One-pot Route Research Articles

Identifying a robust alcohol dehydrogenase for developing one-pot chemobiocatalytic route toward 2,5-bis(hydroxymethyl)furan from glucose

Identifying a robust alcohol dehydrogenase for developing one-pot chemobiocatalytic route toward 2,5-bis(hydroxymethyl)furan from glucose

Highly Green Fluorescent Carbon Dots from Gallic Acid: A Turn-On Sensor toward Pb2+ Ions.

Carbon dots (CDs) are emerging novel fluorescent sensing nanomaterials owing to their tunable optical properties, biocompatibility, and eco-friendliness. Herein, we report a facile one-pot hydrothermal route for the synthesis of highly green fluorescent CDs using gallic acid (GA) as a single carbon source in N,N-dimethylformamide (DMF) solvent, which serves as a nitrogen source and reaction medium. The optical properties of the synthesized GA-DMF CDs were systematically characterized by using UV-vis and photoluminescence spectroscopy, revealing strong green fluorescence. Further, to gain insights into their size and structural, elemental, and chemical composition, Fourier transform infrared, dynamic light scattering, high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction, and X-ray photoelectron spectroscopy characterization techniques were performed. HR-TEM analysis confirmed the formation of uniformly spherical GA-DMF CDs with an average particle size of 16 ± 6.1 nm. Notably, the GA-DMF CDs exhibited a highly selective and turn-on fluorescent response to Pb2+ ions in aqueous solutions, which was attributed to a chelation-enhanced fluorescence mechanism. The detection limit for Pb2+ ions was determined to be as low as 7.15 × 10-7 M, with a broad linear detection range of 30-130 μM, underscoring their sensitivity and practical application in water quality monitoring. This study introduces a novel, sustainable approach for synthesizing nitrogen-doped CDs with outstanding optical properties and highlights their unprecedented selectivity toward Pb2+ ions, advancing the development of efficient and eco-friendly sensing platforms for heavy metal detection.

Combining Photochemical Oxyfunctionalization and Enzymatic Catalysis for the Synthesis of Chiral Pyrrolidines and Azepanes.

Chiral heterocyclic alcohols and amines are frequently used building blocks in the synthesis of fine chemicals and pharmaceuticals. Herein, we report a one-pot photoenzymatic synthesis route for N-Boc-3-amino/hydroxy-pyrrolidine and N-Boc-4-amino/hydroxy-azepane with up to 90% conversions and >99% enantiomeric excess. The transformation combines a photochemical oxyfunctionalization favored for distal C-H positions with a stereoselective enzymatic transamination or carbonyl reduction step. Our study demonstrates a mild and operationally simple asymmetric synthesis workflow from easily available starting materials.

Precipitated-crosslinked multi-enzyme hybrid nanoflowers for efficient synthesis of α-ketoglutaric acid

Cascade catalysis of glutamate oxidase (GLOX) and catalase (CAT) to perform one-pot synthetic route for α-ketoglutarate (α-KG) production offers several advantages including simplicity of operation and the generation of few reaction by-products. Nevertheless, the instability of free GLOX and CAT, the high production cost and the difficulty of recycling severely limits its industrial utilisation. Here, catalase-inorganic hybrid nanoflowers were first prepared, and cross-linked with GLOX precipitates by a macromolecular cross-linking agent dextran polyaldehyde to form a novel dual enzyme precipitation-cross-linking hybrid nanoflower (GLOX@CAT-HNFs). The resultant GLOX@CAT-HNFs exhibited higher catalytic activity than conventional combined cross-linked enzyme aggregates (combi-CLEAs) and hybrid nanoflowers (GLOX&CAT-HNFs). The GLOX@CAT-HNFs exhibited 92 % activity recovery whereas combi-CLEAs and GLOX&CAT-HNFs was 87 % and 72 %, respectively. Meanwhile, the GLOX@CAT-HNFs showed better thermal stability, pH and storage stability than free enzymes. After incubation at 60 °C for 100 min, GLOX@CAT-HNFs maintained 70 % of its initial activity while free enzyme was only 18.52 %. Furthermore, after 7 cycles of use, GLOX@CAT-HNFs maintained 68.79 % of its initial activity, indicating excellent reusability. Benefiting from the excellent stability and reusability of GLOX@CAT-HNFs, a nearly 100 % (99.64 %) conversion of L-glutamate to α-KG was achieved, over 1.79 times higher than that of the free GLOX system (55.53 %). This work provides a feasibility for constructing a high-performance cascade catalyst of multiple enzymes.

