Response surface methodology (RSM) was used to optimize the fermentation medium for enhancing pyruvic acid production by Torulopsis glabrata TP19. In the first step of optimization, with Plackett-Burman design, ammoni...Response surface methodology (RSM) was used to optimize the fermentation medium for enhancing pyruvic acid production by Torulopsis glabrata TP19. In the first step of optimization, with Plackett-Burman design, ammonium sulfate, glucose and nicotinic acid were found to be the important factors affecting pyruvic acid production significantly. In the second step, a 23 full factorial central composite design and RSM were applied to determine the optimal concentration of each significant variable. A second-order polynomial was determined by the multiple regression analysis of the experimental data. The optimum values for the critical components were obtained as follows: ammonium sulfate 0.7498 (10.75 g/L), glucose 0.9383 (109.38 g/L) and nicotinic acid 0.3633 (7.86 mg/L) with a predicted value of maximum pyruvic acid production of 42.2 g/L. Under the optimal conditions, the practical pyruvic acid production was 42.4 g/L. The determination coefficient (R2) was 0.9483, which ensures adequate credibility of the model. By scaling up fermentation from flask to jar fermentor, we obtained promising results.展开更多
Uptakes of pyruvic acid for two types of commercially available weakly basic polymer sorbents, D301G and D301R, have been measured over a wide pH range and at various salinities of MgSO4. The results show that the ove...Uptakes of pyruvic acid for two types of commercially available weakly basic polymer sorbents, D301G and D301R, have been measured over a wide pH range and at various salinities of MgSO4. The results show that the overloading adsorption of pyruvic acid occurs on both weakly basic polymer sorbents, and the overloading models can predict the experimental data of uptake very well. The overloading value for D301G is larger than that for D301R. The adsorption isotherm of pyruvic acid for both polymeric sorbents is greatly affected by the solution pH and MgSO4 concentration in the aqueous phase, and a high recovery efficiency of pyruvic acid from aqueous solution can be obtained at the solution pH around 2.展开更多
One‐step production of pyruvic acid through selective oxidation of glycerol was investigated using lead promoted platinum/activated carbon(Pb‐Pt/AC)catalysts under mild conditions.The results of N2physisorption,X‐r...One‐step production of pyruvic acid through selective oxidation of glycerol was investigated using lead promoted platinum/activated carbon(Pb‐Pt/AC)catalysts under mild conditions.The results of N2physisorption,X‐ray diffraction,X‐ray photoelectron spectroscopy,and high‐resolution transmission electron microscopy revealed that the alloy phases of PtPb and PtxPb were favorable for pyruvic acid production from glycerol oxidation,whereas the Pb3(CO3)2(OH)2and surface Pb0species inhibited the glycerol conversion.The loading of Pb and the catalyst preparation method(including impregnation and deposition precipitation)affected the formation of different metal species.Pyruvic acid was obtained at a yield of18.4%on a5.0wt%Pb‐5.0wt%Pt/AC catalyst prepared by co‐deposition precipitation method and500°C argon treatment.展开更多
A new cis-dioxovanadium （V） complex [VO2（C9H8N3O3）]（C5H5N） involving a carboxyl group coordination employing a tridentate Schiff Base derived from pyruvic acid and isonicotinyl hydrazide is reported. This comple...A new cis-dioxovanadium （V） complex [VO2（C9H8N3O3）]（C5H5N） involving a carboxyl group coordination employing a tridentate Schiff Base derived from pyruvic acid and isonicotinyl hydrazide is reported. This complex crystallizes in triclinic, space group P1^- with a = 7.3522 （12）, b = 7.8376（13）, c = 14.898（2） ,A°, a = 84.010（2）, β = 86.568（2）, γ= 64.586（2）°, V = 771.1（2）A °^3 ,Z = 2, F（000） = 376, Mr = 368.22, D, = 1.586 g/cm^3, g = 0.677 mm ^-1, R = 0.0421 and wR = 0.1253. The vanadium atom of the dioxovanadium （V） is five-coordinated to furnish a distorted trigonal bipyramid geometry.展开更多
Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5...Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5, 63%) have been successfully synthesized. The conventional method was used and a series of novel linear and cyclic Schiff bases were obtained with or without catalyst. All the Schiff bases were fully characterized by CHN elemental analysis, FT-IR, 1H & 13C NMR, EI-MS and two of the Schiff bases were further characterized by X-ray crystallographic structure analysis. Compound 2 crystallizes in the triclinic space group P-1 and unit cell dimensions are: a = 4.1777(8), b = 5.9538(11), c = 13.458(3) Å, α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0439. Compound 3 crystallizes in the orthorhombic space group P n a 2(1) and unit cell dimensions are: a = 5.5992(2), b = 11.3962(5), c = 10.6473(5), α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0285. Compounds 2 and 3 were obtained as cyclic Schiff bases which are triazine derivatives.展开更多
It is important to study the solvent effect on keto-enol tautomerism that has applications in many areas of chemical engineering.In this work,we use a multiscale reaction density functional theory(Rx DFT)to study the ...It is important to study the solvent effect on keto-enol tautomerism that has applications in many areas of chemical engineering.In this work,we use a multiscale reaction density functional theory(Rx DFT)to study the keto-enol tautomerism and isomerization of pyruvic acid.The results show that both effects of solvation and water assistance could reduce the reaction barriers.The water molecule participates the reaction as a catalyst to accept/give the protons with forming a hexagonal ring in the transition state.As a result of this temporary and intermediate hexagonal ring,the solute configuration undergoes a small variation during the reaction,giving a diminished contribution to the intrinsic reaction free energy.The solvent distribution shows a local ordering behavior near the solute that also reduces the contribution of solvation effect to the reaction barrier.Water assistance plays a major role in both pre-reaction and postreaction process.In terms of the driving force for the reaction,the effects of both solvation and water assistance are important.展开更多
