoionic pyrido[1,2-α]pyrimidinones insecticide, which acts on nicotinic acetylcholine receptors (nAChRs) and has no cross-resistance with other insecticides. Herein, we firstly developed a new continuous flow approach to synthesis 2-[3-(trifluoromethyl)phenyl]malonic acid, a key intermate of TFM, coupling with esterification, condensation, and hydrolysis. All three-step reactions were optimized and transformed into a continuous synthesis mode by three micro reaction units. Compared with the batch mode, the total reaction time and overall separation yield were improved from more than 12 h and 60 % to 18 min and 73.38 %, respectively. The solvent consumption and waste emission were significantly reduced, which also provides an eco-friendly and efficient potential tool for the development and production of mesoionic pyrido[1,2-α]pyrimidinones insecticide.

Metabolomic Profiling Reveals the Quality Variations in Citri Reticulatae Pericarpium (Citrus reticulata Blanco cv. Chachiensis) with Different Storage Ages in Response to "Candidatus Liberibacter Asiaticus" Infection.

Citri Reticulatae Pericarpium, especially the pericarp of Citrus reticulata Blanco cv. Chachiensis (PCRC), is an important edible and medicinal ingredient for health and pharmacological properties. Citrus Huanglongbing, a devastating disease that currently threatens the citrus industry worldwide, is caused by a phloem-limited alpha-proteobacterium, "Candidatus Liberibacter asiaticus" (CLas). The industry of cultivar Chachiensis has been suffering from HLB. Although HLB affected the quality of citrus fruit, whether the quality of PCRC was affected by HLB remains unclear. In this study, we compared the metabolite profiles between HLB-affected and healthy PCRC from three sources: fresh, 6-month-old, and 9-year-old PCRC, through the untargeted LC-MS method. Compared to healthy controls, various types of bioactive compounds, mainly flavonoids, terpenoids, alkaloids, coumarins, polysaccharides, and phenolic acids, accumulated in HLB-affected PCRC, especially in the HLB-affected 9-year PCRC. In particular, isorhamnetin, isoliquiritigenin, luteolin 7-O-beta-D-glucoside, limonin, geniposide, pyrimidodiazepine, scoparone, chitobiose, m-coumaric acid, malonate, and pantothenic acid, which contributed to the pharmacological activity and health care effects of PCRC, were highly accumulated in HLB-affected 9-year-old PCRC compared to the healthy control. Multibioassay analyses revealed that HLB-affected 9-year-old PCRC had a higher content of total flavonoids and total polyphenols and exhibited similar antioxidant capacity as compared to healthy controls. The results of this study provided detailed information on the quality of HLB-affected PCRC.

Recovery of Strategic Metals from Waste Printed Circuit Boards with Deep Eutectic Solvents and Ionic Liquids

The recycling of metals from waste printed circuit boards (WPCBs) has been presented as a solid–liquid extraction process using two deep eutectic solvents (DESs) and four ionic liquids (ILs). The extraction and separation of Cu(II), Ag(I), and other metals, such as Al(III), Fe(II), and Zn(II), from the solid WPCBs (after the physical, mechanical, and thermal pre-treatments) with different solvents are demonstrated. Two popular DESs were used to recover valuable metal ions: (1) choline chloride + malonic acid, 1:1, and (2) choline chloride + ethylene glycol, 1:2. The extraction efficiencies of DES 1 after two extraction and two stripping stages were only 15.7 wt% for Cu(II) and 17.6 wt% for Ag(I). The obtained results were compared with those obtained with four newly synthetized ILs as follows: didecyldimethylammonium propionate ([N10,10,1,1][C2H5COO]), didecylmethylammonium hydrogen sulphate ([N10,10,1,H][HSO4]), didecyldimethylammonium dihydrogen phosphate ([N10,10,1,1][H2PO4]), and tetrabutylphosphonium dihydrogen phosphate ([P4,4,4,4][H2PO4]). Various additives, such as didecyldimethyl ammonium chloride surfactant, DDACl; hydrogen peroxide, H2O2; trichloroisocyanuric acid, TCCA; and glycine or pentapotassium bis(peroxymonosulphate) bis(sulphate), PHM, were used with ILs during the extraction process. The solvent concentration, quantity of additivities, extraction temperature, pH, and solid/liquid, as well as organic/water ratios, and the selectivity and distribution ratios were described for all of the systems. The utilization of DESs and the new ILs with different additives presented in this work can serve as potential alternative extractants. This will help to compare these extractants, additives, extraction efficiency, temperature, and time of extraction with those of others with different formulas and procedures. The metal ion content in aqueous and stripped organic solutions was determined by the ICP-MS or ICP-OES methods. The obtained results all show that solvent extraction can successfully replace traditional hydrometallurgical and pyrometallurgical methods in new technologies for the extraction of metal ions from a secondary electronic waste, WPCBs.