Photocurable Sol-Gel Formulations for the Fabrication of Titanium Carbide/Carbon Nanocomposites via Digital Light Processing.

Additive manufacturing of carbide materials has received significant attention in the past years due to the ability to fabricate complex structures over different length scales. However, the typical limitations for powder-laden inks, such as nozzle clogging, rheological and geometric constraints, particle sedimentation, light-scattering and absorbing phenomena, narrow the range of available processes to manufacture carbide materials via conventional particle-based systems. To address these shortcomings, we have developed a one-pot synthetic route for the preparation of sol-gel-based UV-photocurable formulations, aiming at the fabrication of titanium carbide/carbon nanocomposites using digital light processing printing, pointing to potential applications in the field of nuclear physics. Carbides have attracted increasing interest as a target material for the production of radioisotopes in the ISOL facilities; however, the release of radioisotopes strictly relies on the presence of open porous structures, thus enhancing the diffusion and effusion phenomena from the target component. Through our approach, we have successfully fabricated hierarchical porous structures of TiC with a high specific surface area. By controlling the positioning of the building blocks within the framework and the supramolecular interactions during the polymerization of the molecular precursors, we achieved multiscale structuring of the network with precise control over the local arrangement of the pores.

(Invited) Gyroid 3D Network in Si@SiOx/C Nanoarchitecture for Lithium Ion Battery

Silicon-based materials are the most promising candidates to surpass the capacity limitation of conventional graphite anode for lithium ion batteries. Unfortunately, Si-based materials suffer from poor cycling performance and dimensional instability induced by the large volume changes during cycling. To resolve such problems, nanostructured silicon-based materials with delicately controlled microstructure and interfaces have been intensively investigated. Nevertheless, they still face problems related to their high synthetic cost and their limited electrochemical properties and thermal stability. To overcome these drawbacks, we demonstrate the strategic design and synthesis of a gyroid three-dimensional network in a Si@SiO x /C nanoarchitecture (3D-Si@SiO x /C) with synergetic interaction between the computational prediction and the synthetic optimization. This 3D-Si@SiO x /C exhibits not only excellent electrochemical performance due to its structural stability and superior ion/electron transport but also enhanced thermal stability due to the presence of carbon, which was formed by a cost-effective one-pot synthetic route. We believe that our rationally designed 3D-Si@SiO x /C will lead to the development of anode materials for the next-generation lithium ion batteries.

One-pot fabrication of sodium deoxycholate based supramolecular self-healing antibacterial double network hydrogels

Double network (DN) hydrogels have emerged as a significant technology for enhancement of mechanical strength of weak supramolecular gels. In the present study, we report the one-pot route for design of a low molecular weight gelator based DN hydrogel wherein sodium deoxycholate (NaDC) forms the primary network entangled with agar matrix. Various compositions of the reported agar-NaDC hydrogels were examined through FTIR, sol-gel transition temperature (Tsg), XRD, circular dichroism (CD), scanning electron microscopy (SEM), hydrophobicity probe studies, Zeta potential studies and rheology measurements. Analysis of all studies together reveal that 1 mg/ml agar-NaDC DN hydrogel is the optimum composition that exhibits dense networking with primarily β-sheet like structure, highest mechanical strength as well as self-healing characteristics with reversed optical activity and highest Tsg. Antibacterial activity studied using inhibition zone method suggests that 1 mg/ml agar-NaDC gel demonstrates significant bactericidal effect unlike the pure gel with an inhibition zone of ∼25 mm against E.coli after 24 h and ∼32 mm after 48 h incubation. The antibacterial activity was unique for this composition of the DN hydrogel which is attributed to its reversal in optical activity exhibiting positive cotton effect resulting in stronger interaction with the bacterial cell wall. Additionally, nearly 2 times reduced water absorption capacity of the 1 mg/ml agar-NaDC DN hydrogel compared to pure NaDC hydrogel ensures the retention of its mechanical strength as well as other properties in high moisture containing environment. Hence, the 1 mg/ml agar-NaDC DN hydrogel holds appreciable potential as a novel strong supramolecular self-healing antibacterial hydrogel with sustained release characteristics primarily important for biomedical applications.

