4-pentenoic Acid Research Articles

Bioderived Thiol-Ene Emulsion Polymerization for Hybrid Latex Particles.

The thiol-ene emulsion polymerization of three dienes synthesized from bioderived compounds, and subsequent preparation of core-shell polymer latexes, is reported. Levoglucosan (LGA), levogucosenone (LGO) and isosorbide were first modified with 4-pentenoic acid to install polymerizable groups. These monomers were used along with a dithiol to prepare poly(thioether) particles via ab initio emulsion polymerization using potassium persulfate as initiator and sodium dodecyl sulfate as surfactant. The structure of the diene significantly influenced the size of the resulting polymer latex particles. Given their low glass transition temperature, the LGA-derived poly(thioether) particles were used as a seed for the seeded emulsion polymerization of either styrene or methyl methacrylate. Core-shell latex particles with a high Tg core and a low Tg bioderived shell were formed, as verified by electron microscopy and in agreement with theoretical predictions of the equilibrium particle morphology based on the interfacial tensions of each particle phase.

Pd-catalyzed Markovnikov selective oxidative amination of 4-pentenoic acid.

Pd-catalyzed regioselective amination of unactivated alkene remains a challenge and is of great interest. Herein, a palladium-catalyzed and ligand-controlled strategy for the Markovnikov selective oxidative amination of 4-pentenoic acid has been described. The protocol effectively reverses the carboxylic acid-directed anti-Markovnikov selectivity in oxidative amination of 4-pentenoic acid, successfully constructing γ-ketoamide derivatives.

Redox dual-responsive diaryl ditelluride-containing nanoparticles as peroxidase mimetics

Polymeric nanoparticles with peroxidase-like enzyme mimetic activity were developed by incorporating catalytically active tellurium (Te) functionalities into cross-linked block copolymers. Bis(2-aminophenyl) ditelluride was used as a cross-linker to react with a diblock copolymer bearing pendent activated ester groups to generate of core-cross-linked nanoparticles (DiTe-NP) containing diaryl ditelluride bonds. DiTe-NP nanoparticles exhibit dual redox-responsiveness inherited from the sensitivity of ditelluride to both oxidants and reductants. When DiTe-NP nanoparticles were treated with H2O2, the oxidation of the ditellurides triggered the cleavage of Te-Te bonds to form Te(IV)-associated species. The oxidation-responsiveness endows DiTe-NP nanoparticles with haloperoxidase (HPO)-mimic activity. With NaBr and hydrogen peroxide, they catalyzed the oxidative bromination of phenol red, bromolactonization of 4-pentenoic acid, and bromination of 1,3,5-trimethoxybenzene due to the in-situ generation of hypobromous acid (HOBr) for halogenations. These ditelluride-containing nanoparticles also exhibited glutathione peroxidase (GPx)-like activity and accelerated the reduction of hydroperoxide by a thiol substrate. The cleavage of ditelluride bonds by a thiol substrate leads to the formation of key intermediates in the catalytic cycle of DiTe-NP nanoparticles. DiTe-NP nanoparticles showed enhanced activity for the reduction of hydrophobic cumene peroxide by 4-nitrothiophenol. These dual redox-responsive ditelluride-containing nanoparticles are promising candidates as peroxidase mimetics to apply as catalysts for green halogenation reactions and decompositions of toxic peroxides.

Regioselectivity in Carbonylation of Pentenoic Acid to Synthesize Cyclic Anhydrides

AbstractPentenoic acids (PEA) obtained from biomass‐derived γ‐valerolactone (GVL) can serve as a platform for sustainable and atom‐economic synthesis of adipic acid and its derivatives. Herein, the results are reported on the cyclocarbonylation reaction of PEA to synthesize five‐ (5 a), six‐ (6 a), or seven‐membered (7 a) cyclic anhydrides, with the aim to drive the reaction towards 7 a, a potential intermediate to caprolactam. Carbonylation of 4‐PEA yielded up to 73 % cyclic anhydrides, 7 a and 6 a in ratio 79 : 21. However, from 3‐PEA the same palladium‐based catalytic system in the absence of strong acids yielded 61 % 6 a and 5 a (41 : 59), indicating the inability of the catalyst to force isomerization. Isomerization, which is essential to obtain 7 a from a mixture of PEA isomers derived from GVL, does occur in presence of strong acids; however, this led predominantly to formation of smaller rings (6 a and 5 a) from 4‐PEA. Catalytic systems containing ligands with bulky tert‐butyl substituents yielded 6 a and trace amounts of 7 a. Although 7 a can be obtained from 4‐PEA in reasonable selectivity, there still remains a challenge to selectively synthesize 7 a from a mixture of PEA isomers.

