Equilibrium of Extraction of Succinic, Malic, Maleic and Fumaric Acids with Trioctylamine

Extraction equilibrium features of succinic acid, malic acid,maleic acid and fumaric acid were investi- gated systematically withtrioctylamine (TOA) in chloroform, 4-methyl-2-pentanone (MIBK) and1-octanol. Fourier transform-infrared (FTIR) spectroscopic analysisof organic samples loaded with the acid shows that amine forms 1:1complex of ion-pair association with succinic acid, malic acid andmaleic acid, and 1:1, 2:1 complex of ion-pair association withfumaric acid. It is proposed that the complex forms depend on thesecond dissociation constant of the dibasic acid, pK_a2.

Long-term and combined effects of N-[2-(nitrooxy)ethyl]-3-pyridinecarboxamide and fumaric acid on methane production,rumen fermentation, and lactation performance in dairy goats

Background:In recent years,nitrooxy compounds have been identified as promising inhibitors of methanogenesis in ruminants.However,when animals receive a nitrooxy compound,a high portion of the spared hydrogen is eructated as gas,which partly offsets the energy savings of CH4mitigation.The objective of the present study was to evaluate the long-term and combined effects of supplementation with N-[2-(nitrooxy)ethyl]-3-pyridinecarboxamide(NPD),a methanogenesis inhibitor,and fumaric acid(FUM),a hydrogen sink,on enteric CH4production,rumen fermentation,bacterial populations,apparent nutrient digestibility,and lactation performance of dairy goats.Results:Twenty-four primiparous dairy goats were used in a randomized complete block design with a 2×2factorial arrangement of treatments:supplementation without or with FUM(32 g/d)or NPD(0.5 g/d).All samples were collected every 3 weeks during a 12-week feeding experiment.Both FUM and NPD supplementation persistently inhibited CH4yield(L/kg DMI,by 18.8%and 18.1%,respectively)without negative influence on DMI or apparent nutrient digestibility.When supplemented in combination,no additive CH4suppression was observed.FUM showed greater responses in increasing the molar proportion of propionate when supplemented with NPD than supplemented alone(by 10.2%vs.4.4%).The rumen microbiota structure in the animals receiving FUM was different from that of the other animals,particularly changed the structure of phylum Firmicutes.Daily milk production and serum total antioxidant capacity were improved by NPD,but the contents of milk fat and protein were decreased,probably due to the bioactivity of absorbed NPD on body metabolism.Conclusions:Supplementing NPD and FUM in combination is a promising way to persistently inhibit CH4emissions with a higher rumen propionate proportion.However,the side effects of this nitrooxy compound on animals and its residues in animal products need further evaluation before it can be used as an animal feed additive.

The ornithine-urea cycle involves fumaric acid biosynthesis in Aureobasidium pullulans var.aubasidani,a green and eco-friendly process for fumaric acid production

The current petroleum chemical methods for fumaric acid production can cause heavy pollution and global warming.In this study,the engineered strains of A.pullulans var.aubasidani were found to be suitable for green fumaric acid producer.Removal and complementation of the relevant genes showed only the ornithine-urea cycle(OUC)was involved in high level fumarate biosynthesis which was controlled by the Ca^(2+)signaling pathway.Removal of both the GOX gene encoding glucose oxidase and the PKS1 gene encoding the polyketide synthase for 3,5-dihydroxydecanoic acid biosynthesis and overexpression of the PYC gene encoding pyruvate carboxylase made the strain e-PYC produce 88.1±4.3 g/L of fumarate at flask level and 93.9±0.8 g/L of fumarate during the fed-batch fermentation.As a yeast-like fungal strain,it was very easy to cultivate A.pullulans var.aubasidani DH177 and their mutants in the bioreactor and to edit its genomic DNAs to enhance fumarate production.It was found that 2 mol of CO_(2) could be fixed during a maximal theoretical yield of 2 mol of fumarate per mole of glucose consumed in the OUC.Therefore,the OUC-mediated fumarate biosynthesis pathway in A.pullulans var.aubasidani was a green and eco-friendly process for the global sustainable development and carbon neutrality.