Honey-Derived Hydrochar Containing 2,2,6,6-tetramethylpiperidine-1-oxyl Free Radical for Degradation of Aqueous Organic Pollutants

The increasing demand for greener technologies in environmental remediation makes carbon materials from biomass and its derivatives some of the most attractive resources for a sustainable future. However, integrating these materials with stable free radicals remains challenging. This study presents a straightforward one-pot hydrothermal route using raw honey as the carbon source and 4-amino 2,2,6,6-tetramethylpiperidine-1-oxyl (4-amino-TEMPO) as the free radical. The addition of TEMPO derivative initiates Maillard reactions between its amino group and the carbonyl groups of the carbohydrates in honey, resulting in the formation of a functionalized hydrochar with a spherical morphology (~ 8 μm). The presence of free radicals within the carbonaceous matrix was confirmed by electron spin resonance spectroscopy, supported by infrared spectroscopy, elemental analysis, thermal analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy. The free radical content was estimated at 0.4 mmol∙g-1. The material effectively removed methylene blue, fluorescein, and doxorubicin from water in the presence of green oxidants like hydrogen peroxide and sodium hypochlorite. After 24 h, removal efficiencies reached 92% for doxorubicin, 73% for methylene blue, and 23% for fluorescein. Moreover, the hydrochar demonstrated good regeneration capability, maintaining its dye removal efficiency over several cycles.

Amorphous mesoporous sulfur-rich 1T/2H-MoS2 nanospheres as high-capacity cathode materials for advanced magnesium ion batteries

Two-dimensional layered-structure MoS2 has been explored as the promising cathode materials for magnesium ion batteries benefited by its wide layer distance and satisfactory capacity. However, such strong interaction between Mg2+ and MoS2 brings about the sluggish diffusion kinetics and irreversible electrochemical reaction, leading to a decreased specific capacity and poor rate capability. How to adopt its structure engineering and interface engineering to boost the Mg2+ diffusion kinetics and enhance the electrochemical reversibility of MoS2 is still a huge challenge. Herein, the amorphous sulfur-rich 1T/2H-MoS2 mesoporous nanospheres (a-MoS2+x, 0<x<1) have been developed via a facile one-pot hydrothermal route. Acted as a cathode material for magnesium ion batteries, owing to the cooperate effects of inherent rich active sites, high conductivity and wide layer distance induced by the coexistence of sulfur-rich, 1T phase and nearly amorphous features, the as-prepared a-MoS2+x demonstrates an ultra-high discharge capacity (438.7 mAh g−1 for 50 cycles at 0.1 A g−1), promising rate capability (97.6 mAh g−1 at 1.0 A g−1), and good cyclic stability (110 cycles at 0.5 A g−1), superior to the crystalline MoS2 (c-MoS2) and other previously reported MoS2 counterparts. Besides, the kinetics results indicate that the a-MoS2+x manifests good charge transfer and diffusion kinetics, and its entire charge storage is a combination of surface-controlled capacitance behavior and diffusion-controlled battery behavior. Moreover, some ex-situ Raman, XPS and HRTEM characterization techniques are employed to disclose the Mg2+ storage mechanism. Such remarkable magnesium storage properties of a-MoS2+x demonstrates its promising application as cathode for magnesium ion batteries.

