Transesterification For Production Research Articles

Synthesis of the acidic/magnetic catalyst x-MoO3/Ni0.5Zn0.5Fe2O4 by combustion reaction and evaluation of its catalytic potential/reuse in biodiesel production

The objective of this work was to synthesize a new catalyst x-MoO3/Ni0.5Zn0.5Fe2O4 using the combustion reaction method and to evaluate its catalytic potential and reuse in biodiesel production from waste oil, optimizing the process through experimental design. The catalysts were characterized in terms of structure by X-ray diffraction and phase quantification by Rietveld refinement, surface area by the Brunauer-Emmett-Teller technique, experimental density by helium pycnometry, acidity tests by ammonia desorption at programmed temperature, chemical analysis by X-ray fluorescence, morphology by scanning and transmission electron microscopy, and catalytic properties. The products of the simultaneous transesterification and esterification reactions were characterized by gas chromatography and acidity index. The results indicate the formation of catalysts with surface area ranging from 1.5 to 1.7 m2/g and density ranging from 4.5 to 5.1 g/cm3, composed of major crystalline phases of MoO3 in the orthorhombic configuration and cubic Ni0.5Zn0.5Fe2O4 ferrite, with total acidity ranging from 70 to 182 μmol/g of NH3. Morphological characterization revealed that the catalyst comprises irregular plates of various sizes and shapes with a wide range of cluster sizes. In the simultaneous transesterification and esterification reactions of residual oil, the catalysts were active under all conditions tested, with emphasis on the catalyst containing 50 % Mo ions and 50 % Ni0.5Zn0.5Fe2O4 presenting the best catalytic performance with a conversion of 95 % in ethyl esters and a reduction of 71 % in acidity, with a service life of 6 cycles, an average conversion of 90 % and good thermal and structural stability after use. The experimental design was significant and predictive, with a confidence level of 95 %. Statistical analysis identified that all input variables (temperature, time, and amount of catalyst) were significant for the adopted design. The new catalyst composed of molybdenum, iron, nickel, and zinc has a positive impact on biodiesel synthesis from frying oil and ethanol.

Production of biodiesel from non-edible waste palm oil and sterculia foetida using microwave irradiation

Abstract The environmental damage stemming from traditional diesel begins during crude oil extraction and persists throughout its usage. The burning of fossil fuels has further deteriorate the environmental effect and added to global warming by emitting harmful substances. Moreover, the reduction of finite fossil fuel reserves due to widespread extraction has made the adoption of renewable resources essential. Given these considerations, biodiesel emerges as a highly promising alternative to conventional diesel due to its environmentally beneficial nature, renewable source, and economic feasibility. In this study, biodiesel was prepared by a microwave reactor in the presence of potassium methoxide using blended waste palm oil and sterculia foetida. The effects of raw materials characteristics on transesterification products were studied. The studied process parameters were methanol/oil ratio, microwave temperature, catalyst concentration, reaction time, and stirring speed. The optimal yield with 98.5% FAME content was obtained at a methanol/oil ratio of 60 vol. %, microwave temperature of 120 °C, catalyst concentration of 0.3 wt.%, and 3 min reaction time, and stirring speed of 500 rpm. The potassium methoxide was used to catalyse the transesterification process. The physicochemical properties and the fatty acid methyl ester composition were discussed thoroughly. The flash point of biodiesel, at 157.5°C, exceeds that of diesel fuel by more than two times. The cetane index is 59.5 which is higher than diesel (49.6). The biodiesel’s fuel properties conformed to the requirements of both ASTM D6751 and EN 14214. High biodiesel conversion and low sulphur content show that waste palm oil and sterculia foetida are sustainable and economical feedstocks that produce clean fuel to aid the feasibility of the energy transition of the global energy sector. In addition, the selection of synthesis approaches can be further explored for potential catalysts to ensure eco-green biodiesel’s sustainability with minimised.