A novel pour point depressant with diesel cold-flow properties: Performance evaluation of benzene-containing ternary copolymers

The addition of pour point depressants (PPDs) represents the most direct and efficient approach for improving the cold-flow properties of diesel. Nevertheless, the high doses of additives have consistently been a constraining factor. To address this challenge, the study synthesized tetradecyl methacrylate–N-hydroxymethacrylamide–benzyl acrylate (C14MC–NMA–BA), tetradecyl methacrylate–N-hydroxymethacrylamide–4-pentenoic acid benzyl ester (C14MC–NMA–PB), and tetradecyl methacrylate–N-hydroxymethacrylamide–10-undecenoic acid benzyl ester (C14MC–NMA–UB) at various molar ratios (1:1:1, 5:1:1, 10:1:1, 15:1:1, and 20:1:1) as PPDs for diesel. The aim of these PPDs is to efficiently improve the cold-flow properties of diesel at low doses. The cold filter plugging point (CFPP) and solidification point (SP) of diesel were tested before and after treatment with PPDs. The results confirmed that C14MC–NMA–UB with longer carbon chains exhibited superior performance compared to C14MC–NMA–PB and C14MC–NMA–BA. Considering both cost-effectiveness and performance metrics, 400 ppm C14MC–NMA–UB (5:1:1) was identified as the optimal choice for significantly enhancing diesel cold-flow properties, leading to reductions of CFPP and SP by 11 °C and 25 °C, respectively. Furthermore, the study delved into the inhibitory mechanisms of PPDs by examining the crystallization behavior of diesel at low temperatures, utilizing techniques such as differential scanning calorimetry, viscosity-temperature profiles, and polarized optical microscopy.

Biodegradable polycarbonates from lignocellulose based 4-pentenoic acid and carbon dioxide.

The production of biodegradable polycarbonate by copolymerizing CO2 with epoxides has emerged as an effective method to utilize CO2 in response to growing concerns about CO2 emissions and plastic pollution. Previous studies have mainly focused on the preparation of CO2-based polycarbonates from petrochemical-derived propylene oxide (PO) or cyclohexene oxide (CHO). However, to reduce dependence on fossil fuels, the development of 100% bio-based polymers has gained attention in polymer synthesis. Herein, we reported the synthesis of glycidyl 4-pentenoate (GPA) from lignocellulose based 4-pentenoic acid (4-PA), which was further copolymerized with CO2 using a binary catalyst SalenCoCl/PPNCl to produce bio-based polycarbonates with vinyl side chains and molecular weights up to 17.1kg/mol. Introducing a third monomer, PO, allows for the synthesis of the GPA/PO/CO2 terpolymer, and the glass transition temperature (T g) of the terpolymer can be adjusted from 2°C to 19°C by controlling the molar feeding ratio of GPA to PO from 7:3 to 3:7. Additionally, post-modification of the vinyl side chains enables the production of functional polycarbonates, providing a novel approach to the preparation of bio-based materials with diverse side chains and functions.

Simultaneous Differentiation of C═C Position Isomerism in Fatty Acids through Ion Mobility and Theoretical Calculations.

