This study was conducted to evaluate the effect of lactic acid bacteria and propionic acid on the fermentation quality, aer- obic stability and in vitro gas production kinetics and digestibility of whole-crop corn bas...This study was conducted to evaluate the effect of lactic acid bacteria and propionic acid on the fermentation quality, aer- obic stability and in vitro gas production kinetics and digestibility of whole-crop corn based totalmixed ration （TMR） silage. Total mixed ration was ensiled with four treatments： （1） no additives （control）; （2） an inoculant （Lactobacillus plantarum） （L）; （3） propionicacid （P）; （4） propionic acid＋lactic acid bacteria （PL）. All treatments were ensiled in laboratory-scale silos for 45 days, and then subjected to an aerobic stability test for12 days. Further, four TMR silages were incubated in vitro with buffered rumen fluid to study in vitro gas production kinetics and digestibility. The results indicated that all TMR silages had good fermentation characteristics with low pH （〈3.80） and ammonia nitrogen （NH3-N） contents, and high lactic acid contents as well as Flieg points. Addition of L further improved TMR silage quality with more lactic acid production. Addition of P and PL decreased lactic acid and NH3-N contents of TMR silage compared to the control （P〈0.05）. After 12 days aerobic exposure, P and PL silages remained stable, but L and the control silages deteriorated as indicated by a reduction in lactic acid and an increase in pH, and numbers of yeast. Compared to the control, addition of L had no effects on TMR silage in terms of 72 h cumulative gas production, in vitro dry matter digestibility, metabolizable energy, net energy for lactation and short chain fatty acids, whereas addition of PL significantly （P〈0.05） increased them. L silage had higher （P〈0.05） in vitro neutral detergent fiber digestibility than the control silage. The results of our study suggested that TMR silage prepared with whole-crop corn can be well preserved with or without additives. Furthermore, the findings of this study suggested that propionic acid is compatible with lactic acid bacteria inoculants, and when used together, although they reduced lactic acid production of TMR silage, they improved aerobic stability and in vitro nutrients digestibility of TMR silage.展开更多
The title compound was synthesized and its crystal structure was determined by single-crystal X-ray diffraction.The crystal is of orthorhombic system（C21H18ClNO4,Mr = 383.81）,space group Pca21 with a = 13.913（3）,b...The title compound was synthesized and its crystal structure was determined by single-crystal X-ray diffraction.The crystal is of orthorhombic system（C21H18ClNO4,Mr = 383.81）,space group Pca21 with a = 13.913（3）,b = 10.273（2）,c = 26.488（5）,V = 3786.1（13） 3,Z = 8,Dc = 1.347 g/cm3,F（000） = 1600,μ = 0.228 mm-1,the final R = 0.0550 and wR = 0.1278 for 5065 observed reflections（I 2σ（I））.The title compound in a racemic form was found to exist as a mixture of two enantiomers in an equal ratio in the unit cell.The intermolecular hydrogen bonds link the molecules in a head-to-end manner to generate an infinite chain.展开更多
Neuronal mitochondrial dysfunction increases inflammatory mediators and leads to free radical generation and anti-oxidant enzymatic alterations,which are major neuropathological hallmarks responsible for autism.Mitoch...Neuronal mitochondrial dysfunction increases inflammatory mediators and leads to free radical generation and anti-oxidant enzymatic alterations,which are major neuropathological hallmarks responsible for autism.Mitochondrial dysfunction in autism is associated with decreased ATP levels due to reduced levels of cyclic adenosine monophosphate.Rat models of autism were established by intracerebroventricular injection of propionic acid.These rat models had memory dysfunction,decreased muscle coordination and gait imbalance.Biochemical estimation of propionic acid-treated rats showed changes in enzyme activity in neuronal mitochondrial electron transport chain complexes and increases in pro-inflammatory cytokines,oxidative stress and lipid biomarkers.Oral administration of 10,20 and 30 mg/kg adenylate cyclase activator forskolin for 15 days reversed these changes in a dose-dependent manner.These findings suggest that forskolin can alleviate neuronal mitochondrial dysfunction and improve neurological symptoms of rats with autism.This study was approved by the RITS/IAEC,SIRSA,HARYANA on March 3,2014(approval No.RITS/IAEC/2014/03/03).展开更多