New oscillating reaction with the participation of a macrocyclic nickel(Ⅱ) complex ion [Ni(TIM )]2+ as catalyst and pyruvic acid as organic substrate in acidic bromate medium are described' This complex ion cont...New oscillating reaction with the participation of a macrocyclic nickel(Ⅱ) complex ion [Ni(TIM )]2+ as catalyst and pyruvic acid as organic substrate in acidic bromate medium are described' This complex ion contains the ligand: 2, 3,9, 10-tetramethyl - 1, 4, 8, 11 - tetraazacyclotetradeca - 1, 3, 8, 10 - tetraene. The [Ni (TIM ) ]2+ion can undergo oxidation reaction of Ni (Ⅱ ) Ni (Ⅲ ). Detailed research on the system's oscillation characters and influential factors is made and the mechanism is briefly discussed.展开更多
In this paper a new chemical oscillating reaction in the pyruvic acid-BrO-H2SO4 - [CuL](ClO4)2 system, where L is 5, 7, 12, 14-tetraethyl-7, 14-dimethyl-1, 4, 8, 11 -tetraazacyclotetradeca-4, 11-diene, is reported. Th...In this paper a new chemical oscillating reaction in the pyruvic acid-BrO-H2SO4 - [CuL](ClO4)2 system, where L is 5, 7, 12, 14-tetraethyl-7, 14-dimethyl-1, 4, 8, 11 -tetraazacyclotetradeca-4, 11-diene, is reported. The features of the oscillations are studied in detail. The effects of Ag+,Hg2+,CCl4, Vc, H2O2, acrylonitrile, and temperature on the oscillation system are also discussed.展开更多
Density functional theory BLYP (using Becke's and Lee-Yang-Pars's correlation functionals), ab initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibratio...Density functional theory BLYP (using Becke's and Lee-Yang-Pars's correlation functionals), ab initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of pyruvic acid. The scaled B3LYP/6-31G* frequencies correspond well with available experimental assignment of the functional vibrational modes and the mean absolut devation is only 12.3cm^(-1).展开更多
The products of basic hydrolysis of ethyl oxal-acetate and the preparation of 3-ethoxy carbonyl pyruvic acid 1 are reported.Esterification reaction of 1 with unhindered alcohols could be carried out smoothly, but it w...The products of basic hydrolysis of ethyl oxal-acetate and the preparation of 3-ethoxy carbonyl pyruvic acid 1 are reported.Esterification reaction of 1 with unhindered alcohols could be carried out smoothly, but it was unsuccessful with hindered alcohols.展开更多
The production of biodiesel generates a significant amount of glycerol by-products.One way to utilize glycerol is converting it into lactic acid,which can then be further transformed into pyruvic acid.In this review,w...The production of biodiesel generates a significant amount of glycerol by-products.One way to utilize glycerol is converting it into lactic acid,which can then be further transformed into pyruvic acid.In this review,we examine existing reaction pathways and propose a new approach for the indirect synthesis of pyruvic acid using glycerol and lactic acid as intermediates.Noble metals and transition metals are suitable for the oxidation of glycerol and lactic acid,and the combination of different metal sites may exhibit synergy effect and promote the process.It should be noted that the dehydration and isomerization of 1,3-dehydroxyacetone to lactic acid can be catalyzed by Lewis acids,which can be utilized in the base-free system that simplifies the postprocess procedure.Excepting noble metals,synergistic effect between iron and molybdenum also shows promising performance in catalyzed oxidation of lactic acid.Furthermore,many research results also suggest that mass transfer plays a critical role in this cascade reaction,which shed light on the catalysts modification for the similar reactions.展开更多
Background Streptococcus （S.） oligofermentans is a newly identified bacteria with a yet to be defined mechanism of sucrose metabolism that results in acid production. This study aimed to investigate the biochemical ...Background Streptococcus （S.） oligofermentans is a newly identified bacteria with a yet to be defined mechanism of sucrose metabolism that results in acid production. This study aimed to investigate the biochemical mechanisms of S. oligoferm-entans glucose metaolism. Methods The S. oligofermentans LMG21532, Lactobacillus （L.） fermentum 38 and the S. mutans UA140 were used to characterize sucrose metabolism by measuring lactate dehydrogenase （LDH） activity and lactic acid production. Continuous dynamics and high performance capillary electrophoresis were used to determine LDH activity and lactic acid production, respectively, from bacteria collected at 0, 10 and 30 minutes after cultured in 10% sucrose. Results These analyses demonstrated that LDH activity of the three bacterial strains examined remained stable but significantly different throughout the sucrose fermentation process. The S. oligofermentans LDH activity （（0.61±0.05） U/mg） was significantly lower than that of L. fermentum （（52.91±8.97） U/mg）. In addition, the S. oligofermentans total lactate production （（0.048±0.021） mmol/L） was also significantly lower than that of L. fermentum （（0.958±0.201） mmol/L）. Although the S. oligofermentans LDH production was almost double of that produced by S. mutans （（0.32±0.07） U/mg）, lactic acid production was approximately one sixth that of S. mutans （（0.296±0.058） mmol/L）. Additional tests examining pyruvic acid production （the LDH substrate） demonstrated that lactic acid concentrations correlated with pyruvic acid production. That is, pyruvic acid production by S. oligofermentans was undetectable following sucrose incubation, however, （0.074±0.024） and （0.175±0.098） mmol/L pyruvic acid were produced by S. mutans and L. fermentum, respectively. Conclusion S. oligofermentans is incapable of fermenting carbohydrates to produce enough pyruvic acid, which results in reduced lactic acid production.展开更多
The pyruvic acid salicylhydrazone and its new complex of Pr(III) were synthesized. The formulae C 10 H 10 N 2O 4 (mark as H 3L) and [Pr 2(L) 2(H 2O) 2]·3H 2O (L=the triad form of the pyruvic acid...The pyruvic acid salicylhydrazone and its new complex of Pr(III) were synthesized. The formulae C 10 H 10 N 2O 4 (mark as H 3L) and [Pr 2(L) 2(H 2O) 2]·3H 2O (L=the triad form of the pyruvic acid salicylhydrazone [C 10 H 7N 2O 4] 3- ) were determined by elemental and EDTA volumetric analysis. Molar conductance, IR, UV, X ray and 1H NMR were carried out for the characterizations of the complex and the ligand. The thermal decompositions of the ligand and the complex with the kinetic study were carried out by non isothermal thermogravimetry. The Kissinger's method and Ozawa's method are used to calculate the activation energy value of the main step decomposition. The stages of the decompositions were identified by TG DTG DSC curve. The non isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equation were investigated by comparing the kinetic parameters.展开更多
