Tricarboxylic Acids Research Articles

Metabolomic analysis of grapes and leaves from symptomatic and asymptomatic Vitis vinifera grapevines with Esca disease

Esca is a grapevine trunk disease spreading in vineyards worldwide, and of rising concern since no efficient treatment is available to mitigate its impact. Trunks, grapes and leaves from symptomatic and asymptomatic Aragonês vines were collected at harvest stage to characterise plant responses associated with this fungal disease. Presence of Esca associated fungi in the trunks was confirmed by molecular methods using ITS region. Metabolomics of grapes and leaves was analysed by Gas chromatography coupled to electron impact ionization time-of-flight mass spectrometry (GC-EI/TOF-MS) and GC coupled to an EI/quadrupole MS (GC-EI/QUAD-MS and showed that both organs from symptomatic plants exhibited a different metabolic reprogramming than those from asymptomatic. Symptomatic leaves present lesser content in tricarboxylic and polyhydroxy acids, and this metabolic adjustment may involve salicylic acid metabolism. On the other hand, symptomatic fruits accumulate long-chain fatty acids probably related with cuticle reinforcement to mitigate changes in water transport caused by trunk damage, and defence-related metabolites such as α-tocopherol. Symptomatic berries also presented alterations in volatile aroma compounds such as C6-volatiles, and acetic acid suggesting an impact on subsequent wine quality. Altogether this study, identified putative metabolic markers associated with Esca disease in plants with different symptomatology and contributed to a physiological understanding of this fungal disease that could help in the development of mitigation strategies for its spread.

Primordial aqueous alteration recorded in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu

We report primordial aqueous alteration signatures in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu by the Hayabusa2 spacecraft of JAXA. Newly identified low-molecular-weight hydroxy acids (HO-R-COOH) and dicarboxylic acids (HOOC-R-COOH), such as glycolic acid, lactic acid, glyceric acid, oxalic acid, and succinic acid, are predominant in samples from the two touchdown locations at Ryugu. The quantitative and qualitative profiles for the hydrophilic molecules between the two sampling locations shows similar trends within the order of ppb (parts per billion) to ppm (parts per million). A wide variety of structural isomers, including α- and β-hydroxy acids, are observed among the hydrophilic molecules. We also identify pyruvic acid and dihydroxy and tricarboxylic acids, which are biochemically important intermediates relevant to molecular evolution, such as the primordial TCA (tricarboxylic acid) cycle. Here, we find evidence that the asteroid Ryugu samples underwent substantial aqueous alteration, as revealed by the presence of malonic acid during keto–enol tautomerism in the dicarboxylic acid profile. The comprehensive data suggest the presence of a series for water-soluble organic molecules in the regolith of Ryugu and evidence of signatures in coevolutionary aqueous alteration between water and organics in this carbonaceous asteroid.

Two new High-Connectivity topological networks constructed from tricarboxylic acids and 1,2,4,5-tetra(4-pyridyl)benzene

Two new coordination polymers [Co3(pta)2(bztpy)(H2O)2]·2H2O (1) and [Co3(bta)2(bztpy)1.5(H2O)2]·4H2O (2) (H3pta = 1,2,3-propanetricarboxylic acid, H3bta = 1,2,3-benzenetricarboxylic acid, bztpy = 1,2,4,5-tetra(4-pyridyl)benzene) have been hydrothermally synthesized and structurally characterized. In 1, pta connects with a trinuclear cobalt cluster to form a (4,4) net, while bztpy also connects with the trinuclear cobalt cluster to form a (4,4) net, thereby creating a very rare (4,8)-connected mixed-node topological network that exhibits ferrimagnetic behavior. 2 is a rare (4,4,12)-connected topological network formed by hexanuclear cobalt rings connected through 12 bztpy ligands, showing antiferromagnetic properties. Both compounds demonstrate the potential of the large tetradentate pyridyl ligand bztpy in constructing high-connectivity topological networks.