The feeding method of propionic acid for production ofpoly(3-hydroxybutyrate-co-3-hydro xyvalerate) [P(3HB-co-3HV)] by fed-batch culture of Ralstoniaeutropha was optimized to achieve high cell density and high 3HV yie...The feeding method of propionic acid for production ofpoly(3-hydroxybutyrate-co-3-hydro xyvalerate) [P(3HB-co-3HV)] by fed-batch culture of Ralstoniaeutropha was optimized to achieve high cell density and high 3HV yield. Effects of different feedingstrategies of propionic acid on the production of P(3HB-co-3HV) were investigated. A decline ofspecific synthesis rate of copolymer and the yield of 3HV unit from propionic acid were observed dueto the propionic acid accumulation in culture broth when the feeding solution with highP/G(propionic acid to glucose) ratio was employed. It was further confirmed by controlling propionicacid concentration at a low level in the separate feeding of propionic acid. An optimal feedingstrategy was demonstrated to reduce the propionic acid accumulation. The cell concentration,P(3HB-co-3HV) productivity and 3HV unit fraction reached to 163.9kg·m^(-3), 1.8kg·m^(-3)·h^(-1),and 10.6%(by mass), respectively, resulting in a yield of 0.33g HV per g propionic acid.展开更多
R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2p...R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2phenoxypropionic acid(RPPA)at C4 position with microbes.In order to provide sufficient RPPA for the industrial production of RHPPA,an effective RPPA synthesis method was established and optimized in this work.The synthesis process mainly consisted of two steps:(1)synthesis of S2chloropropionic acid from Lalanine via diazotization and chlorination reactions;and(2)synthesis of RPPA from S2chloropropionic acid and phenol via etherification reaction.The optimal reaction conditions were as follows:HCl:NaNO_(2):KI:LAla=2.0:1.2:0.7:1.0(in molar),125℃reflux for 1.5 h,with KI as catalyst,and KI:S2chloropropionic acid:phenol=0.075:1.2:1.0(in molar).Under these conditions,an improved molar conversion rate(74.9%,calculated in phenol)was achieved.After extraction using anionic exchange resin Amberlite IRA400(CI),RPPA product with a purity of 95.08%was obtained.The purified RPPA was identified and evaluated in the application of the biotransformative production of RHPPA.The results indicated that the synthesized RPPA supported the RHPPA biosynthesis with a comparable yield as that of the standard RPPA.The RPPA synthesis method provided herein exhibited the advantages of low price and easy availability of raw materials,less toxicity of reagents,simple manipulations,and low equipment/instrument requirements.展开更多
A rapid and simple method is presented for determining β-N-oxalyl-α. β- diaminopropionic acid (β -ODAP) and its much less toxic α -isomer (α -ODAP) in Lathyrus sativus. Seed and foliage extracts of Lathyrus sat...A rapid and simple method is presented for determining β-N-oxalyl-α. β- diaminopropionic acid (β -ODAP) and its much less toxic α -isomer (α -ODAP) in Lathyrus sativus. Seed and foliage extracts of Lathyrus sativus were treated with 1-fluoro-2,4-dinitrobenzene (FDNB) and a reversed-phase high-performance liquid chromatographic method for the separation of the derivatives in the pmol range is reported.展开更多
Effects of salt and temperature on the liquid phase equilibrium of the(water + propionic acid + cyclohexanol) system were investigated.The liquid-liquid equilibrium data in the presence of KCl for various salt ionic s...Effects of salt and temperature on the liquid phase equilibrium of the(water + propionic acid + cyclohexanol) system were investigated.The liquid-liquid equilibrium data in the presence of KCl for various salt ionic strength of 0.5,1.0,1.5,2.0,and 2.5 mol·dm3 and in absence of the salt at T=(298.2,303.2,and 308.2)K were determined.The experimental results were correlated based on the Othmer-Tobias equation and Pitzer ion-interaction model.Thermodynamic properties such as distribution coefficients and activity coefficients of propionic acid in water + cyclohexanol were determined.In addition,the separation factor,S,of the chosen solvent was obtained for the investigated system.展开更多
This paper reports on the resolution of(R,S)-2-(4-methylphenyl)propionic acid(MPPA)enantiomers by enzymatic esterification in organic solvent.Novozym 435(CALB)has the best catalytic performance compared with other lip...This paper reports on the resolution of(R,S)-2-(4-methylphenyl)propionic acid(MPPA)enantiomers by enzymatic esterification in organic solvent.Novozym 435(CALB)has the best catalytic performance compared with other lipases.Of the alcohols screened,n-hexanol is the best acyl acceptor and gives the highest enzyme activity and enantioselectivity in n-hexane.Response surface methodology(RSM)was used to evaluate the influence of the factors,such as temperature,enzyme amount,substrate concentration and reaction time on the substrate conversion(c)and enantiomeric excess(ee).The correlation coefficient R2 for enantiomeric excess and the conversion are 0.9827 and 0.9910,respectively,indicating that can accurately predict the experimental results.By simulation and optimization,the optimal conditions were obtained,involving 600 mmol·L^-1 MPPA concentration(0.60 mmol),850 mmol·L^-1 hexanol concentration(0.85 mmol),58 mg enzyme amount,75℃temperature and 4.5 h reaction time,respectively.Under the optimized conditions,the experimental values of conversion and enantiomeric excess were 89.34%and 97.84%,respectively,which are in good agreement with the model predictions.展开更多
