Tanshinone analog inhibits castration-resistant prostate cancer cell growth by inhibiting glycolysis in an AR-dependent manner

Androgen receptor (AR) is one of the key targets for the treatment of castration-resistant prostate cancer (CRPC). Current endocrine therapy can greatly improve patients with CRPC. However, with the change of pathogenic mechanism, acquired resistance often leads to the failure of treatment. Studies have shown that tanshinone IIA (TS-IIA) and its derivatives have significant antitumor activity, and have certain AR-targeting effects, but the mechanism is unknown. In this study, the TS-IIA analog TB3 was found to significantly inhibit the growth of CRPC in vitro and in vivo. Molecular docking, cellular thermal shift assay, and cycloheximide experiments confirmed that AR was the target of TB3 and promoted the degradation of AR. Furthermore, TB3 can significantly inhibit glycolysis metabolism by targeting the AR/PKM2 axis. The addition of pyruvic acid could significantly alleviate the inhibitory effect of TB3 on CRPC cells. Besides, the knockdown of AR or PKM2 also could reverse the effect of TB3 on CRPC cells. Taken together, our study suggests that TS-IIA derivative TB3 inhibits glycolysis to prevent the CRPC process by targeting the AR/PKM2 axis.

Simultaneous Analysis of Organic Acids, Glycerol and Phenolic Acids in Wines Using Gas Chromatography-Mass Spectrometry

Fermented beverages, particularly wines, exhibit variable concentrations of organic and phenolic acids, posing challenges in their accurate determination. Traditionally, enzymatic methods or chromatographic analyses, mainly high-performance liquid chromatography (HPLC), have been employed to quantify these compounds individually in the grape must or wine. However, chromatographic analyses face limitations due to the high sugar content in the grape must. Meanwhile, phenolic acids, found in higher quantities in red wines than in white wines, are typically analyzed using HPLC. This study presents a novel method for the quantification of organic acids (OAs), glycerol, and phenolic acids in grape musts and wines. The approach involves liquid-liquid extraction with ethyl acetate, followed by sample derivatization and analysis using gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) detection mode. The results indicated successful detection and quantification of all analyzed compounds without the need for sample dilution. However, our results showed that the method of adding external standards was more suitable for quantifying wine compounds, owing to the matrix effect. Furthermore, this method is promising for quantifying other metabolites present in wines, depending on their extractability with ethyl acetate. Fermented beverages, particularly wines, exhibit variable concentrations of organic and phenolic acids, posing challenges in their accurate determination. Traditionally, enzymatic methods or chromatographic analyses, mainly high-performance liquid chromatography (HPLC), have been employed to quantify these compounds individually in the grape must or wine. The approach of this proposed method involves (i) methoximation of wine compounds in a basic medium, (ii) acidification with HCl, (iii) liquid-liquid extraction with ethyl acetate, and (iv) silyl derivatization to analyze samples with gas chromatography-mass spectrometry (GC-MS) in ion monitoring detection mode (SIM). The results indicated successful detection and quantification of all analyzed compounds without the need for sample dilution. However, our results showed that the method of adding external standards was more suitable for quantifying wine compounds, owing to the matrix effect. Furthermore, this method is promising for quantifying other metabolites present in wines, depending on their extractability with ethyl acetate. In other words, the proposed method may be suitable for profiling (targeted) or fingerprinting (untargeted) strategies to quantify wine metabolites or to classify wines according to the type of winemaking process, grape, or fermentation.

Phytochemical Profile of Trigonella caerulea (Blue Fenugreek) Herb and Quantification of Aroma-Determining Constituents

The herb of Trigonella caerulea (Fabaceae), commonly known as blue fenugreek, is used for the production of traditional cheese and bread varieties in the Alpine region. Despite its frequent consumption, only one study so far has focused on the constituent pattern of blue fenugreek, revealing qualitative information on some flavor-determining constituents. However, with regard to the volatile constituents present in the herb, the applied methods were insufficient and did not take relevant terpenoids into account. In the present study, we analyzed the phytochemical composition of T. caerulea herb applying a set of analytical methods, such as headspace-GC, GC-MS, LC-MS, and NMR spectroscopy. We thus determined the most dominant primary and specialized metabolites and assessed the fatty acid profile as well as the amounts of taste-relevant α-keto acids. In addition, eleven volatiles were quantified, of which tiglic aldehyde, phenylacetaldehyde, methyl benzoate, n-hexanal, and trans-menthone were identified as most significantly contributing to the aroma of blue fenugreek. Moreover, pinitol was found accumulated in the herb, whereas preparative works led to the isolation of six flavonol glycosides. Hence, our study shows a detailed analysis of the phytochemical profile of blue fenugreek and provides an explanation for its characteristic aroma and its health-beneficial effects.

The Effects of Iron on In Silico Simulated Abiotic Reaction Networks

Iron is one of the most abundant elements in the Universe and Earth's surfaces, and undergoes a redox change of approximately 0.77 mV in changing between its +2 and +3 states. Many contemporary terrestrial organisms are deeply connected to inorganic geochemistry via exploitation of this redox change, and iron redox reactions and catalysis are known to cause significant changes in the course of complex abiotic reactions. These observations point to the question of whether iron may have steered prebiotic chemistry during the emergence of life. Using kinetically naive in silico reaction modeling we explored the potential effects of iron ions on complex reaction networks of prebiotic interest, namely the formose reaction, the complexifying degradation reaction of pyruvic acid in water, glucose degradation, and the Maillard reaction. We find that iron ions produce significant changes in the connectivity of various known diversity-generating reaction networks of proposed prebiotic significance, generally significantly diversifying novel molecular products by ~20%, but also adding the potential for kinetic effects that could allow iron to steer prebiotic chemistry in marked ways.

The Production of Pyruvate in Biological Technology: A Critical Review

Pyruvic acid has numerous applications in the food, chemical, and pharmaceutical industries. The high costs of chemical synthesis have prevented the extensive use of pyruvate for many applications. Metabolic engineering and traditional strategies for mutation and selection have been applied to microorganisms to enhance their ability to produce pyruvate. In the past decades, different microbial strains were generated to enhance their pyruvate production capability. In addition to the development of genetic engineering and metabolic engineering in recent years, the metabolic transformation of wild-type yeast, E. coli, and so on to produce high-yielding pyruvate strains has become a hot spot. The strategy and the understanding of the central metabolism directly related to pyruvate production could provide valuable information for improvements in fermentation products. One of the goals of this review was to collect information regarding metabolically engineered strains and the microbial fermentation processes used to produce pyruvate in high yield and productivity.

