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Toward high‐strength bio‐based polyamide 56 (PA56) fiber, we first in situ precipitate graphene oxide (GO), adipic acid and 1,5‐pentanodiamine together by reaction crystallization in ethanal to obtain PA56 salt/GO particles with well dispersed GO, then prepare PA56/GO nanocomposite with PA56 salt/GO via solvent‐free polymerization including solid‐state prepolycondensation and melt polycondensation. Finally, PA56/GO nanocomposite fiber is prepared by extrusion drawing. With 0.2 wt% GO, the tensile strength of PA56/GO fiber reaches 1050 MPa, which is 3.3 times that of pure PA56 fiber. Furtherly, we add PA56/GO with high GO content to commercial PA56 to prepare the hybrid fiber, of which the tensile strength reaches 1248 MPa. The great improvement is mainly due to the good dispersion of GO in the whole process, which increases the heterogeneous nucleation in favor of higher and oriented PA56 crystallization. Highlights: Bio‐based PA56/GO nanocomposite fiber with 1.2 GPa strength has been prepared.PA56 salt/GO particles with well‐dispersed GO are in situ precipitated.Solvent‐free polymerization is used instead of solution melt polymerization.Well‐dispersed GO results in high and oriented crystallinity of PA56/GO fiber.Tensile strength of PA56/GO fiber is 2.3 times that of commercial PA56 fiber. [ABSTRACT FROM AUTHOR]

Supramolecular self-assembly–directed two unique organogels were achieved by varying gel-immobilized solvents. One gel is comprised of adipic acid (ADP) and triethanolamine (TEA) in pure dimethylformamide medium (i.e., ADP-TEA-DMF), while the other is formed from the combination of adipic acid and triethanolamine in a 1 : 1 mixed solvent system of DMF and acetonitrile (i.e., ADP-TEA-DMF-MeCN). Furthermore, we observed robust crystallization behaviour under the different stoichiometric conditions of adipic acid with triethanolamine in pure dimethylformamide (i.e., Crystal-DMF) and in pure dimethyl sulfoxide (i.e., Crystal-DMSO). To evaluate the mechanical strength and viscoelastic attributes, rheological experiments were executed on these supramolecular organogels of ADP-TEA-DMF and ADP-TEA-DMF-MeCN. Additionally, comprehensive microstructural analyses were conducted in order to unravel the architectural variations arising from the involvement of different solvent-directed semi-solid gel-state. Scanning electron microscopy (FESEM) images of xerogel specimens obtained from the two organogels revealed distinctive morphological patterns. Notably, perceptible variations in the morphology were also observed in both the crystalline phases. The crystal structure of both the crystalline phases (i.e., Crystal-DMF and Crystal-DMSO) were explored using single crystal X-ray diffraction study at 296 K for Crystal-DMF and under liquid nitrogen atmosphere for Crystal-DMSO. Crystal-DMF and Crystal-DMSO have identical crystal structures that are composed of the adipate dianion (ADP2−) and the protonated triethanolamine (TEAH+). The crystal engineering pattern of Crystal-DMSO was elucidated through this study. These findings of versatile organogelation and robust crystallization emphasize the significance of solvent polarity and its diversity in attaining both the gel and crystalline phases. The organogel-formation strategy of ADP-TEA-DMF and ADP-TEA-DMF-MeCN was unravelled using infrared spectroscopic analyses. ESI-Mass spectral studies demonstrate the basic gel-constructing units, which are repeating to offer stable organogels. Thus, the solvent and the gelator concentration-directed organogelation process and the robust crystal-formation strategy are critically visualized in this study. [ABSTRACT FROM AUTHOR]

Two isolates of Roseateles were discovered in soil samples collected from Uiwang-si, Gyeonggi-do, Republic of Korea. These isolates exhibited rod-shaped morphology and were facultatively anaerobic, non-motile, and tested positive for oxidase and catalase. Designated as strains R3-3T and R3-11, their growth was hindered by NaCl concentrations exceeding 0.5%, while their optimal growth conditions were observed at temperatures ranging from 25 °C to 30 °C and pH levels between 7.0 and 9.0. Both strains exhibited positive results for the hydrolysis of Tween 80 and DNA, but tested negative for starch, casein, chitin, and gelatin hydrolysis. Additionally, they assimilated L-Arabinose, D-mannitol, and D-Maltose, while exhibiting negative results for the fermentation of D-glucose, esculin ferric citrate, D-mannose, N-acetyl-glucosamine, potassium gluconate, capric acid, adipic acid, trisodium citrate, and phenylacetic acid. The DNA G+C content of strain R3-3T was measured at 67.5 mol%. Comparative analysis revealed that the average nucleotide identity (ANI) values between R3-3T and the Roseateles type strains ranged from 75.14% to 78.30% while the digital DNA-DNA hybridization (dDDH) values ranged from 20.70% to 22.70%. Consequently, based on comprehensive genomic, chemotaxonomic, phenotypic, and phylogenomic evaluations, the isolated strains have been designated as a new species within the genus Roseateles, named Roseateles agri sp. nov. (with type strain R3-3T = KACC 23678T = NBRC 116681T). [ABSTRACT FROM AUTHOR]

Smart materials represent an emerging and highly exploited category, particularly in the creation of textiles that can sense and respond to various external stimuli, such as temperature or humidity. This study introduces for the first time the hygroscopic elongation and drying shrinkage properties of stimulus-responsive single-component polyamide (PA) fibers copolymerized with polyetherdiamine and diethylenetriamine (DETA). PA copolymers containing 5-15% polyetherdiamine were comprehensively characterized, including nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FT-IR), relative viscosity, and differential scanning calorimetry (DSC) analyses. Subsequently, these PA copolymers were successfully melt-spun into fibers and knitted into double-layered fabrics. PA fibers containing 15% polyetherdiamine showed significant results, with a moisture-absorbing elongation of 15.6% and a drying shrinkage of 94.9%. The Qmax and moisture regain of the PA fabric are 0.206 W·cm-2 and 4.4%, respectively. These moisture-driven, fiber-based smart textiles exhibit changes in breathability and shape retention at different humidity levels, thereby maintaining a more comfortable microclimate. Such textiles have great potential for widespread use in clothing, helping to improve comfort and adaptability. [ABSTRACT FROM AUTHOR]

The global market of fossil carbon-derived adipic acid (AA) was over 3 million tons in 2022, emitting 3.1 million tons of the potent greenhouse gas N2O. Alternative biomass-derived feedstocks offer a sustainable option to replace fossil carbon, but alternative pathways for AA synthesis are also required to curb the substantial emissions associated with the process. A novel and sustainable approach to synthesize AA is by coupling biomanufacturing and electrocatalysis. Biologically-produced cis,cis-muconic acid (ccMA) from sugars and lignin monomers has recently gained significant attention as a precursor to AA, as it can be electrochemically hydrogenated to AA using water-derived (instead of fossil-derived) hydrogen and electricity generated from wind energy. For the first time in literature, we demonstrate appreciable electrochemical production of AA using supported palladium nanoparticles. The performance of this system contrasts with that of palladium foil or platinum-based catalysts, which produced little AA. Density functional theory calculations on model surfaces of palladium and platinum suggest that the reduction of ccMA to trans-3-hexenedioic acid occurs through an outer sphere proton-coupled electron transfer mechanism, while subsequent reduction to AA preferentially occurs on surface terrace sites. Our calculations also explain the exceptional performance of palladium nanoparticles compared to palladium- and platinum-based foils, attributing the more favorable activation energy barriers found on palladium terraces to the relatively moderate binding strength of adsorbed species. These results suggest structure-sensitive catalyst design strategies that maximize the exposure of terrace atoms for further improvement of the ccMA electrochemical hydrogenation process. [ABSTRACT FROM AUTHOR]