Developing efficient photocatalysts to address collaborative energy and environmental crises still faces significant challenges.In this report,we present a highly efficient MXene–based photocatalyst,which is combined...Developing efficient photocatalysts to address collaborative energy and environmental crises still faces significant challenges.In this report,we present a highly efficient MXene–based photocatalyst,which is combined with MoS_(2)nano patches and TiO_(2)/Ti_(3)C_(2)(TTC)nanowires through hydrothermal treatment.Of all the composites tested,the optimized photocatalyst gave a remarkable H_(2)and revolving polylactic acid(PLA)into pyruvic acid(PA).Achieving a remarkable H_(2)evolution rate of 637.1 and 243.2μmol g^(−1)h^(−1),in the presence of TEOA and PLA as a sacrificial reagent under UV-vis(λ≥365 nm)light irradiation.The improved photocatalytic activity is a result of the combination of dual cocatalyst on the surface of TTC photocatalyst,which create an ideal synergistic effect for the generation of PA and the production of H_(2)simultaneously.The MoS_(2)TiO_(2)/Ti_(3)C_(2)(MTT)composite can generate more photoexcited charge carriers,leading to the generation of more active radicals,which may enhance the system's photocatalytic activity.This work aims at demonstrating its future significance and guide the scientific community towards a more efficient approach to commercializing H_(2)through photocatalysis.展开更多
High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the ex...High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the extracellular space functions as a pro-inflammatory damage-associated molecular pattern,which has been proven to play an important role in a wide variety of central nervous system disorders such as ischemic stroke,Alzheimer’s disease,frontotemporal dementia,Parkinson’s disease,multiple sclerosis,epilepsy,and traumatic brain injury.Several drugs that inhibit high-mobility group box 1 as a damage-associated molecular pattern,such as glycyrrhizin,ethyl pyruvate,and neutralizing anti-high-mobility group box 1 antibodies,are commonly used to target high-mobility group box 1 activity in central nervous system disorders.Although it is commonly known for its detrimental inflammatory effect,high-mobility group box 1 has also been shown to have beneficial pro-regenerative roles in central nervous system disorders.In this narrative review,we provide a brief summary of the history of high-mobility group box 1 research and its characterization as a damage-associated molecular pattern,its downstream receptors,and intracellular signaling pathways,how high-mobility group box 1 exerts the repair-favoring roles in general and in the central nervous system,and clues on how to differentiate the pro-regenerative from the pro-inflammatory role.Research targeting high-mobility group box 1 in the central nervous system may benefit from differentiating between the two functions rather than overall suppression of high-mobility group box 1.展开更多
[Objective]To construct an Escherichia coli mutant strain that accumulates pyruvate by genetic modification guided by the genome-scale metabolic network model.[Methods]Using a genome-scale metabolic network model as a...[Objective]To construct an Escherichia coli mutant strain that accumulates pyruvate by genetic modification guided by the genome-scale metabolic network model.[Methods]Using a genome-scale metabolic network model as a guide,we simulated pyruvate production of E.coli,screened key genes in metabolic pathways,and developed gene editing procedures accordingly.We knocked out the acetate kinase gene ackA,phosphate acetyltransferase gene pta,alcohol dehydrogenase adhE,glycogen synthase gene glgA,glycogen phosphorylase gene glgP,phosphoribosyl pyrophosphate(PRPP)synthase gene prs,ribose 1,5-bisphosphate phosphokinase gene phnN,and transporter encoding gene proP.Furthermore,we knocked in the transporter encoding gene ompC,flavonoid toxin gene fldA,and D-serine ammonia lyase gene dsdA.[Results]A shake flask process with the genetically edited mutant strain MG1655-6-2 under anaerobic conditions produced pyruvate at a titer of 10.46 g/L and a yield of 0.69 g/g.Metabolomic analysis revealed a significant increase in the pyruvate level in the fermentation broth,accompanied by notable decreases in the levels of certain related metabolic byproducts.Through 5 L fed-batch fermentation and an adaptive laboratory evolution,the strain finally achieved a pyruvate titer of 45.86 g/L.[Conclusion]This study illustrated the efficacy of a gene editing strategy predicted by a genome-scale metabolic network model in enhancing pyruvate accumulation in E.coli under anaerobic conditions and provided novel insights for microbial metabolic engineering.展开更多
OBJECTIVE:To investigate the impact of Shenhua tablet(肾华片,SHT)on renal macrophage polarization and renal injury in mice with diabetic kidney disease(DKD)and to explore the potential mechanism involving the hypoxia-...OBJECTIVE:To investigate the impact of Shenhua tablet(肾华片,SHT)on renal macrophage polarization and renal injury in mice with diabetic kidney disease(DKD)and to explore the potential mechanism involving the hypoxia-inducible factor-1α(HIF-1α)and pyruvate kinase M2(PKM2)signaling pathway,along with the glycolysis metabolism pathway.METHODS:The animals were divided into the following groups:Model,Control,dapagliflozin,SHT low-dose,SHT medium-dose,and SHT high-dose.We assessed 24-hour urine protein(24 h-UTP)levels,urinary albuminto-creatinine ratio,and regularly monitored fasting blood glucose during the treatment period.After treatment,we examined renal tissue structure,renal function(urea nitrogen,uric acid,creatinine,cystatin C,β2-microglobulin),and glycolysis in renal macrophages.Additionally,we observed macrophage polarization in renal tissue and measured inflammatory factors(tumor necrosis factor-α,interleukin-1β,interleukin-6,interleukin-10,monocyte chemoattractant protein-1)to assess the immunoinflammatory status of the renal tissue.Finally,we investigated the expression of the HIF-1α/PKM2 signaling pathway in macrophages to explore its role in the glycolysis process.RESULTS:SHT shows a beneficial effect in treating DKD by reducing 24 h-UTP,regulating blood glucose levels,improving renal tissue structure,protecting renal function,inhibiting macrophage glycolysis,reducing macrophage transformation to the M1 state,and suppressing the expression of the HIF-1α/PKM2 signaling pathway.CONCLUSION:SHT may exert renoprotective effects by inhibiting macrophage glycolysis via the HIF-1α/PKM2 signaling pathway.This inhibition decreases macrophage M1 polarization and reduces immunoinflammatory injury in the renal tissue of DKD mice.展开更多
