Ionic liquid-assisted preparation of hydroxyapatite and its catalytic performance for decarboxylation of itaconic acid

The synthesis of methacrylic acid from biomass-derived itaconic acid is a green route,for it can get rid of the dependence on fossil resource.In order to solve the problems on this route such as use of a preciousmetal catalyst and a corrosive homogeneous alkali,we prepared a series of hydroxyapatite catalysts by an ionic liquid-assisted hydrothermal method and evaluated their catalytic performance.The results showed that the ionic liquid[Bmim]BF_(4) can affect the crystal growth of hydroxyapatite,provide fluoride ion for fluorination of hydroxyapatite,and adjust the surface acidity and basicity,morphology,textural properties,crystallinity,and composition of hydroxyapatite.The[Bmim]BF4 dosage and hydrothermal temperature can affect the fluoride ion concentration in the hydrothermal system,thus changing the degree of fluoridation of hydroxyapatite.High fluoride-ion concentration can lead to the formation of CaF_(2) and thus significantly decrease the catalytic performance of hydroxyapatite.The hydrothermal time mainly affects the growth of hydroxyapatite crystals on the c axis,leading to different catalytic performance.The suitable conditions for the preparation of this fluoridized hydroxyapatite are as follows:a mass ratio of[Bmim]BF4 to calcium salt=0.2:1,a hydrothermal time of 12 h,and a hydrothermal temperature of 130℃.A maximal methacrylic acid yield of 54.7%was obtained using the fluoridized hydroxyapatite under relatively mild reaction conditions(250℃ and 2 MPa of N_(2))in the absence of a precious-metal catalyst and a corrosive homogeneous alkali.

Influence of Ca/P ratio on the catalytic performance of hydroxyapatite for decarboxylation of itaconic acid to methacrylic acid

Methacrylic acid,an important organic chemical,is commercially manufactured starting from fossil feedstock.The decarboxylation of itaconic acid derived for biomass is a green route to the synthesis of methacrylic acid.In view of the problems existing in the researches on this route such as use of noble metal catalyst,harsh reaction conditions and low desired-product yield,we prepared a series of hydroxyapatite catalysts with different Ca/P molar ratios and evaluated their catalytic performance.The results showed that the hydroxyapatite catalyst with a Ca/P molar ratio of 1.58 had the best catalytic activity.The highest yield of MAA up to 61.2%was achieved with basically complete conversion of itaconic acid under the suitable reaction conditions of 1 equivalent of NaOH,2 MPa of N_(2),250℃,and 2 h.On this basis,a reaction network for the decarboxylation of itaconic acid to methacrylic acid catalyzed by hydroxyapatite was established.With the aid of catalyst characterization using X-ray powder diffraction,NH3/CO2 temperature-programmed desorption,N_(2)physisorption,inductively coupled plasma optical emission spectrometry,and scanning electron microscopy,we found that the distribution of surface acid sites and basic sites,crystal growth orientation,texture properties and morphology of hydroxyapatite varied with the Ca/P molar ratio.Furthermore,the change of the crystal growth orientation and its influence on the surface acidity and alkalinity were clarified.

Synthesis and Characterization of the Terpolymer of Itaconic Acid with Acrylamide and 2-Acrylamido-2-methylpropanesulfonic Acid

The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.

Investigation of the Reaction Mechanism of Itaconic Acid/Maleic Acid Copolymer System and Cotton Cellulose

The reaction mechanism of IA/MA copolymer system andcotton cellulose is conjectured and verified, the two keysteps, such as the formation of cyclic anhydride interme-diates and the building of ester crosslinklng, and the ef-fect of sodium hypophosphite are especially emphasized,by FT - IR spectroscopy and acid- base titration anal-yses. The experiments reveal that carboxylic acids main.ly change to cyclic anhydride in the pre - drying step andSodium Hypophosphite (SHP) has effect on it, but mostester - crosslinkages are built in the curing step and SHPhas effects on both anhydride formation and ester -crosslinking formation.

Kinetics of Maleic Acid/Itaconic Acid In-situ Polymerization on Cotton

Cotton fabric samples are padded with maleic acid (MA) and itaconic acid (IA) finishing bath in the presence of potassium persulfate (K 2S 2O 8), and then dried at different temperatures for different time intervals. The portion of unreacted monomers on cotton fabric samples is determined by means of measuring the double bond content. The kinetic data (rate constants, Arrhenius activation energy, frequency factor) of the in-situ polymerization have been calculated.