Zinc solubilization and organic acid production by the entomopathogenic fungus, Metarhizium pingshaense sheds light on its key ecological role in the environment

We report for the first-time higher zinc (Zn) solubilization efficiency and plant growth promotion by an entomopathogenic fungus (EPF), Metarhizium pingshaense IISR-EPF-14, which was earlier isolated from Conogethes punctiferalis, a pest of global importance. The Zn solubilizing efficiency of the fungus varied depending on the type of insoluble source of Zn used, which was observed to be 1.6 times higher in Zn3(PO4)2–amended media compared to ZnO media. In liquid media, there was a 6.2-fold increase in available Zn in ZnO–amended media, whereas a 20.2-fold increase in available Zn was recorded in Zn3(PO4)2 medium. We ascribe the production of various organic acids such as gluconic, keto-gluconic, oxalic, tartaric, malonic, succinic and formic acids, which in general, interact with insoluble Zn sources and make them soluble by forming metal cations and displacing anions as the major mechanism for Zn solubilization by M. pingshaense. However, the type and amount of organic acid produced in the media varied depending on the source of Zn used and the incubation period. Application of the fungus alone and in combination with insoluble Zn sources enhanced various plant growth parameters in rice and cardamom plants. Moreover, the uptake of Zn in rice plants was enhanced up to ~2.5-fold by fungal application. The fungus also exhibited various other plant growth-promoting traits, such as production of Indole-3-acetic acid, ammonia, siderophores, solubilization of mineral phosphate, and production of hydrolytic enzymes such as α-amylase, protease, and pectinase. Hence, apart from its use as a biological control agent, M. pingshaense has the potential to be used as a bio-fortifier to enhance the solubilization and uptake of Zn from nutrient poor soils under field conditions. Our findings shed light on the broader ecological role played by this fungus and widen its scope for utilization in sustainable agriculture.

Docking, Synthesis and Evaluation of 4-hydroxy-1-phenyl-2(1H)-quinolone Derivatives as Anticancer Agents.

The estimated number of cancer cases in India for the year 2022 was found to be 14,61,427. The development of chemotherapeutic agents has reduced the mortality rate, however, they have high toxicity which is a disadvantage. Many researchers have found out that quinolin-2- one possesses anticancer activity, with this background we thought of synthesizing the quinolin-2-one derivatives. This study aimed to carry out docking, synthesis, characterization, and evaluation of 2-(2- (4-Hydroxy-2-oxoquinolin-1(2H)-yl)phenyl/ substituted phenyl)-3-(phenylamino) thiazolidon-4-one derivatives (IVa-g) as an anticancer agent. Diphenylamine and malonic acid treated with phosphoryl chloride gave compound I, which on formylation afforded compound II, which on reaction with various substituted aromatic phenylhydrazine derivatives gave compounds IIIa-g, which on further reaction with thioglycolic acid and anhydrous zinc chloride yielded the compounds IVa-g. Among all the synthesized novel derivatives, compounds IV a-d showed 50% lysis in the IC50 range of 25-50μg for the A549 cell line, and compounds IVa, and IVb showed 50% lysis in the IC50 range of 25-50μg for the MDA-MB cell line. The compound, 3-((4-fluorophenyl)amino)-2-(2-(4- hydroxy-2-oxoquinolin-1(2H)-yl)phenyl)thiazolidin-4-one (IVg) was found to be the most active against both the cell line, A549 and MDA-MB with IC50 value of 0.0298μmol and 0.0338μmol respectively. The docking results revealed that the synthesized compounds exhibited well-conserved hydrogen bonding with one or more amino acid residues in the active pocket of EGFR tyrosine kinase domain with 4-anilinoquinazoline inhibitor erlotinib (PDB ID:1M17). Compound IVg showed the highest MolDock score of -137.813 compared to the standard drug Imatinib having a MolDock score of -119.354. Compound IVg showed the highest MolDock score and was also found to be most potent against both the cell line, A549, and MDA-MB.

