Methanol Solvent Research Articles

Catalytic Role of Methanol in Anodic Coupling Reactions Involving Alcohol Trapping of Cation Radicals.

In anodic electrosynthesis, cation radicals are often key intermediates that can be highly susceptible to nucleophilic attack and/or deprotonation, with the selectivity of competing pathways dictating product yield. In this work, we computationally investigate the role of methanol in alcohol trapping of enol ether cation radicals for which substantial modulation of the reaction yield by the solvent environment was previously observed. Reaction free energies computed for intramolecular coupling unequivocally demonstrate that the key intramolecular alcohol attack on the oxidized enol ether group is catalyzed by methanol, proceeding through overall second-order kinetics. Methanol complexation with the formed oxonium ion group gives rise to a "Zundel-like", shared proton conformation, providing a critical driving force for the intramolecular alcohol attack. Free energies computed for methanol solvent attack of enol ether cation radicals demonstrate an analogous mechanism and overall third-order kinetics, due to similar complexation from a secondary methanol molecule to form the "Zundel-like", shared proton conformation. As catalyzed by methanol, both intramolecular alcohol attack and methanol attack on the oxidized enol ether group are barrierless or low-barrier reactions, with kinetic competition dictated by the conformational free energy profile of the cation radical substrate and the difference in reaction rate orders.

Synthesis of Some Novel 4-bromobenzoic Acid Clubbed Hydrazone Schiff Base Derivatives as Potent α-amylase Inhibitors: In vitro and In silico Studies

Aims: Synthesis of novel 4-bromobenzoic acid-based hydrazone-Schiff base derivatives and to screen them for their α-amylase inhibitory activity. Objective: The biological activities of hydrazone-Schiff base compounds encouraged us to evaluate the synthesized derivatives (4-32) for in-vitro inhibition activity against the α-amylase enzyme. Methods: In current research work twenty-nine Schiff base derivatives (4-32) of 4-bromobenzoic acid were synthesized in worthy yields by treating various replaced aldehydes with 4- bromobenzohydrazide using methanol solvent in catalytic quantity of acetic acid. The products were structurally described through the support of several spectroscopic methods (EI-MS and 1HNMR) and finally evaluated against α-amylase enzyme. Results: All the made derivatives exhibited worthy inhibition potential from IC50 = 0.21 ± 0.01 to 5.50 ± 0.01 μM when equated to the usual acarbose drug having IC50 = 1.34 ± 0.01 μM. Compound 21 (IC50 = 0.21 ± 0.01 μM) was established as the most active inhibitor among the series better than standard. The structure-activity relationship study showed that the alteration in the activity of the produced products might be due to the attached position and nature of the substituents. Furthermore, in-silico study supported the effects of groups attached on the binding interaction with α-amylase enzyme. Conclusion: A series of substituted hydrazone Schiff bases based on 4-bromobenzoic acid were produced, confirmed the structures by EI-MS and 1H-NMR spectroscopic methods and lastly tested for their in-vitro α-amylase inhibitory potential. Among the series, twenty-four products indicated brilliant inhibition potential having IC50 values from 0.21 ± 0.01 to 1.30 ± 0.01 μM. The structure-activity relationship study showed that the alteration in the activity of the synthesized products might be due to the attached position and nature of the substituents. On the other hand, in silico studies advocated that the synthesized Schiff base derivatives have prevalent interactions of binding within the active site of the α-amylase enzyme, and because of their various attached substituent, their conformation is altered in the active site of the enzyme. The current study recognized a number of lead candidates derived from 4-bromobenzoic acid. Additional investigation of the synthesized derivatives for coming research to get novel α-amylase inhibitors.