Background:Metabolic abnormalities are considered to play a key regulatory role in vascular remodeling of pulmonary arterial hypertension.However,to date,there is a paucity of research documenting the changes in metab...Background:Metabolic abnormalities are considered to play a key regulatory role in vascular remodeling of pulmonary arterial hypertension.However,to date,there is a paucity of research documenting the changes in metabolome profiles within the su-pernatants of pulmonary artery smooth muscle cells(PASMC)during their transition from a contractile to a synthetic phenotype.Methods:CCK-8 and Edu staining assays were used to evaluate the cell viability and proliferation of human PASMCs.IncuCyte ZOOM imaging system was used to continuously and automatically detect the migration of the PASMCs.A targeted me-tabolomics profiling was performed to quantitatively analyze 121 metabolites in the supernatant.Orthogonal partial least squares discriminant analysis was used to dis-criminate between PDGF-BB-induced PASMCs and controls.Metabolite set enrich-ment analysis was adapted to exploit the most disturbed metabolic pathways.Results:Human PASMCs exhibited a transformation from contractile phenotype to synthetic phenotype after PDGF-BB induction,along with a significant increase in cell viability,proliferation,and migration.Metabolites in the supernatants of PASMCs treated with or without PDGF-BB were well profiled.Eleven metabolites were found to be significantly upregulated,whereas seven metabolites were downregulated in the supernatants of PASMCs induced by PDGF-BB compared to the vehicle-treated cells.Fourteen pathways were involved,and pyruvate metabolism pathway was ranked first with the highest enrichment impact followed by glycolysis/gluconeogen-esis and pyrimidine metabolism.Conclusions:Significant and extensive metabolic abnormalities occurred during the phenotypic transformation of PASMCs.Disturbance of pyruvate metabolism pathway might contribute to pulmonary vascular remodeling.展开更多
This review focuses on the metabolic issues related to mitochondrial pyruvate dehydrogenase phosphatase(PDP)in malignant tumors and its potential mechanisms.Recent research on tumor metabolic mechanisms has shown that...This review focuses on the metabolic issues related to mitochondrial pyruvate dehydrogenase phosphatase(PDP)in malignant tumors and its potential mechanisms.Recent research on tumor metabolic mechanisms has shown that PDP dysregulation is closely linked to metabolic reprogramming in tumor cells,and potentially promotes tumor.Research has comprehensively explored the structural-functional characteristics of PDP,its metabolic regulatory mechanisms,and its role in various types of malignant tumors.Nevertheless,several questions still exist regarding its potential mechanisms within acetylation,phosphorylation,hypoxia,immune infiltration,mitochondrial metabolism,drug resistance,oxidative phosphorylation,and tumor prognosis.This article intends to summarize the latest research,examine PDP’s potential as a therapeutic target,and propose future research directions to enhance cancer treatment strategies.展开更多
The development of cancer cell resistance to conventional treatments continues to be a major obstacle in the successful treatment of tumors of many types.The discovery of a highly efficient direct and indirect free ra...The development of cancer cell resistance to conventional treatments continues to be a major obstacle in the successful treatment of tumors of many types.The discovery of a highly efficient direct and indirect free radical scavenger,melatonin,in the mitochondrial matrix may be a factor in determining both the occurrence of cancer cell drug insensitivity as well as radioresistance.This relates to two of the known hallmarks of cancer,i.e.,exaggerated free radical generation in the mitochondria and the development ofWarburg type metabolism(glycolysis).The hypothesis elaborated in this report assumes that the high oxidative environment in the mitochondria contributes to a depression of local melatonin levels because of its overuse in neutralizing the massive amount of free radial produced.Moreover,Warburg typemetabolism and chemoresistance are functionally linked and supplementalmelatonin has been shown to reverse glycolysis and convert glucose processing to the type that occurs in normal cells.Since thismetabolic type is a key factor in determining chemoresistance,melatonin would predictably also negate cancer drug insensitivity.The possible mechanisms by which melatonin may interfere either directly or indirectly with drug resistance are summarized in the current review.展开更多
文摘Response surface methodology (RSM) was used to optimize the fermentation medium for enhancing pyruvic acid production by Torulopsis glabrata TP19. In the first step of optimization, with Plackett-Burman design, ammonium sulfate, glucose and nicotinic acid were found to be the important factors affecting pyruvic acid production significantly. In the second step, a 23 full factorial central composite design and RSM were applied to determine the optimal concentration of each significant variable. A second-order polynomial was determined by the multiple regression analysis of the experimental data. The optimum values for the critical components were obtained as follows: ammonium sulfate 0.7498 (10.75 g/L), glucose 0.9383 (109.38 g/L) and nicotinic acid 0.3633 (7.86 mg/L) with a predicted value of maximum pyruvic acid production of 42.2 g/L. Under the optimal conditions, the practical pyruvic acid production was 42.4 g/L. The determination coefficient (R2) was 0.9483, which ensures adequate credibility of the model. By scaling up fermentation from flask to jar fermentor, we obtained promising results.