Mild stir-assisted membrane dispersion extraction(MDE) method was employed to enhance propionic acid(HA)extraction and compared to the mechanical stirred extraction(MSE) method. Triocylamine(TOA) and tributyl phosphat...Mild stir-assisted membrane dispersion extraction(MDE) method was employed to enhance propionic acid(HA)extraction and compared to the mechanical stirred extraction(MSE) method. Triocylamine(TOA) and tributyl phosphate(TBP) were chosen as model extractant to extract HA. Firstly, droplet size and the size distribution of organic phase were analyzed, and then the effects of phase ratio, extractant and HA concentration on extraction performance were investigated. Comparing the two extraction methods, the results show mild stir-assisted MDE method reduced the mass transfer equilibrium time compared to MSE method. The mass transfer mechanism was explored by analyzing mass transfer resistance. Mild stir-assisted MDE had less total mass transfer resistance than MSE. When the extractant concentration was 40%, the extraction process was controlled by organic phase mass transfer process with HA volume fraction was 1% and controlled by both of reaction process and organic phase mass transfer process when HA concentration increased to 5%. This work may provide a new type of extraction method for the recovery of organic carboxylic acid.展开更多
(S)-2-(6'-methoxyl alpha:-naphthyl) propionic acid ((S) Naproxen,: ee 99%) has been prepared starting from (6-methoxyl-alpha -naphthyl)propan-1-one and D-Sorbitol under SmCl3 catalysis.
This study aimed to investigate the number of amino methyl isoxazole propionic acid （AMPA） receptors and production of endogenous neural stem cells in the SOD1 G93AG1H transgenic mouse model of amyotrophic lateral s...This study aimed to investigate the number of amino methyl isoxazole propionic acid （AMPA） receptors and production of endogenous neural stem cells in the SOD1 G93AG1H transgenic mouse model of amyotrophic lateral sclerosis, at postnatal day 60 following administration of basic fibroblast growth factor （FGF-2）. A radioligand binding assay and immunohistochemistry were used to estimate the number of AMPA receptors and endogenous neural stem cells respectively. Results showed that the number of AMPA receptors and endogenous neural stem cells in the brain stem and sensorimotor cortex were significantly increased, while motor function was significantly decreased at postnatal days 90 and 120. After administration of FGF-2 into mice, numbers of endogenous neural stem cells increased, while expression of AMPA receptors decreased, whilst motor functions were recovered. At postnatal day 120, the number of AMPA receptors was negatively correlated with the number of endogenous neural stem cells in model mice and FGF-2-treated mice. Our experimental findings indicate that FGF-2 can inhibit AMPA receptors and increase the number of endogenous neural stem cells, thus repairing neural injury in amyotrophic lateral sclerosis mice.展开更多
Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55℃?- 60℃, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa i...Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55℃?- 60℃, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa is formed. The constitution is based on dates of spectrums 1Н and 13С NMR. At 95℃?- 97℃, mixtures of 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa and of 6,8-di-tert-butyl-3-(N-acetylamine)spiro(4,5)deca-1-oxa-5,8-dien-2,7-dione are produced. Structures are calculated by the method of Hartrii-Foka. Values of enthalpies and of entropies allow to assume dynamic isomerism.展开更多
AIM： To compare the anti-inflammatory properties of butyrate with two other SCFAs, namely acetate and propionate, which have less well-documented effects on inflammation. METHODS： The effect of SCFAs on cytokine rel...AIM： To compare the anti-inflammatory properties of butyrate with two other SCFAs, namely acetate and propionate, which have less well-documented effects on inflammation. METHODS： The effect of SCFAs on cytokine release from human neutrophils was studied with EHSA. SCFA- dependent modulation of NF-κB reporter activity was assessed in the human colon adenocarcinoma cell line, Colo320DM. Finally, the effect of SCFAs on gene expression and cytokine release, measured with RT-PCR and ELISA, respectively, was studied in mouse colon organ cultures established from colitic mice. RESULTS： Acetate, propionate