One-pot aqueous-phase synthesis of polyimides from typical monomers

One-pot aqueous-phase synthesis of polyimides (PIs) offers great economic and environmental benefits and improves the hydrolytic stability of the precursor (polyamic acid) obviously. However, this method is only suitable for the polymerization of very limited dianhydride and diamine monomers up to now. In this study, the most commonly used dianhydrides and diamines for the preparation of commercially available PI products were selected for one-pot aqueous-phase synthesis of various polyamic acid salts (PAAS). The effects of the structure of monomers, the reaction temperature and the adding process of the organic base on the polymerization reaction were explored by rotational rheology, nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy. The polymerization products obtained via the aqueous-phase route show high molecular weight when the reaction conditions have been optimized. Various PI films prepared by the thermal imidization of corresponding PAAS demonstrate good optical transparency, excellent thermal stability, and outstanding mechanical and electrical properties. This work proposes the reaction mechanism of PAAS via one-pot aqueous-phase route and utilizes this novel polymerization strategy to synthesize high-molecular-weight PIs from typical aromatic dianhydride and diamine monomers.

Activation of persulfate over double S-scheme photocatalyst fabricated by decoration of Fe2(MoO4)3 and MoO3 on modified g-C3N4 for degradation of pollutants

The development of nanostructured photocatalysts with high activity is essential for the remediation of effluents. Herein, modified g-C3N4 (M-CN) was integrated with Fe2(MoO4)3/MoO3 (FMO/MO) nanoparticles by one-pot hydrothermal route, and employed to activate persulfate (PS) under visible light. The M-CN/FMO/MO nanocomposites exhibited superior performance in photocatalytic removal of three antibiotics, containing amoxicillin (AMX), azithromycin (AZT), and tetracycline (TC), and three dye pollutants, including rhodamine B (RhB), methylene blue (MB), and methyl orange (MO). The activity of M-CN/FMO/MO (20 %)/PS system for the removal of TC was 1.83, 5.86, and 55.0 folds as high as M-CN/FMO/MO (20 %), M-CN, and CN photocatalysts, respectively. The formation of a double S-scheme system enhanced the photocatalytic performance by effectively retaining electrons and holes, which have strong redox capabilities. This configuration significantly minimized charge recombination, thereby promoting efficient charge transfer and migration. Moreover, there was a significant increases in surface area compared to pure components, which provided active sites for pollutants. Eventually, the recycling test and successful growth of wheat seeds exhibited that the M-CN/FMO/MO (20 %)/PS system can be suitable for wastewater treatment. It is hoped that this system with attractive properties could be used as a promising system in wastewater detoxification.

Synthesis and assessment of the Mo/MoO3/CZTS/Ag diode fabricated by one-pot hydrothermal route: impact of temperature

A facile one-step hydrothermal method was utilized to prepare Cu2ZnSnS4 film employing EDTA as a complexing agent. An effective Molybdenum oxide layer was also formed in the same approach for forming the Cu2ZnSnS4 film. The influence of preparation temperature on structural, morphology, and optical characteristics was studied. The formation of crystalline kesterite phase Cu2ZnSnS4 films with preferred orientation along the (112) plane was confirmed by X-ray diffraction and Raman spectroscopy, and it was also demonstrated that structure property changes with preparation temperatures: kesterite phase Cu2ZnSnS4 is formed at lower preparation temperatures and kesterite phase Cu2ZnSnS4 and Cu2S are formed with increasing preparation temperature. Also, Raman analysis confirmed the formation of a Molybdenum oxide layer on the Mo substrate. Field emission scanning electron microscopy revealed that surface morphology changes from leaves of trees to flake-flowers. According to UV-visible analysis, Cu2ZnSnS4 films exhibited high and wide absorbance spectra in the visible and infrared regions and a band gap between (1.67-1.9) eV. Photoluminescence analysis revealed emission peaks at (1.569, 1.55, and 1.56) eV for samples prepared at (160, 200, and 230)0C, respectively, which is very close to the band's gap of Cu2ZnSnS4. Finally, the electrical study of Mo/MoO3/CZTS/Ag junctions was performed by using current-voltage (I-V) measurement.