A new visible light-sensitive, oxygen-tolerant photoinitiator system for the synthesis of polyacrylamide gels by maskless photopolymerization

A new bis(2,2’-bypiridine)(1,10-phenanthroline)ruthenium(II) chloride–sodium bromate–malonic acid system has been developed for visible light-initiated polymerization of acrylamide. Its application allows the use of digital maskless photolithography to create 2D figures from polyacrylamide gel and their ansamblies. The system was used to create a chemical logic element ‘AND’.

Comparison of the Antibacterial Activity of Selected Deep Eutectic Solvents (DESs) and Deep Eutectic Solvents Comprising Organic Acids (OA-DESs) Toward Gram-Positive and Gram-Negative Species.

Deep eutectic solvents (DESs) have been intensively investigated in recent years for their antibacterial properties, with DESs that comprise organic acids (OA-DESs) showing promising antibacterial action. However a majority of the reports focused only on a limited number strains and techniques, which is not enough to determine the antibacterial potential of a substance. To bridge this gap, the antibacterial activity of classical DESs and OA-DESs is assessed on twelve Gram-negative and Gram-positive bacteria strains, with some of them exhibiting specific resistance toward antibiotics. The investigated formulations of OA-DESs comprise glycolic, malic, malonic, and oxalic acids as representatives of this group. Using a range of microbiological assays as well as physicochemical characterization methods, a major difference of the effectiveness between the two groups is demonstrated, with OA-DESs exhibiting, as expected, greater antibacterial effectiveness than classical DESs. Most interestingly, slight differences in the minimum inhibitory and bactericidal concentration values as well as time-kill kinetics profiles are observed between Gram-positive and Gram-negative strains. Transmission electron microscopy analysis reveals the effect of the treatment of the bacteria with the representatives of both groups of DESs, which allows us to better understand the possible mechanism-of-action of these novel materials.

Solid dicarboxylic acid assisted deliming in beamhouse to reduce nitrogen compounds in tannery wastewater

In leather manufacturing, ammonia salts in deliming operations contribute to the significant addition of ammonia-nitrogen (NH3–N) into wastewater. Wastewater containing NH3–N serious affects aquatic life and the operations of effluent treatment plants. In this study, the strategy of reducing NH3–N released into tannery wastewater, uses non-ammonia deliming agent-solid dicarboxylic acid (malonic acid) to replace the conventional deliming agent (ammonium sulfate). Utilizing a laboratory experiment, a pilot scale test was carried out and found to be almost comparable with the former experimental work. The generated delimed wastewater, delimed pelts, and manufactured crust leathers were subjected to various physicomechanical analyses. Results revealed that the reductions of NH3–N, TKN, and hydroxyproline amounted, respectively, to 98.78%, 88.69%, and 26.9%, compared to conventional deliming agents. The other pollutants, namely TDS, BOD, COD, and EC were significantly reduced. The physicomechanical properties of the crust leathers met the standard requirements. SEM images of delimed pelt and crust leathers revealed a similar fiber structure. The wastewater emitted during deliming with malonic acid is probably an easier way to conduct effluent treatment by reducing nitrogen pollution. This investigation is a novel approach to finding a viable technology that can satisfy the need for modern leather manufacturing being done in environmentally friendly ways.

Study on separation of methanol and dimethyl carbonate azeotropic system with deep eutectic solvents

Dimethyl carbonate (DMC) is an important diesel and gasoline additive that is also a low-toxic and environmentally friendly chemical raw material. However, it will form an azeotrope with methanol (MeOH) during the actual chemical production process. Therefore, separating high-purity DMC from the azeotrope is of significance. In extractive distillation, deep eutectic solvents (DESs) have demonstrated superior separation performance as green extractants. This study calculated the σ-profiles of DMC, MeOH, and DESs by the COSMO-SAC model to examine the most appropriate DES for the MeOH and DMC separation. Eventually, DES1(1:2 choline chloride (ChCl): malonic acid (MA)), DES2(1:2 ChCl: urea), DES3(1:2 ChCl: glycerol (G)), DES4(1:2 ChCl: ethylene glycol (EG)), DES5(1:2 ChCl: pyruvic acid (PA)) were designated as preferred extractants. The vapor pressures of five DESs at different temperatures were determined using a thermogravimetric analyzer, while their critical properties, normal boiling points, and acentric factors were predicted. The vapor–liquid equilibrium (VLE) data measured for DMC + MeOH + DESs ternary systems at 101.3 kPa showed that the addition of 15 mol % of any of the five DESs could successfully break the azeotrope and DES2 achieved a higher degree of separation in the MeOH-DMC binary azeotrope compared to the other DESs evaluated. The binary interaction parameters between MeOH/DMC and DESs were calculated through the NRTL (Non-Random Two-Liquid) model, and the fitting results were found to be consistent with the experimental data. The mechanism of the MeOH-DMC separation by DES2 was elucidated through quantum chemical (QC) calculations. The improved independent gradient model (IGMH) and the theory of atoms in molecules (AIM) demonstrated that the stronger interaction between DES2 and MeOH molecules is the key for DES2 to break the azeotrope of the system.