A series of seven novel amorphous amides and polyamides were synthesized from four biodegradable carboxylic acids by direct polycondensation with aliphatic diamines using Yamazaki-Higashi phosphorylation. Aliphatic carboxylic acids like acrylic acid, lactic acid, and adipic acid whereas aromatic carboxylic acid like terephthalic acid were reacted with ethylenediamine and diamino-propane respectively. The monocarboxylic acids yielded amides, whereas the dicarboxylic acids formed polyamides. The obtained products were characterized by FT-IR, 1H NMR, LCMS, SEM, TGA, and DSC along with microbial biodegradation. The TGA thermogram comparison studies show a decrease in thermal degradation with an increase in the aliphatic chain. Also, the introduction of an aromatic ring decreases degradability. Glass transition of aliphatic polyamide at 140 °C has negligible melting endotherm. Also, the samples were structurally degraded after 15 days of biological treatment which was confirmed via FT-IR. [ABSTRACT FROM AUTHOR]

A lot of research is constantly underway in the world to develop new or improve the current processes of the chemical industry to make them more effective and environmentally friendly. The described research on the oxidation of cyclohexane or cyclohexanone to adipic acid with a coupled action of UV radiation and oxygen–ozone mixture, instead of the currently used oxidation with HNO3, is part of this trend. Gas chromatography was used to determine process indicators, such as cyclohexane conversion and selectivity to AA, which exceeded 50% at 25 oC, after 16 h. This method can also be used for the preparation of other dicarboxylic acids from cycloalkanes, which proves its universal character. [ABSTRACT FROM AUTHOR]

Polyamide 66 was extensively utilized in various applications contributed by its excellent mechanical performance and outstanding durability. However, its high crystallinity renders it to have low transparency, which seriously limits its application in optical devices. Herein, a highly transparent polyamide (PA) 66-based copolymer was reported using 4,4′-diaminodicyclohexylmethane (PACM), adipic acid, and polyamide 66 salt as the reaction monomers. Wide-angle X-ray diffraction (WAXD) analysis revealed that the crystal phase of the synthesized PA66/PACM6 displayed a clear transition from α to γ as the PACM6 increased accompanied by a decreased intensity in the diffraction peak of the copolymer, whose transmittance was successfully adjusted reaching as high as 92.5% (at 550 nm) when the PACM6 was 40 wt%. Moreover, the copolymer with a higher content of PACM6 exhibited larger toughness. On the other hand, the biaxially oriented films of PA66/PACM6 (20 wt%) were also prepared, and it was found that the transparency of the PA66/PACM6 copolymer could be further enhanced via adjusting the stretching ratio of the film. Furthermore, the mechanical strength of the biaxially oriented PA66/PACM6 was also improved with the increase in the orientation degree in the stretching process, indicating that the physical properties of the transparent PA66 were significantly influenced by its alicyclic structure, and the introduction of PACM into PA66 was capable of effectively improving the optical and crystalline characteristics of PA66, revealing that the synthetic strategy has great potential for guiding the design and development of transparent polyamide materials. [ABSTRACT FROM AUTHOR]

Poly (butylene adipate-co-terephthalate) (PBAT) has been extensively used in every field of life, but the PBAT hydrolyzing microorganisms had rarely been studied. In this project, the synergistic degradation effect of bacteria identified from the farm soil of Shaanxi village yuan Jia cun was studied. To improve the degradation of PBAT, a co-culture system was made using SUST B1, SUST B2, and SUST B3. It was noted that the synergistic degradation of PBAT days was greater as compared to the monoculture system. Maximum lipase activity was observed after 6 days of incubation, the lipase activity (24.3 U/mL) of the co-culture surpassed the monoculture which was substantially complex as compared to individual bacterium SUST B1 (9.42 U/mL), SUST B2 (10.1 U/mL), and SUST B3 (8.7 U/mL) degrading 26.1% of PBAT. These results were further confirmed using XRD, FTIR, and SEM analysis. The mechanism of PBAT degradation was also studied using LC/MS. PBAT degradation is comprised of numerous phases that generate oligomers, dimers, and monomers. The microorganisms secreted the PBAT-degrading lipase that catalyzes the ester bonds present in the PBAT backbone and convert it into respective monomers like terephthalic acid, 1, 4-butanediol, and adipic acid. Microbes then uptake them to fulfill their carbon need and degrade them. Hence, PBAT bioremediation can be accomplished by a co-culture system. This is the first study to report the synergistic degradation of PBAT in the co-culture system. [ABSTRACT FROM AUTHOR]

Bioactive compounds in plants are essential for the formation of novel chemotherapeutic drugs, which have been used in Ayurveda to treat a variety of illnesses. Indian medicinal herbs have been used for thousands of years to treat a variety of illnesses, such as fever, cancer, snake bites, rheumatism, skin problems, and neurodegenerative diseases. GC–MS was used to locate and categorize bioactive components in Olea dioica leaves. The results showed that presence of octanoic acid, methyl ester, decanoic acid, methyl ester, desulphosinigrin, l-gala-l-ido-octose, methyl tetradecanoate, Tetradecanoic acid, 6-benzoxazolesulfonamide, N-(2-hydroxyethyl)-2-methyl-, 10-chloro-5-methoxy-5H-dibenzo[a,d][7]annulene, pentadecanoic acid, oleic acid, n-hexadecanoic acid, hexanedioic acid, dioctyl ester, and squalene. The methanol extract of Olea dioica was effective against a wide spectrum of pathogenic bacteria at four different concentrations, with the highest activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Xanthomonas campestris, and Salmonella typhimurium. It also showed moderate activity against Agrobacterium tumefaciens, Pseudomonas aeruginosa, Streptomyces pneumonia, and Pseudomonas syringae. The pharmacological properties of O. dioica, as well as their variety and comprehensive phytochemistry, could be exploited as a potent antimicrobial agent for future therapeutics. [ABSTRACT FROM AUTHOR]

Adipic acid (AA) is a crucial feedstock for nylon polymers, and is industrially produced by thermal oxidation of cyclohexanone/cyclohexanol mixture (KA oil). However, this process consumes large quantities of corrosive nitric acid as oxidants, while emits ozone‐depleting greenhouse gas N2O. Here, an electrocatalytic strategy for selective oxidation of KA oil to AA coupled with H2 evolution over a Co3O4/graphdiyne cooperative catalyst (Co3O4/GDY) is reported. The Co3O4/GDY displays high electrooxidation activity of KA oil to AA (100 mA cm−2 at ≈1.5 V vs RHE), outperforming all the reported findings. Detailed ex situ and in situ experimental studies, theoretical calculations, and molecular dynamic simulations reveal that GDY not only facilitates the enrichment of cyclohexanone on the catalyst surface in aqueous medium, but also upshifts the d‐band center of Co sites, strengthening the adsorption/activation of cyclohexanone. This study offers a green route for AA synthesis and proposes a GDY interface engineering strategy for efficient electrooxidation. [ABSTRACT FROM AUTHOR]

An effective synthesis of four potentially biologically active O- and N-containing 23-, 28-, 30-, and 31-membered macroheterocycles from undec-10-enal was carried out. First, undec-10-enal was converted to undec-10-enyl undec-10-enoate via the Tishchenko disproportionation reaction catalyzed by Al(i-PrO)3. The subsequent Wacker–Tsuji oxidation of undec-10-enyl undec-10-enoate gave 10-oxoundecanyl 10-oxoundecanoate. Finally, the [1+1]-condensation of 10-oxoundecanyl-10-oxoundecenoate with hydrazine hydrate or malonic, glutaric, or adipic acid dihydrazides resulted in the synthesis of four macroheterocycles. [ABSTRACT FROM AUTHOR]