Metabolic vulnerability of cancer stem cells and their niche.

Cancer stem cells (CSC) are the leading cause of the failure of anti-tumor treatments. These aggressive cancer cells are preserved and sustained by adjacent cells forming a specialized microenvironment, termed niche, among which tumor-associated macrophages (TAMs) are critical players. The cycle of tricarboxylic acids, fatty acid oxidation path, and electron transport chain have been proven to play central roles in the development and maintenance of CSCs and TAMs. By improving their oxidative metabolism, cancer cells are able to extract more energy from nutrients, which allows them to survive in nutritionally defective environments. Because mitochondria are crucial bioenergetic hubs and sites of these metabolic pathways, major hopes are posed for drugs targeting mitochondria. A wide range of medications targeting mitochondria, electron transport chain complexes, or oxidative enzymes are currently investigated in phase 1 and phase 2 clinical trials against hard-to-treat tumors. This review article aims to highlight recent literature on the metabolic adaptations of CSCs and their supporting macrophages. A focus is provided on the resistance and dormancy behaviors that give CSCs a selection advantage and quiescence capacity in particularly hostile microenvironments and the role of TAMs in supporting these attitudes. The article also describes medicaments that have demonstrated a robust ability to disrupt core oxidative metabolism in preclinical cancer studies and are currently being tested in clinical trials.

First comprehensive untargeted metabolomics study of suramin-treated Trypanosoma brucei: an integrated data analysis workflow from multifactor data modelling to functional analysis.

Human African trypanosomiasis, commonly known as sleeping sickness, is a vector-borne parasitic disease prevalent in sub-Saharan Africa and transmitted by the tsetse fly. Suramin, a medication with a long history of clinical use, has demonstrated varied modes of action against Trypanosoma brucei. This study employs a comprehensive workflow to investigate the metabolic effects of suramin on T. brucei, utilizing a multimodal metabolomics approach. The primary aim of this study is to comprehensively analyze the metabolic impact of suramin on T. brucei using a combined liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (NMR) approach. Statistical analyses, encompassing multivariate analysis and pathway enrichment analysis, are applied to elucidate significant variations and metabolic changes resulting from suramin treatment. A detailed methodology involving the integration of high-resolution data from LC-MS and NMR techniques is presented. The study conducts a thorough analysis of metabolite profiles in both suramin-treated and control T. brucei brucei samples. Statistical techniques, including ANOVA-simultaneous component analysis (ASCA), principal component analysis (PCA), ANOVA 2 analysis, and bootstrap tests, are employed to discern the effects of suramin treatment on the metabolomics outcomes. Our investigation reveals substantial differences in metabolic profiles between the control and suramin-treated groups. ASCA and PCA analysis confirm distinct separation between these groups in both MS-negative and NMR analyses. Furthermore, ANOVA 2 analysis and bootstrap tests confirmed the significance of treatment, time, and interaction effects on the metabolomics outcomes. Functional analysis of the data from LC-MS highlighted the impact of treatment on amino-acid, and amino-sugar and nucleotide-sugar metabolism, while time effects were observed on carbon intermediary metabolism (notably glycolysis and di- and tricarboxylic acids of the succinate production pathway and tricarboxylic acid (TCA) cycle). Through the integration of LC-MS and NMR techniques coupled with advanced statistical analyses, this study identifies distinctive metabolic signatures and pathways associated with suramin treatment in T. brucei. These findings contribute to a deeper understanding of the pharmacological impact of suramin and have the potential to inform the development of more efficacious therapeutic strategies against African trypanosomiasis.

Regulation of tricarboxylate transport and metabolism in Acinetobacter baylyi ADP1.