Concise Approach towards Tetramic Acid Derivatives via Ugi Reaction/Dieckmann Cyclization Sequence

AbstractTetramic acids exhibit intriguing biological activity and are particularly attractive scaffolds for drug design. In this paper, we present a convenient approach based on the Dieckmann cyclization of Ugi adducts of malonic monoesters to afford a series of medically important polysubstituted tetramic acid derivatives. This simple and versatile method tolerates various substituents in both the amine, aldehyde and isocyanide moieties allowing the use of α‐substituted malonic acid monoesters. Examples of further functionalization of the free methylene group in the synthesized compounds have been presented.

Translational and reorientational dynamics in carboxylic acid-based deep eutectic solvents.

The glass formation and the dipolar reorientational motions in deep eutectic solvents (DESs) are frequently overlooked, despite their crucial role in defining the room-temperature physiochemical properties. To understand the effects of these dynamics on the ionic conductivity and their relation to the mechanical properties of the DES, we conducted broadband dielectric and rheological spectroscopy over a wide temperature range on three well-established carboxylic acid-based natural DESs. These are the eutectic mixtures of choline chloride with oxalic acid (oxaline), malonic acid (maline), and phenylacetic acid (phenylaceline). In all three DESs, we observe signs of a glass transition in the temperature dependence of their dipolar reorientational and structural dynamics, as well as varying degrees of motional decoupling between the different observed dynamics. Maline and oxaline display a breaking of the Walden rule near the glass-transition temperature, while the relation between the dc conductivity and dipolar relaxation time in both maline and phenylaceline is best described by a power law. The glass-forming properties of the investigated systems not only govern the orientational dipolar motions and rheological properties, which are of interest from a fundamental point of view, but they also affect the dc conductivity, even at room temperature, which is of high technical relevance.

Feeding a Saccharomyces cerevisiae fermentation product during a gut barrier challenge in lactating Holstein cows impacts the ruminal microbiota and metabolome

Through its influence on the gut microbiota, feeding of Saccharomyces cerevisiae fermentation products (SCFP) has been a successful strategy to enhance the health of dairy cows during periods of physiological stresses. Although production and metabolic outcomes from feeding SCFP are well-known, combined impacts on the ruminal microbiota and metabolome during gut barrier challenges remain unclear. To address this gap in knowledge, multiparous Holstein cows (97.1 ± 7.6 DIM; n = 8/group) fed a control diet (CON) or CON plus 19 g/d SCFP for 9 wk were subjected to a feed restriction (FR) challenge for 5 d, during which they were fed 40% of their ad-libitum intake from the 7 d before FR. DNA extracted from ruminal fluid was subjected to PacBio Full-Length 16S rRNA gene sequencing, RT-PCR of 12 major ruminal bacteria, and metabolomics analysis of up to 189 metabolites via GC-MS. High-quality amplicon sequence analyses were performed with Targeted Amplicon Diversity Analysis (TADA), MicrobiomeAnalyst, PICRUSt2, and STAMP software, while metabolomics data were analyzed via MetaboAnalyst 5.0. Ruminal fluid metabolites from the SCFP group exhibited a greater α diversity Chao 1 (P = 0.03) and Shannon indices (P = 0.05), and the PLS-DA analysis clearly discriminated metabolite profiles between dietary groups. The abundance of CPla_4_termite_group, Candidatus_Saccharimonas, Oribacterium, and Pirellula genus in cows fed SCFP was greater. In the SCFP group, concentrations of ethanolamine, 2-amino-4,6-dihydroxypyrimidine, glyoxylic acid, serine, threonine, cytosine, stearic acid, and pyrrole-2-carboxylic acid were greater in ruminal fluid. Both Fretibacterium and Succinivibrio abundance were positively correlated with metabolites across various biological processes: gamma-aminobutyric acid, galactose, butane-2,3-diol, fructose, 5-amino pentanoic acid, β-aminoisobutyric acid, ornithine, malonic acid, 3-hydroxy-3-methylbutyric acid, hexanoic acid, heptanoic acid, cadaverine, glycolic acid, β-alanine, 2-hydroxybutyric acid, methyl alanine, and alanine. In the SCFP group, compared with CON, the mean proportion of 14 predicted pathways based on metabolomics data was greater, while 10 predicted pathways were lower. Integrating metabolites and upregulated predicted enzymes (NADP+-dependent glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, serine: glyoxylate aminotransferase, and D-glycerate 3-kinase) indicated that the pentose phosphate pathway and photorespiration pathway were most upregulated by SCFP. Overall, SCFP during FR led to alterations in ruminal microbiota composition and key metabolic pathways. Among those, there was a shift from the tricarboxylic acid (TCA) cycle to the glyoxylate cycle and nitrogenous base production was enhanced.