and butyrate at 30 mmol/L decreased LPS-stimulated TNFα release from neutrophils, without affecting IL-8 protein release. All SCFAs dose dependently inhibited NF-κB reporter activity in Colo320DM cells. Propionate dose-dependently suppressed IL-6 mRNA and protein release from colon organ cultures and comparative studies revealed that propionate and butyrate at 30 mmol/L caused a strong inhibition of immune-related gene expression, whereas acetate was less effective. A similar inhibition was achieved with the proteasome inhibitor MG-132, but not the p38 MAPK inhibitor SB203580. All SCFAs decreased IL-6 protein release from organ cultures. CONCLUSION： In the present study propionate and butyrate were equipotent, whereas acetate was less effective, at suppressing NF-κB reporter activity, immune-related gene expression and cytokine release in vitro. Our findings suggest that propionate and acetate, in addition to butyrate, could be useful in the treatment of inflammatory disorders, including IBD.展开更多
Ruminal acidosis is a prevalent disorder in ruminants such as dairy cows and feedlot beef cattle, caused primarily by the inclusion of a high percentage of readily fermentable concentrates in the diet. The disorder pr...Ruminal acidosis is a prevalent disorder in ruminants such as dairy cows and feedlot beef cattle, caused primarily by the inclusion of a high percentage of readily fermentable concentrates in the diet. The disorder presents as an accumulation of lactic acid, a decrease of pH in the rumen and a subsequent imbalance of the rumen fermentation process with detrimental impacts on the animal＇s health and productivity. Dairy propionibacteria, a group of bacteria characterised by utilization of lactic acid as the favoured carbon source, with propionic acid produced as a by-product, were evaluated in this study as potential direct-fed microbials for use in controlling ruminal acidosis. Acidosis was simulated by introduction of high concentrations of lactic acid into rumen fluid samples and a multi-strain in vitro analysis was conducted, whereby changes in pH and lactic acid metabolism were compared in identical acidified rumen samples, following inoculation with various propionibacteria. This was followed by a study to evaluate the effect of bacterial inoculation dosage on acid metabolism. The results indicated that lactic acid levels in the rumen fluid were significantly reduced, and propionic acid and acetic acid concentrations both significantly increased, following addition of propionibacteria. Significant ＇between strains＇ differences were observed, with Propionibacterium acidopropionici 341, Propionibacterium freudenreichfi CSCC 2207, Propionibacterium jensenfi NCFB 572 and P. jensenii 702 each producing more rapid reduction of lactic acid concentration than P. freudenreich# CSCC 2206, P. acidopropionici ATCC 25562 and Propionibacterium thoenii ATCC 4874. Furthermore, the efficacy of this application was dosage related, with the rates of reduction in lactic acid levels and production of propionic acid, both significantly greater for the higher （10^10 cfu mL-1） compared with lower （10^5 cfu mL-1） dosage inoculation. The results confirmed that the introduction of propionibacteria could promote more rapid reduction of lactic acid levels than would occur without their addition, demonstrating their potential in controlling ruminal acidosis.展开更多
Background: It is postulated that the concentrations of the major strong ions (Na, K, and Cl) in oral electrolyte solutions play a major role in clinical efficacy of these solutions for rehydration and corrections of ...Background: It is postulated that the concentrations of the major strong ions (Na, K, and Cl) in oral electrolyte solutions play a major role in clinical efficacy of these solutions for rehydration and corrections of metabolic acid base derangements. Objectives: The purpose of this study was to test prospectively the efficacy of an OES (OESexp) formulated based on concentration of strong ion difference (SID) and propionate in a group of calves with naturally occurring neonatal diarrhea and clinically detectable dehydration and acid base abnormalities. Animals: Ten client owned calves of varying breeds, 2 - 22 days old, presented to a veterinary teaching hospital with a history of naturally occurring acute undifferentiated diarrhea, progressive depression and dehydration for treatment. Methods: Clinical and laboratory parameters were measured pre and post two oral electrolyte treatments to assess efficacy of the experimental OES to correct clinical and clinico pathological parameters. For the clinical trial the calves served as their own controls. For control of safety of medication 4 normal calves were force fed 4 L of OESexp and followed over a 24 hour period. Results: All calves had severe diarrhea and metabolic acidosis. The metabolic acidosis observed in the plasma of these calves and reflected by pH, HCO3- SID and base deficit was corrected significantly towards reference ranges (p < 0.05) with two 2 L feedings 12 hours apart. Dehydration was significantly corrected and all calves were discharged 1 - 3 days post admission. Conclusion and Clinical Importance: The use of SID is a valid approach when formulating oral electrolytes solutions for use in calves with acute diarrhea and metabolic derangement. Sodium propionate is valid substitute for commonly used sodium base equivalents in North America in oral electrolyte solutions.展开更多