Despite the significant presence of plant-derived tricarboxylic acids in some environments, few studies detail the bacterial metabolism of trans-aconitic acid (Taa) and tricarballylic acid (Tcb). In a soil bacterium, Acinetobacter baylyi ADP1, we discovered interrelated pathways for the consumption of Taa and Tcb. An intricate regulatory scheme tightly controls the transport and catabolism of both compounds and may reflect that they can be toxic inhibitors of the tricarboxylic acid cycle. The genes encoding two similar LysR-type transcriptional regulators, TcuR and TclR, were clustered on the chromosome with tcuA and tcuB, genes required for Tcb consumption. The genetic organization differed from that in Salmonella enterica serovar Typhimurium, in which tcuA and tcuB form an operon with a transporter gene, tcuC. In A. baylyi, tcuC was not cotranscribed with tcuAB. Rather, tcuC was cotranscribed with a gene, designated pacI, encoding an isomerase needed for Taa consumption. TcuC appears to transport Tcb and cis-aconitic acid (Caa), the presumed product of PacI-mediated periplasmic isomerization of Taa. Two operons, tcuC-pacI and tcuAB, were transcriptionally controlled by both TcuR and TclR, which have overlapping functions. We investigated the roles of the two regulators in activating transcription of both operons in response to multiple effector compounds, including Taa, Tcb, and Caa.IMPORTANCEIngestion of Taa and Tcb by grazing livestock can cause a serious metabolic disorder called grass tetany. The disorder, which results from Tcb absorption by ruminants, focuses attention on the metabolism of tricarboxylic acids. Additional interest stems from efforts to produce tricarboxylic acids as commodity chemicals. Improved understanding of bacterial enzymes and pathways for tricarboxylic acid metabolism may contribute to new biomanufacturing strategies.

Dissociation constants of relevant secondary organic aerosol components in the atmosphere

The presented studies focus on measuring the determination of the acidity constant (pKa) of relevant secondary organic aerosol components. For our research, we selected important oxidation products (mainly carboxylic acids) of the most abundant terpene compounds, such as α-pinene, β-pinene, β-caryophyllene, and δ-3-carene. The research covered the synthesis and determination of the acidity constant of selected compounds. We used three methods to measure the acidity constant, i.e., 1H NMR titration, pH-metric titration, Bates-Schwarzenbach spectrophotometric method. Moreover, the pKa values were calculated with Marvin 21.17.0 software to compare the experimentally derived values with those calculated from the chemical structure. pKa values measured with 1H NMR titration ranged from 3.51 ± 0.01 for terebic acid to 5.18 ± 0.06 for β-norcaryophyllonic acid. Moreover, the data determined by the 1H NMR method revealed a good correlation with the data obtained with the commonly used potentiometric and UV-spectroscopic methods (R2 = 0.92). In contrast, the comparison with in silico results exhibits a relatively low correlation (R2Marvin = 0.66). We found that most of the values calculated with the Marvin Program are lower than experimental values obtained with pH-metric titration with an average difference of 0.44 pKa units. For di- and tricarboxylic acids, we obtained two and three pKa values, respectively. A good correlation with the literature values was observed, for example, Howell and Fisher (1958) used pH-metric titration and measured pKa1 and pKa2 to be 4.48 and 5.48, while our results are 4.24 ± 0.10 and 5.40 ± 0.02, respectively.

Electrical conductivity of heterogeneous ion exchange membranes in solutions of mono-, di- and tricarboxylic acids and its effect on the process of electrodialysis of solutions containing organic acids