6-Aminocaproic acid and adipic acid are the key value-added chemical precursors in the pharmaceutical, solvent and polyamide industry, including nylon-6, and nylon-6, 6. An enzymatic interconversion of the two precursors can provide a convenient and eco-friendly biosynthetic route to each of the precursors and thus, require analysis of the reaction process. Herein, an in vitro enzymatic method was employed to convert the two precursors while most studies so far have focused on the whole cell bioconversion to investigate the process. 4-Aminobutyrate aminotransferase was utilized to mediate the reactions between 6-aminocaproic acid and the intermediate 6-oxohexanoic acid with the aid of pyridoxal 5'-phosphate and amine donor/acceptor. 6-Oxohexanoate dehydrogenase was utilized for the reaction from 6-oxohexanoic acid to adipic acid with NADP+. A range of reaction conditions were investigated including the type of amine donor, pH conditions, the concentrations of enzyme and amine donor/acceptor. The optimum condition resulted in 78% yield for the reaction from 6-oxohexanoic acid to 6-aminocaproic acid. The yield for the one-pot, two-step enzymatic cascade from 6-aminocaproic acid via 6-oxohexanoate intermediate to adipic acid was 88%, which was higher than the yield for each individual step in the cascade, with 31% and 32%, for the first and second step, respectively. Furthermore, structural analysis on the active site of the 4-aminobutyrate aminotransferase docked with a range of amine donors implicates the optimal donor is glutamate in accordance with the experimental data and suggests enzyme engineering possibilities for more readily available donors to facilitate the industrial application of the process. [ABSTRACT FROM AUTHOR]

The solubility, permeability, and dissolution rate of an active pharmaceutical ingredient (API) are critical factors in determining its pharmacokinetic performance in oral dosage forms. Modifying these properties can potentially enhance the drug's pharmacokinetics. Vandetanib (VDTB), classified as a class II anti-cancer drug in the biopharmaceutical classification system (BCS), suffers from low solubility (0.008 mg mL−1) and an extended pharmacokinetic half-life (19 days), necessitating the administration of high doses, which leads to undesirable side effects. To address this issue, we have employed a crystal engineering approach to enhance the solubility of VDTB. We employed the liquid-assisted grinding (LAG) method followed by the slow evaporation technique to prepare novel solid forms of VDTB by incorporating various aliphatic dicarboxylic acids, including succinic acid (SUA), adipic acid (ADA), pimelic acid (PIA), azelaic acid (AZA), and sebacic acid (SBA). These newly obtained solid forms were characterized by SC-XRD, PXRD, TGA, and DSC experiments. The crystal structure analyses revealed a proton transfer between the carboxylic acid group of aliphatic acids and the N-methyl piperidine moiety of VDTB, confirming salt/adduct formation. Additionally, all of the molecular salts were stabilized by charge-assisted N+–H⋯O− hydrogen bonds, while the parent VDTB crystal structure is stabilised by N–H⋯N interactions. Moreover, the solubility and dissolution rate of these new solid forms were assessed in a pH 7.4 phosphate buffer medium, with the results indicating that all of the solid forms, except for VDTB:SBA, exhibited higher solubility compared to pure VDTB. These findings offer promising prospects for the development of an improved VDTB formulation with enhanced pharmacokinetic properties. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O), as the third largest greenhouse gas in the world, also has great applications in daily life and industrial production, like anesthetic, foaming agent, combustion supporting agent, N or O atomic donor. The capture of N2O in adipic acid tail gas is of great significance but remains challenging due to the similarity with CO2 in molecular size and physical properties. Herein, the influence of cation types on CO2−N2O separation in zeolite was studied comprehensively. In particular, the inverse adsorption of CO2−N2O was achieved by AgZK‐5, which preferentially adsorbs N2O over CO2, making it capable of trapping N2O from an N2O/CO2 mixture. AgZK‐5 shows a recorded N2O/CO2 selectivity of 2.2, and the breakthrough experiment indicates excellent performance for N2O/CO2 separation. The density functional theory (DFT) calculation shows that Ag+ has stronger adsorption energy with N2O, and the kinetics of N2O is slightly faster than that of CO2 on AgZK‐5. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O), as the third largest greenhouse gas in the world, also has great applications in daily life and industrial production, like anesthetic, foaming agent, combustion supporting agent, N or O atomic donor. The capture of N2O in adipic acid tail gas is of great significance but remains challenging due to the similarity with CO2 in molecular size and physical properties. Herein, the influence of cation types on CO2−N2O separation in zeolite was studied comprehensively. In particular, the inverse adsorption of CO2−N2O was achieved by AgZK‐5, which preferentially adsorbs N2O over CO2, making it capable of trapping N2O from an N2O/CO2 mixture. AgZK‐5 shows a recorded N2O/CO2 selectivity of 2.2, and the breakthrough experiment indicates excellent performance for N2O/CO2 separation. The density functional theory (DFT) calculation shows that Ag+ has stronger adsorption energy with N2O, and the kinetics of N2O is slightly faster than that of CO2 on AgZK‐5. [ABSTRACT FROM AUTHOR]

Simple Summary: Ammonia gases are produced from urea in the urine and slurry due to the action of urease. Odorous compounds are produced by microbial fermentation that utilizes an undigested nutrient in pig slurry. Various additives have been researched to mitigate ammonia emissions or odorous compound production. These studies involve inducing acidic conditions in urine or slurry, enhancing nitrogen utilization, inhibiting urease, or absorbing odorous compounds in pig slurry. However, information about the comparison of these additives is lacking. In this study, we evaluate and compare the effects of each additive on nitrogen utilization, urinary pH, slurry pH, and odorous compound concentrations. The five experimental diets were (1) a control diet, (2) the control diet with 1% benzoic acid, (3) the control diet with 1% adipic acid, (4) the control diet with 1% bromelain, and (5) the control diet with 1% humic substances. Fecal dry matter and nitrogen output were greatest in pigs fed the humic substances diet. Daily retained nitrogen and the nitrogen retention rate tended to be lowest in pigs fed an adipic acid diet. Urinary pH was lowest in pigs fed the adipic acid diet. In addition, slurry pH did not affect odorous compound concentrations, and some odorous compounds tended to be lowest in pigs fed the humic substances diet. The objective was to evaluate the effects of benzoic acid, bromelain, adipic acid, and humic substance supplementation on nitrogen balance, urinary pH, slurry pH, and manure odorous compounds in pigs. Fifteen castrated male pigs with an initial body weight of 37.9 kg (standard deviation = 4.1) were individually housed in metabolism crates. The animals were allocated to a triplicated 5 × 2 incomplete Latin square design with 15 animals, 5 experimental diets, and 2 periods. The basal diet mainly consisted of corn, soybean meal, and rapeseed meal. Four experimental diets were prepared by supplementing each additive at a concentration of 10 g/kg at the expense of corn starch to the basal diet. Each period consisted of a 4-day adaptation period, a 24 h collection period for slurry sampling, and a 4-day collection period for feces and urine. The feces and urine collected for 24 h on day 5 were mixed at a ratio of fecal weight and urine weight to obtain slurry samples. The apparent total tract digestibility N in pigs fed the humic substance diet was the least (p < 0.05) compared to the other groups. The daily retained N and N retention as % ingested tended (p < 0.10) to be the lowest in the adipic acid group among the treatments. The urinary pH in pigs fed the adipic acid diet was less (p < 0.05) than that in other groups except the benzoic acid group. The slurry pH tended to differ among the treatment groups (p = 0.074) with the lowest value in the pigs fed the adipic acid diet. The concentrations of indole in slurry (p = 0.084) and isovalerate in feces (p = 0.062) tended to differ among the groups with the lowest values in the pigs fed the humic substance diet. In conclusion, adipic acid supplementation in pig diets can decrease urinary pH and slurry pH. Although benzoic acid and adipic acid have limited effects in reducing odorous compounds, humic substances have the potential to reduce some odorous compounds. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the use of direct heterogeneous esterification method of extracted fibers from Leptadenia pyrotechnica khimp (Leptadenia pyrotechnica) and date palm tree (Phoenix dactylifera L.) using adipic and citric acids. Homogeneous esterification leads to the degradation of lignocellulosic material, making it impossible to obtain a pure ester of extracted crude fiber by this method. Methods. The esterification reaction was carried out from three samples of the plant Leptadenia pyrotechnica, Phoenix dactylifera L. leaf, and fiber) were extracted as crude fibers and used in the heterogeneous esterification process. The total esterified fibers were six esters (each sample esterified with citric and adipic acid). The study employed ordinary laboratory equipment together with Fourier Transformation Infrared (FTIR) spectroscopy. The results showed that the ester contents were in the range 21.6% to 28%. The degree of substitutions was in the range 0.38 to 0.57. Conclusion. This process was simple and effective in producing esterified extracted plants fibers with a desirable degree of substitution. [ABSTRACT FROM AUTHOR]