Fatty acids play a pivotal role in biological processes and have many isomers, particularly at the C═C position, that influence their biological function. Distinguishing between isomers is crucial to investigating their role in health and disease. However, separating the isomers poses a significant analytical challenge. In this study, we developed a simple and rapid strategy combining ion mobility spectrometry and theoretical chemical calculations to differentiate and quantify the C═C positional isomers in 2-/3-butenoic acid (BA), 2-/3-/4-pentenoic acid (PA), and 2-/3-/5-hexenoic acid (HA). C═C positional isomerism was mobility-differentiated by simple complexation with crown ethers (12C4, 15C5, and 18C6) and divalent metal ions (Mg2+, Ca2+, Mn2+, Fe2+, Co2+, Ni2+, Zn2+, Sr2+, and Ba2+), that is, converting C═C positional isomers with small structural differences into complexes with large structural differences through the interaction with metal ions and crown ethers. Metallized isomers were formed but could not be differentiated due to their complex and overlapping extracted ion mobiliograms (EIMs). Binary crown ether-isomer complexes were not observed, indicating that C═C positional isomers could not be separated by simple mixing with crown ethers. However, significant EIM differences were obtained for the formed ternary complexes, allowing baseline separation for the isomers. Notably, all crown ethers and metal ions have a separation effect with the isomers, with a calculated separation resolution (Rp-p) of 0.07-2.44. Theoretical chemical calculations were performed to provide in-depth structural information for the complexes and explain the separation principle. Theoretical conformational space showed that the divalent metal ions act as a bridge connecting the crown ether and the isomer. Additionally, the ternary complex becomes more compact as the distance between C═C and -COOH increases. Theoretical results can reflect the features of mobility experiments, with relative errors between the experiment collision cross-section (CCS) and theoretical CCS of no more than ±8.06%. This method was also evaluated in terms of quantification, accuracy, and precision repeatability. Overall, this study establishes that the crown ether-metal ion pair can function as a robust unit for differentiating C═C positional isomerism.

Catalyst characterization and catalytic evaluation of 3wt%Al-KIT-6 toward biomass-derived γ-valerolactone decarboxylation to butene

Biomass-derived γ-Valerolactone (GVL) has been identified as a promising, sustainable platform molecule. The production of butene from GVL is of great significant in the situation of the fossil fuel resource crisis. In present work, xwt%Al-KIT-6 catalyst were prepared and employed for catalyzing GVL decarboxylation to butene. It was found that the suitable Brønsted/Lewis acid ratio and large amount of weak acid sites played a major role for the decarboxylation of γ-protonated pentenoic acid (PEA), which endowed 3wt%Al-KIT-6 with excellent catalytic performance. Over the 3wt%Al-KIT-6 catalyst, the GVL conversion and butene yield can up to 99.68% and 94.28% at 300 ℃, respectively. The corresponding Ea was as low as 86.97 kJ·mol−1. Moreover, 3wt%Al-KIT-6 also exhibited an outstanding regenerable performance for cycle tests. Most importantly, the presence of an appropriate amount of H2O was beneficial to catalyzing GVL decarboxylation to butene by inhibiting the deposition of carbon.

Improving the Mechanical Properties of Conventional Glass Ionomer Cement Through Using 4-Pentenoic Acid Modified Polycarboxylic Acid (PCA)

With the aim to enhance the mechanical properties of conversional glass ionomer cements (GICs), 4-pentenoic acid (PA) was used as a co-monomer to synthesize a new kind of polycarboxylic acid (PCA) through free radical polymerization with acrylic acid (AA) and itaconic acid (IA). The chemical structures of the PCA were confirmed by 1H-NMR and FT-IR. Number average molecular weights (Mn) and glass transition temperatures (Tg) of the synthesized PCA were investigated and the results showed that the Mn and Tg were in a trend of decreasing with increasing of the PA content in the raw materials. The synthesized PCA was dissolved in water with a mass ratio of 50 wt.% to prepare the liquid part of the GIC, and then mixed with glass powders of commercial GIC Fuji IX to prepare the GICs samples. The results of mechanical tests showed that the PCA with 5 wt% of 4-pentenoic acid as a comonomer showed the best comprehensive mechanical properties.

A PDK-1 allosteric agonist neutralizes insulin signaling derangements and beta-amyloid toxicity in neuronal cells and in vitro.