Antioxidant and antimicrobial activities of different extracts of Tragopogon dubius and Tragopogon porrifolium L. subsp. longirostris: Determination of their phytochemical contents by UHPLC-Orbitrap®-HRMS analysis

In this study, dichloromethane (DCM), n-hexane, ethanol, methanol, and natural deep eutectic solvents (NADES) were used to extract Tragopogon porrifolium L. subsp. longirostris (Sch. Bip.) Greuter and Tragopogon dubius L. Antioxidant properties (Cu2+ reduction capacity, DPPH, ABTS and Fe3+ reduction) and antimicrobial activities of these extracts were determined. Also, metabolite profiles were determined using UHPLC-Orbitrap®-HRMS. NADES extracts of both species (MIC: 0.18-0.71 mg/ml) showed significantly better antimicrobial activity against Klebsiella pneumoniae, Bacillus subtilis, and Staphylococcus aureus compared to other solvents (MIC: 25 mg/ml). The study showed that T. dubius methanol and NADES extracts had better inhibitory effects on DPPH (EC50:45.17 μg/mL, EC50:108.73 μg/mL) and ABTS (EC50:59.54 μg/mL, EC50:95.98 μg/mL) radical scavenging activities than other extracts. Similarly, T. porrifolium methanol and NADES extracts had better inhibitory effects on DPPH (EC50:48.33 μg/mL, EC50:38.72 μg/mL) and ABTS (EC50:77 μg/mL, EC50:58.93 μg/mL) radical scavenging activities than other extracts. Furthermore, Fe3+ and Cu2+ reducing capacities were highest in methanol and NADES extracts of both plants.UHPLC-Orbitrap®-HRMS was used to profile the chemical composition, validating 71 phytochemicals, with the R2 value ranging from 0.9903 to 0.9993. The method's LOD values ranged from 0.45 to 2.94, and LOQ values ranged from 1.50 to 9.78. Recovery percentages at 10, 60, and 100 ng/mL concentrations ranged from 71.73% to 116.91%, 85.36% to 115.38%, and 97.08% to 109.65%, respectively. The analysis identified 29 phytochemicals, with major compounds including chlorogenic acid, quinic acid, apigenin 7-glucuronide, vitexin, schaftoside, orientin+isoorientin, luteoloside, and isoquercitrin. The significant biological impacts of these plants as a compelling reservoir of phytochemicals with therapeutic properties.

Phytochemical Composition and Antioxidant Properties of Canarium odontophyllum (Sarawak Olive): A Seasonal Fruit from Borneo, East Malaysia.

BackgroundCanarium species are reported rich of polyphenol, alkaloids, flavones, and saponins compounds. Canarium odontophyllum from Borneo's variety, on the other hand is remaining unclear especially on the antioxidant activity towards radicals. PurposeTo investigate phytochemical composition and antioxidant properties of C. odontophyllum. MethodsAntioxidant properties were evaluated using 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH) assay, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) assay, and ferric-reducing antioxidant power (FRAP) assay with different polarity of extraction solvents (methanol, acetone and hexane). The phytochemical composition was determined by Liquid Chromatography Mass Spectrometry Quadrupole Time of Flight (LCMS-QTOF). ResultsAcetone showed the highest scavenging activity in the DPPH (0.0307 mg/ml) and FRAP (3.926 mg/ml) assays, while hexane exhibited the highest activity in the ABTS assay (0.119 mg/ml). The LCMS-QTOF chromatogram identified 22 potential compounds. Among these, the major compounds oleamide (10.49%) and emmotin A (7.23%) have previously been reported to exhibit antioxidant activity. Other health-beneficial compounds were also found, such as palmitic amide (2.46%), deoxymiroestrol (6.23%), and N-Cyclohexanecarbonylpentadecylamine (48.92%), which are important in preventing metal corrosion, regulating hormones, and distinguishing between N-palmitoylethanolamine-hydrolyzing acid amidase (NPAA) and fatty acid amide hydrolase (FAAH), respectively. ConclusionThe results indicate that C. odontophyllum shows a promising potential an alternative drug in pharmaceutical developments.