Microdermabrasion with 40% Pyruvic Acid on Biomechanical Skin Parameters in the Treatment of Acne Vulgaris

The synergy of cosmetic acids, with their keratolytic and antibacterial properties, with the mechanical exfoliation of the epidermis brings faster and better treatment results. The aim of the study was to compare the effects of using only pyruvic acid and the synergy of microdermabrasion and chemical exfoliation. In total, 14 women diagnosed with acne took part in the study. Two areas were marked on the participants' faces: the right side (microdermabrasion treatment and a preparation containing pyruvic acid 40%) and the left side (preparation containing pyruvic acid 40%) without mechanical exfoliation. A series of four treatments was performed at 2-week intervals. Skin parameters such as stratum corneum hydration and sebum secretion were measured. Before the treatments, all patients had moderate acne according to GAGS (Min: 19, Max: 22, Md: 20), and after the treatments, it decreased to mild acne according to GAGS (Min: 13, Max: 17, Md: 140). On the right side of the face, there was a statistically significant reduction in sebum secretion in all the examined areas of the face and increase in the hydration of the stratum corneum. On the left side of the face, the differences were also observed in the decrease of sebum value and increase of hydration level; however, they were smaller than on the right side. The use of microdermabrasion in combination with pyruvic acid led to better results in the case of increased hydration and reduction of sebum secretion than using only pyruvic acid treatment.

Urine NMR Metabolomics for Precision Oncology in Colorectal Cancer

Metabolomics is a fundamental approach to discovering novel biomarkers and their potential use for precision medicine. When applied for population screening, NMR-based metabolomics can become a powerful clinical tool in precision oncology. Urine tests can be more widely accepted due to their intrinsic non-invasiveness. Our review provides the first exhaustive evaluation of NMR metabolomics for the determination of colorectal cancer (CRC) in urine. A specific search in PubMed, Web of Science, and Scopus was performed, and 10 studies met the required criteria. There were no restrictions on the query for study type, leading to not only colorectal cancer samples versus control comparisons, but also prospective studies of surgical effects. With this review, all compounds in the included studies were merged into a database. In doing so, we identified up to 100 compounds in urine samples, and 11 were found in at least three articles. Results were analyzed in three groups: case (CRC and adenomas)/control, pre-/post-surgery, and combining both groups. When combining the case-control and the pre-/post-surgery groups, up to twelve compounds were found to be relevant. Seven down-regulated metabolites in CRC were identified, creatinine, 4-hydroxybenzoic acid, acetone, carnitine, d-glucose, hippuric acid, l-lysine, l-threonine, and pyruvic acid, and three up-regulated compounds in CRC were identified, acetic acid, phenylacetylglutamine, and urea. The pathways and enrichment analysis returned only two pathways significantly expressed: the pyruvate metabolism and the glycolysis/gluconeogenesis pathway. In both cases, only the pyruvic acid (down-regulated in urine of CRC patients, with cancer cell proliferation effect in the tissue) and acetic acid (up-regulated in urine of CRC patients, with chemoprotective effect) were present.

Aqueous Photochemistry of 2-Oxocarboxylic Acids: Evidence, Mechanisms, and Atmospheric Impact

Atmospheric organic aerosols play a major role in climate, demanding a better understanding of their formation mechanisms by contributing multiphase chemical reactions with the participation of water. The sunlight driven aqueous photochemistry of small 2-oxocarboxylic acids is a potential major source of organic aerosol, which prompted the investigations into the mechanisms of glyoxylic acid and pyruvic acid photochemistry reviewed here. While 2-oxocarboxylic acids can be contained or directly created in the particles, the majorities of these abundant and available molecules are in the gas phase and must first undergo the surface uptake process to react in, and on the surface, of aqueous particles. Thus, the work also reviews the acid-base reaction that occurs when gaseous pyruvic acid meets the interface of aqueous microdroplets, which is contrasted with the same process for acetic acid. This work classifies relevant information needed to understand the photochemistry of aqueous pyruvic acid and glyoxylic acid and motivates future studies based on reports that use novel strategies and methodologies to advance this field.

A bacterial effector protein uncovers a plant metabolic pathway involved in tolerance to bacterial wilt disease

Bacterial wilt caused by the soil-borne plant pathogen Ralstonia solanacearum is a devastating disease worldwide. Upon plant colonization, R. solanacearum replicates massively, causing plant wilting and death; collapsed infected tissues then serve as a source of inoculum. In this work, we show that the plant metabolic pathway mediated by pyruvate decarboxylases (PDCs) contributes to plant tolerance to bacterial wilt disease. Arabidopsis and tomato plants respond to R. solanacearum infection by increasing PDC activity, and plants with deficient PDC activity are more susceptible to bacterial wilt. Treatment with either pyruvic acid or acetic acid (substrate and product of the PDC pathway, respectively) enhances plant tolerance to bacterial wilt disease. An effector protein secreted by R. solanacearum, RipAK, interacts with PDCs and inhibits their oligomerization and enzymatic activity. Collectively, our work reveals a metabolic pathway involved in plant resistance to biotic and abiotic stresses, and a bacterial virulence strategy to promote disease and the completion of the pathogenic life cycle.

Large Amplitude Motions of Pyruvic Acid (CH3-CO-COOH)

Torsional and rotational spectroscopic properties of pyruvic acid are determined using highly correlated ab initio methods and combining two different theoretical approaches: Second order perturbation theory and a variational procedure in three-dimensions. Four equilibrium geometries of pyruvic acid, Tc, Tt, Ct, and CC, outcome from a search with CCSD(T)-F12. All of them can be classified in the C_s point group. The variational calculations are performed considering the three internal rotation modes responsible for the non-rigidity as independent coordinates. More than 50 torsional energy levels (including torsional subcomponents) are localized in the 406-986 cm^-1 region and represent excitations of the ν₂₄ (skeletal torsion) and the ν₂₃ (methyl torsion) modes. The third independent variable, the OH torsion, interacts strongly with ν₂₃. The A₁/E splitting of the ground vibrational state has been evaluated to be 0.024 cm^-1 as it was expected given the high of the methyl torsional barrier (338 cm^-1). A very good agreement with respect to previous experimental data concerning fundamental frequencies (ν^CAL - ν^EXP ~ 1 cm^-1), and rotational parameters (B₀^CAL - B₀^EXP < 5 MHz), is obtained.