The Alzheimer’s brain is affected by multiple pathophysiological processes, which include a unique, organ-specific form of insulin resistance that begins early in its course. An additional complexity arises from the four-fold risk of Alzheimer’s Disease (AD) in type 2 diabetics, however there is no definitive proof of causation. Several strategies to improve brain insulin signaling have been proposed and some have been clinically tested. We report findings on a small allosteric molecule that reverses several indices of insulin insensitivity in both cell culture and in vitro models of AD that emphasize the intracellular accumulation of β-amyloid (Aβi). PS48, a chlorophenyl pentenoic acid, is an allosteric activator of PDK-1, which is an Akt-kinase in the insulin/PI3K pathway. PS48 was active at 10 nM to 1 μM in restoring normal insulin-dependent Akt activation and in mitigating Aβi peptide toxicity. Synaptic plasticity (LTP) in prefrontal cortical slices from normal rat exposed to Aβ oligomers also benefited from PS48. During these experiments, neither overstimulation of PI3K/Akt signaling nor toxic effects on cells was observed. Another neurotoxicity model producing insulin insensitivity, utilizing palmitic acid, also responded to PS48 treatment, thus validating the target and indicating that its therapeutic potential may extend outside of β-amyloid reliance. The described in vitro and cell based-in vitro coupled enzymatic assay systems proved suitable platforms to screen a preliminary library of new analogs.

Determination of in vitro metabolic hepatic clearance of valproic acid (VPA) and five analogues by UPLC-MS-QTOF, applicable in alternatives to animal testing

Laboratory measurements of intrinsic clearance support the development of TK models, with potential relevance to weight of evidence toxicity assessments of xenobiotics, including read-across, the concept of predictive estimation by data extrapolation between chemicals of similar structure (analogues).In this work a procedure with analytical method for determination of in vitro hepatic metabolic clearance, relevant to biotransformation toxicokinetic (TK) modelling, is presented. Cryopreserved primary human hepatocytes represent a suitable cells, due to their biological characteristics, for providing an in vitro model for simulating in vivo metabolic clearance.The experimental part considered an adequate sequential time-frame for collecting samples and controls for all chemicals tested, including centrifugation and aliquoting of the corresponding fractions until the instrumental session.For the first time, in vitro hepatocyte intrinsic clearance was measured for six analogue test chemicals: valproic acid, 2-ethyl caproic acid, octanoic acid, valeric acid, 2-methyl butyric acid and 2-trans pentenoic acid, during incubated cell culture exposure up to 2 h or 3.5 h. The time dependence of any metabolism was determined from analysis of the supernatant at intervals using a new developed analytical method for UPLC coupled with QTOF mass spectrometer. The chemicals could then be ranked by their relative intrinsic clearance.The analyses were reproducible, with coherence of the calculated in vitro intrinsic clearance between experiments.

Volatile organic compound profiling of Capsicum annuum var. longum grown under different concentrations of nitrogen

Summary Emission of volatile organic compounds (VOCs) in plants is triggered by several biotic and abiotic factors, such as nutrient deficiency, environmental stress, and pathogenic attacks. For instance, plants suffering from limited or excessive nitrogen (N) supply may experience internal stress which can ultimately lower their stability and immunity making them susceptible to infection and infestation. In this study, VOCs from Capsicum annuum var. longum (Solanaceae) exposed to nitrogen (1.8 g/L, 4.5 g/L, and 9 g/L urea) were extracted using a 100 μm Solid Phase Microextraction (SPME) fiber coated with polydimethylsiloxane (PDMS). Using Gas Chromatography-Mass Spectrometry (GC-MS), extracted VOCs from N-treated plants were identified as Butanoic acid, 3-hexenyl ester, (E)-; Butanoic acid, hexyl ester; Hexanoic acid, 3-hexenyl ester, (Z)-; Hexanoic acid, 4-hexen-1-yl ester; cis-3-Hexenyl cis-3-hexenoate and 4-Pentenoic acid 2-methyl-, hexyl ester. Among these volatiles, butanoic acid, 3-hexenyl ester showed the most distinctive peak from the N-treated plants in comparison with the untreated. In addition, the Green Leaf Volatiles (GLV) 3-Hexenal; 2-Hexenal; 3-Hexen-1-ol, (Z)-; 2-Hexen-1-ol, (E) and 1-Hexanol were also detected from the N-treated plants. The identification of plant volatiles provides useful information that can be used in agricultural practices and plant phenotyping.