基金Supported by the National Natural Science Foundation of China （No.29836130）.
文摘Uptakes of pyruvic acid for two types of commercially available weakly basic polymer sorbents, D301G and D301R, have been measured over a wide pH range and at various salinities of MgSO4. The results show that the overloading adsorption of pyruvic acid occurs on both weakly basic polymer sorbents, and the overloading models can predict the experimental data of uptake very well. The overloading value for D301G is larger than that for D301R. The adsorption isotherm of pyruvic acid for both polymeric sorbents is greatly affected by the solution pH and MgSO4 concentration in the aqueous phase, and a high recovery efficiency of pyruvic acid from aqueous solution can be obtained at the solution pH around 2.
基金supported by the National Natural Science Foundation of China(21176236)~~
文摘One‐step production of pyruvic acid through selective oxidation of glycerol was investigated using lead promoted platinum/activated carbon(Pb‐Pt/AC)catalysts under mild conditions.The results of N2physisorption,X‐ray diffraction,X‐ray photoelectron spectroscopy,and high‐resolution transmission electron microscopy revealed that the alloy phases of PtPb and PtxPb were favorable for pyruvic acid production from glycerol oxidation,whereas the Pb3(CO3)2(OH)2and surface Pb0species inhibited the glycerol conversion.The loading of Pb and the catalyst preparation method(including impregnation and deposition precipitation)affected the formation of different metal species.Pyruvic acid was obtained at a yield of18.4%on a5.0wt%Pb‐5.0wt%Pt/AC catalyst prepared by co‐deposition precipitation method and500°C argon treatment.
基金Project was supported by Scientific Research common program of Beijing municipal commission of education (KM20051028005)
文摘A new cis-dioxovanadium （V） complex [VO2（C9H8N3O3）]（C5H5N） involving a carboxyl group coordination employing a tridentate Schiff Base derived from pyruvic acid and isonicotinyl hydrazide is reported. This complex crystallizes in triclinic, space group P1^- with a = 7.3522 （12）, b = 7.8376（13）, c = 14.898（2） ,A°, a = 84.010（2）, β = 86.568（2）, γ= 64.586（2）°, V = 771.1（2）A °^3 ,Z = 2, F（000） = 376, Mr = 368.22, D, = 1.586 g/cm^3, g = 0.677 mm ^-1, R = 0.0421 and wR = 0.1253. The vanadium atom of the dioxovanadium （V） is five-coordinated to furnish a distorted trigonal bipyramid geometry.
文摘Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5, 63%) have been successfully synthesized. The conventional method was used and a series of novel linear and cyclic Schiff bases were obtained with or without catalyst. All the Schiff bases were fully characterized by CHN elemental analysis, FT-IR, 1H & 13C NMR, EI-MS and two of the Schiff bases were further characterized by X-ray crystallographic structure analysis. Compound 2 crystallizes in the triclinic space group P-1 and unit cell dimensions are: a = 4.1777(8), b = 5.9538(11), c = 13.458(3) Å, α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0439. Compound 3 crystallizes in the orthorhombic space group P n a 2(1) and unit cell dimensions are: a = 5.5992(2), b = 11.3962(5), c = 10.6473(5), α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0285. Compounds 2 and 3 were obtained as cyclic Schiff bases which are triazine derivatives.
基金National Natural Science Foundation of China(Nos.21978079,and 21878078).
文摘It is important to study the solvent effect on keto-enol tautomerism that has applications in many areas of chemical engineering.In this work,we use a multiscale reaction density functional theory(Rx DFT)to study the keto-enol tautomerism and isomerization of pyruvic acid.The results show that both effects of solvation and water assistance could reduce the reaction barriers.The water molecule participates the reaction as a catalyst to accept/give the protons with forming a hexagonal ring in the transition state.As a result of this temporary and intermediate hexagonal ring,the solute configuration undergoes a small variation during the reaction,giving a diminished contribution to the intrinsic reaction free energy.The solvent distribution shows a local ordering behavior near the solute that also reduces the contribution of solvation effect to the reaction barrier.Water assistance plays a major role in both pre-reaction and postreaction process.In terms of the driving force for the reaction,the effects of both solvation and water assistance are important.