The synthesis of dimethyl adipate (DAP), a stable configuration of adipic acid, from biomass-derived cyclopentanone (CPO) and dimethyl carbonate (DMC) constitutes an attractive greener route than petroleum-based industrial processes. Solid basic catalysts such as MgO, Mg5(CO3)4(OH)2·4H2O, KOCH3 and Ca(OCH3)2 have been used achieving a DAP yield up to 30% at 533 K. In addition to the type of catalyst, other operating conditions such as the substrate, reaction time, temperature and CPO concentration have been studied. The methylation of DAP and CPO and the self-aldol condensation of CPO to form dimers and oligomers are reactions that occur in parallel with the production of DAP. It has been established that the main challenge is the self-aldol condensation of CPO. It has been identified that at short reaction times, to prevent methylation, and at dilute concentrations, to avoid CPO self-condensation, the DAP formation rate is much higher than these other competitive reactions. Finally, it should be noted that a DAP productivity up to 3.45 g·gcat−1·h−1 has been achieved under mild conditions. [ABSTRACT FROM AUTHOR]

As industrial shochu yeast is a diploid strain, obtaining a strain with mutations in both allelic genes was considered difficult. We investigated a method for disrupting two copies of a homozygous gene with a single transformation. We designed a disruption cassette containing an intact LYS5 flanked by nonfunctional ura3 gene fragments divided into the 5′- and 3′-regions. These fragments had overlapping sequences that enabled LYS5 removal as well as URA3 regeneration through loop-out. Furthermore, both ends of the disruption cassette had an additional repeat sequence that allowed the cassette to be removed from the chromosome through loop-out. First, 45 bases of 5′- and 3′-regions of target gene sequences were added on both ends of this cassette using polymerase chain reaction; the resultant disruption cassette was introduced into a shochu yeast strain (ura3 / ura3 lys5 / lys5); then, single allele disrupted strains were selected on Lys drop-out plates; and after cultivation in YPD medium, double-disrupted strains, in which replacement of another allelic gene with disruption cassette by loss of heterozygosity and regeneration of URA3 in one of the cassettes by loop-out, were obtained by selection on Ura and Lys drop-out plates. The disruption cassettes were removed from the double-disrupted strain via loop-out between repeat sequences in the disruption cassette. The strains that lost either URA3 or LYS5 were counter-selected on 5-fluoroorotic acid or α-amino adipic acid plates, respectively. Using this method, we obtained leu2 / leu2 and leu2 / leu2 his3 / his3 strains in shochu yeast, demonstrating the effectiveness and repeatability of this gene disruption technique in diploid yeast Saccharomyces cerevisiae. [Display omitted] [ABSTRACT FROM AUTHOR]

3D-printing has gained popularity in recent years due to the many advantages it offers over the traditional approaches for instance this technology reduces the time a dentist needs to create and fit dentures to just 2–3 sessions. Fumaric, maleic, and adipic acids with the percentage (0.1 wt.%) were added to chitosan solution (2 wt.%) and the final composite was added to the 3D printable acrylic resin. The specimens were examined for several chemical analyses (XRD, SEM, FTIR) and mechanical tests (impact strength and surface hardness tests), where the total number (115) of specimens used in the study was specimens divided into five groups. In chemical analysis, one specimen was constructed for each modified group and one specimen was used as the control group (3d printable resin without addition (non-modified) for each test. For mechanical tests ten specimens were constructed for each modified group and ten specimens were used as the control group (3d printable resin without addition (non-modified) for each test. The results of chemical analysis showed improvement in the properties of modified 3d printable acrylic denture base resin, additionally the mechanical test results showed that the (Fumaric acid and Maliec acid with Chitosan) specimens have the highest properties in comparison with other specimens, while the lowest properties were for specimens of 3D printable acrylic resin with chitosan. The chemical and mechanical properties of the modified 3D-printed denture base are improved when chitosan is modified with dicarboxylic acids. Conversely, if chitosan alone is used to modify the 3D-printed polymers, the mechanical and chemical properties would be decreased. [ABSTRACT FROM AUTHOR]

This work describes the comparison of the catalytic performances of α‐MnO2 nanorods synthesized by a facile hydrothermal approach at varying temperatures (140–200 °C). The structure and morphology of these nanorods were analyzed by XRD, N2‐physisorption, NH3‐TPD, Raman, SEM, HRTEM, and XPS. The prepared α‐MnO2 nanorods also performed exceptionally well in the catalytic oxidation of cyclohexanone to dicarboxylic acids under mild reaction conditions. The characterization results conferred that there is a significant influence of hydrothermal temperatures on the textural properties, morphology, and catalytic activity. Notably, the α‐MnO2 nanorods obtained from 180 °C hydrothermal conditions outperformed other catalysts with 77.3 % cyclohexanone conversion and 99 % selectivity towards acid products such as adipic acid (AA), glutaric acid (GA) and succinic acid (SA). The improved catalytic activity may be attributed to the interaction of the bifunctional Mn3+/4+ redox metal centres and surface acidic sites. The present oxidation reaction was found to be a promising eco‐benign process with high selectivity for the production of commercially significant carboxylic acids from cyclohexanone. [ABSTRACT FROM AUTHOR]

While modern research into biodegradable and renewable plastics has expanded to cover a wide variety of applications, some characteristics, such as desirable elastic properties, are still difficult to achieve without the use of petroleum-based monomers. In addition, 100% biomass-based polymers are in high demand as environmental regulations increasingly require the use of biomass-based monomers. In this study, biomass-derived monomers, such as adipic acid (AA), 2,5-furandicarboxylic acid (FDCA), and 1,3-propanediol (PDO), were used to synthesize terpolyesters with elastic properties. The unsymmetrical structure of FDCA led to a spiral motif that biodegrades efficiently, and its ring structure also plays an important role as a hard elastomer domain. Applying the "odd–even effect" of PDO resulted in very high biodegradation rates, low melting points, and low degrees of crystallinity. An FDCA : AA ratio of 7 : 3 led to an elongation of around 600% and a recovery rate of 89% (to the original state) at a fixed PDO concentration. [ABSTRACT FROM AUTHOR]