Assessment of milling and the green biosolvents ethyl lactate and 2-methyltetrahydrofuran (2-methyloxolane) for the ultrasound-assisted extraction of carotenoids in common and phytoene-rich Dunaliella bardawil microalgae

This study aimed to evaluate the efficiency of green solvents (ethyl lactate and 2-methyltetrahydrofuran (MeTHF)) compared to conventional solvents (ethanol, methanol, and dimethyl sulfoxide) in the ultrasound-assisted extraction of carotenoids from Dunaliella bardawil. Two types of algae were evaluated, a control (common) and a phytoene-enriched algae obtained by treatment with norfluorazon. The extractions were performed on fresh, freeze-dried, and encapsulated samples, with and without ball-milling pre-treatment. The pre-treatment had no significant effect on carotenoid extraction for any of the solvents tested. The solvents that achieved the highest carotenoid yield from fresh samples were MeTHF, methanol, and ethanol (control: 2105.3, 2001.8, and 1919.1 μg/g, respectively; phytoene-rich: 3220.9, 3669.1, and 3275.0 μg/g, respectively). In freeze-dried samples, ethanol was most effective in the control strain (14337.1 μg/g), while methanol yielded the most in the phytoene-rich strain (8464.1 μg/g). For encapsulated samples, MeTHF and ethanol were the top performers (control: 421.0 and 394.0 μg/g, respectively; phytoene-rich: 186.9 and 166.4 μg/g, respectively). Overall, the green solvent MeTHF proved to be a promising alternative to traditional solvents in the food industry.

Efficient Removal of Lipophilic Compounds from Sewage Sludge: Comparative Evaluation of Solvent Extraction Techniques

Municipal sewage sludge, a by-product of wastewater treatment plants, presents environmental challenges due to its complex composition. Particular concern is the lipophilic and aliphatic compounds that pose risks to the environment and human health. This study focuses on the efficient removal of those compounds from sewage sludge using several organic solvents (hexane, toluene, chloroform, dichloromethane, acetone, hexane-methanol mixture, ethanol, and methanol) and ionic liquids (ILs) like tetrakis(hydroxymethyl)phosphonium chloride and 1-ethyl-3-methylimidazolium acetate by solvent extraction techniques. To determine optimal conditions, various factors such as solvent types, contact time, and temperature were examined. The results reveal that solvent polarity significantly impacts extract composition, with non-polar solvents like hexane and toluene yielding profiles characteristic of lipid-type compounds. An in-depth analysis of contaminants present in the sewage sludge was studied by Fourier-transform infrared spectroscopy (FTIR). Additionally, nuclear magnetic resonance (NMR) was used to identify the extracted compounds, including triglycerides, aliphatic esters, aliphatic alcohols, and free carboxylic acids. NMR provides data on the composition of the sewage sludge and indicates that among all the solvents used, tetrakis(hydroxymethyl) phosphonium chloride was the most suitable solvent for removing lipophilic and aliphatic compounds. Regeneration potential and reusability of the IL were conducted and verified by NMR. The results showed that tetrakis(hydroxymethyl) phosphonium chloride ionic liquid could be used for several extraction cycles. Identifying these compounds in the extracted mixture demonstrates that it adds value and potential for various applications. Towards environmental sustainability and circular economy, this effort develops strategies for the safe management, disposal, and recyclability of sewage sludge and, the reduction in environmental and health hazards associated with organic compounds.

Analysis GC-MS (Gas Chromatography-Mass Spectrometry) 96% ethanol extract from turmeric (Curcuma longa Linn. Syn. Curcuma Domestica Val.)