文摘New oscillating reaction with the participation of a macrocyclic nickel(Ⅱ) complex ion [Ni(TIM )]2+ as catalyst and pyruvic acid as organic substrate in acidic bromate medium are described' This complex ion contains the ligand: 2, 3,9, 10-tetramethyl - 1, 4, 8, 11 - tetraazacyclotetradeca - 1, 3, 8, 10 - tetraene. The [Ni (TIM ) ]2+ion can undergo oxidation reaction of Ni (Ⅱ ) Ni (Ⅲ ). Detailed research on the system's oscillation characters and influential factors is made and the mechanism is briefly discussed.
文摘In this paper a new chemical oscillating reaction in the pyruvic acid-BrO-H2SO4 - [CuL](ClO4)2 system, where L is 5, 7, 12, 14-tetraethyl-7, 14-dimethyl-1, 4, 8, 11 -tetraazacyclotetradeca-4, 11-diene, is reported. The features of the oscillations are studied in detail. The effects of Ag+,Hg2+,CCl4, Vc, H2O2, acrylonitrile, and temperature on the oscillation system are also discussed.
基金This work was supported by the Natural Science Foundation of Shandong Province. the National Key Laboratory Foundation of Cry
文摘Density functional theory BLYP (using Becke's and Lee-Yang-Pars's correlation functionals), ab initio Hartree-Fock (HF) and hybrid DFT/HF B3LYP calculations were carried out to study the structure and vibrational spectra of pyruvic acid. The scaled B3LYP/6-31G* frequencies correspond well with available experimental assignment of the functional vibrational modes and the mean absolut devation is only 12.3cm^(-1).
文摘The products of basic hydrolysis of ethyl oxal-acetate and the preparation of 3-ethoxy carbonyl pyruvic acid 1 are reported.Esterification reaction of 1 with unhindered alcohols could be carried out smoothly, but it was unsuccessful with hindered alcohols.
基金support from The National Key Research and Development Program of China(2022YFB3805602)Science Foundation of China University of Petroleum,Beijing(No.2462021QNXZ007).
文摘The production of biodiesel generates a significant amount of glycerol by-products.One way to utilize glycerol is converting it into lactic acid,which can then be further transformed into pyruvic acid.In this review,we examine existing reaction pathways and propose a new approach for the indirect synthesis of pyruvic acid using glycerol and lactic acid as intermediates.Noble metals and transition metals are suitable for the oxidation of glycerol and lactic acid,and the combination of different metal sites may exhibit synergy effect and promote the process.It should be noted that the dehydration and isomerization of 1,3-dehydroxyacetone to lactic acid can be catalyzed by Lewis acids,which can be utilized in the base-free system that simplifies the postprocess procedure.Excepting noble metals,synergistic effect between iron and molybdenum also shows promising performance in catalyzed oxidation of lactic acid.Furthermore,many research results also suggest that mass transfer plays a critical role in this cascade reaction,which shed light on the catalysts modification for the similar reactions.
基金This study was supported by grants from 115-National Key Technologies R＆D Programme, the Ministry of Science and Technology of China （No. 2007BAI18B01）, National Natural Science Foundation of China （No. 8107088）, and Beijing Municipal Natural Science Foundation （No. 7102163）. Conflict of interests： None.
文摘Background Streptococcus （S.） oligofermentans is a newly identified bacteria with a yet to be defined mechanism of sucrose metabolism that results in acid production. This study aimed to investigate the biochemical mechanisms of S. oligoferm-entans glucose metaolism. Methods The S. oligofermentans LMG21532, Lactobacillus （L.） fermentum 38 and the S. mutans UA140 were used to characterize sucrose metabolism by measuring lactate dehydrogenase （LDH） activity and lactic acid production. Continuous dynamics and high performance capillary electrophoresis were used to determine LDH activity and lactic acid production, respectively, from bacteria collected at 0, 10 and 30 minutes after cultured in 10% sucrose. Results These analyses demonstrated that LDH activity of the three bacterial strains examined remained stable but significantly different throughout the sucrose fermentation process. The S. oligofermentans LDH activity （（0.61±0.05） U/mg） was significantly lower than that of L. fermentum （（52.91±8.97） U/mg）. In addition, the S. oligofermentans total lactate production （（0.048±0.021） mmol/L） was also significantly lower than that of L. fermentum （（0.958±0.201） mmol/L）. Although the S. oligofermentans LDH production was almost double of that produced by S. mutans （（0.32±0.07） U/mg）, lactic acid production was approximately one sixth that of S. mutans （（0.296±0.058） mmol/L）. Additional tests examining pyruvic acid production （the LDH substrate） demonstrated that lactic acid concentrations correlated with pyruvic acid production. That is, pyruvic acid production by S. oligofermentans was undetectable following sucrose incubation, however, （0.074±0.024） and （0.175±0.098） mmol/L pyruvic acid were produced by S. mutans and L. fermentum, respectively. Conclusion S. oligofermentans is incapable of fermenting carbohydrates to produce enough pyruvic acid, which results in reduced lactic acid production.
基金ProjectsupportedbytheNaturalScienceFoundationofShaanxiProvince (No .98H0 10 )andStateKeyLaboratoryofRareEarthMaterialsChemistryandApplication&PekingUniversity .