Pyruvate Production by Escherichia coli by Use of Pyruvate Dehydrogenase Variants

Altering metabolic flux at a key branch point in metabolism has commonly been accomplished through gene knockouts or by modulating gene expression. An alternative approach to direct metabolic flux preferentially toward a product is decreasing the activity of a key enzyme through protein engineering. In Escherichia coli, pyruvate can accumulate from glucose when carbon flux through the pyruvate dehydrogenase complex is suppressed. Based on this principle, 16 chromosomally expressed AceE variants were constructed in E. coli C and compared for growth rate and pyruvate accumulation using glucose as the sole carbon source. To prevent conversion of pyruvate to other products, the strains also contained deletions in two nonessential pathways: lactate dehydrogenase (ldhA) and pyruvate oxidase (poxB). The effect of deleting phosphoenolpyruvate synthase (ppsA) on pyruvate assimilation was also examined. The best pyruvate-accumulating strains were examined in controlled batch and continuous processes. In a nitrogen-limited chemostat process at steady-state growth rates of 0.15 to 0.28 h-1, an engineered strain expressing the AceE[H106V] variant accumulated pyruvate at a yield of 0.59 to 0.66 g pyruvate/g glucose with a specific productivity of 0.78 to 0.92 g pyruvate/g cells·h. These results provide proof of concept that pyruvate dehydrogenase complex variants can effectively shift carbon flux away from central carbon metabolism to allow pyruvate accumulation. This approach can potentially be applied to other key enzymes in metabolism to direct carbon toward a biochemical product. IMPORTANCE Microbial production of biochemicals from renewable resources has become an efficient and cost-effective alternative to traditional chemical synthesis methods. Metabolic engineering tools are important for optimizing a process to perform at an economically feasible level. This study describes an additional tool to modify central metabolism and direct metabolic flux to a product. We have shown that variants of the pyruvate dehydrogenase complex can direct metabolic flux away from cell growth to increase pyruvate production in Escherichia coli. This approach could be paired with existing strategies to optimize metabolism and create industrially relevant and economically feasible processes.

Estimation of serum pyruvic acid levels in oral squamous cell carcinoma

Introduction:

Cancer cells generally exhibit increased glycolysis for adenosine triphosphate generation (the Warburg effect) due to mitochondrial respiration injury and hypoxia, which are frequently associated with resistance to therapeutic agents. Pyruvic acid is produced as an end product of glycolysis along with lactic acid. At room temperature, lactic acid converts into pyruvic acid as it is chemically unstable.

Aim:

To evaluate the serum pyruvic acid levels in patients with oral squamous cell carcinoma (OSCC).

Materials and Methods:

Thirty clinically and histopathologically confirmed cases of OSCC were included in the study. The cases were staged clinically (tumor–node–metastasis staging) and graded histopathologically (modified Broder's classification). A control group of 30 age-matched individuals with no systemic diseases were selected and the serum levels of pyruvic acid were measured and the absorbance was read using a spectrophotometer at a wavelength of 540 nm. The results were evaluated statistically and discussed.

Results:

Pair-wise comparison of clinical stages and histological grades of OSCC was done using Tukey's multiple post hoc procedure. The increase in mean serum pyruvic acid levels between any two groups and grades was found to be statistically significant respectively (P<0.05).

Conclusion:

Serum pyruvic acid levels gradually increased from individuals without OSCC to individuals with OSCC. Higher levels of serum pyruvic acid were seen with increasing clinical stage and the mean serum pyruvic acid levels were also found to be significantly increasing with advancing histopathological grades of OSCC.

Rehabilitation Improves Mitochondrial Energetics in Progressive Multiple Sclerosis: The Significant Role of Robot-Assisted Gait Training and of the Personalized Intensity

Abnormal levels of pyruvate and lactate were reported in multiple sclerosis (MS). We studied the response of markers of mitochondrial function to rehabilitation in relation to type, intensity and endurance performance in severely disabled MS patients. Forty-six progressive MS patients were randomized to receive 12 walking sessions of robot-assisted gait training (RAGT, n = 23) or conventional overground therapy (CT, n = 23). Ten healthy subjects were also studied. Blood samples were collected to determine lactate, pyruvate, and glutathione levels and lactate/pyruvate ratio pre–post rehabilitation. In vivo muscle metabolism and endurance walking capacity were assessed by resting muscle oxygen consumption (rmVO₂) using near-infrared spectroscopy and by six-minute walking distance (6MWD), respectively. The levels of mitochondrial biomarkers and rmVO₂, altered at baseline with respect to healthy subjects, improved after rehabilitation in the whole population. In the two groups, an enhanced response was observed after RAGT compared to CT for lactate (p = 0.012), glutathione (<0.001), lactate/pyruvate ratio (p = 0.08) and rmVO₂ (p = 0.07). Metabolic biomarkers and 6MWD improvements were exclusively correlated with a training speed markedly below individual gait speed. In severely disabled MS patients, rehabilitation rebalanced altered serum metabolic and muscle parameters, with RAGT being more effective than CT. A determinable slow training speed was associated with better metabolic and functional recovery. Trial Registration: ClinicalTrials.gov NCT02421731.

Variability in Bulb Organosulfur Compounds, Sugars, Phenolics, and Pyruvate among Greek Garlic Genotypes: Association with Antioxidant Properties

In order to assess the diversity of Greek garlic (Allium sativum L.) landraces, 34 genotypes including commercial ones were grown in the same field and their content in organosulfur compounds, pyruvate, total sugars, and total phenolics, alongside antioxidant capacity, was determined. The organosulfur compounds were studied by Gas Chromatography–Mass Spectrometry (GC–MS) after ultrasound-assisted extraction in ethyl acetate, identifying 2-vinyl-4H-1,3-dithiin and 3-vinyl-4H-1,2-dithiin as the predominant compounds, albeit in different ratios among genotypes. The bioactivity and the polar metabolites were determined in hydromethanolic extracts. A great variability was revealed, and nearly one-third of landraces had higher concentration of compounds determining bioactivity and organoleptic traits than the imported ones. We recorded strong correlations between pyruvate and total organosulfur compounds, and between antioxidant capacity and phenolics. In conclusion, chemical characterization revealed great genotype-dependent variation in the antioxidant properties and the chemical characters, identifying specific landraces with superior traits and nutritional and pharmaceutical value.