In this study, the electrical conductivity of cation-exchange and anion-exchange membranes was studied in solutions containing both strong (sodium chloride and acetate) and weak (acetic, succinic and citric acids) electrolytes. The results obtained indicate that the concentration dependence of the electrical conductivity of membranes in weak electrolytes differs significantly from that observed for solutions of strong electrolytes. In the case of an acetic acid solution, the electrical conductivity of the membranes is higher than that of the equilibrium solution over the entire range of concentrations that were studied. It has been shown that existing models of the transport and structural organization of membranes allows describing the structural parameters of ion-exchange membranes in contact with strong electrolytes. In sodium chloride and sodium acetate solutions, the obtained dependences were processed within the framework of microheterogeneous and three-wire models to establish the influence of the nature of the electrolyte on the transport and structural characteristics of the membranes. The dependence of electrical conductivity on the concentration of a weak electrolyte solution does not allow the use of either microheterogeneous or extended three-wire models for the description of the structure-property relationship of ion-exchange materials. It has been shown that in acetic acid and partially succinic acid solutions, the solution provides the main contribution to the resistance of the electromembrane system. Based on the results obtained from measuring electrical conductivity, changes in the design of a laboratory electrodialyzer were proposed and experiments were carried out on desalting a solution of acetic acid. It has been shown that the use of thinner intermembrane separators in the desalting chamber leads to an increase in the integral current efficiency (from 0.32 to 0.44 at 0.6 A/dm2 and the same degree of desalination) and a reduction in specific energy consumption (from 3.0 to 1.9 kWh/mol at 0.6 A/dm2) during desalination of acetic acid. The results obtained can be further used to improve the parameters of the process of obtaining weak acids by bipolar electrodialysis.

Glutathione: synthesis, mechanism of action, antioxidant and detoxifying role

Annotation. Under the conditions of entry of toxic substances into the body and activation of redox processes, compounds of natural origin with antioxidant properties are widely used to correct metabolic disorders. The purpose of the work is to conduct an analysis and systematization of basic and modern scientific sources of literature on the role of the glutathione system in the development of pathologies. For the scientific review, data from the scientometric databases PubMed, ScienceDirect, Web of Science, Google Scholar, etc. were used, and the analysis of scientific textbooks and monographs was carried out. Among water-soluble antioxidants, low- and high-molecular compounds containing SH-groups are popular in medicine, mono-, di- and tricarboxylic acids and other anions. Glutathione, a thiol-containing tripeptide, is the main endogenous non-enzymatic antioxidant that exerts cytoprotective and detoxifying properties. Various epithelial cells – enterocytes, endotheliocytes, alveolar cells of the lungs, epithelium of the proximal renal tubules, absorb and use glutathione most intensively, in particular, taken orally, so the idea of using glutathione in diseases of organs that actively participate in detoxification processes: kidneys, liver, lungs, as well as under the conditions of systemic diseases accompanied by endothelial dysfunction and oxidative stress – diabetes, atherosclerosis, nephropathy. Under physiological conditions, the body maintains a dynamic balance between the content of oxidants, which stimulate the processes of free radical oxidation of biomolecules, and the activity of antioxidant systems. But under the conditions of damage to any link of the living system, increased formation of reactive oxygen species (ROS) and inhibition of antioxidant systems contributes to the activation of free radical oxidation processes, the intensity of which depends on the concentration of oxygen in the tissues and on the enzymatic and non-enzymatic systems of antioxidant protection, which prevents the destruction of cells by active forms of oxygen.

Pathophysiological mechanisms of adaptation of muscle tissue of descendants of irradiated animals to altering influence of ionizing radiation

Biochemical processes occurring in a living organism take part in the development of radiation-induced structural disorders, realizing primary damage. As a result, morphological manifestations of radiation damage are preceded by chemical shifts determining them. In the descendants of animals irradiated in different doses, a decrease in physical performance is observed, which is due to a violation of the efficiency of the use of the unique biosubstrate of muscle tissue - creatinephosphate, a change in the ratio of the activity of aerobic and anaerobic metabolism, and processes of trans-deamination of amino acids. The purpose of the work is to investigate the the mechanisms of disruption of metabolic processes in the muscle tissue of the descendants of irradiated animals. It was concluded that, unlike skeletal muscle, the activity of the tricarboxylic acid cycle, in particular the NAD-dependent malate dehydrogenase, in the myocardium is quite significant both in the cytoplasm and in the mitochondria of the tissue, as evidenced by the higher level of tricarboxylic acid cycle metabolites acids - malic and oxaloacetic, as well as the activity of NADP-dependent malate dehydrogenase, which performs a connecting role between glycolysis and the cycle of tricarboxylic acids in providing them with metabolites and transferring protons from NADH+H+ to NADP. The author revealed that myocardium is characterized by a larger pool of adenyl nucleotides due to ATP. Tha data obrtained shiowed hyperglycemia which is observed in the blood of the descendants of irradiated animals. Gluconeogenesis is enhanced in the liver of the descendants of irradiated animals and this explains the hyperglycemia and accumulation of glycogen in the liver. At the same time, the penetration of glucose into muscle cells is weakened, which is associated with a decrease in their glycogen content, and this can be explained by the decrease in adaptation to physical exertion in the descendants of irradiated animals. The author made a cionclusion that the pathophysiological mechanisms of radiation-induced energy supply restructuring are aimed at short-term processes of strengthening the supply of energy to vital organs and systems for destroyed biochemical, physiological, functional and regulatory processes restoration and sanogenetic mechanisms activation.