An experimental study of the gas-phase reaction between Cl atoms and trans-2-pentenal: Kinetics, products and SOA formation

The gas-phase reaction of trans-2-pentenal (T2P) with Cl atoms was studied at atmospheric pressure and room temperature. A rate coefficient of (2.56 ± 0.83) × 10-10 cm3 molecule-1 s-1 was obtained using the relative rate method and isoprene, cyclohexane and ethanol as reference compounds. The kinetic study was carried out using a 300-L Teflon bag simulation chamber (IMT Lille Douai-France) and a 16-L Pyrex cell (UCLM-Ciudad Real-Spain), both coupled to the Fourier transform infrared (FTIR) technique. Gas-phase products and secondary organic aerosol (SOA) formation were studied at UCLM using a 16-L Pyrex cell and a 264-L quartz simulation chamber coupled to the FTIR and gas-chromatography-mass spectrometry (GC-MS) techniques. HCl, CO, and propanal were identified as products formed from the studied reaction and quantified by FTIR, the molar yield of the latter being (5.2 ± 0.2)%. Formic acid was identified as a secondary product and was quantified by FTIR with a yield of (6.2 ± 0.4)%. In addition, 2-chlorobutanal and 2–pentenoic acid were identified, but not quantified, by GC-MS as products. The SOA formation was investigated using a fast mobility particle sizer spectrometer. The observed SOA yields reached maximum values of around 7% at high particle mass concentrations. This work provides the first study of the formation of gaseous and particulate products for the reaction of Cl with T2P. A reaction mechanism is suggested to explain the formation of the observed gaseous products. The results are discussed in terms of structure-reactivity relationship, and the atmospheric implications derived from this study are commented as well.

γ-Valerolactone converting to butene via ring-opening and decarboxylation steps over amorphous SiO2-Al2O3 catalyst

γ-Valerolactone (GVL) as a sustainable platform compound could be converted to renewable fuels and chemicals, whereas directly converting GVL to target products remains still the challenge. In this work, we report an amorphous SiO2-Al2O3 catalyst with adjustable acidity, which presented an excellent selectivity of 97.5 % butene at GVL conversion of 99.5 %, and remained an outstanding stability for 50 h. Appropriate weak and strong acid sites were the key for the ring-opening of GVL. Lower acid sites facilitated the decarboxylation of pentenoic acid (PEA), while higher acid sites promoted the cracking of PEA. Besides, a two-stage integration system was developed for converting GVL to C5+ hydrocarbons via butene intermediate, giving a good yield of 57.6 % C5+ hydrocarbons via combining the SiO2-Al2O3 catalyst with nano-HZSM-5 together.

Enhancing glutaric acid production in Escherichia coli by uptake of malonic acid

Glutaric acid is an important organic acid applied widely in different fields. Most previous researches have focused on the production of glutaric acid in various strains using the 5-aminovaleric acid (AMV) or pentenoic acid synthesis pathways. We previously utilized a five-step reversed adipic acid degradation pathway (RADP) in Escherichia coli BL21 (DE3) to construct strain Bgl146. Herein, we found that malonyl-CoA was strictly limited in this strain, and increasing its abundance could improve glutaric acid production. We, therefore, constructed a malonic acid uptake pathway in E. coli using matB (malonic acid synthetase) and matC (malonic acid carrier protein) from Clover rhizobia. The titer of glutaric acid was improved by 2.1-fold and 1.45-fold, respectively, reaching 0.56g/L and 4.35g/L in shake flask and batch fermentation following addition of malonic acid. Finally, the highest titer of glutaric acid was 6.3g/L in fed-batch fermentation at optimized fermentation conditions.

Conversion of levulinic acid using CuO/WO3(x)-Al2O3 catalysts

The CuO/WO3(x)-Al2O3 catalysts were tested for the conversion of levulinic acid into chemicals of high added-value compounds. The WO3(x)-Al2O3 modified supports with 5 different WO3 contents (2, 4, 6, 8, and 10 wt%) were prepared by the wet impregnation method, consequently 5 wt% CuO was impregnated on the modified supports. The optimum catalytic activity was obtained with CuO/WO3(6%)-Al2O3 catalyst, which was directly related to the highest acidity of the catalyst showed by NH3-TPD and acid strength by titration analysis. The distribution of products observed on CuO/WO3(x)-Al2O3, was correlated with a change in acid site type and acid strength. The changes in the acidity by the addition of CuO over modified support was attributed to structural changes (distortions) stabilizing the active phase. This distortion is increasing the acidity strength, and favoring a higher catalytic activity with changes in the selectivity in function of CuO content over WO3(x)-Al2O3 modified support, obtaining the maximum formation of 2-MTHF and possibly other higher value-added chemicals from GVL such as: 1,4-pentanediol, pentenoic acid, pentanoic acid, 2-pentanol, and gaseous products were on CuO/WO3(6%)-Al2O3 catalyst.