Ultrasound-assisted intensification of Pickering interfacial biocatalysis preparation of vitamin A aliphatic esters

A novel approach to ultrasound-assisted Pickering interfacial biocatalysis (PIB) has been proposed and implemented for the efficient enzymatic transesterification production of vitamin A fatty acid esters. This is the first instance of exploiting the synergistic effect of ultrasound and the bifunctional modification of enzyme supports to accelerate biocatalytic performance in PIB systems. The optimal conditions were determined to be ultrasound power of 70 W, on/off time of 5 s/5 s, substrate molar ratio of 1:1, enzyme addition of 2 %, and a volume ratio of n-hexane to PBS of 3:1, a temperature of 40 °C, and a time of 30 min. The application of ultrasound technology not only improved lipase activity but also allowed for a reduction in emulsion droplet size to enhance interfacial mass transfer.Bifunctional modification of silica-based supports enhanced stability of immobilized enzymes by increasing hydrogen bonding while maintaining the active interface microenvironment. Compared with a non-ultrasound-assisted PIB system stabilized by mono-modified immobilized enzyme particles, the catalytic efficacy (CE) of the novel system reached 8.18 mmol g−1 min−1, which was enhanced by 3.33-fold, while the interfacial area was found to have increased by 17.5-fold. The results facilitated the conversion of vitamin A palmitate (VAP), vitamin A oleate (VAO), vitamin A linoleate (VAL), and vitamin A linolenate (VALn), with conversion rates of approximately 98.2 %, 97.4 %, 96.1 %, and 94.7 %, respectively. This represents the most efficient example that has been reported to our knowledge. Furthermore, the system demonstrated improved reusability, with a conversion rate of 62.1 % maintained even after 10 cycles. The findings presented in this paper provide valuable insights into an efficient and conveniently promising protocol for the development of PIB systems.

The effect of the unsaturation degree on the gas-phase autoignition of methyl oleate and methyl linoleate: Experimental and modeling study

As the product of transesterification between various oils and alcohols, biodiesel exhibits characteristics of renewability and a wide range of raw materials. The ignition delay times (IDTs) of methyl oleate (MEOLE) and methyl linoleate (MLINO), the primary constituents of biodiesels, were measured in a heated rapid compression machine (RCM) to investigate the impact of CC double bond on the reactivity and autoignition characteristics. The experiment was conducted under two pressures of 8 bar and 10 bar at an equivalence ratio of 0.3–0.8 and a temperature range of 800–1000 K. The qualitative investigation unveiled the influence of compressed pressure, equivalence ratio, and oxygen mole fraction on the IDT of MEOLE and MLINO under varying compressed temperatures. Besides, a comparison of the IDTs for two fuels with different unsaturation degrees under identical conditions revealed that MEOLE exhibited greater reactivity at low temperatures compared to MLINO, while the increase in unsaturation degree can moderate and enhance reactivity at high temperatures. Moreover, three kinetic models in the literature were validated against the newly measured IDTs. The results indicate that the detailed lumped kinetic model exhibits better predictive capacity compared to other models, but it still underestimates the reactivity of MEOLE and MLINO within the investigated temperature range. Subsequently, the detailed kinetic model was optimized based on sensitivity analysis, resulting in excellent agreement between the predicted values of the optimized model and experimental data. Furthermore, accurate predictions were made regarding the relative reactivity changes of MEOLE and MLINO with temperature. Finally, different types of experimental data in the literature were employed to validate the optimized model, yielding satisfactory results.

Optimizing biodiesel production from waste with computational chemistry, machine learning and policy insights: a review

AbstractThe excessive reliance on fossil fuels has resulted in an energy crisis, environmental pollution, and health problems, calling for alternative fuels such as biodiesel. Here, we review computational chemistry and machine learning for optimizing biodiesel production from waste. This article presents computational and machine learning techniques, biodiesel characteristics, transesterification, waste materials, and policies encouraging biodiesel production from waste. Computational techniques are applied to catalyst design and deactivation, reaction and reactor optimization, stability assessment, waste feedstock analysis, process scale-up, reaction mechanims, and molecular dynamics simulation. Waste feedstock comprise cooking oil, animal fat, vegetable oil, algae, fish waste, municipal solid waste and sewage sludge. Waste cooking oil represents about 10% of global biodiesel production, and restaurants alone produce over 1,000,000 m3 of waste vegetable oil annual. Microalgae produces 250 times more oil per acre than soybeans and 7–31 times more oil than palm oil. Transesterification of food waste lipids can produce biodiesel with a 100% yield. Sewage sludge represents a significant biomass waste that can contribute to renewable energy production.

Lyso-phosphatidylethanol detected by LC-MS/MS as a potential new marker for alcohol consumption.