Examining Quality of Life After Treatment with Azelaic and Pyruvic Acid Peels in Women with Acne Vulgaris

Purpose

This randomized parallel study aims to investigate the azelaic acid (AA), and pyruvic acid (PA) peels treatment effect on health-related quality of life (QOL) in young adult women with acne vulgaris.

Patients and Methods

The participants were 120 female undergraduate students, with mild to moderate facial acne and an average age of 22 years old (M = 22.2, SD = 16.1). Eligibility criteria were as follows: female gender, 18–25 years of age, no dermatological treatment within the last 12 months and mild to moderate papulopustular acne. Patients were randomly divided into two groups, the first group was treated with AA, and the second group was treated with PA. Both groups received treatment every 2 weeks, for a total of 12 weeks. The Hellgren–Vincent scale was used to assess acne severity, and the Dermatology Life Quality Index (DLQI) and Skindex-29 were used to evaluate the quality of life of each patient. These scores were calculated before treatment, and after finishing the final treatment.

Results

All scoring systems used (Hellgren–Vincent scale, DLQI, and Skindex-29) demonstrated improvement in both groups. QOL scores were slightly better in the group using pyruvic acid compared with azelaic acid.

Conclusion

Both AA and PA have a significant impact on the objective assessment of acne symptoms, as well as the subjectively measured quality of life of young adult women with acne. There is a slightly greater improvement in QOL scores with PA compared with AA peeling treatment.

TiO2 Modified with Organic Acids for the Decomposition of Chlorfenvinphos under the Influence of Visible Light: Activity, Performance, Adsorption, and Kinetics

Photocatalytic decomposition of chlorfenvinphos (CFVP) in the presence of titanium dioxide (TiO₂) modified with organic acids: pyruvic (PA) and succinic (SA) under the visible light radiation has been studied. The following tests were examined: dose of photocatalysts, adsorption time, pH of the model solution, deactivation of catalysts, the role of oxygen, identification of free radicals for the CFVP decomposition, Langmuir-Hinshelwood kinetics. The synthesized materials were characterized by Scanning Electron Microscopy (SEM) and UV-Vis. At 10 wt.% of acid (90:10) decomposition of chlorfenvinphos was the most effective in the following conditions: dose of catalyst 50.0 mg/L, time of adsorption = 20 min, pH of model solution = 3.0. Under these conditions the order of photocatalyst efficiency has been proposed: TiO₂/PA/90:10 > TiO₂/SA/90:10 > TiO₂ with the removal degree of 85, 72 and 48%. The mathematically calculated half-life at this conditions was 27.0 min and 39.0 min for TiO₂/PA/90:10 and TiO₂/SA/90:10 respectively, compared to 98 min for pure TiO₂. It has been determined that the O₂^- radicals and holes (h⁺) are the main reactive species involved in the photodegradation of chlorfenvinphos. The results of this study showed that method may be an interesting alternative for the treatment of chlorfenvinphos contaminated wastewater.

The Effects of Reactant Concentration and Air Flow Rate in the Consumption of Dissolved O₂ during the Photochemistry of Aqueous Pyruvic Acid

The sunlight photochemistry of the organic chromophore pyruvic acid (PA) in water generates ketyl and acetyl radicals that contribute to the production and processing of atmospheric aerosols. The photochemical mechanism is highly sensitive to dissolved oxygen content, [O₂(aq)], among other environmental conditions. Thus, herein we investigate the photolysis (λ ≥ 305 nm) of 10–200 mM PA at pH 1.0 in water covering the relevant range 0 ≤ [O₂(aq)] ≤ 1.3 mM. The rapid consumption of dissolved oxygen by the intermediate photolytic radicals is monitored in real time with a dissolved oxygen electrode. In addition, the rate of O₂(aq) consumption is studied at air flow rates from 30.0 to 900.0 mL min⁻¹. For the range of [PA]₀ covered under air saturated conditions and 30 mL min⁻¹ flow of air in this setup, the estimated half-lives of O₂(aq) consumed by the photolytic radicals fall within the interval from 22 to 3 min. Therefore, the corresponding depths of penetration of O₂(g) into water (x = 4.3 and 1.6 µm) are determined, suggesting that accumulation and small coarse mode aqueous particles should not be O₂-depleted in the presence of sunlight photons impinging this kind of chromophore. These photochemical results are of major tropospheric relevance for understanding the formation and growth of secondary organic aerosol.

Pyruvic acid/ethyl pyruvate inhibits melanogenesis in B16F10 melanoma cells through PI3K/AKT, GSK3β, and ROS-ERK signaling pathways

Melanin is the main product of human melanocytes and functions to protect skin from ultraviolet (UV) radiation while conferring color to skin and hair. Tyrosinase is the rate-limiting enzyme for melanin synthesis along with tyrosinase-related protein (TRP)-1 and TRP-2. Microphthalmia-associated transcription factor regulates tyrosinase gene expression and is in turn regulated by extracellular signal-regulated kinase (ERK), phosphoinositide 3-kinase (PI3K)/AKT, and glycogen synthase kinase (GSK)3β signaling pathways. Pyruvic acid (PA) is an energy source for ATP synthesis in the tricarboxylic acid cycle that also acts as a reactive oxygen species (ROS) scavenger. As UV irradiation induces melanin synthesis and ROS generation, we speculated that PA or ethyl pyruvate (EP), a stable form of pyruvate, regulates melanogenesis. B16F10 melanoma cells served as a melanin synthesis model. Treatment with PA or EP suppressed melanin synthesis while increasing intracellular ROS levels, which was accompanied by increased ERK phosphorylation in the case of EP treatment. PA and EP induced GSK3β phosphorylation and activated PI3K/AKT signaling, leading to decreased melanin synthesis. These results indicate that PA and EP inhibit melanogenesis via PI3K/AKT and GSK3β signaling and targeting the ERK and GSK3β pathways, respectively. Thus, PA and EP can potentially be used for treatment of hyperpigmentation disorders.

Impact of Cultivation Method and Cultivar Selection on Soluble Carbohydrates and Pungent Principles in Onions ( Allium cepa L.)