Luminescence intensity-tunable X-ray scintillation based on zirconium-based metal-organic frameworks

The low-energy ultraviolet or visible photons can be produced by the interaction between the scintillator materials and ionizing radiation. For this reason, scintillator materials are widely used as radiation detectors, which are prevalently utilized in different applications such as nuclear medicine imaging, homeland security, high-energy physics, oil drilling explorations, etc. Herein, a high-atomic-number (Z) zirconium-based metal-organic framework nanoflower material CJLU-1 (Zr6(μ3-O)4(μ3-OH)4(OH)6(TCA)2(H2O)6) (H3TCA = tri-carboxylic acids 4,4′,4″-nitrilotribenzoic acid) was synthesized and can effectively convert X-ray into visible light. CJLU-1 is composed of secondary structural unit hexagonal Zr metal cluster and connected by TCA ligands. The photo luminescence spectra (PL) emission peak and excitation peak of CJLU-1 are at 470 nm and 395 nm respectively. CJLU-1 exhibited radioluminescence (RL) peak with a maximum at 480 nm under steady-state excitation with X-rays. Moreover, by accommodating different guest molecules such as xylene and RhB in the same MOF material, intensity-tunable X-ray scintillation can be facilely achieved, providing a new class of scintillating materials with luminescence intensity tunability. The high-Z hexagonal Zr clusters, which are arranged in an orderly fashion, absorb and interact with the ionizing radiation and sensitize the adjacent organic ligands TCA to produce efficient RL. This work contributes to the development of high-Z zirconium-based MOFs and RL intensity-tunable scintillation materials towards future practical nuclear sensing applications.

Immunometabolic actions of trabectedin and lurbinectedin on human macrophages: relevance for their anti-tumor activity.

In recent years, the central role of cell bioenergetics in regulating immune cell function and fate has been recognized, giving rise to the interest in immunometabolism, an area of research focused on the interaction between metabolic regulation and immune function. Thus, early metabolic changes associated with the polarization of macrophagesinto pro-inflammatoryorpro-resolving cells under different stimuli have been characterized. Tumor-associated macrophages are among the most abundant cells in the tumor microenvironment; however, it exists an unmet need to study the effect of chemotherapeutics on macrophage immunometabolism. Here, we use a systems biology approach that integrates transcriptomics and metabolomics to unveil the immunometabolic effects of trabectedin (TRB) and lurbinectedin (LUR), two DNA-binding agents with proven antitumor activity. Our results show that TRB and LUR activate human macrophages toward a pro-inflammatory phenotype by inducing a specific metabolic rewiring program that includes ROS production, changes in the mitochondrial inner membrane potential, increased pentose phosphate pathway, lactate release, tricarboxylic acids (TCA) cycle, serine and methylglyoxal pathways in human macrophages. Glutamine, aspartate, histidine, and proline intracellular levels are also decreased, whereas oxygen consumption is reduced. The observed immunometabolic changes explain additional antitumor activities of these compounds and open new avenues to design therapeutic interventions that specifically target the immunometabolic landscape inthe treatment of cancer.