基金supported by the project of Jiangsu Independent Innovation,China(CX(15)1003-3)the Key Technologies R&D Program of China during the 13th Five-Year Plan period(2016YFC0502005)the Special Project of Grass of Tibet Autonomous Region for the 13th Five-Year Plan,China
文摘This study was conducted to evaluate the effect of lactic acid bacteria and propionic acid on the fermentation quality, aer- obic stability and in vitro gas production kinetics and digestibility of whole-crop corn based totalmixed ration （TMR） silage. Total mixed ration was ensiled with four treatments： （1） no additives （control）; （2） an inoculant （Lactobacillus plantarum） （L）; （3） propionicacid （P）; （4） propionic acid＋lactic acid bacteria （PL）. All treatments were ensiled in laboratory-scale silos for 45 days, and then subjected to an aerobic stability test for12 days. Further, four TMR silages were incubated in vitro with buffered rumen fluid to study in vitro gas production kinetics and digestibility. The results indicated that all TMR silages had good fermentation characteristics with low pH （〈3.80） and ammonia nitrogen （NH3-N） contents, and high lactic acid contents as well as Flieg points. Addition of L further improved TMR silage quality with more lactic acid production. Addition of P and PL decreased lactic acid and NH3-N contents of TMR silage compared to the control （P〈0.05）. After 12 days aerobic exposure, P and PL silages remained stable, but L and the control silages deteriorated as indicated by a reduction in lactic acid and an increase in pH, and numbers of yeast. Compared to the control, addition of L had no effects on TMR silage in terms of 72 h cumulative gas production, in vitro dry matter digestibility, metabolizable energy, net energy for lactation and short chain fatty acids, whereas addition of PL significantly （P〈0.05） increased them. L silage had higher （P〈0.05） in vitro neutral detergent fiber digestibility than the control silage. The results of our study suggested that TMR silage prepared with whole-crop corn can be well preserved with or without additives. Furthermore, the findings of this study suggested that propionic acid is compatible with lactic acid bacteria inoculants, and when used together, although they reduced lactic acid production of TMR silage, they improved aerobic stability and in vitro nutrients digestibility of TMR silage.
基金Supported by the Key Project of National Innovative Drug(2011ZX09401-009)
文摘The title compound was synthesized and its crystal structure was determined by single-crystal X-ray diffraction.The crystal is of orthorhombic system（C21H18ClNO4,Mr = 383.81）,space group Pca21 with a = 13.913（3）,b = 10.273（2）,c = 26.488（5）,V = 3786.1（13） 3,Z = 8,Dc = 1.347 g/cm3,F（000） = 1600,μ = 0.228 mm-1,the final R = 0.0550 and wR = 0.1278 for 5065 observed reflections（I 2σ（I））.The title compound in a racemic form was found to exist as a mixture of two enantiomers in an equal ratio in the unit cell.The intermolecular hydrogen bonds link the molecules in a head-to-end manner to generate an infinite chain.
文摘Neuronal mitochondrial dysfunction increases inflammatory mediators and leads to free radical generation and anti-oxidant enzymatic alterations,which are major neuropathological hallmarks responsible for autism.Mitochondrial dysfunction in autism is associated with decreased ATP levels due to reduced levels of cyclic adenosine monophosphate.Rat models of autism were established by intracerebroventricular injection of propionic acid.These rat models had memory dysfunction,decreased muscle coordination and gait imbalance.Biochemical estimation of propionic acid-treated rats showed changes in enzyme activity in neuronal mitochondrial electron transport chain complexes and increases in pro-inflammatory cytokines,oxidative stress and lipid biomarkers.Oral administration of 10,20 and 30 mg/kg adenylate cyclase activator forskolin for 15 days reversed these changes in a dose-dependent manner.These findings suggest that forskolin can alleviate neuronal mitochondrial dysfunction and improve neurological symptoms of rats with autism.This study was approved by the RITS/IAEC,SIRSA,HARYANA on March 3,2014(approval No.RITS/IAEC/2014/03/03).