The composition of soluble carbohydrates such as fructooligosaccharides (FOS) in onions ( Allium cepa L.) plays a role regarding their digestibility, long-term storability, and processability. Qualitative and quantitative profiles of soluble carbohydrates were determined in 23 different onion samples comprising 20 cultivars grown at two different locations in 2014 and 2015. FOS concentrations were 1.1-fold higher in set grown onions than in seed grown onions ( p = 0.001). FOS levels of dehydrator cultivars were higher (overall average: 130.8 ± 42.4 g/L FOS) than those of common set and seed (61.8 ± 20.0 and 29.4 ± 14.7 g/L FOS) grown cultivars. Consequently, cultivation method (seed vs. set planting) and cultivar selection were crucial when aiming at onions with defined FOS contents. Besides FOS and other carbohydrate-related parameters, levels of alk(en)yl cysteine sulfoxides, indicating onion oil yield and pungency of onions, were determined to be different in dehydrator onions (13.1 ± 2.6 μmol/mL), seed (8.4 ± 1.3 μmol/mL), and set grown onions (7.5 ± 1.6 μmol/mL).

Nutritional Value, Chemical Characterization and Bulb Morphology of Greek Garlic Landraces

Garlic (Allium sativum L.) is an important vegetable crop throughout the world. In Greece there are many areas which have specialized in garlic cultivation through the last decades, considered the main production areas. However, despite the significance of garlic as a food product and the high annual income of this crop, there is a decreasing trend in total cultivated area in Greece, and the local landraces are gradually neglected in favor of new imported genotypes. In the present study, garlic genotypes (local landraces/varieties, imported genotypes, commercial cultivars) from the main production regions of Greece were assessed for their chemical composition and quality (total soluble solids, dry matter content, nutritional value, mineral composition, organic acids, fatty acids content and free sugars content), and bulb morphology. The results of the present study showed significant diversity in quality features and bulb morphology, not only between the genotypes from different growing regions, but also between those of the same region. This result is interesting since it could be implemented for further improvement and valorization of this important vegetable crop through extensive breeding programs within the framework of sustainability and genetic, material conservation.

Yeast alter micro-oxygenation of wine: oxygen consumption and aldehyde production

BACKGROUND

Micro-oxygenation (MOx) is a common winemaking treatment used to improve red wine color development and diminish vegetal aroma, amongst other effects. It is commonly applied to wine immediately after yeast fermentation (phase 1) or later, during aging (phase 2). Although most winemakers avoid MOx during malolactic (ML) fermentation, it is often not possible to avoid because ML bacteria are often present during phase 1 MOx treatment. We investigated the effect of common yeast and bacteria on the outcome of micro-oxygenation.

RESULTS

Compared to sterile filtered wine, Saccharomyces cerevisiae inoculation significantly increased oxygen consumption, keeping dissolved oxygen in wine below 30 µg L^-1 during micro-oxygenation, whereas Oenococcus oeni inoculation was not associated with a significant impact on the concentration of dissolved oxygen. The unfiltered baseline wine also had both present, although with much higher populations of bacteria and consumed oxygen. The yeast-treated wine yielded much higher levels of acetaldehyde, rising from 4.3 to 29 mg L^-1 during micro-oxygenation, whereas no significant difference was found between the bacteria-treated wine and the filtered control. The unfiltered wine exhibited rapid oxygen consumption but no additional acetaldehyde, as well as reduced pyruvate. Analysis of the acetaldehyde-glycerol acetal levels showed a good correlation with acetaldehyde concentrations.

CONCLUSION

The production of acetaldehyde is a key outcome of MOx and it is dramatically increased in the presence of yeast, although it is possibly counteracted by the metabolism of O. oeni bacteria. Additional controlled experiments are necessary to clarify the interaction of yeast and bacteria during MOx treatments. Analysis of the glycerol acetals may be useful as a proxy for acetaldehyde levels. © 2017 Society of Chemical Industry.

The Combined Use of Schizosaccharomyces pombe and Lachancea thermotolerans-Effect on the Anthocyanin Wine Composition

The most popular methodology to make red wine is through the combined use of Saccharomyces cerevisiae yeast and lactic acid bacteria, for alcoholic fermentation and malolactic fermentation respectively. This classic winemaking practice produces stable red wines from a microbiological point of view. This study aims to investigate a recent red winemaking biotechnology, which through the combined use of Lachancea thermotolerans and Schizosaccharomyces pombe is used as an alternative to the classic malolactic fermentation. In this new methodology, Schizosaccharomycespombe totally consumes malic acid, while Lachancea thermotolerans produces lactic acid, avoiding excessive deacidification of musts with low acidity in warm viticulture areas such as Spain. This new methodology has been reported to be a positive alternative to malolactic fermentation in low acidity wines, since it has the advantage to produce wines with a more fruity flavor, less acetic acid, less ethyl carbamate originators and less biogenic amines than the traditional wines produced via conventional fermentation techniques. The study focuses on unexplored facts related to this novel biotechnology such as color and anthocyanin profile.

A New Chemical Pathway Yielding A-Type Vitisins in Red Wines

A new chemical pathway yielding A-type vitisins in red wines is proposed herein from the reaction between anthocyanins and oxaloacetic acid (OAA). This new chemical path is thought to occur in the first stages of the wine production even during the fermentation process. This is due to the revealed high reactivity of OAA with anthocyanins compared with the already known precursor (pyruvic acid, PA). In model solutions at wine pH (3.5), when malvidin-3-O-glucoside (mv-3-glc) is in contact with OAA and PA a decrease in the OAA concentration is observed along with the formation of A-type vitisin. Moreover, part of the OAA is also chemically converted into PA in model solutions. The reaction yields were also determined for OAA and PA using different mv-3-glc:organic acid molar ratios (1:0.5, 1:1, 1:5, 1:10; 1:50, and 1:100) and these values were always higher for OAA when compared to PA, even at the lowest molar ratio (1:0.5). The reaction yields were higher at pH 2.6 in comparison to pH 1.5 and 3.5, being less affected at pH 3.5 for OAA. These results support the idea that OAA can be at the origin of A-type vitisins in the first stages of wine production and PA in the subsequent ageing process.