文摘The pyruvic acid salicylhydrazone and its new complex of Pr(III) were synthesized. The formulae C 10 H 10 N 2O 4 (mark as H 3L) and [Pr 2(L) 2(H 2O) 2]·3H 2O (L=the triad form of the pyruvic acid salicylhydrazone [C 10 H 7N 2O 4] 3- ) were determined by elemental and EDTA volumetric analysis. Molar conductance, IR, UV, X ray and 1H NMR were carried out for the characterizations of the complex and the ligand. The thermal decompositions of the ligand and the complex with the kinetic study were carried out by non isothermal thermogravimetry. The Kissinger's method and Ozawa's method are used to calculate the activation energy value of the main step decomposition. The stages of the decompositions were identified by TG DTG DSC curve. The non isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equation were investigated by comparing the kinetic parameters.
文摘Developing efficient photocatalysts to address collaborative energy and environmental crises still faces significant challenges.In this report,we present a highly efficient MXene–based photocatalyst,which is combined with MoS_(2)nano patches and TiO_(2)/Ti_(3)C_(2)(TTC)nanowires through hydrothermal treatment.Of all the composites tested,the optimized photocatalyst gave a remarkable H_(2)and revolving polylactic acid(PLA)into pyruvic acid(PA).Achieving a remarkable H_(2)evolution rate of 637.1 and 243.2μmol g^(−1)h^(−1),in the presence of TEOA and PLA as a sacrificial reagent under UV-vis(λ≥365 nm)light irradiation.The improved photocatalytic activity is a result of the combination of dual cocatalyst on the surface of TTC photocatalyst,which create an ideal synergistic effect for the generation of PA and the production of H_(2)simultaneously.The MoS_(2)TiO_(2)/Ti_(3)C_(2)(MTT)composite can generate more photoexcited charge carriers,leading to the generation of more active radicals,which may enhance the system's photocatalytic activity.This work aims at demonstrating its future significance and guide the scientific community towards a more efficient approach to commercializing H_(2)through photocatalysis.
基金supported by a grant of the M.D.-Ph.D./Medical Scientist Training Program through the Korea Health Industry Development Institute(KHIDI)funded by the Ministry of Health&Welfare,Republic of Korea(to HK)+3 种基金supported by National Research Foundation of Korea(NRF)grants funded by the Korean government(MSITMinistry of Science and ICT)(NRF2019R1A5A2026045 and NRF-2021R1F1A1061819)a grant from the Korean Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI),funded by the Ministry of Health&Welfare,Republic of Korea(HR21C1003)New Faculty Research Fund of Ajou University School of Medicine(to JYC)。
文摘High-mobility group box 1 was first discovered in the calf thymus as a DNA-binding nuclear protein and has been widely studied in diverse fields,including neurology and neuroscience.High-mobility group box 1 in the extracellular space functions as a pro-inflammatory damage-associated molecular pattern,which has been proven to play an important role in a wide variety of central nervous system disorders such as ischemic stroke,Alzheimer’s disease,frontotemporal dementia,Parkinson’s disease,multiple sclerosis,epilepsy,and traumatic brain injury.Several drugs that inhibit high-mobility group box 1 as a damage-associated molecular pattern,such as glycyrrhizin,ethyl pyruvate,and neutralizing anti-high-mobility group box 1 antibodies,are commonly used to target high-mobility group box 1 activity in central nervous system disorders.Although it is commonly known for its detrimental inflammatory effect,high-mobility group box 1 has also been shown to have beneficial pro-regenerative roles in central nervous system disorders.In this narrative review,we provide a brief summary of the history of high-mobility group box 1 research and its characterization as a damage-associated molecular pattern,its downstream receptors,and intracellular signaling pathways,how high-mobility group box 1 exerts the repair-favoring roles in general and in the central nervous system,and clues on how to differentiate the pro-regenerative from the pro-inflammatory role.Research targeting high-mobility group box 1 in the central nervous system may benefit from differentiating between the two functions rather than overall suppression of high-mobility group box 1.
基金supported by the Hebei Provincial Key Research and Development Project(21372803D)。
文摘[Objective]To construct an Escherichia coli mutant strain that accumulates pyruvate by genetic modification guided by the genome-scale metabolic network model.[Methods]Using a genome-scale metabolic network model as a guide,we simulated pyruvate production of E.coli,screened key genes in metabolic pathways,and developed gene editing procedures accordingly.We knocked out the acetate kinase gene ackA,phosphate acetyltransferase gene pta,alcohol dehydrogenase adhE,glycogen synthase gene glgA,glycogen phosphorylase gene glgP,phosphoribosyl pyrophosphate(PRPP)synthase gene prs,ribose 1,5-bisphosphate phosphokinase gene phnN,and transporter encoding gene proP.Furthermore,we knocked in the transporter encoding gene ompC,flavonoid toxin gene fldA,and D-serine ammonia lyase gene dsdA.[Results]A shake flask process with the genetically edited mutant strain MG1655-6-2 under anaerobic conditions produced pyruvate at a titer of 10.46 g/L and a yield of 0.69 g/g.Metabolomic analysis revealed a significant increase in the pyruvate level in the fermentation broth,accompanied by notable decreases in the levels of certain related metabolic byproducts.Through 5 L fed-batch fermentation and an adaptive laboratory evolution,the strain finally achieved a pyruvate titer of 45.86 g/L.[Conclusion]This study illustrated the efficacy of a gene editing strategy predicted by a genome-scale metabolic network model in enhancing pyruvate accumulation in E.coli under anaerobic conditions and provided novel insights for microbial metabolic engineering.