Microwave-Assisted Synthesis of Poly(Aspartic Acid-Itaconic Acid) Copolymer and Its Characterization

Poly(aspartic acid-itaconic acid) copolymer was synthesized from aspartic acid(Asp) and itaconic acid(Ita) under microwave irradiation. The effects of microwave power, microwave irradiation time, molar ratio of itaconic acid and aspartic acid, catalyst type, catalyst and organic solvent content on copolymer yield, and the performance for inhibition of CaCO_3 fouling were investigated. It was found that the product yield achieved a highest record of 95% when the amount of catalyst Na H_2PO_4 was 0.012 mol, the amount of organic solvent propylene carbonate was 16 m L, the molar ratio of Asp/Ita was 3:1, the microwave output power was 1200 W and the irradiation time was 5.5 min. And the product performance for inhibition of calcium carbonate also reached a highest value of 94.38%. Structural characterization of the product showed that the product was the aspartic acid-itaconic acid copolymer.

Directional Breeding of High Itaconic Acid Yielding Strain of <i>Aspergillus terreus</i>with a New Plate Technique

Itaconic acid is commercially produced by the cultivation of Aspergillus terreus using starch hydrolysate as carbon source. The degree of hydrolysis had a great influence on itaconic acid production which was suitable when corn starch was saccharified at 35 DE. The α-amylase was sufficient to drive the starch hydrolysis to the degree. The agar plate assay with LiCl treatment provided a rapid, simple and unequivocal method for screening large numbers of colonies for itaconic acid producing strains. It was learned by experience that the strains on the plates with thick hyphae and light-colored spores often accompanied high itaconic acid production. A strain, designated Ast165, producing itaconic acid with a high yield, was successfully obtained by directional breeding of metabolic end products resistant strains. The itaconic acid concentration produced by Ast165 was 53.8 g/l from 100 g/l of starch hydrolysate in shake flasks. The conversion rate was 61.3%, which was the highest value found in tests.

Preparation and Characterization of Functionalized Polypropylene with Acrylamide and Itaconic Acid

Functionalized polypropylene with acryl amide (AAm) and itaconic acid (IA) were prepared in the molten state in the presence of dicumyl peroxide. The effects of the concentration of both mono- mers on the degree of functionalization and properties of the products were investigated by FT-IR, contact angle measurement and DSC analysis. It was found that the degree of functionalization depends on the initial concentration of both monomers that used in the reaction. The influence of the AAm and IA content on the melting and crystallization temperature of PP was investigated by DSC. The contact angle of water on film surfaces of the functionalized PP (PP-g-AAm and PP-g-IA) decreased with increasing modified polymer content. From FT-IR spectra of functionalized PP a calculation was made of carbonyl index on the films surfaces. It was found that the higher intensity of the carbonyl index, the lower contact angle value and the lower crystallinity confirmed the ex- istence of functionalized AAm and/or IA in PP. It was concluded from the different characteriza- tion methods that the polarity and percentage of functionalized PP were increased up to 3 phr for both monomers, and then it was decreased by increasing the amount of monomers and had a threshold value, due to nucleating agents of monomers in PP.

Alleviating glucose repression and enhancing respiratory capacity to increase itaconic acid production

The Crabtree effect products ethanol and acetic acid can be used for itaconic acid(IA)production in Saccharomyces cerevisiae.However,both the IA synthesis and oxidative phosphorylation pathways were hampered by glucose repression when glucose was used as the substrate.This study aimed to improve IA titer by increasing gene expressions related to glucose derepression without impairing yeast growth on glucose.Engineering the acetyl-CoA synthesis pathway increased the titer of IA to 257 mg/L in a urea-based medium.Instead of entire pathway overexpression,we found that some signaling pathways regulating glucose repression were effective targets to improve IA production and respiratory capacity.As a consequence of the reduced inhibition,IA titer was further increased by knocking out a negative regulator of the mitochondrial retrograde signaling MKS1.SNF1/MIG1 signaling was disturbed by deleting the hexokinase HXK2 or an endoplasmic reticulum membrane protein GSF2.The shaking results showed that XYY286(BY4741,HO::cadA,Y::Dz.ada,208a::Mt.acs,Δhxk2,pRS415-cadA,pRS423-aac2)accumulated 535 mg/L IA in 168 h in the YSCGLU medium.qRT-PCR results verified that deletion of MKS1 or HXK2 upregulated the gene expressions of the IA synthesis and respiratory pathways during the growth on glucose.