Krebs Cycle Intermediates Protective against Oxidative Stress by Modulating the Level of Reactive Oxygen Species in Neuronal HT22 Cells

Krebs cycle intermediates (KCIs) are reported to function as energy substrates in mitochondria and to exert antioxidants effects on the brain. The present study was designed to identify which KCIs are effective neuroprotective compounds against oxidative stress in neuronal cells. Here we found that pyruvate, oxaloacetate, and α-ketoglutarate, but not lactate, citrate, iso-citrate, succinate, fumarate, or malate, protected HT22 cells against hydrogen peroxide-mediated toxicity. These three intermediates reduced the production of hydrogen peroxide-activated reactive oxygen species, measured in terms of 2′,7′-dichlorofluorescein diacetate fluorescence. In contrast, none of the KCIs—used at 1 mM—protected against cell death induced by high concentrations of glutamate—another type of oxidative stress-induced neuronal cell death. Because these protective KCIs did not have any toxic effects (at least up to 10 mM), they have potential use for therapeutic intervention against chronic neurodegenerative diseases.

Combined Use of S. pombe and L. thermotolerans in Winemaking. Beneficial Effects Determined Through the Study of Wines' Analytical Characteristics

The most common way to produce red wine is through the use of Saccharomyces cerevisiae strains for alcoholic fermentation and lactic acid bacteria for malolactic fermentation. This traditional winemaking methodology produces microbiologically stable red wines. However, under specific conditions off-flavours can occur, wine quality can suffer and human health problems are possible, especially after the second fermentation by the lactic acid bacteria. In warm countries, problems during the malolactic fermentation arise because of the high pH of the must, which makes it very difficult to properly control the process. Under such conditions, wines with high acetic acid and histamine concentrations are commonly produced. This study investigates a recent red wine-making technology that uses a combination of Lachancea thermotolerans and Schizosaccharomyces pombe as an alternative to the conventional malolactic fermentation. This work studies new parameters such as aroma compounds, amino acids, ethanol index and sensory evaluation. Schizosaccharomyces pombe totally consumes malic acid while Lachancea thermotolerans produces lactic acid, avoiding excessive deacidification of musts with low acidity in warm viticulture areas. This methodology also reduces the malolactic fermentation hazards in wines with low acidity. The main products are wines that contain less acetic acid, less biogenic amines and precursors and less ethyl carbamate precursors than the traditional wines produced via conventional fermentation techniques.

Metabolic Fate of the Carboxyl Groups of Malate and Pyruvate and their Influence on δ(13)C of Leaf-Respired CO2 during Light Enhanced Dark Respiration

The enhanced CO2 release of illuminated leaves transferred into darkness, termed "light enhanced dark respiration (LEDR)", is often associated with an increase in the carbon isotope ratio of the respired CO2 (δ(13)CLEDR). The latter has been hypothesized to result from different respiratory substrates and decarboxylation reactions in various metabolic pathways, which are poorly understood so far. To provide a better insight into the underlying metabolic processes of δ(13)CLEDR, we fed position-specific (13)C-labeled malate and pyruvate via the xylem stream to leaves of species with high and low δ(13)CLEDR values (Halimium halimifolium and Oxalis triangularis, respectively). During respective label application, we determined label-derived leaf (13)CO2 respiration using laser spectroscopy and the (13)C allocation to metabolic fractions during light-dark transitions. Our results clearly show that both carboxyl groups (C-1 and C-4 position) of malate similarly influence respiration and metabolic fractions in both species, indicating possible isotope randomization of the carboxyl groups of malate by the fumarase reaction. While C-2 position of pyruvate was only weakly respired, the species-specific difference in natural δ(13)CLEDR patterns were best reflected by the (13)CO2 respiration patterns of the C-1 position of pyruvate. Furthermore, (13)C label from malate and pyruvate were mainly allocated to amino and organic acid fractions in both species and only little to sugar and lipid fractions. In summary, our results suggest that respiration of both carboxyl groups of malate (via fumarase) by tricarboxylic acid cycle reactions or by NAD-malic enzyme influences δ(13)CLEDR. The latter supplies the pyruvate dehydrogenase reaction, which in turn determines natural δ(13)CLEDR pattern by releasing the C-1 position of pyruvate.

Quality and Composition of Airén Wines Fermented by Sequential Inoculation of Lachancea thermotolerans and Saccharomyces cerevisiae

This study evaluates the influence of Lachancea thermotolerans on low-acidity Airén grape must from the south of Spain. For this purpose, combined fermentations with Lachancea thermotolerans and Saccharomyces cerevisiae were compared to a single fermentation by S. cerevisiae. Results of all developed analyses showed significant differences in several parameters including acidity, population growth kinetics, concentration of amino acids, volatile and non-volatile compounds, and sensorial parameters. The Airén wine quality increased mainly due to the acidification by L. thermotolerans. The acidification process caused a lactic acid increment of 3.18 g/L and a reduction of 0.22 in pH compared to the control fermentation, performed by S. cerevisiae.

Comparison the effectiveness of pyruvic acid 50% and salicylic acid 30% in the treatment of acne

BACKGROUND

Acne vulgaris is a chronic inflammatory disease of the pilosebaceous follicles and one of the most common skin diseases. The peeling method has been recently found to be effective for acne treatment. This study aimed to compare the efficacy of pyruvic acid 50% and salicylic acid 30% peeling in the treatment of mild to moderate acne.

MATERIALS AND METHODS

In a prospective single-blinded clinical trial, 86 patients with acne were randomly assigned into two groups. In both groups, the routine treatment of acne (topical solution of erythromycin 4%, triclorocarban soap, and sunscreen) were used twice a day for 8 weeks. In addition, salicylic acid 30% for the control group and pyruvic acid 50% for the case group were used. In both groups, acne severity index (ASI) was calculated before and at week 2, 4, 6, and 8 of the treatment. Patient satisfaction was assessed at the end of the treatment. Side effects were recorded using a checklist.

RESULTS

In both groups, the reduction in the number of comedones, papules, and ASI were statistically significant (P < 0.001) in the course of treatment. However, it was not significant regarding the number of pustules (P = 0.09). None of the number of comedone, papules, pustules, and ASI was statistically different between study groups. Both treatment groups had similar side effects except for scaling in the fifth session, which was significantly lower in salicylic acid - treated patients (P = 0.015).

CONCLUSION

Both pyruvic acid 50% and salicylic acid 30% are effective in the improvement of mild to moderate acne with no significant difference in efficacy and side effects.