基金National Natural Science Foundation of China:Basic Research on the Mechanism of Organ Immune Damage and the Diagnosis and Treatment of Integrated Traditional Chinese and Western Medicine(No.32141005)。
文摘OBJECTIVE:To investigate the impact of Shenhua tablet(肾华片,SHT)on renal macrophage polarization and renal injury in mice with diabetic kidney disease(DKD)and to explore the potential mechanism involving the hypoxia-inducible factor-1α(HIF-1α)and pyruvate kinase M2(PKM2)signaling pathway,along with the glycolysis metabolism pathway.METHODS:The animals were divided into the following groups:Model,Control,dapagliflozin,SHT low-dose,SHT medium-dose,and SHT high-dose.We assessed 24-hour urine protein(24 h-UTP)levels,urinary albuminto-creatinine ratio,and regularly monitored fasting blood glucose during the treatment period.After treatment,we examined renal tissue structure,renal function(urea nitrogen,uric acid,creatinine,cystatin C,β2-microglobulin),and glycolysis in renal macrophages.Additionally,we observed macrophage polarization in renal tissue and measured inflammatory factors(tumor necrosis factor-α,interleukin-1β,interleukin-6,interleukin-10,monocyte chemoattractant protein-1)to assess the immunoinflammatory status of the renal tissue.Finally,we investigated the expression of the HIF-1α/PKM2 signaling pathway in macrophages to explore its role in the glycolysis process.RESULTS:SHT shows a beneficial effect in treating DKD by reducing 24 h-UTP,regulating blood glucose levels,improving renal tissue structure,protecting renal function,inhibiting macrophage glycolysis,reducing macrophage transformation to the M1 state,and suppressing the expression of the HIF-1α/PKM2 signaling pathway.CONCLUSION:SHT may exert renoprotective effects by inhibiting macrophage glycolysis via the HIF-1α/PKM2 signaling pathway.This inhibition decreases macrophage M1 polarization and reduces immunoinflammatory injury in the renal tissue of DKD mice.
基金Joint Fund of Science and Technology R&D Plan of Henan Province,Grant/Award Number:232103810056Special Project for Key R&D and Promotion of Henan Province,Grant/Award Number:232102311233 and 242102311034National Natural Science Foundation of China,Grant/Award Number:82170058 and 82241007。
文摘Background:Metabolic abnormalities are considered to play a key regulatory role in vascular remodeling of pulmonary arterial hypertension.However,to date,there is a paucity of research documenting the changes in metabolome profiles within the su-pernatants of pulmonary artery smooth muscle cells(PASMC)during their transition from a contractile to a synthetic phenotype.Methods:CCK-8 and Edu staining assays were used to evaluate the cell viability and proliferation of human PASMCs.IncuCyte ZOOM imaging system was used to continuously and automatically detect the migration of the PASMCs.A targeted me-tabolomics profiling was performed to quantitatively analyze 121 metabolites in the supernatant.Orthogonal partial least squares discriminant analysis was used to dis-criminate between PDGF-BB-induced PASMCs and controls.Metabolite set enrich-ment analysis was adapted to exploit the most disturbed metabolic pathways.Results:Human PASMCs exhibited a transformation from contractile phenotype to synthetic phenotype after PDGF-BB induction,along with a significant increase in cell viability,proliferation,and migration.Metabolites in the supernatants of PASMCs treated with or without PDGF-BB were well profiled.Eleven metabolites were found to be significantly upregulated,whereas seven metabolites were downregulated in the supernatants of PASMCs induced by PDGF-BB compared to the vehicle-treated cells.Fourteen pathways were involved,and pyruvate metabolism pathway was ranked first with the highest enrichment impact followed by glycolysis/gluconeogen-esis and pyrimidine metabolism.Conclusions:Significant and extensive metabolic abnormalities occurred during the phenotypic transformation of PASMCs.Disturbance of pyruvate metabolism pathway might contribute to pulmonary vascular remodeling.
基金funded by National Social Science Foundation if Gansu Province(24JRRA694)Scientific and Technological Development Guiding Plan Project of Lanzhou City(2023-ZD-62,2024-9-52)GanSu Health Industry Planning Project(GSWSKY2024-51).
文摘This review focuses on the metabolic issues related to mitochondrial pyruvate dehydrogenase phosphatase(PDP)in malignant tumors and its potential mechanisms.Recent research on tumor metabolic mechanisms has shown that PDP dysregulation is closely linked to metabolic reprogramming in tumor cells,and potentially promotes tumor.Research has comprehensively explored the structural-functional characteristics of PDP,its metabolic regulatory mechanisms,and its role in various types of malignant tumors.Nevertheless,several questions still exist regarding its potential mechanisms within acetylation,phosphorylation,hypoxia,immune infiltration,mitochondrial metabolism,drug resistance,oxidative phosphorylation,and tumor prognosis.This article intends to summarize the latest research,examine PDP’s potential as a therapeutic target,and propose future research directions to enhance cancer treatment strategies.
文摘The development of cancer cell resistance to conventional treatments continues to be a major obstacle in the successful treatment of tumors of many types.The discovery of a highly efficient direct and indirect free radical scavenger,melatonin,in the mitochondrial matrix may be a factor in determining both the occurrence of cancer cell drug insensitivity as well as radioresistance.This relates to two of the known hallmarks of cancer,i.e.,exaggerated free radical generation in the mitochondria and the development ofWarburg type metabolism(glycolysis).The hypothesis elaborated in this report assumes that the high oxidative environment in the mitochondria contributes to a depression of local melatonin levels because of its overuse in neutralizing the massive amount of free radial produced.Moreover,Warburg typemetabolism and chemoresistance are functionally linked and supplementalmelatonin has been shown to reverse glycolysis and convert glucose processing to the type that occurs in normal cells.Since thismetabolic type is a key factor in determining chemoresistance,melatonin would predictably also negate cancer drug insensitivity.The possible mechanisms by which melatonin may interfere either directly or indirectly with drug resistance are summarized in the current review.