The rhizobial inoculation effects on the peanut rhizosphere bacterial community and metabolites were studied under different N availability following the five N application rates without rhizobial inoculation (N1–N5; 0, 40, 80, 110, 170 kg N ha−1) or with rhizobial inoculation (RN1–RN5) in a 3-year field trial. The effects of rhizobia on peanut growth, the rhizobacterial community, and root metabolites differed depending on the N availability. Plant height and nodule number were significantly increased by rhizobial inoculation, especially in RN3. Rhizobacterial abundance and richness were increased by rhizobial inoculation, except in RN1 (no N added). The number of 16S rRNA gene copies was higher in RN1–RN3 than in N1–N3 in both years. The largest number of differential bacterial genera between an inoculated treatment and its corresponding uninoculated treatment was in RN1 vs. N1. The beneficial bacteria Saccharimonadales and c_JG30-KF-CM66 (Chloroflexi) were most abundant in RN3. The concentrations of organic acids (3-methylglutaric acid, adipic acid, 3-hydroxyoctanoic acid, and octenedioic acid) were significantly increased in RN3 and were positively correlated with c_JG30-KF-CM66 (Chloroflexi), soil available N, and biomass. No metabolic pathways were significantly enriched by rhizobial inoculation at the highest N application rate (RN5). These results demonstrate that rhizobia positively affect peanut growth and yield under the best N availability via their ability to reshape the soil microbiome and metabolites. [ABSTRACT FROM AUTHOR]

Adipic acid (AA), an important precursor to produce nylon‐6, nylon‐6,6, and polyurethanes, can be synthesized from biomass‐derived 1,6‐hexanediol (HDO). Herein, we examined the selective oxidation of 1,6‐hexanediol to adipic acid over Pd/support (support‐ Rice husk ash (RHA), TiO2, C, ZnO, Al2O3, La2O3, Mg(OH)2, and hydroxyapatite (HAP)) catalyst in water at 70 °C under base‐free conditions. Pd/HAP exhibited high catalytic activity among the catalysts explored, affording adipic acid (AA) selectively in 89 % yield with complete conversion of HDO. Investigating these Pd/support catalysts and several control experiments inferred that the basicity of the HAP support concertedly with Pd nanoparticle participated in achieving efficient aerial oxidation of HDO to AA, and hence avoided the need for any additional base additives. Advantageously, Pd/HAP exhibited high activity for gram‐scale reactions and long‐term stability during reusing the catalyst for several cycles without any considerable loss in the catalytic activity. [ABSTRACT FROM AUTHOR]

This work reports on the synthesis of statistical copolymers of bio‐based PA 6.19 and PA 6.6 together with the production of melt‐spun monofilaments for the production of sustainable textile fibers. The plant oil‐based 1.19‐nonadecanedioic acid is synthesized from bio‐derived oleic acid via isomerizing methoxycarbonylation. The homopolymer PA 6.19 with a carbon‐based bio‐content of 72% shows a good elongation at break of 166%, but lower tensile strength than commercial PA 6 (43 MPa versus 82 MPa). Addition of adipic acid to form statistical PA 6.6/6.19 copolymers improves toughness while maintaining the high elongation at break. Two PA 6.6/6.19 copolymers with a carbon‐based bio‐content of 26% and 33% are successfully synthesized and exhibited comparable toughness (94 ± 6 MPa and 92 ± 2 MPa) to the commercial PA 6 (92 ± 15 MPa). The bio‐based copolymers also exhibit a much lower water uptake than PA 6 and PA 6.6, resulting in a higher dimensional stability. Melt spinning of the oleic acid‐based polyamides is successfully carried out to produce monofilaments with sufficient properties for further processing in a knitting process, demonstrating the capabilities of the bio‐based PA 6.6/6.19 copolymers for use in the textile industry. [ABSTRACT FROM AUTHOR]

Epoxidized oleic acid can be transformed into vegetable oil-based polyesters through a self-polymerization reaction. This study aims to develop the kinetic model for the polymerization reaction between epoxide and carboxyl groups and the product characterization regarding its functional groups, molecular weight, and thermal stability. The polymerization reaction was carried out at the temperature of 120–180 °C for 2–6 h with the highest conversion of oxirane number up to 97%. Kinetic study showed one-step reaction model between oxirane and carboxylic group gives the activation energy value of 34.71 kJ/mol. Furthermore, the two simultaneous reaction model with further reaction between oxirane group and hydroxyl group also taken into account. The later provides a better agreement between the experimental data and the calculated conversion value. The activation energy values in the first and second steps are 38.61 and 26.00 kJ/mol, respectively. The product characterization showed that adding adipic acid did not significantly affect the polymer's molecular weight and thermal stability. The polydisperse characteristics of the poly(oleic acid) produced in this study enable poly(oleic acid) to be used as a lubricant, a polymer additive, or a precursor to produce polymers with higher molecular weights by taking advantage of the accessibility of OH groups. [ABSTRACT FROM AUTHOR]

As new luminescent materials, room temperature phosphorescent (RTP) carbon dots (CDs) are widely used in bioimaging, theranostics, anti-counterfeiting encryption, optoelectronic devices, etc. However, the synthesis of RTP CDs with multi-color and high quantum yield (QY) remains a major challenge. Herein, a strategy is designed and developed to synthesize metal-free multi-color (blue, green, yellow, and brown) RTP CDs within a B2O3 matrix via pyrolysis of boric acid and adipic acid. A long lifetime of 901.4 nm and a high quantum yield of 34.2% have been achieved, and their RTP can be observed by the naked eye for ∼ 9 s. The structural characterization indicates that the highly rigid B2O3 matrix and covalent network structure with C＝O, B–C, C–O, and C–O–B efficiently suppress non-radiative recombination by locking the triplet excitons. More importantly, the phosphorescent color of CDs can be regulated efficiently by the degree of oxidation and carbonization. These excellent optical properties allow CDs to be more applicable in anti-counterfeiting encryption, information protection, and bioimaging. This discovery will facilitate understanding the luminescence mechanism of multi-color RTP CDs and expand their practical applications. [ABSTRACT FROM AUTHOR]

Two hybrid composite photocatalysts, denoted as SnP/AA@ZnO and SnP@ZnO, were fabricated by a reaction of trans-dihydroxo[5,10,15,20-tetrakis(4-pyridyl)porphyrinato]tin(IV) (SnP) and ZnO with and without pretreatment of adipic acid (AA), respectively. In SnP@ZnO, SnP and ZnO are likely held together by a coordinative interaction between the pyridyl N atoms of SnP and the Zn atoms on the surface of ZnO. In the case of SnP/AA@ZnO, the SnP centers were robustly coupled with ZnO nanoparticles through the AA anchors. SnP/AA@ZnO exhibited largely enhanced photocatalytic activities for the degradation of anionic amaranth (AM) dye under a visible light irradiation, compared to SnP, ZnO, and SnP@ZnO. The degradation efficiency of AM by SnP/AA@ZnO was 95% within 60 min at a rate constant of 0.048 min−1. The remarkable photocatalytic oxidation performance of SnP/AA@ZnO was mainly attributed to the synergistic effect between SnP and ZnO. This study is valuable for the development of highly effective composite photocatalytic systems in advanced oxidation processes and is of importance for the treatment of wastewater containing dyes. [ABSTRACT FROM AUTHOR]