Determination of pKa and Hydration Constants for a Series of α-Keto-Carboxylic Acids Using Nuclear Magnetic Resonance Spectrometry

The determination of the acid-base dissociation constants, and thus the pKa values, of α-keto acids such as pyruvic acid is complex because of the existence of these acids in their hydrated and nonhydrated or oxo state. Equilibria involved in the hydration and dehydration of the α-keto group of pyruvic acid and three other α-keto acids, 3-methyl-2-oxobutanoic acid, 4-methyl-2-oxopentanoic acid, and 2-oxo-2-phenylacetic acid, were investigated by proton and carbon nuclear magnetic resonance spectrometry, at constant ionic strength, 0.15, and 25 °C. Dissociation constants for the oxo (pKa(oxo)) and hydrated (pKa(hyd)) acids of each compound were estimated from the change in the degree of hydration with changes in pH and directly from the changes in chemical shifts of various hydrogen and carbons nuclei with pH. α-Keto acids showed greater hydration in their acidic forms than their carboxylate forms. The degree of hydration was sensitive to steric and electronic/resonance factors. As expected, the oxo forms of the acids were stronger acids compared with their hydrated analogs, and their dissociation constants were also sensitive to steric and electronic factors.

Mechanism of Decarboxylation of Pyruvic Acid in the Presence of Hydrogen Peroxide

The purpose of this work was to probe the rate and mechanism of rapid decarboxylation of pyruvic acid in the presence of hydrogen peroxide (H2O2) to acetic acid and carbon dioxide over the pH range 2-9 at 25 °C, utilizing UV spectrophotometry, high performance liquid chromatography (HPLC), and proton and carbon nuclear magnetic resonance spectrometry ((1)H, (13)C-NMR). Changes in UV absorbance at 220 nm were used to determine the kinetics as the reaction was too fast to follow by HPLC or NMR in much of the pH range. The rate constants for the reaction were determined in the presence of molar excess of H2O2 resulting in pseudo first-order kinetics. No buffer catalysis was observed. The calculated second-order rate constants for the reaction followed a sigmoidal shape with pH-independent regions below pH 3 and above pH 7 but increased between pH 4 and 6. Between pH 4 and 9, the results were in agreement with a change from rate-determining nucleophilic attack of the deprotonated peroxide species, HOO(-), on the α-carbonyl group followed by rapid decarboxylation at pH values below 6 to rate-determining decarboxylation above pH 7. The addition of H2O2 to ethyl pyruvate was also characterized.

Flavonol Glucoside and Antioxidant Enzyme Biosynthesis Affected by Mycorrhizal Fungi in Various Cultivars of Onion (Allium cepa L.)

The objective of this study was to investigate the impact of mycorrhizal symbiosis on qualitative characteristics of onion (Allium cepa L.). For this reason, five onion cultivars with different scale color and three different strains of arbuscular mycorrhizal fungi (Diversispora versiformis, Rhizophagus intraradices, Funneliformis mosseae) were used. Red cultivars, mainly 'Red Azar-shahr', showed the highest content in vitamin C, flavonols, and antioxidant enzymes. Mycorrhizal inoculation increased total phenolic, pyruvic acid, and vitamin C of onion plants. Considerable increase was observed in quercetin-4'-O-monoglucoside and isorhamnetin-4'-O-monoglucoside content in plants inoculated with Diversispora versiformis, but quercetin-3,4'-O-diglucoside was not significantly influenced. Analyses for phenylalanine ammonia-lyase (PAL) and antioxiodant enzyme activities such as polyphenol oxidase (PPO), catalase (CAT), and peroxidase (POD) revealed that all except PPO were enhanced by mycorrhizal inoculation. Overall, these findings suggested that mycorrhizal inoculation influenced biosynthesis of flavonol glucosides and antioxidant enzymes by increasing nutrient uptake or by induction of the plant defense system.

Pyruvic acid levels in serum and saliva: A new course for oral cancer screening?

OBJECTIVE

Cancerous cells show increased glycolysis rate. This will increase overall levels of pyruvate as it is one of the end products of glycolysis. The present on-going study is to estimate the levels of pyruvate in saliva and serum among healthy and oral cancer subjects.

SETTINGS AND DESIGN

Hospital-based cross-sectional comparative study.

METHODOLOGY

A total of 50 subjects among healthy and oral cancer subjects were selected based on clinical and histological criteria. Saliva and serum samples were collected and subjected to pyruvate level estimation using biochemical analysis.

STATISTICAL ANALYSIS

Descriptive analysis and Mann-Whitney test were used to find the statistical difference between the two independent groups.

RESULTS

Serum pyruvic acid levels of the healthy group were 1.09 ± 0.14 and for oral cancer, it was 2.95 ± 0.59 and salivary level were 3.49 ± 0.47 and 1.32 ± 0.10 respectively. Mann-Whitney test showed statistically significant difference in serum and salivary pyruvate level in between two groups (P < 0.000 respectively).

CONCLUSION

The present study showed noticeable variation in the level of pyruvic acid among healthy and oral cancer subjects. This generates the hypothesis that estimation of the pyruvic acid can be a new tool to screening of the cancer.

Toxicity of aerosols of nicotine and pyruvic acid (separate and combined) in Sprague-Dawley rats in a 28-day OECD 412 inhalation study and assessment of systems toxicology

Toxicity of nebulized nicotine (Nic) and nicotine/pyruvic acid mixtures (Nic/Pyr) was characterized in a 28-day Organization for Economic Co-operation and Development 412 inhalation study with additional transcriptomic and lipidomic analyses. Sprague-Dawley rats were nose-only exposed, 6 h/day, 5 days/week to filtered air, saline, nicotine (50 µg/l), sodium pyruvate (NaPyr, 33.9 µg/l) or equimolar Nic/Pyr mixtures (18, 25 and 50 µg nicotine/l). Saline and NaPyr caused no health effects, but rats exposed to nicotine-containing aerosols had decreased body weight gains and concentration-dependent increases in liver weight. Blood neutrophil counts were increased and lymphocyte counts decreased in rats exposed to nicotine; activities of alkaline phosphatase and alanine aminotransferase were increased, and levels of cholesterol and glucose decreased. The only histopathologic finding in non-respiratory tract organs was increased liver vacuolation and glycogen content. Respiratory tract findings upon nicotine exposure (but also some phosphate-buffered saline aerosol effects) were observed only in the larynx and were limited to adaptive changes. Gene expression changes in the lung and liver were very weak. Nic and Nic/Pyr caused few significant changes (including Cyp1a1 gene upregulation). Changes were predominantly related to energy metabolism and fatty acid metabolism but did not indicate an obvious toxicity-related response. Nicotine exposure lowered plasma lipids, including cholesteryl ester (CE) and free cholesterol and, in the liver, phospholipids and sphingolipids. Nic, NaPyr and Nic/Pyr decreased hepatic triacylglycerol and CE. In the lung, Nic and Nic/Pyr increased CE levels. These data suggest that only minor biologic effects related to inhalation of Nic or Nic/Pyr aerosols were observed in this 28-day study.