Engineering a fumaric acid-responsive two-component biosensor for dynamic range improvement in Escherichia coli

Due to the selective permeability of the cytomembrane,high-yield fumaric acid strains form a steep difference between intra-and extracellular concentrations.Intracellular biosensors cannot detect the real concentration change of extracellular fumaric acid.To overcome this limitation,a two-component biosensor(TCB)that could respond to extracellular fumaric acid was designed based on the DcuS-DcuR two-component system.The two-component system consists of a histidine kinase(SK)and response regulator.SK is a transmembrane histidine kinase sensor that can detect concentration changes in extracellular compounds.To improve the dynamic range of the constructed fumaric acid TCB,we optimized the expression ratio and expression intensity of dcuS and dcuR.We found that the optimum expression ratio of dcuS:dcuR was 46:54.Under this ratio,the higher was the expression level,the greater the dynamic range.In addition,we modified the ATP-binding site on the DcuS,and the final dynamic range of the TCB reached 6.6-fold.Overall,the obtained fumaric acid-responsive TCB with a high dynamic range is reported for the first time,providing a synthetic biology tool for high-throughput screening and dynamic metabolic regulation of fumaric acid cell factories.

Syntheses and Crystal Structure of a New 3D Ag(I)-Fumaric Acid Framework, [Ag(hmt)(fma)_(1/2)·2H_2O]_n

A new silver(I) coordination polymer, [Ag(hmt)(fma) 1/2 ·2H 2O] n (1), (hmt=hexamethylenetetramine, fma=furmaric acid), was obtained by self assembly of hmt, fma and AgNO 3 in the mixed solvent of methanol, dichloromethane and water (CH 3OH∶CH 2Cl 2∶H 2O=5∶5∶1), and characterized by X ray diffraction analysis. Complex 1 belongs to orthorhombic space group Pbcn with cell parameters a =1 72043(5) nm, b = 1 19704(2) nm, c =1 11685(3) nm, V =2 30007(10) nm 3, Z =8, CCDC number: 194381. In complex 1, each hmt ligand acts as a μ 3 bridge to link three Ag(I) atoms and in turn every Ag(I) ion attaches to three hmt ligands to produce a 2D honeycomb network, which is further linked by the bidentate fma ligands to form a 3D noninterpenetrating open framework with one dimensional channels being filled by guest molecules.

Oxidation of furfural to maleic acid and fumaric acid in deep eutectic solvent(DES)under vanadium pentoxide catalysis

Furfural is an alternative feedstock and has been used for the production of maleic acid(MA)and fumaric acid(FA)by an oxidation process.Deep eutectic solvents(DESs)were used as the green solvents while sodium chlorate was used as an oxidant and vanadium pentoxide was used as the catalyst at 70-90°C under atmospheric pressure.It was found that several acidic DESs are valid,such as acetic acid/choline chloride(AA/ChCl)and propionic acid/choline chloride(PA/ChCl),and AA/ChCl DES was selected as the solvent for the conversion.The optimal DES is AA/ChCl,and the effect of the amount of oxidant,time,and temperature on the yield of the MA and FA has been systematically studied,and the conversion of furfural can reach 100%while the yield of the MA and FA reached 66.5%under reaction temperature of 80℃ for 12 h,which provides a new green route to synthesis valuable monomers from furfural.

Metabolically based liver damage pathophysiology in patients with urea cycle disorders-A new hypothesis

The underlying pathophysiology of liver dysfunction in urea cycle disorders(UCDs) is still largely elusive. There is some evidence that the accumulation of urea cycle(UC) intermediates are toxic for hepatocyte mitochondria. It is possible that liver injury is directly caused by the toxicity of ammonia. The rarity of UCDs, the lack of checking of iron level in these patients, superficial knowledge of UC and an underestimation of the metabolic role of fumaric acid, are the main reasons that are responsible for the incomprehension of the mechanism of liver injury in patients suffering from UCDs. Owing to our routine clinical practice to screen for iron overload in severely ill neonates, with the focus on the newborns suffering from acute liver failure, we report a case of citrullinemia with neonatal liver failure and high blood parameters of iron overload. We hypothesize that the key is in the decreased-deficient fumaric acid production in the course of UC in UCDs that causes several sequentially intertwined metabolic disturbances with final result of liver iron overload. The presented hypothesis could be easily tested by examining the patients suffering from UCDs, for liver iron overload. This could be easily performed in countries with a high population and comprehensive national register for inborn errors of metabolism. Conclusion: Providing the hypothesis is correct, neonatal liver damage in patients having UCD can be prevented by the supplementation of pregnant women with fumaric or succinic acid, prepared in the form of iron supplementation pills. After birth, liverdamage in patients having UCDs can be prevented by supplementation of these patients with zinc fumarate or zinc succinylate, as well.