Adipic acid is an industrially important chemical, but the current approach to synthesize it can be of serious pollution to the environment. Rencently, bio-based production of adipic acid has significantly advanced with the development of metabolic engineering and synthetic biology. However, genetic heterogeneity-caused decrease of product titer has largely limited the industrialization of chemicals like adipic acid. Therefore, in the attempt to overcome this challenge, we constitutively expressed the reverse adipate degradation pathway, designed and optimized an adipic acid biosensor, and established a high-throughput screening platform to screen for high-performance strains based on the optimized biosensor. Using this platform, we successfully screened a strain with an adipic acid titer of 188.08 mg·L−1. Coupling the screening platform with fermentation optimization, the titer of adipic acid reached 531.88 mg·L−1 under shake flask fermentation, which achieved an 18.78-fold improvement comparing to the initial strain. Scale-up fermentation in a 5-L fermenter utilizing the screened high-performance strain was eventually conducted, in which the adipic acid titer reached 3.62 g·L−1. Overall, strategies developed in this study proved to be a potentially efficient method in reducing the genetic heterogeneity and was expected to provide guidance in helping to build a more efficient industrial screening process. Key points: • Developed a fine-tuned adipic acid biosensor. • Established a high-throughput screening platform to screen high-performance strains. • The titer of adipic acid reached 3.62 g·L−1 in a 5-L fermenter. [ABSTRACT FROM AUTHOR]

Mole fraction solubilities are reported for acenaphthene, o-acetoacetanisidide, anthracene, benzil, benzoic acid, benzoin, 4-tert-butylbenzoic acid, 1-chloroanthraquinone, 4-chlorobenzoic acid, 2-chloro-5-nitrobenzoic acid, 4-chloro-3-nitrobenzoic acid, 3,4-dichlorobenzoic acid, 3,4-dimethoxybenzoic acid, 3,5-dinitrobenzoic acid, diphenyl sulphone, 2-ethylanthraquinone, 2-naphthoxyacetic acid, 2-hydroxybenzoic acid, N-hydroxyphthalimide, 2-methoxybenzoic acid, 4-methoxybenzoic acid, 3-methylbenzoic acid, 2-methyl-3-nitrobenzoic acid, 3-methyl-4-nitrobenzoic acid, 4-methyl-3-nitrobenzoic acid, 3-nitrobenzoic acid, 4-nitrobenzoic acid, salicylamide, 3,4,5-trimethoxybenzoic acid, trans-stilbene, thioxanthen-9-one and xanthene dissolved in dimethyl adipate at 298.15 K. Results of these measurements, combined with published literature data for adipic acid, glutaric acid and succinic acid, are used to derive predictive Abraham model correlations. The derived correlations back-calculate the observed solubility data to within ±0.12 log units. [ABSTRACT FROM AUTHOR]

This paper presents a not previously reported catalytic system consisting of transition metals Co2+ and Mn2+ and alkyl nitrites R-ONO for the oxidation of cyclohexanone with oxygen to adipic acid. The influence of type and amount of catalyst, temperature, time, and type of raw material on conversion and product composition were determined. In addition, the oxidation of selected cyclic ketones such as cyclopentanone, cyclohexanone, cyclooctanone, cyclododecanone, 2-methylcyclohexanone, 3-methylcyclohexanone, and 4-methylcyclohexanone in acetic acid as solvent was performed. The results showed that R-ONO systems, under established reaction conditions, form NO·radicals, which oxidize to NO2 under a strong oxidization reaction environment. The Co2+/Mn2+/NO2 system was shown to be highly active in the oxidation of cyclic ketones with oxygen. [ABSTRACT FROM AUTHOR]

A series of controlled‐hydrogen‐reduction VOx (CHR‐VOx) were prepared after our controllable hydrogen treatment, and CHR‐VOx were controlled to be reduced to the states dominated by V5+ and V4+ species, subsequently the catalytic roles of V‐species and O‐species for cyclohexane (CHA) oxidation were explored. As expected, the surface properties of CHR‐VOx have occurred remarkable change resulting in a significantly improvement on catalytic performance determined by V‐species and O‐species. The reduction behavior of the properties was recognized by XPS and Raman. Generally, the moderate‐reduced CHR‐VOx which possessed most 78.7 % multi‐liganded‐oxygen (LO) performed the best conversion for CHA (11.8 %), and the over‐reduced CHR‐VOx with a large content of V4+ species (33 %) performed a best selectivity for adipic acid (44.3 %). In this case, LO sites were regarded as the active site to accelerate the activation of CHA, while V4+ species were regarded as the oxygen vacancies (OVs) through V4+−OV to contribute to the further oxidation to adipic acid. [ABSTRACT FROM AUTHOR]

The work is aimed at elucidation of metabolite profile of probiotic yoghurts prepared from cow milk (CPY) and goat milk (GPY) using gas chromatography–mass spectrometry‐based untargeted metabolomics approach. A total of 192 metabolites including 49 differentially expressed metabolites (DEMs) were observed, wherein amino‐acids, peptides and analogues constituted 41.93% of the metabolite sub‐class. Acetic acid, glycine, Thr‐Ala, octanoic acid, l‐kynurenine and 2‐amino adipic acid were among the top 15 DEMs. A significant relationship with seven key metabolic pathways including glycolysis, lysine degradation, purine metabolism, fatty acid biosynthesis, tryptophan metabolism, nicotinate and nicotinamide metabolism and glycine, serine and threonine metabolism has been established based on their impact values. [ABSTRACT FROM AUTHOR]

With the recognition that traditional phthalate plasticizers readily migrate from a polymer matrix into which they have been incorporated, have become widespread environmental pollutants and pose risks to human health, the development of new, effective, nontoxic, nonmigrating plasticizers has gained urgency. A focus has been the generation of plasticizers from renewable, inexpensive, nontoxic biobased precursors. Many small molecule plasticizers have been prepared from readily-available bioprecursors. However, the most promising are branched oligomeric materials. Fully compatible oligomeric plasticizers do not migrate from a polymer matrix. Highly branched materials are effective in increasing free volume and display good plasticizing impact. Using new technology that permits the generation of hyperbranched poly(ester) without gelation and with control of molecular weight and endgroup identity, oligomeric materials have been prepared from the nontoxic biomonomers, glycerol and adipic acid. The monomers are readily available at modest cost. The oligomers may be obtained in a simple one-step process and function as very effective plasticizers for polymeric materials. [ABSTRACT FROM AUTHOR]

A visible-light-active photocatalyst, SnP/AA@TiO2, was fabricated by utilizing the coordination chemistry between the axial hydroxo-ligand in the (trans-dihydroxo)(5,10,15,20-tetraphenylporphyrinato)Sn(IV) complex (SnP) and adipic acid (AA) on the surface of TiO2 nanoparticles. The SnP center was strongly bonded to the surface of the TiO2 nanoparticles via the adipic acid linkage in SnP/AA@TiO2, as confirmed by various instrumental techniques. SnP/AA@TiO2 exhibited remarkably enhanced photocatalytic activity toward the degradation of rhodamine B dye (RhB) in aqueous solution under visible-light irradiation. The RhB degradation efficiency of SnP/AA@TiO2 was 95% within 80 min, with a rate constant of 0.0366 min−1. The high degradation efficiency, low catalyst loading and high reusability make SnP-anchored photocatalysts more efficient than other photocatalysts, such as TiO2 and SnP@TiO2. [ABSTRACT FROM AUTHOR]