Background: Turmeric (Curcuma longa Linn. syn. Curcuma domestica Val.) is a plant that people believe can cure several diseases. According to a study conducted, it can treat gallbladder disease, colds, coughs, diabetes, hepatic disease, rheumatism and sinusitis, the content of turmeric extract (Curcuma longa Linn. syn. Curcuma domestica Val.) that turmeric rhizome (Curcuma domestica val) has antipyretic effects etc. Objective: This research aims to determine the polar bioactive compounds contained in turmeric (Curcuma longa Linn. syn. Curcuma domestica Val.). Method: The method used is extraction of turmeric (Curcuma longa Linn. syn. Curcuma domestica Val.) methanol solvent with a maceration process then analyzed using gas chromatography - mass spectrometry (GC-MS) to obtain information on the content of turmeric (Curcuma longa Linn. syn. Curcuma domestica Val.). Results: The results of GC-MS analysis from this study showed that there were 35 peaks and 105 possible compound components that were successfully extracted from ethanol solvent from turmeric. compounds extracted using methanol solvent. The research results also show that there are three possible polar bioactive compounds in the highest peak of the GC-MS analysis results, namely 2-Methyl-6-(4-methylcyclohexa-1,3-dien-1-yl)hept-2-en-4-one;2-Methyl-6-(4-methyl-1,3-cyclohexadien-1-yl)-2-hepten-4-one; α-Turmerone; Turmerone. Conclusion: There were 35 peaks and 105 possible compound components that were successfully extracted from ethanol solvent from turmeric. There are three compounds at the highest peak, namely tumerone, tumerone, and Verbenyl angelate, cis.

Metabolite profile analysis of methanol extract of belulang grass (Eleusine indica (L.) GAERTN) leaves by gas chromatography-mass spectrophotometry (GC-MS) method

Leaf of belulang grass (Eleusine indica (L.) Gaertn) is one of the wild plants that is used as herbal medicine by the community because of its many health benefits for the treatment of certain diseases such as diabetes, high blood pressure, and cholesterol. A materil is said to have potential as a medicine because the composition of the chemical compounds contained in a plant is not always the same and requires further testing. Differences in chemical compound content can be influenced by environmental factors and plant metabolism. The aim of this research is to analyze the metabolite profile and abundance of metabolite compounds using the GC-MS instrument analysis approach. Sampling was conducted in Sidomulyo Village, Air Kumbang District, Banyuasin Regency, South Sumatra. Samples of belulang grass leaves obtained were dried, pulverized, and extracted with methanol solvent. The methanol extract was analyzed using GC-MS. The results showed that the highest 20 compound peaks were obtained based on the relative area percent of the 69 compounds obtained with an abundance of compounds amounting to 80.86%. At the highest peak, the compounds n-hexadecanoic acid, I-(+)-ascorbic acid 2, 6- dihexadecanoate, and pentadecanoic acid were found with a percent area of 31.25%.

Synthesis, X-ray characterization of new copper-benzimidazole complex and investigation of its homogenous catalytic oxidation activity on selected primary and secondary alcohols

A new bis(benzimidazole)copper(II) complex, [Cu(Eap)2(CH3OH)](ClO4)2 was synthesized by the reaction between 2-(1-ethyl-2-(2-aminophenyl)-1H-benzimidazole (Eap) and copper(II)perchlorate hexahydrate (Cu(ClO)4·6H2O). Complex structure is mainly characterized by single crystal X-ray diffraction and other spectroscopic methods. Penta-coordinated copper(II) center surrounded with four nitrogen atoms of two identical benzimidaole ligands and an oxygen atom of methanol solvent. Designed complex is shown to be an active catalyst for the homogenous oxidation of selected primary and secondary alcohols. The effects of solvent, temperature, sub/cat ratio, time and substrate type on the catalytic reactions were investigated. The designed catalytic system showed good catalytic activity, and 100 % total product yields (aldehyde + acid) were achieved after 2 h.

Toxicity and Anti-Trypanosomal Studies of Aqueous and Methanol Leaf Extracts of Acacia Nilotica on Trypanosoma Brucei-Induced Infection in Mice