Metabolic fingerprinting of systemic sclerosis: a systematic review.

Introduction: Systemic sclerosis (SSc) is a chronic autoimmune disease, marked by an unpredictable course, high morbidity, and increased mortality risk that occurs especially in the diffuse and rapidly progressive forms of the disease, characterized by fibrosis of the skin and internal organs and endothelial dysfunction. Recent studies suggest that the identification of altered metabolic pathways may play a key role in understanding the pathophysiology of the disease. Therefore, metabolomics might be pivotal in a better understanding of these pathogenic mechanisms. Methods: Through a systematic review of the literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA), searches were done in the PubMed, EMBASE, Web of Science, and Scopus databases from 2000 to September 2022. Three researchers independently reviewed the literature and extracted the data based on predefined inclusion and exclusion criteria. Results: Of the screened studies, 26 fulfilled the inclusion criteria. A total of 151 metabolites were differentially distributed between SSc patients and healthy controls (HC). The main deregulated metabolites were those derived from amino acids, specifically homocysteine (Hcy), proline, alpha-N-phenylacetyl-L-glutamine, glutamine, asymmetric dimethylarginine (ADMA), citrulline and ornithine, kynurenine (Kyn), and tryptophan (Trp), as well as acylcarnitines associated with long-chain fatty acids and tricarboxylic acids such as citrate and succinate. Additionally, differences in metabolic profiling between SSc subtypes were identified. The diffuse cutaneous systemic sclerosis (dcSSc) subtype showed upregulated amino acid-related pathways involved in fibrosis, endothelial dysfunction, and gut dysbiosis. Lastly, potential biomarkers were evaluated for the diagnosis of SSc, the identification of the dcSSc subtype, pulmonary arterial hypertension, and interstitial lung disease. These potential biomarkers are within amino acids, nucleotides, carboxylic acids, and carbohydrate metabolism. Discussion: The altered metabolite mechanisms identified in this study mostly point to perturbations in amino acid-related pathways, fatty acid beta-oxidation, and in the tricarboxylic acid cycle, possibly associated with inflammation, vascular damage, fibrosis, and gut dysbiosis. Further studies in targeted metabolomics are required to evaluate potential biomarkers for diagnosis, prognosis, and treatment response.

Abundance and sources of particulate polycyclic aromatic hydrocarbons and aromatic acids at an urban site in central China

We conducted a simultaneous field study of PM2.5-bound particulate polycyclic aromatic hydrocarbons (PAHs) and aromatic acids (AAs) in a polluted city Zhengzhou to explore the concentration, sources and potential conversion pathways between PAHs and AAs in different seasons. The average concentrations of PM2.5, 28PAHs and 8AAs during the sampling period were 77 µg/m3, 75 ng/m3, and 283 ng/m3, respectively. The concentration of both 28PAHs and 8AAs were highest in winter and lowest in summer with ratios of 6.3 and 2.3, respectively. PAHs with 5–7 rings were the main components of PAHs (52%), followed by 4 rings PAHs (30%) and 2–3 rings PAHs (18%). According to the source appointment results obtained by positive matrix factorization, the main sources of PAHs were combustion and vehicle emissions, which account for 37% and 34%, respectively. 8AAs were divided into three groups, including four benzene dicarboxylic acids (B2CAs), three benzene tricarboxylic acids (B3CAs) and one benzene tetracarboxylic acid (B4CA). And interspecies correlation analysis with PM2.5 source markers were used to investigate potential sources. Phthalic acid (o-Ph) was the most abundant specie of 8AAs (157 ng/m3, 55% of 8AAs), which was well correlated with sulfate. Meanwhile, B3CAs and B4CA were highly correlated with sulfate and weakly correlated with levoglucosan, suggesting that secondary formation was their main source. As logical oxidation products of PAHs, o-Ph and B3CAs showed good correlations with a number of PAHs, indicating possible photochemical oxidation pathway by PAHs. In addition, O3, NO2, temperature and relative humidity have positive effects on the secondary formation of B3CAs.