The aim of the present study is the preparation of a novel magnetic ferrofluid (FF) based on a hydrophobic deep eutectic solvent (DES), which is used for the extraction of trace quantities of clozapine from biological samples. For this purpose, a highly stable FF was prepared through the combination of adipic acid-coated magnetic nanoparticles (MNPs) plus tetraethylammonium chloride/thymol hDES without an additional stabilizer. These solvents were synthesized by the available and less-toxic materials, which is the appropriate option to support the solvents for the preparation of FF. In this study, a water-immiscible DES acts simultaneously as a carrier and stabilizer for the MNPs. In addition, the strong interactions between clozapine and magnetic FF could increase the extraction efficiency. The fractional factorial design was used for screening the experimental parameters. Then, the effective factors were optimized using the Box–Behnken design. The optimum extraction conditions were the following: pH of the sample solution: 8, the volume of the desorption solvent: 200 μL and desorption time: 5 min. Moreover, the suggested method exhibited low limits of detection in the range of 2.8–3.1 μg L−1. The linear range was 10.0–500.0 μg L−1 for human plasma and urine samples with acceptable recoveries greater than 91.4%. In addition, the proposed method is convenient, sensitive, effective, rapid and environmentally friendly. [ABSTRACT FROM AUTHOR]

We show that adipic acid (AA), a major building block for polyamides like Nylon-6,6, can be synthesized from lignin-derived feedstock by combining electrochemical hydrogenation with biotransformation. Up to 68% yield of cyclohexanol from phenol at 69% coulombic efficiency is achieved for electrochemical hydrogenation, and further, the electrochemical hydrogenation of an aromatic mixture as gained from lignin depolymerization allows 83% yield. Subsequent biotransformation of cyclohexanol with recombinant Pseudomonas taiwanensis VLB120 gains AA at a rate of 0.02 g L−1 h−1 with a yield of up to 61% in 5 h. [ABSTRACT FROM AUTHOR]

Using Escherichia coli MG1655 lacIQ, ∆ackA-pta, ∆poxB, ∆ldhA, ∆adhE, ∆fadE, PL-SDφ10-atoB, Ptrc-ideal-4-SDφ10-fadB, PL-SDφ10-tesB, ∆yciA as a core strain, derivatives capable of synthesizing adipic acid from glucose through the inverted fatty acid β-oxidation pathway were obtained. Biosynthesis of the target compound by recombinants was ensured by the primary condensation of acetyl-CoA and succinyl-CoA by 3-oxoacyl-CoA thiolase PaaJ and the catalysis of the final reaction of the cycle by acyl-CoA dehydrogenases FadE and FabI. Deletion in the strains of sucCD genes encoding components of succinyl-CoA synthase did not increase the relative intracellular availability of succinyl-CoA for target biosynthetic reactions and did not lead to an increase in adipic acid accumulation by the recombinants. The secretion of succinic and malic acids by the strains with an impaired tricarboxylic acid cycle remained almost unchanged, indicating the activity in the cells of glyoxylate shunt reactions that compete with the cycle reactions for isocitrate, required for succinyl-CoA formation. When isocitrate lyase, malate synthases A and G, and bifunctional kinase/phosphatase of isocitrate dehydrogenase were inactivated in strains due to deletion of the aceBAK operon genes and glcB, adipic acid synthesis by recombinants increased three-fold and reached 0.33 mM. [ABSTRACT FROM AUTHOR]

Copper(II) clusters of the type [CuII4OCl6L4] (L = ligand or solvent) are a well-studied example of inverse coordination compounds. In the past, they have been studied because of their structural, magnetic, and spectroscopic features. They have long been believed to be redox-inactive compounds, but recent findings indicate a complex chemical equilibrium with diverse mononuclear as well as multinuclear copper(I) and copper(II) compounds. Furthermore, depending on the ligand system, such cluster compounds have proven to be versatile catalysts, e.g., in the oxidation of cyclohexane to adipic acid. This report covers a systematic study of the formation of [CuII4OCl6(TPP)4] and [CuII4OCl6(TPPO)4] (TPP = triphenylphosphine, PPh3; TPPO = triphenylphosphine oxide, O=PPh3) as well as the redox equilibrium of these compounds with mononuclear copper(I) and copper(II) complexes such as [CuIICl2(TPPO)2], [{CuIICl2}2(TPPO)2], [{CuIICl2}3(TPPO)2], [{CuII4Cl4}(TPP)4], and [CuICl(TPP)n] (n = 1–3). [ABSTRACT FROM AUTHOR]

Oxidation of 2‐hydroxycyclohexanone (2‐HCO) which can be synthesized from both petroleum and biomass was investigated with heteropolyacids and oxygen as catalysts and oxidant, respectively. 2‐Hydroxyadipic acid (2‐HAA) was obtained in moderate yields, and H4PVW11O40 gave the highest yield (39 %). 2‐HAA is a dicarboxylic acid expected to be a monomer, and this work is the first report for production of 2‐HAA by catalytic oxidation reactions. The oxidation of 1,2‐cyclohexanedione (CHDO), which is a potential intermediate of 2‐HCO oxidation, produced similar yield of 2‐HAA even without catalyst. The effects of catalyst amount (first order), oxygen pressure (almost zero order) and the addition of radical scavenger (no effect) on the 2‐HCO oxidation with H4PVW11O40 catalyst were similar to those in a related case of 2‐methoxycyclohexanone oxidation to adipic acid with heteropolyacid catalyst. 2‐HCO is proposed to be oxidized to CHDO as a precursor of 2‐HAA in a similar mechanism to 2‐methoxycyclohexanone oxidation. [ABSTRACT FROM AUTHOR]

In this research, quinoa starch samples were evaluated in 9 treatments with different proportions of adipic acid and acetic anhydride mixture (ratio 1 to 30), along with a control sample in terms of physicochemical and functional characteristics and determining the optimal conditions for chemical modification. The mentioned treatments were designed by 3 independent variables affecting chemical modification, including chemical modifier concentration (2%, 4% and 6%), suspension pH (8, 8.5 and 9) and reaction time (60, 90, 120 minutes) by Taguchi method. became The swelling power and water absorption capacity of sample T2 (modifier concentration 2%, suspension pH 9 and reaction time 120 minutes) significantly increased compared to the control sample, which is a sign of the formation of crosslinks along with the formation of stable three - dimensional gel networks. Spectroscopy results showed that except for T2 sample, the rest of the samples had a slight tendency to retrogradation, which was a sign of the high stability of the said sample during the retention period to syneresis (p<0.05). Acetylation significantly improved the solubility characteristics compared to the control sample due to the better dispersion of starch in the aqueous medium. With the increase in the modifier concentration, the stability of the samples against the freeze -thaw cycle decreased significantly (p<0.05). The investigated parameters in measuring the thermal characteristics of modified quinoa starch were evaluated with a significant difference more than the control sample. The apparent viscosity of the T2 sample at the shear speed of 20, 50 and 100 rpm increased significantly compared to the control sample, but the other samples showed a lower viscosity. Also, using Taguchi analysis, the optimal treatment of modified quinoa starch with 2% modifier concentration, suspension pH 9 and reaction time 120 minutes was determined. [ABSTRACT FROM AUTHOR]

Chemical exchange saturation transfer (CEST) MRI is a versatile molecular imaging approach that holds great promise for clinical translation. A number of compounds have been identified as suitable for performing CEST MRI, including paramagnetic CEST (paraCEST) agents and diamagnetic CEST (diaCEST) agents. DiaCEST agents are very attractive because of their excellent biocompatibility and potential for biodegradation, such as glucose, glycogen, glutamate, creatine, nucleic acids, et al. However, the sensitivity of most diaCEST agents is limited because of small chemical shifts (1.0–4.0 ppm) from water. To expand the catalog of diaCEST agents with larger chemical shifts, herein, we have systematically investigated the CEST properties of acyl hydrazides with different substitutions, including aromatic and aliphatic substituents. We have tuned the labile proton chemical shifts from 2.8–5.0 ppm from water while exchange rates varied from ~680 to 2340 s−1 at pH 7.2, which allows strong CEST contrast on scanners down to B0 = 3 T. One acyl hydrazide, adipic acid dihydrazide (ADH), was tested on a mouse model of breast cancer and showed nice contrast in the tumor region. We also prepared a derivative, acyl hydrazone, which showed the furthest shifted labile proton (6.4 ppm from water) and excellent contrast properties. Overall, our study expands the catalog of diaCEST agents and their application in cancer diagnosis. [ABSTRACT FROM AUTHOR]