African Animal Trypanosomiasis constitutes one of the greatest threats to the health of animals and socioeconomic status of people, particularly in developing countries. Chemotherapy, the main means of controlling the disease is limited due to parasite resistance and toxicity of the current anti-trypanosomal drugs. The development of a vaccine has been thwarted by antigenic variation of the parasite. Thus, plant extracts are one of the strategies being explored to address some of the problems encountered. The main objective of the current study was to investigate the toxicity and anti-trypanosomal activity of methanol and aqueous extracts of Acacia nilotica through in vivo assays against Trypanosoma brucei brucei. The chosen plants' healthy, fresh, matured leaves were air dried under shade, pulverized with mortar and pestle into powder, and passed through a 0.5mm mesh to standardize their particles. The plant samples were extracted using aqueous, methanol solvents. Qualitative and quantitative phytochemical analysis of the active chemical constituents of the extracts was conducted to determine saponins, flavonoids, tannins, terpenoids, steroids, and cardiac glycosides according to standard procedure. It was established that aqueous and methanol leaf extracts of the selected plants were safe in rats at dose levels of 1000, 3000, and 5000 mg/kg body weight for 72 hours. However, Sedation and abnormal movement were observed for both A. nilotica and Z. mucronata as manifestations of clinical toxicity at 5000mg/kg body weight. The fatal dose of all extracts exceeds the maximum dose of 5000mg/kg. Prolonged oral administration of the extracts for 21 days with A. nilotica extracts did not reveal major changes in body and organs weights, liver and kidney functions, the biochemical analysis showed a slight, non-significant increase in Alanine transaminase, Aspatate transaminase, and Alkaline phosphatase at (4000mg/kg) in rats, the average creatinine and urea levels were within the normal range, the relative organ weight and isolated organ are within the normal reference value. The photomicrographs of the liver and kidney sections showed mild histological changes. The in vivo assay showed the aqueous and methanol extracts from A. nilotica at 200mg/kg, 100mg/kg, and positive control (diminazine aceturate 3.5mg) reduced parasitaemia (p < 0.05), improved anaemia (p < 0.05), prevented body weight loss (p < 0.05) compared to the negative control. This study showed that the leaf of A. nilotica is safe and possess antitrypanosomal properties, suggesting that they may be a source of novel drugs for treatment of tropical diseases caused by trypanosomes.

Antibiofilm, Antidiabetic and Antioxidant Potentials of Vitis labrusca L. Skin Extracts

This study examined the antioxidant, antimicrobial, antibiofilm, and α-glucosidase inhibitory activities and the total phenolic and flavonoid contents of the different solvent (methanol, 50:50% methanol:water, and water) extracts from Vitis labrusca L. skin parts. The 50:50 methanol:water extract exhibited the highest antioxidant activity, exhibiting 153 µM TEAC and 0.0947 mg/mL SC50, as determined by the ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging assays, respectively. Additionally, the data demonstrated that the 50:50 methanol:water extract of the skin part of V. labrusca exhibited a higher total phenolic content, with 141 µg/mL GAE. The α-glucosidase enzyme activity of the 50:50% methanol:water extract (IC₅₀; 0.103 mg/mL) was observed to be higher than that of the other solvent extracts. The MIC values of the 50:50% methanol:water, water and methanol extracts of skin part of V. labrusca was determined as 12.5, 25 and 6.25 mg/mL, aganist to clinical antibiotic resistance Acinetobacter baumanii respectively. The results of this study indicate that the methanol, water and 50:50% methanol:water extracts were found to reduce the biofilm-forming capacity of the Acinetobacter baumannii isolate by approximately 1.7, 1.6 and 1.3-fold, respectively. The findings of our investigation suggest that skin parts of V. labrusca may serve as a promising candidate for the prevention and treatment of diseases associated with oxidative damage and bacterial infections. The results show that the components found in the waste skin extracts of these genotypes can be evaluated in terms of antioxidant, antidiabetic and antibacterial properties.