Exploring dielectric and electrical characteristics in Sr0.5Ba0.5SnxFe12-xO19/CoFe2O4 nanocomposites

This study examined the morphological, structural, electrical, and dielectric characteristics of hard-soft (H-S) Sr0.5Ba0.5SnxFe12-xO19/CoFe2O4 (x ≤ 0.10) ferrite nanocomposites (NCs), created using one-pot sol-gel combustion route. This study systematically investigated the electrical/dielectric features of H-S Sr0.5Ba0.5SnxFe12-xO19/CoFe2O4 NCs where x is within the range of 0.00 ≤ x ≤ 0.10. The examination realizes frequencies that reach 3.0 MHz, conducted within 20 °C–120 °C. A detailed analysis was performed to investigate various conduction mechanisms linked with dielectric constant, dissipation factor, AC/DC conductivity, loss of dielectric capacity, and real/imaginary modulus, which were explored across the entire range of Sn ion substitution ratios. Observations reveal that the conductivity variations adhere to power law dynamics concerning frequency, predominantly influenced by the Sn ion substitution ratios within the NCs. Furthermore, the frequency dependency of the dielectric coefficient across all NCs substantiates the common propagation of dielectric behavior, prominently contingent upon the substitution ratio of "x". Notably, the majority of dielectric parameters observed in H-S Sr0.5Ba0.5SnxFe12-xO19/CoFe2O4 (x ≤ 0.10) NCs are attributable to grain-to-grain boundaries, elucidated by conduction mechanisms similar to those observed in most compositional ferrites, explicable through Koop's model.

Synthesis, Crystal Structure and Antifungal Activity of (E)-1-(4-Methylbenzylidene)-4-(3-Isopropylphenyl) Thiosemicarbazone: Quantum Chemical and Experimental Studies.

A novel (E)-1-(4-methylbenzylidene)-4-(3-isopropylphenyl) thiosemicarbazone was synthesized in a one-pot four-step synthetic route. Fourier transform infrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonances (NMR), single-crystal X-ray diffraction, and UV-visible absorption spectroscopy were utilized to confirm the successful preparation of the title compound. Single-crystal data indicated that the intramolecular hydrogen bond N(3)-H(3)···N(1) and intermolecular hydrogen bond N(2)-H(2)···S(1) (1 - x, 1 - y, 1 - z) existed in the crystal structure and packing of the title compound. Besides the covalent interaction, the non-covalent weak intramolecular hydrogen bond N(3)-H(3)···N(1) discussed by atoms in molecules (AIM) theory also functioned in maintaining the title compound's crystal structure. The strong intermolecular hydrogen bond N(2)-H(2)···S(1) (1 - x, 1 - y, 1 - z) discussed by Hirshfeld surface analysis played a major role in maintaining the title compound's crystal packing. The local maximum and minimum electrostatic potential of the title compound was predicted by electrostatic potential (ESP) analysis. The UV-visible spectra and HOMO-LUMO analysis revealed that the title compound has a low ΔEHOMO-LUMO energy gap (3.86 eV), which implied its high chemical reactivity due to the easy occurrence of charge transfer interactions within the molecule. Molecular docking and in vitro antifungal assays evidenced that its antifungal activity is comparable to the reported pyrimethanil, indicating its usage as a potential candidate for future antifungal drugs.

Synthesis and characterization of (Ba2Zn2Fe12O22)1−x(NiFe2O4)x ferrite composites for antenna applications

A series of (Ba2Zn2Fe12O22)1−x(NiFe2O4)x ferrites (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were successfully synthesized by one-pot coprecipitation route. XRD analysis reveals the formation of Ba2Zn2Fe12O22 and NiFe2O4 composite after sintering calcined precursor powder at 1200 °C/4 h. Densification behaviour was evaluated by Archimedes’ principle. Field emission scanning electron microscopy was used to study morphological characteristics. Room temperature magnetization behaviour was evaluated using a vibrating sample magnetometer. In composite, it was observed that the saturation magnetization (Ms) and coercivity (Hc) increased with increasing NiF content. With the increase of NiF in the composite, the permittivity (ε) decreased from 28.6 (for x = 0.2) to 13.6 (for x = 0.8) with the corresponding decrease in dielectric loss (tanδε) at 100 MHz. The permeability (μ) also decreased from 21.3 (x = 0.2) to 17.9 (x = 0.8) with the associated decrease of the magnetic losses (tanδμ) at 100 MHz. Miniaturization factor (n) of 19.2 and characteristic impedance of 1.1 were obtained for x = 0.4 composition at 100 MHz along with low dielectric loss factor (tan δε/ε) and magnetic loss factor (tan δµ/µ). The ferrite resonator antenna was fabricated using FR4 as substrate and ferrite pellet as magneto-dielectric resonator material. The antenna characteristics parameters reflection loss S (1,1) and voltage standing wave ratio (VSWR) were measured by vector network analyser (VNA).