The effects of Fumaderm~ on immunological function and cytokines in a rat model of adjuvant-induced arthritis

Objective To study the therapeutic effect of Fumaderm in Freund’s complete adjuvant-induced arthritis(AIA)in Spraque-Dawley rats.Methods Adjuvant-induced arthritis(AIA)was established by intradermal injection of 0.1 mL of Freund’s complete adjuvant(CFA)in the palmar surface of the right hindpaw and Fumaderm was delivered by oral gavage for 28 days.After CFA injection,the edema of the hindpaw was determined every two days.On 28 days after CFA injection,the lymphocyte subsets of peripheral blood and the cytokines were determined by flow cytometry,meanwhile the histopathological examination of ankle-joints of the animals was performed.Results Fumaderm had a significant therapeutic effect on AIA.The hindpaw swelling was reduced significantly in a dose-dependent manner.The ratio of peripheral blood T lymphocytes was improved obviously.Multiparameter cytokine analysis from peripheral blood CD4+ T cells showed a decrease of proinflammatory cytokines and an increase of anti-inflammatory cytokines in Fumaderm treated animals.A strongly reduced inflammatory response in the joint synovium was observed.Conclusion Fumaderm has potential anti-inflammatory effects on AIA rats.Further investigation is needed to elucidate the molecular mechanism involved in the clinical effect observed in the AIA model.

A 2-D Copper Coordination Polymer[Cu(4,4'-bpy)(H_(2)O)_(4)](C_(4)H_(2)O_(4))(H_(2)O)_(4)Integrated by Hydrogen Bonds and VDW Interactions

The title compound, [Cu(4,4-bpy)(H2O)4](C4H2O4)(H2O)4 1, has been syn- thesized by the reaction of Cu(NO3)23H2O with 4,4-bipyridine and fumaric acid, and structurally characterized by X-ray diffraction analysis. Its crystal structure belongs to monoclinic, space group C2/c with a = 16.6350(5), b = 11.1667(2), c = 13.1371(4) ? = 125.144(1), C14H26CuN2O12, Mr = 477.91, Z = 4, V = 1995.47(9) 3, Dx = 1.591 g/cm3, m = 1.160 mm-1, F(000) = 996, R = 0.0331 and wR = 0.0883 for 1765 observed reflections (I > 2(I)). A two-dimensional network is formed in complex 1 through the hydrogen bonds and VDW interactions.

Synthesis and Crystal Structure of a Nitronyl Nitroxide Complex {[Zn(NIT4Py)(fum)(H_2O)_2]·H_2O}_n

The title compound {[Zn（NIT4Py）（fum）（HEO）2]·H2O}n, where NIT4Py = 2-（4＇- pyridinyl）-4,4,5,5-tetra-methylimidazoline-looxyl-3-oxide and fum = fumarate, has been prepared and structurally characterized by X-ray diffraction. It crystallizes in triclinic, space group P1^- with a = 6.9533（9）, b = 9.805（1）, c = 15.248（2） A, α= 94.608（2）, β = 92.328（2）, γ = 105.840（2）°, C16H24N3O9Zn, Mr = 467.75, V = 994.8（2） A^3, Z = 2, Dc = 1.562 g/cm^3,μ（MoKα） = 1.289 mm^-1, F（000） = 486, the final R = 0.0243 and wR = 0.0622 for 3505 independent reflections with Rint = 0.0125. The Zn（II） adopts a distorted five-coordinate triangle bipyramidal geometry. The basic framework structure of the complex is a 1-D chain. The intrachain hydrogen bonds are helpful to stabilize the 1-D chain structure. Furthermore, the chains are connected by O-H…O hydrogen bonds to give a 2-D double-layer network.