文摘The feeding method of propionic acid for production ofpoly(3-hydroxybutyrate-co-3-hydro xyvalerate) [P(3HB-co-3HV)] by fed-batch culture of Ralstoniaeutropha was optimized to achieve high cell density and high 3HV yield. Effects of different feedingstrategies of propionic acid on the production of P(3HB-co-3HV) were investigated. A decline ofspecific synthesis rate of copolymer and the yield of 3HV unit from propionic acid were observed dueto the propionic acid accumulation in culture broth when the feeding solution with highP/G(propionic acid to glucose) ratio was employed. It was further confirmed by controlling propionicacid concentration at a low level in the separate feeding of propionic acid. An optimal feedingstrategy was demonstrated to reduce the propionic acid accumulation. The cell concentration,P(3HB-co-3HV) productivity and 3HV unit fraction reached to 163.9kg·m^(-3), 1.8kg·m^(-3)·h^(-1),and 10.6%(by mass), respectively, resulting in a yield of 0.33g HV per g propionic acid.
文摘R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2phenoxypropionic acid(RPPA)at C4 position with microbes.In order to provide sufficient RPPA for the industrial production of RHPPA,an effective RPPA synthesis method was established and optimized in this work.The synthesis process mainly consisted of two steps:(1)synthesis of S2chloropropionic acid from Lalanine via diazotization and chlorination reactions;and(2)synthesis of RPPA from S2chloropropionic acid and phenol via etherification reaction.The optimal reaction conditions were as follows:HCl:NaNO_(2):KI:LAla=2.0:1.2:0.7:1.0(in molar),125℃reflux for 1.5 h,with KI as catalyst,and KI:S2chloropropionic acid:phenol=0.075:1.2:1.0(in molar).Under these conditions,an improved molar conversion rate(74.9%,calculated in phenol)was achieved.After extraction using anionic exchange resin Amberlite IRA400(CI),RPPA product with a purity of 95.08%was obtained.The purified RPPA was identified and evaluated in the application of the biotransformative production of RHPPA.The results indicated that the synthesized RPPA supported the RHPPA biosynthesis with a comparable yield as that of the standard RPPA.The RPPA synthesis method provided herein exhibited the advantages of low price and easy availability of raw materials,less toxicity of reagents,simple manipulations,and low equipment/instrument requirements.
基金Tshe prOject!(39770469) supported by the National Natural Science Foundation of China.
文摘A rapid and simple method is presented for determining β-N-oxalyl-α. β- diaminopropionic acid (β -ODAP) and its much less toxic α -isomer (α -ODAP) in Lathyrus sativus. Seed and foliage extracts of Lathyrus sativus were treated with 1-fluoro-2,4-dinitrobenzene (FDNB) and a reversed-phase high-performance liquid chromatographic method for the separation of the derivatives in the pmol range is reported.
文摘Effects of salt and temperature on the liquid phase equilibrium of the(water + propionic acid + cyclohexanol) system were investigated.The liquid-liquid equilibrium data in the presence of KCl for various salt ionic strength of 0.5,1.0,1.5,2.0,and 2.5 mol·dm3 and in absence of the salt at T=(298.2,303.2,and 308.2)K were determined.The experimental results were correlated based on the Othmer-Tobias equation and Pitzer ion-interaction model.Thermodynamic properties such as distribution coefficients and activity coefficients of propionic acid in water + cyclohexanol were determined.In addition,the separation factor,S,of the chosen solvent was obtained for the investigated system.
基金supported by the National Natural Science Foundation of China(21676077)。
文摘This paper reports on the resolution of(R,S)-2-(4-methylphenyl)propionic acid(MPPA)enantiomers by enzymatic esterification in organic solvent.Novozym 435(CALB)has the best catalytic performance compared with other lipases.Of the alcohols screened,n-hexanol is the best acyl acceptor and gives the highest enzyme activity and enantioselectivity in n-hexane.Response surface methodology(RSM)was used to evaluate the influence of the factors,such as temperature,enzyme amount,substrate concentration and reaction time on the substrate conversion(c)and enantiomeric excess(ee).The correlation coefficient R2 for enantiomeric excess and the conversion are 0.9827 and 0.9910,respectively,indicating that can accurately predict the experimental results.By simulation and optimization,the optimal conditions were obtained,involving 600 mmol·L^-1 MPPA concentration(0.60 mmol),850 mmol·L^-1 hexanol concentration(0.85 mmol),58 mg enzyme amount,75℃temperature and 4.5 h reaction time,respectively.Under the optimized conditions,the experimental values of conversion and enantiomeric excess were 89.34%and 97.84%,respectively,which are in good agreement with the model predictions.