G-C3N4 tubes decorated with MnMoO4·H2O: Outstanding S-scheme photocatalyst for detoxification of water pollutants upon visible light

Recently, the utilization of heterogeneous photocatalysts has been proposed as an effective solution for environmental purification, as one of the solar energy conversion processes, under mild conditions. In this research, MnMoO4·H2O nanoparticles were anchored on tubular g-C3N4 (abbreviated as TGCN) by a one-pot hydrothermal route. The phase structure, electronic environment, spectroscopic characteristics, composition, morphology, surface area, and electrochemical properties of the resultant materials were explored using XRD, XPS, EDX, FESEM, HRTEM, FTIR, PL, photocurrent, EIS, and BET analyses. The photocatalytic activity of TGCN/MnMoO4·H2O (20 %) nanocomposite was 4.25, 5.36, 9.07, 12.4, and 8.84 times better than modified GCN, and 3.91, 2.77, 6.24, 10.9, and 6.82 times higher than MnMoO4·H2O in removals of tetracycline, rhodamine B, methylene blue, methyl orange, and fuchsine pollutants, respectively. The improved visible-light absorption and rapid charge migration/separation between TGCN and MnMoO4·H2O counterparts through S-scheme heterojunction route were the key reasons for the boosted photocatalytic performance. The biocompatibility of solution after decomposition of tetracycline via the growth of wheat seeds was verified. Finally, the stability of the binary TGCN/MnMoO4·H2O (20 %) heterostructure was measured by the stability test after four reuses.

Structural and biological studies on beta – alanine substituted Sulfonamide derivatives: A new class of Juvenile hormone mimics as insect growth regulators

A series of naphthyl-sulfonamide juvenile hormone analogs has been synthesized through one-pot synthesis route using thionyl chloride as an activating agent for carboxylic functional group. The structures of synthesized compounds with general formula C10H7-SO2NH-(CH2)2CON-R1R2 have been confirmed by FT-IR, 1HNMR , 13CNMR , and ESI-MS techniques. The insect growth regulating property of all the synthesized compounds as juvenile hormone analogs (JHAs) has been studied against yellow fever mosquito, Aedes aegypti and tobacco cutworm, Spodoptera litura. The bioassay results demonstrate that the synthesized compounds exhibit insect growth regulating activity in comparison to standard JHAs. The IE50 and IE90 values of B4 are 0.08 and 6.62 ppm, respectively for inhibition of Aedes aegypti and the LC50 and LC90 values of B3 are 11.03 and 45.36 ppm, respectively for Spodoptera litura. Notably, the compounds B3 and B4 showed enhanced efficacy at lower concentrations. Additionally, density functional theory (DFT) technique is used to predict the chemical reactivity and toxicity of the synthesized JHAs in comparison to pyriproxyfen. Further, the DNA-binding study of synthesized JHAs has been carried out using UV–vis spectroscopy for toxicity assessment against DNA and the binding constant values in the range 102 – 103 suggest lower toxicity of all the synthesized molecules in comparison to PYR. All the synthesized JHAs show IGR action and exhibit better reactivity and reduced toxicity as compared to the commercial in use IGRs.