Chemoenzymatic Halocyclization of 4-Pentenoic Acid at Preparative Scale.

The scale-up of chemoenzymatic bromolactonization to 100 g scale is presented, together with an identification of current limitations. The preparative-scale reaction also allowed for meaningful mass balances identifying current bottlenecks of the chemoenzymatic reaction.

Conversion of γ‐Valerolactone to Ethyl Valerate over Metal Promoted Ni/ZSM‐5 Catalysts: Influence of Ni0/Ni2+ Heterojunctions on Activity and Product Selectivity

AbstractPromoter (Cr, Mo and W) modified Ni/ZSM‐5 catalysts were explored in the vapor phase conversion of γ‐valerolactone (GVL) to ethyl valerate (EV; gasoline blender) at atmospheric pressure. Among the three different promoters (Cr, Mo and W) tested the Mo‐modified catalyst was found to be the best candidate. In addition, this catalyst was found to be stable up to 50 h reaction time with an insignificant decrease in activity. The good catalytic performance is related to an optimal ratio of acid and hydrogenation functions provided by Ni2+ and Ni0, respectively. In situ FTIR spectroscopic studies revealed a strong adsorption of GVL on all catalysts which quickly reacts with dosed ethanol by formation of EV, most pronounced on the Mo‐modified catalyst, while VA was identified as side product. These findings suggest the preferred GVL ring opening by cracking the C−O bond on the methyl side of the GVL molecule on this type of catalysts leading to pentenoic acid as intermediate, which is quickly hydrogenated and esterified.

Kinetic Study of the Pyridine-Catalyzed Selenolactonization of 4-Pentenoic Acid

The kinetics and mechanism of the pyridine-catalyzed cyclofunctionalization of 4-pentenoic acid by means of PhSeX (X = Cl, Br) have been investigated spectrophotometrically, under pseudo-first order reaction conditions. The influence of the reaction temperature, the type of cyclization reagent and used catalyst on the reaction rate and mechanism was examined. The obtained data have showed that rate constants go on increasing as the temperatures go up and with use of PhSeCl as reagent. Also, the reaction rate is directly depended on the type of the catalyst used—stronger bases with higher tendency for hydrogen bond formation (DN) are promoting reaction in more efficient way.

Synthesis and performance of bio-based unsaturated oligomer and containing gum arabic as a novel protective steel coating under UV irradiation

The purpose of this study is to prepare UV curable coating based on the reaction of environmental friendly epoxidized olive oil (EOO) with 4-pentenoic acid (PA) to create unsaturated EOO-PA oligomer. The prepared oligomer was confirmed and characterized by FT-IR spectroscopy, viscosity, acid value, and epoxy oxygen content measurements. After that, different thin coating films of prepared oligomer based formulations were applied onto different substrates and subjected to different doses of UV irradiation. All UV cured films of formulations were evaluated in terms of gel content, swelling degree, hardness, bending, gloss, adhesion, scratch, and acid/alkali tests to select the best and high performance formula. Then eco-friendly natural material such as gum Arabic (GA) was evaluated as anticorrosive material for mild steel in 3.5 % sodium chloride by including different concentrations of it to the best prepared formula. The anticorrosion properties of all UV cured coated films containing gum Arabic solution (GAS) were estimated through different tests such as degrees of rusting, blistering, adhesion failure at the scribe, water uptake, and weight loss measurements. Besides, the mechanical, physical, and chemical properties of cured coated panels were examined as well. The results showed that the cured coating films, which contained 7 % of GAS per 100 g coating, could protect the mild steel substrate from corrosion without any significant change in the different properties of cured films.