Reactivity of pyruvic acid and its derivatives towards reactive oxygen species

Pyruvic acid and its derivatives occurring in most biological systems are known to exhibit several pharmacological properties, such as anti-inflammatory, neuroprotective or anticancer, many of which are suggested to originate from their antioxidant and free radical scavenger activity. The therapeutic potential of these compounds is a matter of particular interest, due to their mechanisms of action, particularly their possible antioxidant behaviour. Here, we report the results of a study of the effect of pyruvic acid (PA), ethyl pyruvate (EP) and sodium pyruvate (SP) on reactions generating reactive oxygen species (ROS), such as superoxide anion radicals, hydroxyl radicals and singlet oxygen, and their total antioxidant capacity. Chemiluminescence (CL) and spectrophotometry techniques were employed. The pyruvate analogues studied were found to inhibit the CL signal arising from superoxide anion radicals in a dose-dependent manner with IC50 = 0.0197 ± 0.002 mM for EP and IC50 = 69.2 ± 5.2 mM for PA. These compounds exhibited a dose-dependent decrease in the CL signal of the luminol + H2O2 system over the range 0.5-10 mM with IC50 values of 1.71 ± 0.12 mM for PA, 3.85 ± 0.21 mM for EP and 22.91 ± 1.21 mM for SP. Furthermore, these compounds also inhibited hydroxyl radical-dependent deoxyribose degradation in a dose-dependent manner over the range 0.5-200 mM, with IC50 values of 33.2 ± 0.3 mM for SP, 116.1 ± 6.2 mM for EP and 168.2 ± 6.2 mM for PA. All the examined compounds also showed antioxidant capacity when estimated using the ferric-ferrozine assay. The results suggest that the antioxidant activities of pyruvate derivatives may reflect a direct effect on scavenging ROS and, in part, be responsible for their pharmacological actions.

Hyperlactatemia caused by intra-venous administration of glycerol: A case study

Glyceol(®) is an intracranial pressure reducing agent composed of 5% fructose and concentrated glycerol. Although rapid administration of fructose is known to cause lactic acidosis, little is known about hyperlactatemia caused by Glyceol(®) administration itself in adults. We observed an adult case of hyperlactatemia occurred after administration of 200 mL of Glyceol(®) over a period of 30 minutes. Since there was no evidence of an underlying liver disease or metabolic abnormality, and no findings of sepsis or impaired tissue perfusion, the cause of this condition was deemed to be the rapid loading of fructose contained as a constituent of Glyceol(®). We then performed a retrospective chart review and found other 9 cases admitted to Jichi Medical University Hospital ICU and administered Glyceol(®) during the past year. Their lactate levels increased in general, peaked approximately 45 minutes after Glyceol(®) administration and returned to pre-administration levels around 3 hours after. Although hyperlactatemia is an important indicator of sepsis and impaired tissue perfusion, caution is required when performing such an assessment in patients being administered Glyceol(®).

Influence of organic supplements on production of shoot and callus biomass and accumulation of bacoside in Bacopa monniera (L.) Pennell

Production of valuable secondary metabolites through plant cell or organ culture is the best suited alternative to extraction of whole plant material and to increase production of secondary metabolites in in-vitro systems, feeding precursor or intermediate metabolites is an obvious and popular approach. The present investigation was aimed to study the influence of feeding of organic supplements, glycine (0-125 μM), ferulic acid (0-200 μM), phenylalanine (0-200 μM), α-ketoglutaric acid (0-200 μM) and pyruvic acid (0-200 μM) on production of bacoside-A (a triterpenoid type secondary metabolite responsible for cognition effects) in shoot and callus biomass of Bacopa monniera (L.) Pennell. The shoots were raised in liquid Murashige and Skoog's (MS) medium fortified with 5 μM 6-benzyladenine (BA) and callus biomass on agar solidified MS medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4 -D) in conjunction with 5 μM 1-napthaleneacetic acid (NAA). Among the organic supplements used, 100 μM pyruvic acid effectively enhanced the production of bacoside-A in shoot as well as callus biomass. The bacoside-A content in in-vitro raised shoot biomass was 4.0 and 1.2 times higher as compared to control and shoot biomass of naturally grown plants respectively. Inclusion of pyruvic acid in MS medium for in-vitro shoot cultures of B. monniera, can be adapted for enhanced production of bacoside-A.

Zinc complexes of the biomimetic N,N,O ligand family of substituted 3,3-bis(1-alkylimidazol-2-yl)propionates: the formation of oxalate from pyruvate

The coordination chemistry of the 2-His-1-carboxylate facial triad mimics 3,3-bis(1-methylimidazol-2-yl)propionate (MIm(2)Pr) and 3,3-bis(1-ethyl-4-isopropylimidazol-2-yl) propionate (iPrEtIm(2)Pr) towards ZnCl(2) was studied both in solution and in the solid state. Different coordination modes were found depending both on the stoichiometry and on the ligand that was employed. In the 2:1 ligand-to-metal complex [Zn(MIm(2)Pr)(2)], the ligand coordinates in a tridentate, tripodal N,N,O fashion similar to the 2-His-1-carboxylate facial triad. However, the 1:1 ligand-to-metal complexes [Zn(MIm(2)Pr)Cl(H(2)O)] and [Zn(iPrEtIm(2)Pr)Cl] were crystallographically characterized and found to be polymeric in nature. A new, bridging coordination mode of the ligands was observed in both structures comprising N,N-bidentate coordination of the ligand to one zinc atom and O-monodentate coordination to a zinc second atom. A rather unique transformation of pyruvate into oxalate was found with [Zn(MIm(2)Pr)Cl], which resulted in the isolation of the new, oxalato bridged zinc coordination polymer [Zn(2)(MIm(2)Pr)(2)(ox)].6H(2)O, the structure of which was established by X-ray crystal structure determination.