基金Supported by the Chinese High Technology Research and Development Program(2015CB251402,17-163-12-ZD-001-013-01)the National Natural Science Foundation of China(21676215,21676273,U1507203)+3 种基金China Petroleum Enterprise Cooperation Project(PRIKY17094)China Postdoctoral Science Foundation(2018M633556)the Youth Innovation Promotion Association,CAS(2016043)the Shaanxi Provincial Science Foundation(2017SF-201,2018JQ2052).
文摘Mild stir-assisted membrane dispersion extraction(MDE) method was employed to enhance propionic acid(HA)extraction and compared to the mechanical stirred extraction(MSE) method. Triocylamine(TOA) and tributyl phosphate(TBP) were chosen as model extractant to extract HA. Firstly, droplet size and the size distribution of organic phase were analyzed, and then the effects of phase ratio, extractant and HA concentration on extraction performance were investigated. Comparing the two extraction methods, the results show mild stir-assisted MDE method reduced the mass transfer equilibrium time compared to MSE method. The mass transfer mechanism was explored by analyzing mass transfer resistance. Mild stir-assisted MDE had less total mass transfer resistance than MSE. When the extractant concentration was 40%, the extraction process was controlled by organic phase mass transfer process with HA volume fraction was 1% and controlled by both of reaction process and organic phase mass transfer process when HA concentration increased to 5%. This work may provide a new type of extraction method for the recovery of organic carboxylic acid.
文摘(S)-2-(6'-methoxyl alpha:-naphthyl) propionic acid ((S) Naproxen,: ee 99%) has been prepared starting from (6-methoxyl-alpha -naphthyl)propan-1-one and D-Sorbitol under SmCl3 catalysis.
基金supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars of the State Education Ministry, No. (2007)1108Key Program of Tianjin Municipal Health Bureau, No. 09KR04
文摘This study aimed to investigate the number of amino methyl isoxazole propionic acid （AMPA） receptors and production of endogenous neural stem cells in the SOD1 G93AG1H transgenic mouse model of amyotrophic lateral sclerosis, at postnatal day 60 following administration of basic fibroblast growth factor （FGF-2）. A radioligand binding assay and immunohistochemistry were used to estimate the number of AMPA receptors and endogenous neural stem cells respectively. Results showed that the number of AMPA receptors and endogenous neural stem cells in the brain stem and sensorimotor cortex were significantly increased, while motor function was significantly decreased at postnatal days 90 and 120. After administration of FGF-2 into mice, numbers of endogenous neural stem cells increased, while expression of AMPA receptors decreased, whilst motor functions were recovered. At postnatal day 120, the number of AMPA receptors was negatively correlated with the number of endogenous neural stem cells in model mice and FGF-2-treated mice. Our experimental findings indicate that FGF-2 can inhibit AMPA receptors and increase the number of endogenous neural stem cells, thus repairing neural injury in amyotrophic lateral sclerosis mice.
文摘Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55℃?- 60℃, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa is formed. The constitution is based on dates of spectrums 1Н and 13С NMR. At 95℃?- 97℃, mixtures of 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa and of 6,8-di-tert-butyl-3-(N-acetylamine)spiro(4,5)deca-1-oxa-5,8-dien-2,7-dione are produced. Structures are calculated by the method of Hartrii-Foka. Values of enthalpies and of entropies allow to assume dynamic isomerism.