Solubility behavior of Rosiglitazone in ten pure solvents: Model correlation, thermodynamic calculations, and molecular simulation

Rosiglitazone is an oral antidiabetic medication primarily used to treat type 2 diabetes. Herein, the single crystal structure of Rosiglitazone (a = 14.0613(7) Å, b = 8.4675(4) Å, c = 29.8841(16) Å, space group Pbca, Z = 8, V = 3558.1(3) Å3) was analyzed for the first time. Through solubility measurements, model correlation, thermodynamic calculations, and molecular simulations, the dissolution of Rosiglitazone in ten pure solvents was comprehensively investigated. The solubility order at 298.15 K is acetone > methyl acetate > ethyl acetate > butyl acetate > acetonitrile > alcoholic solvents (methanol, ethanol, n-propanol, iso-propanol, n-butanol). Rosiglitazone exhibits higher solubility in non-alcoholic solvents, whereas its solubility in alcoholic solvents is similar and relatively low. Subsequently, the correlation between the experimentally measured solubility of Rosiglitazone and the Modified Apelblat model, λh model, NRTL model, and Van’t Hoff model was examined. The Van’t Hoff equation calculations proved that the dissolution of Rosiglitazone was an endothermic process driven by entropy and characterized by non-spontaneity. The calculation of solvent polarity and Hansen solubility parameters (HSP) reveals that the primary factor influencing the solubility of Rosiglitazone is polarity in highly polar solvents, while the dominant factor is molecular volume in low-polarity solvents. Furthermore, the molecular interactions of solute and solvents were investigated by molecular simulation, including the calculation of electrostatic potential, 2D fingerprint plots and solvation free energy, which provided insights into the mechanism of Rosiglitazone dissolution behavior in different solvents.

Determination of Antioxidant Activity and Biochemical Content of Homalothecium philippeanum (Spruce) Schimp.

Living organisms produce reactive oxygen species (ROS) during the oxygen processing process. ROS damage biomolecules and causes oxidative stress. Antioxidants prevent cellular damage against these harmful effects of ROS by neutralizing free radicals. Medicinal plants provide a rich source of antioxidants to reduce oxidative stress and play an important role in the treatment of diseases. Bioactive compounds, especially polyphenols and flavonoids, protect cells against oxidative damage by neutralizing free radicals. Bryophytes, especially mosses, are one of the plant groups that attract attention in this area. Mosses show biologically active properties with secondary metabolites such as terpenes and flavonoids they contain. In this study, extraction of Homalothecium philippeanum moss with ethanol, methanol and n-hexane solvents was carried out and the biochemical content analysis of the extracts was investigated. 1,2-Benzenedicarboxylic acid, bis(2-methylpropyl) ester was detected as the major component in the ethanol and methanol extracts of the H. philippeanum. Biologically active alkanes such as Tetradecane and Hexadecane were found in the n-hexane extract. The antioxidant activity of moss ethanol extract was investigated using the DPPH method and the EC50 value was determined as 7.084 mg/ml.

UV Study of the Sun Protection Factor of Some Peels and Seeds in Ethanolic and Methanolic Solvents

UV Study of the Sun Protection Factor of Some Peels and Seeds in Ethanolic and Methanolic Solvents

Microwave-Assisted Enzymatic Green Solvent Technology for the Extraction and Characterization of Sesame Seed Oil

Traditional methods of extracting oil with organic solvents raise issues related to health, safety, and the environment. Microwave-assisted enzymatic green solvent extraction (MAEGSE) technology is environment friendly because it involves less hazardous chemical synthesis, utilizes renewable feedstock, and decreases the chemical load and emissions produced by organic solvents. The solvents methanol, ethanol, and various cell wall degrading enzymes such as hemicellulose, viscozyme L, pectinase, xylanase, and cellulase were used in this study. The MAEGSE process of sesame oil was conducted, and the results indicated that, unlike the controlled group, no enzymes were used during the process. Among all the combinations a higher oil extraction efficiency was obtained with combination of pectinase and ethanol (37.27%) followed by the xylanase with ethanol (36.75%) from sesame seed without compromising the quality of oil. Among the enzymes tested, pectinase resulted in the highest oil extraction efficiency, followed by xylanase. Use of pectinase improved the oil extraction efficiency in both ethanol and methanol mediums. The outcomes suggested that the application of pectinase enzymes plays a significant role in increasing the oil yield in comparison with the control without compromising quality of oil. Oil extracted without the use of enzyme (control) had a lower free fatty acid (FFA) concentration than the oils extracted with MAEGSE. Even though the specific gravity (SG) and refractive index (RI) of extracted oils were not significantly different in the solvents, the saponification value (SV), peroxide value (PV), iodine value (IV), and free fatty acid (FFA) were found to have minor differences among the extraction techniques.