Alcohol biomarkers are able to reflect the degree of recent or long-term alcohol consumption, covering different windows of detection. Phosphatidylethanols (PEths) are an emerging group of direct alcohol biomarkers that are widely applied in clinical and forensic applications. Their quantification can provide insight into an individual's drinking behaviour. Here, we present a new sub-class of yet unknown PEth species, LysoPEths, which are structurally related to PEth, but miss one fatty acyl chain. LysoPEths can be either a degradation product of PEth or a product of transesterification of lyso-phosphatidylcholine (LysoPC) with ethanol. To set up an analytical method, LysoPEth 16:0 was synthesised from PC 16:0/18:1 and characterised by LC-MS/MS, using an enzymatic method: phospholipase D (PLD), followed by phospholipase A2 (PLA2). Then, an LC-MS/MS method in MRM mode for LysoPEth 16:0 with additional LysoPEth species (LysoPEth 18:1, LysoPEth 18:2, and LysoPEth 20:4) and PEth 16:0/20:4 was developed. By incubation of freshly sampled venous blood of a teetotaller with ethanol at different concentrations, the formation of LysoPEth in parallel to PEth was investigated. With increasing ethanol concentrations, LysoPEth 16:0 was formed besides the known PEth species (PEth 16:0/18:1, PEth 16:0/18:2) for up to 72 h with LysoPEth concentrations being about three times lower than PEth concentrations. Storage of ethanol-free PEth-positive blood of an alcohol consumer at 37 °C showed that LysoPEth 16:0 concentrations increased, while PEth 16:0/18:1 concentrations decreased in the first 24 h for frozen/thawed blood, however not for freshly collected blood. Furthermore, LysoPEth 16:0 was detected in venous as well as lyophilised blood from clinical and forensic case work alongside with PEth 16:0/18:1, 16:0/18:2, and other PEth and LysoPEth species (PEth 16:0/20:4, LysoPEth 18:1, LysoPEth 18:2, and LysoPEth 20:4). LysoPEth 16:0 concentrations were found to be in linear correlation with PEth 16:0/18:1 (r2 = 0.75).

Identification of the Hepatic Metabolites of Flumazenil and their Kinetic Application in Neuroimaging.

Studies of the neurobiological causes of anxiety disorders have suggested that the γ-aminobutyric acid (GABA) system increases synaptic concentrations and enhances the affinity of GABAA (type A) receptors for benzodiazepine ligands. Flumazenil antagonizes the benzodiazepine-binding site of the GABA/benzodiazepine receptor (BZR) complex in the central nervous system (CNS). The investigation of flumazenil metabolites using liquid chromatography (LC)-tandem mass spectrometry will provide a complete understanding of the in vivo metabolism of flumazenil and accelerate radiopharmaceutical inspection and registration. The main goal of this study was to investigate the use of reversed-phase high performance liquid chromatography (PR-HPLC), coupled with electrospray ionization triple-quadrupole tandem mass spectrometry (ESI-QqQ MS), to identify flumazenil and its metabolites in the hepatic matrix. Carrier-free nucleophilic fluorination with an automatic synthesizer for [18F]flumazenil, combined with nano-positron emission tomography (NanoPET)/computed tomography (CT) imaging, was used to predict the biodistribution in normal rats. The study showed that 50% of the flumazenil was biotransformed by the rat liver homogenate in 60 min, whereas one metabolite (M1) was a methyl transesterification product of flumazenil. In the rat liver microsomal system, two metabolites were identified (M2 and M3), as their carboxylic acid and hydroxylated ethyl ester forms between 10 and 120 min, respectively. A total of 10-30 min post-injection of [18F]flumazenil showed an immediate decreased in the distribution ratio observed in the plasma. Nevertheless, a higher ratio of the complete [18F]flumazenil compound could be used for subsequent animal studies. [18F] According to in vivo nanoPET/CT imaging and ex vivo biodistribution assays, flumazenil also showed significant effects on GABAA receptor availability in the amygdala, prefrontal cortex, cortex, and hippocampus in the rat brain, indicating the formation of metabolites. We reported the completion of the biotransformation of flumazenil by the hepatic system, as well as [18F]flumazenil's potential as an ideal ligand and PET agent for the determination of the GABAA/BZR complex for multiplex neurological syndromes at the clinical stage.