文摘AIM： To compare the anti-inflammatory properties of butyrate with two other SCFAs, namely acetate and propionate, which have less well-documented effects on inflammation. METHODS： The effect of SCFAs on cytokine release from human neutrophils was studied with EHSA. SCFA- dependent modulation of NF-κB reporter activity was assessed in the human colon adenocarcinoma cell line, Colo320DM. Finally, the effect of SCFAs on gene expression and cytokine release, measured with RT-PCR and ELISA, respectively, was studied in mouse colon organ cultures established from colitic mice. RESULTS： Acetate, propionate and butyrate at 30 mmol/L decreased LPS-stimulated TNFα release from neutrophils, without affecting IL-8 protein release. All SCFAs dose dependently inhibited NF-κB reporter activity in Colo320DM cells. Propionate dose-dependently suppressed IL-6 mRNA and protein release from colon organ cultures and comparative studies revealed that propionate and butyrate at 30 mmol/L caused a strong inhibition of immune-related gene expression, whereas acetate was less effective. A similar inhibition was achieved with the proteasome inhibitor MG-132, but not the p38 MAPK inhibitor SB203580. All SCFAs decreased IL-6 protein release from organ cultures. CONCLUSION： In the present study propionate and butyrate were equipotent, whereas acetate was less effective, at suppressing NF-κB reporter activity, immune-related gene expression and cytokine release in vitro. Our findings suggest that propionate and acetate, in addition to butyrate, could be useful in the treatment of inflammatory disorders, including IBD.
基金The University of Newcastle,Australia for financial support
文摘Ruminal acidosis is a prevalent disorder in ruminants such as dairy cows and feedlot beef cattle, caused primarily by the inclusion of a high percentage of readily fermentable concentrates in the diet. The disorder presents as an accumulation of lactic acid, a decrease of pH in the rumen and a subsequent imbalance of the rumen fermentation process with detrimental impacts on the animal＇s health and productivity. Dairy propionibacteria, a group of bacteria characterised by utilization of lactic acid as the favoured carbon source, with propionic acid produced as a by-product, were evaluated in this study as potential direct-fed microbials for use in controlling ruminal acidosis. Acidosis was simulated by introduction of high concentrations of lactic acid into rumen fluid samples and a multi-strain in vitro analysis was conducted, whereby changes in pH and lactic acid metabolism were compared in identical acidified rumen samples, following inoculation with various propionibacteria. This was followed by a study to evaluate the effect of bacterial inoculation dosage on acid metabolism. The results indicated that lactic acid levels in the rumen fluid were significantly reduced, and propionic acid and acetic acid concentrations both significantly increased, following addition of propionibacteria. Significant ＇between strains＇ differences were observed, with Propionibacterium acidopropionici 341, Propionibacterium freudenreichfi CSCC 2207, Propionibacterium jensenfi NCFB 572 and P. jensenii 702 each producing more rapid reduction of lactic acid concentration than P. freudenreich# CSCC 2206, P. acidopropionici ATCC 25562 and Propionibacterium thoenii ATCC 4874. Furthermore, the efficacy of this application was dosage related, with the rates of reduction in lactic acid levels and production of propionic acid, both significantly greater for the higher （10^10 cfu mL-1） compared with lower （10^5 cfu mL-1） dosage inoculation. The results confirmed that the introduction of propionibacteria could promote more rapid reduction of lactic acid levels than would occur without their addition, demonstrating their potential in controlling ruminal acidosis.
文摘Background: It is postulated that the concentrations of the major strong ions (Na, K, and Cl) in oral electrolyte solutions play a major role in clinical efficacy of these solutions for rehydration and corrections of metabolic acid base derangements. Objectives: The purpose of this study was to test prospectively the efficacy of an OES (OESexp) formulated based on concentration of strong ion difference (SID) and propionate in a group of calves with naturally occurring neonatal diarrhea and clinically detectable dehydration and acid base abnormalities. Animals: Ten client owned calves of varying breeds, 2 - 22 days old, presented to a veterinary teaching hospital with a history of naturally occurring acute undifferentiated diarrhea, progressive depression and dehydration for treatment. Methods: Clinical and laboratory parameters were measured pre and post two oral electrolyte treatments to assess efficacy of the experimental OES to correct clinical and clinico pathological parameters. For the clinical trial the calves served as their own controls. For control of safety of medication 4 normal calves were force fed 4 L of OESexp and followed over a 24 hour period. Results: All calves had severe diarrhea and metabolic acidosis. The metabolic acidosis observed in the plasma of these calves and reflected by pH, HCO3- SID and base deficit was corrected significantly towards reference ranges (p < 0.05) with two 2 L feedings 12 hours apart. Dehydration was significantly corrected and all calves were discharged 1 - 3 days post admission. Conclusion and Clinical Importance: The use of SID is a valid approach when formulating oral electrolytes solutions for use in calves with acute diarrhea and metabolic derangement. Sodium propionate is valid substitute for commonly used sodium base equivalents in North America in oral electrolyte solutions.