Formation and investigation of hydrogen bond liquid crystal binary mixtures for optical and thermal energy applications

Hydrogen bond liquid crystals derived binary mixtures are formed between methyl malonic acid (MM) and p-n heptyloxy benzoic acid (7BAO) abbreviated as MM + 7BAO & p-n dodecyloxy (12BAO) benzoic acid abbreviated as MM + 12BAO. Five binary mixtures are obtained as the molar proportion of the precursor mesogens that varies in odd steps from 0.1 to 0.9. Spectral, optical and thermal investigations of the five binary mixtures are carried out thoroughly for analyzing the mesogenic behaviors that apt the binary mixtures for appropriate applicational utility.

Rh(III)-Catalyzed C7-Alkylation of Isatogens with Malonic Acid Diazoesters.

Rh(III)-catalyzed C7-alkylation of isatogens (indolin-3-one N-oxides) with malonic acid diazoesters has been developed. This strategy utilizes oxygen anion on the N-oxide group of isatogens as a directing group and successfully achieves the synthesis of a series of C7-alkylated isatogens with moderate to good yields (48-86% yields). Moreover, the N-oxides of isatogens can not only serve as the simple directing group for C7-H bond cleavage but also be deoxidized for easy removal.

Pollution Characteristics，Sources，and Secondary Generation of Organic Acids in PM2.5 in Zhengzhou

Organic acids in atmospheric particulate matter are widely involved in various physical and chemical reactions in the atmosphere and contribute greatly to the formation of secondary organic aerosols and haze pollutions. Therefore， the concentration distribution characteristics， sources， and secondary formation of organic acids in particulate matter are of great significance for further investigation of organic aerosols and their secondary transformation. Fine particulate matter （PM2.5） samples were collected in Zhengzhou， and three types of organic acids， including dicarboxylic acids， fatty acids， and resin acids， were analyzed to explore their species distribution， seasonal variations， source contribution， and secondary generation. Malonic acid （di-C3） and succinate acid （di-C4） were the most abundant in the identified dicarboxylic acids， which showed obvious seasonal variations in the order of summer > autumn > winter > spring. Fatty acids had the highest concentration in winter and the lowest concentration in spring， showing obvious bimodal advantages， with the most abundant compounds being palmitic acid and stearic acid （C18）. Principal component analysis and multiple linear regression （MLR） were used to analyze the source of organic acids in PM2.5 in Zhengzhou； the results showed that 35% of the organic acids came from combustion and traffic sources， 24% from cooking sources， 23% from secondary formation， and 17% from natural sources. The ratios of the selected marker species （i.e.， di-C3 / di-C4， F/M， and C18：1 / C18） were used as tracers for the secondary formation of the organic aerosol and its aging process. The results showed that the photochemical reaction was intense in summer， and the proportion of organic aerosol aging or secondary production was high， whereas the photochemical reaction was weak in winter， and the aging degree of organic aerosol was low. Correlation analysis and MLR were used in combination to quantify the relative contribution of gas-phase oxidation and liquid-phase oxidation to dicarboxylic acid formation， and the results showed that gas-phase oxidation played a dominant role in the sampling period （accounting for 58%）， especially in summer （61%）.