Insight into the Molecular Weight of Hydrophobic Starch Laurate-Based Adhesives for Paper.

Instead of using finite petroleum-based resources and harmful additives, starch can be used as a biodegradable, low-cost, and non-toxic ingredient for green adhesives. This work employs K3PO4 catalyzed transesterifications of cassava starch and methyl laurate at varying reaction times (1-10 h), resulting in the enhanced hydrophobicity of starch laurates. At longer reaction times, starch laurates having higher degrees of substitution (DS) were obtained. While starch laurates are the major products of transesterification, relatively low-molecular-weight byproducts (1%) were detected and could be hydrolyzed starches based on gel permeation chromatography results. Contact angle measurements confirmed the relatively high hydrophobicity of the modified starches compared with that of native starch. The modified starches were then employed to prepare water-based adhesives on paper (without any additional additives). Notably, the shear strength of the esterified starch adhesives appears to be independent of the DS of esterified samples, hence the transesterification reaction times. Additionally, the shear strength of water-based adhesives (0.67-0.73 MPa) for bonding to paper substrates is superior to that of two other commercially available glues by a factor of 10 to 80 percent.

Study on the Reaction Parameters on Transesterification of Rubber Seed Oil Using MgO/zeolite-A Catalyst

In this research, transesterification of rubber seed oil (RSO) with methanol in the presence of MgO/zeolite-A composites with different MgO loads as catalysts was investigated. In addition, the effect of different reaction parameters including oil to methanol ratio, the amount of catalyst, and transesterification time were also investigated. Zeolite-A was prepared from rice husk silica (RHS) and food-grade aluminum foil and confirmed using XRD and SEM/EDS techniques. The MgO/zeolite-A composites with different MgO loads were prepared by impregnating the zeolite with Mg (NO3)2 solution of different concentrations. The composites were then characterized using XRF, XRD, and SEM, and finally applied as a catalyst in transesterification of RSO at varied experimental conditions. The XRF results indicated that the zeolite has been successfully impregnated, and the content of MgO varied depending on the concentration of magnesium nitrate solution used for impregnation process. Zeolite-A and also MgO/zeolite-A composites were confirmed by XRD investigations, supported by SEM analysis with indicated the shape of cubic particle, a characteristic feature of zeolite-A, and rod like structure which is most likely the MgO particle. The results of transesterification experiments revealed the appreciable activities of the composites and the effect of reaction parameters on the conversion of the RSO, with the highest conversion of 89 % achieved using 12.5 % catalyst relative to the mass of RSO, with MgO 4.43 %/zeolite-A catalyst, oil to methanol ratio of 1:10, and a transesterification time of 6.0 h. Analysis of the transesterification products using GC-MS confirmed that fatty acids composing the RSO were converted into corresponding methyl esters. HIGHLIGHTS Zeolite A was prepared from rice husk silica and food grade aluminum foil MgO/Zeolite A composites with different MgO load were prepared using impregnation method MgO/Zeolite A composites were used as catalyst for transesterification of rubber seed oil GRAPHICAL ABSTRACT

One-step DMC synthesis from CO2 under catalysis of ionic liquids prepared with 1,2-propylene glycol

Three quaternary ammonium ionic liquids with strong nucleophilicity and distinctive structures were synthesized with high yield and purity based on the 1,2-propylene glycol anion (CH3CH2OHCH2O-) derived from transesterification products. Dimethyl carbonate (DMC) was in turn produced via a one-step reaction among propylene oxide (PO), CO2, and methanol (MeOH) by using the synthesized ionic liquids. The involved two-stage catalytic reaction of PO-CO2 cycloaddition and PC-MeOH transesterification was implemented without catalyst separation. Under mild conditions, the PO conversion reached 99.0%, with a PC yield of 99.0%, and a TON value of 119.5. Following the cycloaddition, MeOH was immediately introduced to achieve a PC conversion of 71.2%, a selectivity to DMC above 99%, and a TON value of 57.4 for the transesterification reaction. The influences of temperature as well as time for cycloaddition and transesterification were investigated. Cycloaddition of CO2 with various epoxides was also examined and all showed good performance. By taking advantage of the decomposability of as-prepared ionic liquids and the recyclability of decomposition products, a new catalyst circulation process was designed to complete the full cycle without introduction of any impurities into the product system.