Differences in plant organs that are used as sources of explants can cause differences in callus growth and synthesized bioactive compounds. The objective of this study was to induce calli from different sources of explants and analyze their growth and bioactive compounds in the calli from leaf and stem explants of kaffir lime seedlings. Kaffir lime seeds were germinated until they grew into seedlings. On day 35, the leaves and stems of seedlings were harvested and callus was induced. Results showed that callus initiation time of stem explants was 5.66 days faster than that of leaf explants, which required 12.42 days. The colors of these calli were slightly different. Furthermore, callus fresh weight of leaf explants was less than that of stem explants, and the stationary phase of leaf explant-derived callus was earlier than for those from stem explant. Bioactive compounds detected in calli derived from leaf and stem explants were different. The main compounds found in the leaf explant-derived callus were n-decanoic acid and hexanedioic acid, bis (2-ethylhexyl) esters, while stem explant-derived callus had n-hexadecanoid acid. The presence of various bioactive compounds in these calli indicates potential for use as a natural medicine. [ABSTRACT FROM AUTHOR]

Objectives: The current study work was aimed to improve the solubility of Apixaban by forming co-crystals. Materials and Methods: Two solvents mainly Dimethyl Sulphoxide (DMSO) and 2,2,2-trifluoroethanol were tried during the formulation of co-crystals. The other chemicals oxalic acid, adipic acid and L-Tartaric acid were used. Results: From the different trials it was concluded that oxalic acid and DMSO combination with the drug gave the better results for improvement in the solubility. Hence the batch F3 was analysed further. The melting point of F3 was found lower than pure drug. Drug content was found optimum as 95.06 ±0.65%. FTIR-spectra demonstrated the combined peaks of drug and oxalic acid. DSC thermogram showed the sharp endothermic peak similar to pure drug. SEM and XRD spectra confirmed the formation of co-crystals. Conclusion: It was found that formation of co-crystals of apixaban and oxalic acid was satisfactory and it was beneficial to improve the solubility of the apixaban. [ABSTRACT FROM AUTHOR]

At present, the development and usage of degradable plastics instead of traditional plastics is an effective way to solve the pollution of marine microplastics. Poly (butylene adipate-co-terephthalate) (PBAT) is known as one of the most promising biodegradable materials. Nevertheless, the degradation rate of PBAT in water environment is slow. In this work, we successfully prepared four kinds of high molecular weight polyester copolyesters (PBATGA) via quaternary copolymerization. The results showed that the intrinsic viscosity of PBATGA copolymers ranged from 0.74 to 1.01 dL/g with a glycolic acid content of 0–40%. PBATGA copolymers had excellent flexibility and thermal stability. The tensile strength was 5~40 MPa, the elongation at break was greater than 460%, especially the elongation at break of PBATGA10 at 1235%, and the thermal decomposition temperature of PBATGA copolyesters was higher than 375 °C. It was found that PBATGA copolyester had a faster hydrolysis rate than PBAT, and the weight loss of PBATGA copolymers showed a tendency of pH = 12 > Lipase ≈ pH = 7 > pH = 2. The quaternary polymerization of PBAT will have the advantage of achieving industrialization, unlike the previous polymerization process. In addition, the polymerization of PBATGA copolyesters not only utilizes the by-products of the coal chemical industry, but also it can be promising in the production of biodegradable packaging to reduce marine plastic pollution. [ABSTRACT FROM AUTHOR]

Lignin represents the most abundant renewable aromatic resource, monophenolics, from which would serve as promising monomers for the synthesis of aromatic polymers in a sustainable manner. Hererin, we report that hydroxycinnamic derivatives, i.e., ethyl coumarate/ferulate (pCA-Et and FA-Et), with a conjugate and rigid structure can be selectively fragmented from herbaceous plant lignin over a ZnMoO4/MCM-41 catalyst, which upon a one-pot fluorosulfonation, carboxylation, and esterification, give aromatic diesters in high yields. Copolymerizing lignin-derived dicarboxylic species with holocellulose-derived butanediol and adipic acid results in a new family of aliphatic–aromatic polyesters, which display controllable mechanical, optical, and thermal performance, especially depending on the methoxyl group in lignin-derived units. The as-prepared copolyesters can be fully converted into monomers via ethanolysis at 80 °C, demonstrating excellent chemical recyclability. Overall, we provide a novel upstream and downstream route to transform sustainable biomass into functional polymers. [ABSTRACT FROM AUTHOR]

This work describes a versatile and efficient condensation polymerization route to aliphatic polyesters by organo-catalyzed (4-dimethylaminopyridine) transesterification reactions between an activated pentafluorophenyl-diester of adipic acid and structurally different diols. By introducing "monofunctional impurity" or "stoichiometric imbalance," this methodology can afford well-defined endfunctionalized polyesters with predictable molecular weights and narrow dispersity under mild conditions without any necessity for the removal of the byproducts to accelerate the polymerization reaction, which remains a major challenge in conventional polyester synthesis with non-activated diesters. Wide substrate scope with structurally different monomers and the synthesis of block copolymers by chain extension following either ring-opening polymerization or controlled radical polymerization have been successfully demonstrated. Some of the polyesters synthesized by this newly introduced approach show high thermal stability, crystallinity, and enzymatic degradation in aqueous environments. [ABSTRACT FROM AUTHOR]

We have previously reported that sequence-controlled copolyesters such as poly((ethylene diglycolate) terephthalate) (poly(GEGT)) showed higher melting temperatures than those of the corresponding random copolymers and high biodegradability in seawater. In this study, to elucidate the effect of the diol component on their properties, a series of new sequence-controlled copolyesters composed of glycolic acid, 1,4-butanediol or 1,3-propanediol, and dicarboxylic acid units was studied. 1,4-Butylene diglycolate (GBG) and 1,3-trimethylene diglycolate (GPG) were prepared by the reactions of 1,4-dibromobutane or 1,3-dibromopropane with potassium glycolate, respectively. Polycondensation of GBG or GPG with various dicarboxylic acid chlorides produced a series of copolyesters. Terephthalic acid, 2,5-furandicarboxylic acid, and adipic acid were used as the dicarboxylic acid units. Among the copolyesters bearing terephthalate or 2,5-furandicarboxylate units, the melting temperatures (Tm) of the copolyesters containing 1,4-butanediol or 1,2-ethanediol units were substantially higher than those of the copolyester containing the 1,3-propanediol unit. Poly((1,4-butylene diglycolate) 2,5-furandicarboxylate) (poly(GBGF)) showed a Tm at 90 °C, while the corresponding random copolymer was reported to be amorphous. The glass-transition temperatures of the copolyesters decreased as the carbon number of the diol component increased. Poly(GBGF) was found to show higher biodegradability in seawater than that of poly(butylene 2,5-furandicarboxylate) (PBF). On the other hand, the hydrolysis of poly(GBGF) was suppressed in comparison with that of poly(glycolic acid). Thus, these sequence-controlled copolyesters have both improved biodegradability compared to PBF and lower hydrolyzability than PGA. [ABSTRACT FROM AUTHOR]