Dynamic changes of volatile compounds and small molecule compounds during curing and drying processes of Megalobrama amblycephala

SummaryIn this study, the changes in volatile compounds, lipids, and small molecule compounds during the curing and drying processes were examined. The results showed that lipid oxidation was enhanced during curing and drying processes. A total of fifty‐two types of volatile compounds in the dry‐cured fish were detected, and the contents of alcohols (such as 3‐methyl‐1‐butanol, 1‐octen‐3‐ol), ketones (such as 2‐heptanone, 2‐octanone), and aldehydes (such as 3‐methylbutyraldehyde, hexanal, nonanal, decanal) were increased during curing and drying processes. A total of 812 metabolites were identified. The metabolites in linoleate, arachidonate, nucleotide, amino acid, and other metabolic pathways showed significant differences between drying stage and curing stage. The oxidative degradation of arachidonate acid, linoleate acid, and amino acid may contribute to the changes in volatile compounds during the curing and drying stages. Seven compounds including shikimic acid, carnitine C5: DC, carnitine C7: DC, 2‐hydroxybutanoic acid, 3‐hydroxybutanoic acid, malonic acid, and methylmalonic acid could be key small molecule compounds in curing and drying processing. These findings are valuable for understanding the mechanisms underlying flavour changes occurring during fish curing and drying processes.

Serum metabonomic study to explore the amelioration mechanisms of co‐fermented collagen peptide‐jackfruit juice on the immunosuppressed mice

AbstractThe main purpose of this study was to investigate the improvement effect and serum metabolomic analysis of co‐fermented collagen peptide‐jackfruit juice (FPJ) against immunosuppression in cyclophosphamide‐induced mice. Serum samples were analyzed using ultra‐performance liquid chromatography coupled with mass spectrometry (UPLC‐MS/MS) targeted metabolomics technology, including the normal group, model group, and FPJ group, and determine if such treatments were able to revert immunosuppression‐related metabolic changes to normal status. The results showed that 32 differential metabolites were upregulated and 42 metabolites were downregulated in the model group compared with the normal group. After FPJ intervention, there was a trend of normal callback. Adenosine, inosine, guanosine, 2‐deoxyadenosine, hypoxanthine, xanthine, d‐xylulose‐5‐phosphate, ribulose‐5‐phosphate, phenylpyruvic acid, hippuric acid, 3‐(3‐hydroxyphenyl)‐propionic acid, 3‐ureidopropionate, uridine, dCDP and malonic acid may be used as predictive markers of immunosuppression. Notably, these biomarkers were involved in purine metabolism, pentose phosphate pathway, phenylalanine metabolism, and pyrimidine metabolism. In this study, FPJ inhibited oxidative stress and improved the gut microbes by regulating the disorders of metabolic pathways. The metabolomics approach developed herein provides novel insight into the metabolic disturbances associated with immunosuppression, which will contribute to understanding the mechanism of FPJ on immunosuppression further and providing a basis for further research.

Impact of acidity and surface-modulated acid dissociation on cloud response to organic aerosol

Abstract. Acid dissociation of the organic aerosol fraction has the potential to impact cloud-activating properties by altering aqueous-phase H+ concentrations and water activity but is currently overlooked in most atmospheric aerosol models. We implemented a simple representation of organic acid dissociation in the aerosol–chemistry–climate box model ECHAM6.3–HAM2.3 and investigated the impact on aerosol-forming aqueous sulfur chemistry, cloud droplet number concentrations, and the shortwave radiative effect. Many atmospheric organic acids are also surface-active and may be strongly adsorbed at the surface of small aqueous droplets. The degree of dissociation has recently been observed for several atmospheric surface-active organics with Brönsted acid character to be significantly shifted in the surface, compared to the bulk aqueous solution. In addition to the well-known bulk acidity, we therefore introduced an empirical account of this surface-modulated dissociation to further explore the potential impact on aerosol climate effects. Malonic acid and decanoic acid were used as proxies for atmospheric organic aerosols of different surface-active and acid strengths. Both acids were found to yield sufficient hydrogen ion concentrations from dissociation in an aqueous droplet population to strongly influence aqueous aerosol sulfur chemistry, leading to enhanced cloud droplet number concentrations and a cooling shortwave radiative effect. Further considering the surface modulation of organic acid dissociation, the impact on cloud microphysics was smaller than according to the well-known bulk solution acidity but still significant. Our results show that organic aerosol acid dissociation can significantly influence predictions of aerosol and cloud droplet formation and aerosol–cloud–climate effects and that, even for a well-known bulk solution phenomenon such as acidity, it may be important to also consider the specific influence of surface effects when surface-active acids comprise a significant fraction of the total organic aerosol mass.