A CRISPRi mediated self-inducible system for dynamic regulation of TCA cycle and improvement of itaconic acid production in Escherichia coli

Itaconic acid(ITA),an effective alternative fossil fuel,derives from the bypass pathway of the tricarboxylic acid(TCA)cycle.Therefore,the imbalance of metabolic flux between TCA cycle and ITA biosynthetic pathway seriously limits the production of ITA.The optimization of flux distribution between biomass and production has the potential to the productivity of ITA.Based on the previously constructed strain Escherichia coli MG1655Δ1-SAS-3(ITA titer:1.87 g/L),a CRISPRi-mediated self-inducible system(CiMS),which contained a responsive module based on the ITA biosensor YpItcR/Pccl and a regulative CRISPRi-mediated interferential module,was developed to regulate the flux of the TCA cycle and to enhance the capacity of the strain to produce ITA.First,a higher ITA-yielding strain,Δ4-Prmd-SAS-3(ITA titer:3.20 g/L),derived fromΔ1-SAS-3,was constructed by replacing the promoter PJ23100,for the expression of ITA synthesis genes,with Prmd and knocking out the three bypass genes poxB,pflB,and ldhA.Subsequently,the CiMS was used to inhibit the expression of key genes icd,pykA,and sucCD to dynamically balance the metabolic flux between TCA cycle and ITA biosynthetic pathway during the ITA production stage.The constructed strainΔ4-Prmd-SAS-3 under the dynamic regulation of the CiMS,showed a 23%increase in the ITA titer,which reached 3.93 g/L.This study indicated that CiMS was a practical strategy to dynamically and precisely regulated the metabolic flux in microbial cell factories.

Production of Itaconic Acid Through Microbiological Fermentation of Inexpensive Materials

Itaconic acid(IA)is a precursor of various chemicals,which has been on the US Department of Energy’s list of the top 12 platform chemicals that can potentially be produced from biomass.The IA is mainly produced through a bio-fermentation method with sugar as raw material.However,the high cost and low yield restrict the industrial application of the IA.This review summarized research advances in the IA production from alternative substrates.In particular,the types of substrates as well as existing problems in the IA fermentation,strain breeding,and process regulation were discussed.And it is pointed that decreasing the price of the IA through use of alternative substrates and increasing the titer of the IA through genetic engineering should be further focused on to support the industrialization of the IA.

Plastic-Free Bioactive Paper Coatings, Way to Next-Generation Sustainable Paper Packaging Application: A Review

Hydrocarbon-derived polymers have been utilized in various packaging applications, such as pouches, films, foamed containers, rigid containers, and multiple components for medical, food, and other uses. However, mounting environmental considerations increased knowledge of the harmful consequences of greenhouse gas emissions, landfills, and disposal difficulties. Rising oil prices are forcing researchers and businesses to produce environmentally friendly packaging. These new sustainability requirements are particularly suited to biomass-based products, instead of petroleum sources;sourced from biomass entities. More functional and performance-oriented packaging is necessary despite the widespread usage of bio-based materials like paper. As a result, the transition to eco-friendly packaging will necessitate the improvement of existing bio-derived packaging and the development of new bio-derived materials like biopolymer paper coatings. The goal of this brief study was to give a synopsis of the present status of bio-derived packaging and an insight into ongoing and prospective developments in sustainable next-generation paper coatings for the packaging industry.

衣康酸及其衍生产品的开发和应用

简述了衣康酸的国内外概况、生产方法,并为促进我国衣康酸工业的健康发展,介绍了其深加工产品的生产和应用。

Liposome cocktail activator modulates hepatocytes and remodels the microenvironment to mitigate acute liver failure

Acute liver failure(ALF)is a mortal and critical hepatic disease,in which oxidative stress,inflammation storm and hepatocyte death are crucial in the pathogenesis.Hence,in contrast to the control of a single link,a combination therapy targeting multiple pathogenic links of the disease will be a favorable means to control the progression of the disease.In this study,we constructed dimethyl itaconate-loaded liposomes modified with dodecyl gallate as a cocktail activator to investigate its functional role in acetaminophen(APAP)-induced ALF.Our results demonstrated that the cocktail activator acted on hepatocytes and triggered cocktail efficacy,thereby simultaneously attenuating APAP-induced hepatocyte damage and remodeling the damage microenvironment.The cocktail activator could effectively scavenge reactive oxygen species,inhibit excessive inflammatory responses and reduce cell death in impaired hepatocytes for detoxification.More importantly,the cocktail activator could remodel the damage microenvironment,thus further promoting hepatocyte expansion and specifically switching macrophages from the M1 to M2 phenotype for a favorable liver regeneration of ALF.Furthermore,in APAP-induced ALF mouse model,the cocktail activator improved liver function,alleviated histopathological damage and increased survival rate.In summary,these findings indicate that the cocktail activator may provide a promising therapeutic approach for ALF treatment as a nanomedicine.