Differentiation of obese and healthy mice by analyzing the carboxylic acids in the TCA cycle in their feces

The tricarboxylic acid cycle is an important metabolic route in almost all living bodies, yet current analytical methods for the detection of the relevant tricarboxylic acids (TCAs) in biological samples are still unsatisfactory due to their complex matrix and physicochemical properties. In this work, a sample method based on solid phase extraction (SPE) in conjunction with liquid chromatography-mass spectrometry (LC-MS) analysis has been developed for the simultaneous determination of 7 TCAs, including α-ketoglutaric acid, malic acid, malonic acid, aconitic acid, citric acid, succinic acid and fumaric acid, in mice faeces. By treatment with macroporous styrene chelate resin and solid phase extraction, the matrix in mice feces was selectively and efficiently removed. Under optimized parameters, the limit of quantitation for the TCAs was in the range of 1-50 ng/mL, and the content of the TCAs in mice feces was determined with a recovery range of 76.2 % to 128.4 %. Interestingly, the content of malic acid, malonic acid, succinic acid and fumaric acid in the normal mice's feces was found to be 2-10 times higher than that of obese mice, indicating a new potential method for the diagnosis of obesity.

The potential of metabolomics in meat science: Current applications, trends, and challenges

Metabolites are the final products of metabolism and provide insights into the biochemical balance of tissue systems. A cascade of reactions involving proteins, carbohydrates, and lipids affects meat color, tenderness, and flavor, specifically, metabolites that are key biomolecules in biochemical reactions associated with attainment of acceptable meat quality. Bioinformatics platforms, such as Kyoto Encyclopedia of Genes and Genomes (KEGG) databases and MetaboAnalyst, are utilized to help understanding the role of differentially abundant metabolites and characterizing their roles in cellular function/metabolism. However, the inability to identify all metabolites using a single platform and limited metabolite libraries specifically for meat/food remains a challenge. Therefore, the advances in metabolite separation, easy-to-use data processing, increased resolution of mass-spectrometry, and data analysis will help to make inferences or develop biomarkers related to meat quality. This review discusses how metabolomics can be exploited to characterize meat quality, the challenges, and current trends. SignificanceMetabolites play an important role in attaining consumer-preferred meat quality traits and nutritive value of foods. Visual appearance of fresh foods, such as muscle foods, are utilized by consumers to assess the quality at the retail market before making purchases. Similarly, tenderness and flavor of meats influence eating satisfaction and re-purchase decisions. Inconsistencies in meat quality lead to enormous economic losses to the food industry. For instance, consumers often associate a bright-cherry red color with freshness, and the US beef industry loses $3.74 billion annually due to discoloration during storage. Both pre-and post-harvest factors influence the extent of meat quality changes. Metabolomics offer robust tools to get a snapshot of small molecules such as acids, amino acids, glycolytic- and tricarboxylic acids, fatty acids, and sugars present in post-mortem muscle tissue and their role in meat quality. Further, using bioinformatics platforms enables characterizing the role of differentially present metabolites in meat quality as well as identifying biomarkers for desirable quality traits such as tender meat or color-stable carcasses. Innovative applications of metabolomics can be exploited to elucidate the underpinnings of meat quality and to develop novel strategies to enhance marketability of retail fresh meats.

Mitoregulin Contributes to Creatine Shuttling and Cardiolipin Protection in Mice Muscle.

Small peptides compose a large share of the mitochondrial proteome. Mitoregulin (Mtln) is a mitochondrial peptide known to contribute to the respiratory complex I functioning and other processes in mitochondria. In our previous studies, we demonstrated that Mtln knockout mice develop obesity and accumulate triglycerides and other oxidation substrates in serum, concomitant with an exhaustion of tricarboxylic acids cycle intermediates. Here we examined the functional role of Mtln in skeletal muscles, one of the major energy consuming tissues. We observed reduced muscle strength for Mtln knockout mice. Decrease of the mitochondrial cardiolipin and concomitant increase in monolysocardiolipin concentration upon Mtln inactivation is likely to be a consequence of imbalance between oxidative damage and remodeling of cardiolipin. It is accompanied by the mitochondrial creatine kinase octamer dissociation and suboptimal respiratory chain performance in Mtln knockout mice.