A comprehensive analysis of phytochemicals, antioxidant, anti-inflammatory, antibacterial, antifungal and phytoestrogenic properties of different parts of Tribulus terrestris.

Tribulus terrestris L., a medicinal plant rich in secondary metabolites, was studied for optimising bioactive compound extraction from various parts of the plant using ethanol-water (50:50), ethanol, and methanol solvents. Analysis of extracts for key phytochemicals like polyphenols, flavonoids, saponins, and alkaloids was performed using HPTLC, HPLC and gas chromatography. The ethanol-water mixture proved best for extracting saponins and polyphenols, ethanol for flavonoids, and methanol for alkaloids. The fruit yielded the highest saponin content (59.34% ± 3.87), while leaves were richest in polyphenols (18.94% ± 1.39), flavonoids (5.15% ± 1.01), and alkaloids (26.46% ± 1.71). Leaf extracts showed the highest antibacterial activity against B. subtilis and P. aeruginosa, and stem extracts were effective against E. coli. Root, stem, and leaf extracts exhibited antifungal activity with leaf extract also demonstrating strong phytoestrogenic activity. These findings highlight the varied phytochemical profiles and biological activities of T. terrestris, suggesting their potential therapeutic uses.

Heteropolyacids promoted NiMo/MOF catalyst for catalytic oxidation of lignin dimers in oxygen atmosphere

Lignin, as an important biomass resource, has significant research value in its oxidative cleavage process. Nickel-based metal catalysts could selectively depolymerize lignin. A series of heteropolyacid doped nickel based bimetallic catalysts Ni4Mo1-MOF-x（x represented heteropolyacid）were prepared by hydrothermal method, which were calcined to catalyze the oxidative cleavage of lignin model compound (2-phenoxy-1-acetophenone). The catalyst Ni4Mo1-MOF-SiWA-0.1(500) showed the best catalytic performance in methanol solvent under conditions of 160 °C, 4 h, 0.5 MPa oxygen pressure, where the conversion rate was nearly 100 % and the yields of phenol and benzoic acid were 54.5 % and 23.3 %, respectively. The catalysts were well characterized to explore the catalytic performance during the oxidation of lignin dimer. This study could provide some interesting and useful information for the catalytic oxidation of lignin to biomass-derived chemicals.

Single-Pass Demonstration of Integrated Capture and Catalytic Conversion of CO2 from Simulated Flue Gas to Methanol in a Water-Lean Carbon Capture Solvent.

Here, we demonstrate an integrated semibatch simultaneous CO2 capture and conversion to methanol process using a water-lean solvent, N-(2-ethoxyethyl)-3-morpholinopropan-1-amine (2-EEMPA), that serves as both the capture solvent and subsequent condensed-phase medium for the catalytic hydrogenation of CO2. CO2 is captured from simulated coal-derived flue gas at a target >90 mol % capture efficiency, with a continuous slipstream of CO2-rich solvent delivered to a fixed bed catalytic reactor for catalytic hydrogenation. A single-pass conversion rate >60 C-mol % and selectivity >80 C-mol % are observed for methanol at relatively low temperatures (<200 °C) in the condensed phase of the carbon capture solvent. Hydrogenation products also include higher alcohols (e.g., ethanol and propanol) and hydrocarbons (e.g., methane and ethane), suggesting that multiple products could be made offering adaptability with varied CO2-derived products. Catalyst activity and selectivity are directly impacted by the water content in the capture solvent. Anhydrous operation provides high catalyst activity and productivity, suggesting that water management will be a critical parameter in real-world operation. Ultimately, we conclude that the integrated capture and catalytic hydrogenation of CO2 are chemically viable and potentially more energetically efficient and cost-effective than conventional separate capture and conversion approaches.