Propylene carbonate synthesis routes using CO2: DFT and thermodynamic analysis

Propylene carbonate (PC) is utilized to improve performance and stability in lithium-ion batteries as an electrolyte component and as a high-performance solvent in paints, varnishes, and adhesives. It is a versatile chemical used in many different industries. It also functions as a plasticizer in polymers and a solvent in pharmaceutical and cosmetic formulations. In the current work, chemical equilibrium analyses of a number of potential processes involved in the synthesis of PC were conducted. To examine the thermodynamic viability of all five approaches, the fluctuation of ΔGmo with temperature for the key processes of PC synthesis was investigated in a specific temperature range of 25 °C-180 °C and at 1 bar and 60 bar pressures. The heat capacity values were estimated using the Rozicka-Domalski method. Benson Group-Increment Theory (BGIT) was used to evaluate the unknown ΔfH for a molecule. By examining the impact of temperature (25 °C-180 °C) and pressure (0–100 bars) on chemical equilibrium constant and equilibrium conversion of reactants, the main reactions of PC synthesis pathways were compared. It was discovered that the one-pot synthesis route and the o-chloropropanol and CO2 approach were superior. The DFT calculations were performed to study the energy changes taking place to convert propylene, glycerol, and propylene glycol (PG) into PC. Both thermodynamic and DFT calculations proved that the PG and urea route is the least favorable for synthesizing PC.

Correlations between in vitro gastrointestinal digestion of β-galactosidase/carboxymethylchitosan-silica dosage powder and its physicochemical properties

Oral administration of β-galactosidase, which alleviate lactose intolerance symptoms, is challenging due to its instability throughout the gastrointestinal tract. The objective of this work was to make correlations between the in-vitro digestion and chemical characteristics of a β-galactosidase/carboxymethylchitosan-silica biocatalyst powder. This was obtained by a one-pot silica gel route assisted by carboxymethyl chitosan, using maltose as lyoprotectant. The chemical characterization allowed to understand as was modulated the calcium incorporation, through electrostatic interactions and as maltose protects the enzyme from agglomeration, by vitrification and formation of hydrogen bonds. The formulated biocatalyst could be a complement of silicon and calcium, in turn, it preserves 96 % and 63 % of the enzymatic activity compared with the biocatalyst control (without simulated digestion), in the gastric and intestinal phases, respectively. This activity was even greater than that observed in the commercial products evaluated in these phases. Likewise, the biocatalyst obtained retained its activity after 12 months of storage at 25 °C and it did not present cytotoxicity in cells derived from human colon epithelial mucosa (NCM460) under the conditions and concentrations evaluated. These results make this biocatalyst in an excellent candidate for release of this enzyme. Therefore, it could be useful for lactose-intolerant people.

One-Pot Preparation of Nitro-Functionalized Bimetallic UiO-66(Zr-Hf) with Hierarchical Porosity for Oxidative Desulfurization Performance.

Preparation of multifunctional metal-organic frameworks (MOFs) offers new opportunities to obtain ultrahigh synergistic catalytic performance for heterogeneous reactions; however, the application of a one-pot method for preparing multifunctional MOFs remains challenging. Herein, we develop a one-pot green route for synthesizing bimetallic nitro-functionalized UiO-66(Zr-Hf)-NO2 with hierarchical porosity under solvent-free conditions. The optimal UiO-66(Zr-Hf0.6)-NO2 shows an ultrahigh enhancement of oxidative desulfurization (ODS) efficiency to oxidize sulfur compounds (1000 ppm sulfur) in a model fuel at 40 °C within 12 min due to the introduction of more active Hf sites in the nodes, the increased Lewis acidity of Zr/Hf-O nodes by the electron-withdrawing NO2 group, and the enhanced diffusion rates by the mesopores. The turnover frequency (TOF) over UiO-66(Zr-Hf0.6)-NO2 at 40 or 50 °C reaches 145.3 or 217.0 h-1 that surpasses the TOF of most reported MOF-based catalysts in the ODS reaction. Quenching and electron paramagnetic resonance experiments confirm that the formed Hf-OH on the Zr/Hf-O nodes can easily decompose the oxidant (H2O2) for generating a Hf-OOH-active intermediate and dominate the ODS efficiency. This contribution provides a one-pot solvent-free avenue to synthesize multifunctional MOFs for enhancing their catalytic activities for targeted applications.