Hereditary definiteness of aspartate aminotransferase level in Holstein cattle

Farm animals’ growth, development and realization of productive qualities are closely interrelated by enzymatic transformations of amino acids, proteins and other complex nitrogenous compounds. Aspartate aminotransferase (AsT) is involved in the metabolism of amino acids in the cycles of urea, tricarboxylic acids and gluconeogenesis. The level of AsT in the blood depends on many paratypical and genetic factors. The paper presents the results of a biochemical analysis of the AsT content in the blood serum of Holstein bulls aged 12-13 months, who are descendants of 4 breeding bulls. Blood sampling was carried out in animals with a live weight of 330-365 kg, bred in the conditions of a large livestock enterprise located in Western Siberia. The level of AsT in the blood serum of animals was determined by the Reitman-Frenkel colourimetric method using reagents “Transaminase AsT Novo” (manufacturer “Vector-Best” Russia). It was found that the average value of the AsT content in the groups of sons was lower than the generally accepted physiological norm and, for all descendants, was 22.44 ± 1.29 E/l. The reference interval for AsT based on the central 95% percentile with 90% confidence intervals was 12.29 (8.67...15.91) - 34.84(31.2... 38.5) E/l. The descendants of different fathers had different phenotypic variability of the indicator and differed in the level of AST. Thus, the descendants of the bull-producer Brio were characterized by a higher level compared to the sons of the bulls Malstrem and Fabio by 1.69 and 1.8 times, respectively. The revealed differences indicate the hereditary determination of the AsT level in Holstein cattle. The strength of the influence of the father’s factor was 0.18.

Molecular Profiling of Athletes Performing High-Intensity Exercises in Extreme Environments.

The aim of this study was to determine the influence of high-intensity training under extreme conditions (T = 40 °C) on the metabolism and immunological reactions of athletes. Male triathletes (n = 11) with a high level of sports training performed load testing to failure (17 ± 2.7 min) and maximum oxygen consumption (64.1 ± 6.4 mL/min/kg). Blood plasma samples were collected before and immediately after exercise. Mass spectrometric metabolomic analysis identified 30 metabolites and 6 hormones in the plasma, of which 21 and 4 changed after exercise, respectively. Changes in the intermediate products of tricarboxylic and amino acids were observed (FC > 1.5) after exercise. The obtained data can be associated with the effect of physical activity on metabolism in athletes. Therefore, constant monitoring of the biochemical parameters of athletes can help coaches identify individual shortcomings in a timely manner and track changes, especially as the volume of training increases. In addition, it was revealed that the immunological reaction (manifestation of a hyperactive reaction to food components) is personalized in nature. Therefore, it is important for coaches and sports doctors to analyze and control the eating behavior of athletes to identify food intolerances or food allergies in a timely manner and develop an individual elimination diet.

THE ENERGY OF ACTIVATION FOR ACCELERATORS AND STABILIZERS IN ELECTROLESS COPPER COATING

The inhibition efficiency of various stabilizers and the enhancing behavior of accelerators were studied by gravimetric analysis in electroless copper plating which is quite in need for industrial applications like electronics industries, very large-scale industries, oil, and textile field. The effect of temperature ranging from 303 K to 343 K could be understood from the Arrhenius plot. The activation energy (Ea) for the stabilizers employed showed a higher value in comparison with blank baths, thus exhibiting the inhibition property of the stabilizers. In a similar way, the accelerators possess higher activation energy for monocarboxylic acid than di and tricarboxylic acids. The trend obtained in the Arrhenius plot correlates well with Tafel polarization studies.