Guide for Nonequilibrium Molecular Dynamics Simulations of Organic Solvent Transport in Nanopores: The Case of 2D MXene Membranes.

Organic solvent nanofiltration (OSN) stands out as an energy-efficient and low-carbon footprint technology, currently reliant on polymeric membranes. With their exceptional chemical stability and tunable sieving properties, two-dimensional (2D) nanolaminate membranes present distinct advantages over conventional polymer-based membranes, attracting tremendous interest in the OSN community. Computational approaches for designing innovative 2D nanolaminates exhibit significant potential for the future of OSN technology. Imitating the pressure gradient in filtration processes by applying an external force to atoms within a predefined slab, boundary-driven nonequilibrium molecular dynamics ((BD)-NEMD) is a state-of-the-art simulation method with a proven track record in investigating the water transport in nanopores. Nevertheless, implementation of (BD)-NEMD for a broad range of solvents poses a challenge in estimating the OSN performance of theoretical membranes. In this work, we developed a (BD)-NEMD protocol that elucidates the effects of several computational details often overlooked in water simulations but are crucial for bulky solvent systems. We employed a MXene (Ti3C2O2) nanochannel as a model membrane and examined the transport of nine solvents (methanol, ethanol, acetone, n-hexane, n-heptane, toluene, ethyl acetate, dichloromethane, and water) having different properties. First, the impact of ensemble type, thermostatting, channel wall model, and restraining force constant was elaborated. After optimizing the thermostatting approach, we demonstrated that the location of the force slab particularly affects the flux of bulky solvents by changing the density distribution in the feed and permeate sides. Similarly, the uniformity of intramolecular force distribution in bulky solvents and resulting flux are shown to be prone to manipulation by slab boundaries. Next, the magnitudes of the external force generating a linear relation between the pressure gradient and solvent flux were identified for each solvent to ensure that calculated fluxes could be extrapolated to experimentally related pressures. This linear relation was also validated for a mixture system containing 50% ethanol and 50% water. We then correlated the calculated solvent permeances with various solvent properties, such as viscosity, Hansen solubility parameters, kinetic diameter, and interaction energy. Remarkably, we observed a linear correlation with an R2 value of 0.96 between permeance and the combined parameter of viscosity and interaction energy. Finally, the solvent permeances calculated with our proposed methodology closely align with the experimentally reported data. Overall, our work aims to serve as a practical guide and bridge the gap in established simulation methods that are suited for a broad range of solvents and membrane materials.

Light Harvesting Materials: A Study on Förster Resonance Energy Transfer and Optoelectronic Properties of Potential Nerium oleander Flowers.

The present study focused on extracting the anthocyanin dyes in ethanol, acidic ethanol, methanol, and acidic methanol solvents from Nerium oleander flowers by a simple maceration extraction process. FTIR spectroscopy and vibrational studies have confirmed the existence of polyphenolic groups in 2-phenyl chromenylium (anthocyanin) dyes. The optoelectronic results show the least direct bandgap (2.89 eV), indirect bandgap (1.98 eV), Urbach energy (0.120 eV), high refractive index (1.654), dielectric constant (3.294) and high optical conductivity (1.813 103 S/m) for the anthocyanin dye extracted found in acidic ethanol solvent. The photoluminescence properties such as Stokes' shift, quantum yield, and lifetime results show that anthocyanin dyes are promising candidates for red-LEDs and optical materials. The excellent correspondence between the absorption and emission spectra reinforces that the anthocyanins are efficient (89%) FRET probes. Further, the donor and acceptor undergo redshift in excitation and emission spectra in all studied solvents. The photometric properties such as CIE, CRI, CCT and color purity results of anthocyanins in all studied solvents revealed that this material exhibits pink to red shades (x = 0.40 → 0.50 and y = 0.46 → 0.39) and is well suitable for have great potential in the manufacturing of Organic-LEDs and other optoelectronic device applications.