Four-Octyl itaconate ameliorates periodontal destruction via Nrf2-dependent antioxidant system

Periodontitis is a widespread oral disease characterized by continuous inflammation of the periodontal tissue and an irreversible alveolar bone loss, which eventually leads to tooth loss. Four-octyl itaconate(4-OI) is a cell-permeable itaconate derivative and has been recognized as a promising therapeutic target for the treatment of inflammatory diseases. Here, we explored, for the first time,the protective effect of 4-OI on inhibiting periodontal destruction, ameliorating local inflammation, and the underlying mechanism in periodontitis. Here we showed that 4-OI treatment ameliorates inflammation induced by lipopolysaccharide in the periodontal microenvironment. 4-OI can also significantly alleviate inflammation and alveolar bone loss via Nrf2 activation as observed on samples from experimental periodontitis in the C57BL/6 mice. This was further confirmed as silencing Nrf2 blocked the antioxidant effect of 4-OI by downregulating the expression of downstream antioxidant enzymes. Additionally, molecular docking simulation indicated the possible mechanism under Nrf2 activation. Also, in Nrf2-/-mice, 4-OI treatment did not protect against alveolar bone dysfunction due to induced periodontitis, which underlined the importance of the Nrf2 in 4-OI mediated periodontitis treatment.Our results indicated that 4-OI attenuates inflammation and oxidative stress via disassociation of KEAP1-Nrf2 and activation of Nrf2 signaling cascade. Taken together, local administration of 4-OI offers clinical potential to inhibit periodontal destruction,ameliorate local inflammation for more predictable periodontitis.

Preparation of Mono-Dispersed Carbon Nanotubes (CNTs) with Dodecyl Itaconate and Its Utilization in Paper-Making

Dodecyl itaconate (DI) was used as the dispersant for preparation of mono-dispersed carbon nanotubes in aqueous solution in this study. It is a unique type of anionic surfactant synthesized by the authors, and its high capability for dispersing CNTs is attributed to the double bond moiety on its head-group. Furthermore, author mixed aqueous mono-dispersed CNTs with pulp to produce the CNT-based paper. Different from the reported papermaking process, a novel adjusting PH process was employed to prepare paper. This method could transfer easily dispersing mono-dispersed CNTs in aqueous onto the surfaces of cellulose fibers, because PH adjustment of CNT-pulp is from the initial neutrality to weak acidity and then raising to alkalinity, The dispersion of tubes in cellulose matrix and characteristics of composite were investigated. Also, electrical resistance for retrieved CNT-based sheets was measured using fore-probe method.

Synergistic scale inhibition of polyaspartic acid composite with magnetic field

Polyaspartic acid(PASP)composite,a scale inhibitor,was prepared from PASP,itaconic acid—acrylic acid—acrylic ester(IA-AA-AE)terpolymer and 2-phosphonobutane-1,2,4-tricarboxylic acid(PBTCA).The scale inhibition of PASP composite and the effect of its synergism with a magnetic field on scale inhibition were investigated.Calcium carbonate crystals in scale samples were characterized by means of SEM and XRD.The static and dynamic experiments show that the chelating function of PASP composite for Ca2+can be enhanced by synergism with a magnetic field.Under Ca2+650 mg/L,HCO3-1,300 mg/L and PASPcomposite 4 mg/L,the scale inhibition rate of PASP composite in magnetic water can increase by 10%in static state and by 20%in dynamic experiments.Scanning electron microscope(SEM)and X-ray diffraction(XRD)results show that calcite and aragonite can be completely transformed into vaterite by using PASP composite.

A urinary proteomic landscape of COVID-19 progression identifies signaling pathways and therapeutic options

Signaling pathway alterations in COVID-19 of living humans as well as therapeutic targets of the host proteins are not clear.We analyzed 317 urine proteomes,including 86 COVID-19,55 pneumonia and 176 healthy controls,and identified specific RNA virus detector protein DDX58/RIG-I only in COVID-19 samples.Comparison of the COVID-19 urinary proteomes with controls revealed major pathway alterations in immunity,metabolism and protein localization.Biomarkers that may stratify severe symptoms from moderate ones suggested that macrophage induced inflammation and thrombolysis may play a critical role in worsening the disease.Hyper activation of the TCA cycle is evident and a macrophage enriched enzyme CLYBL is up regulated in COVID-19 patients.As CLYBL converts the immune modulatory TCA cycle metabolite itaconate through the citramalyl-CoA intermediate to acetyl-CoA,an increase in CLYBL may lead to the depletion of itaconate,limiting its anti-inflammatory function.These observations suggest that supplementation of itaconate and inhibition of CLYBL are possible therapeutic options for treating COVID-19,opening an avenue of modulating host defense as a means of combating SARS-CoV-2 viruses.