High Activity and Selectivity towards Ethyl Methyl Carbonate through Optimizing Surface Acidity and Alkalinity of the Transesterification Catalyst

AbstractEthyl methyl carbonate (EMC) is the product of the partial transesterification of dimethyl carbonate (DMC) with ethanol (EtOH). How to modulate the catalyst with suitable acidity and alkalinity is of key importance for achieving both high activity and selectivity toward EMC. Herein, an Mg−Zn−P/AT‐ZSM‐5 catalyst with moderate basicity and moderate acidity was intelligently designed by the co‐doping of Mg−Zn−P after the desilication of ZSM‐5. Under the optimized reaction conditions, the EtOH conversion can reach 99.1 % with a high EMC selectivity of 96.3 %. Based on the results of multiple characterizations, the enhanced EtOH conversion and high EMC selectivity should be attributed to the well dispersed supported metal species, and enhanced metal‐support interactions, especially the suitable surface acidity and alkalinity property of the catalyst. Such work provides a more reasonable design strategy for the preparation of a catalyst used for the transesterification reaction of DMC and EtOH to selectively produce high‐valued EMC.

N-Cyclohexylcyclohexanaminium {[acetyl(methyl)amino]methyl}bis [4,5-dibromobenzene-1,2-diolato]silicate(IV) 4,5-dibrobenzene-1,2-diol Ethanol Solvate

An X-ray diffraction study of a transesterification product of N-methyl-N-(trimethoxysilylmethyl)acetamide by 4,5-dibromobenzene-1,2-diol was carried out. It was established that the coordination polyhedron of the silicon atom in an anionic complex is a distorted octahedron disordered due to the superposition of the Δ and Λ optical isomers. The presence of various hydrogen donor groups in bis(cyclohexyl)ammonium cations, solvent ethanol molecules, and non-coordinated 4,5-dibromobenzene-1,2-diol caused the formation of H-bonded chains, while dibromobenzenediol also took part in stacking interactions.

Optimization of transesterification production of biodiesel from Pithecellobium dulce seed oil

This study is aimed to produce biodiesel from Pithecellobium dulce seed oil with methanol (CH3OH) and sodium hydroxide (NaOH) using transesterification process. The impact of operating variables including time of reaction, oil to methanol molar ratio, and concentration of catalyst on yield of biodiesel is also studied. The experiments were designed based on Box–Behnken approach considering three factors with three levels. Regression analysis was employed to model the experimental results and a quadratic model was established to study the effects of selected variables on the biodiesel yield. Response surface technique was used to determine the optimal parameters for the transesterification process (RSM). An optimum yield of 96.6% at 6:1 methanol to oil molar ratio, 0.5 weight percentage of catalyst concentration and 3 h of time for reaction was obtained from the developed RSM model and the optimized conditions were validated with experimental results. Finally, the quality of the produced biodiesel was assessed by determining its properties and met with ASTM D6751 standards.

UV irradiation testing of biodiesel from the Alhagi oil and diesel-biodiesel mixtures

The chemical stability of fuels is one of the key factors in ensuring the proper operation of combustion engines. Progressive destruction of components of diesel-biodiesel fuels during storage and transportation can adversely affect their physical and chemical parameters. Besides, the destruction of petroleum products under sunlight and the formation of toxic compounds have ecological importance. The purpose of the presented work is to investigate the influence of UV irradiation (λ = 300–450 nm) on the chemical content of petroleum diesel and B5, B10, B20, B50, and B100 fuel blends for the 24 h. As biodiesel, the product of transesterification of non-edible Alhagi oil with methanol was used. Chemical changes after irradiation were controlled by the BRUKER FT NMR spectrometer. The relationship between changes in the chemical composition and important physicochemical parameters (density, viscosity, flash point, and cetane index), before and after photochemical destructions was discussed. Based on the obtained results, it was determined that the B20 fuel mixture has more chemical stability after UV irradiation than conventional diesel and other diesel-biodiesel mixtures.

Synthetic cannabinoids identification in e-liquid and biological samples through molecular network approach

The detection of new psychoactive substances, including synthetic cannabinoids, remains highly challenging. A wide array of chemical structures must be structurally elucidated, along with their associated metabolites, in biological samples collected from poisoned patients. For this purpose, non-targeted screening using liquid chromatography hyphenated to high resolution tandem mass spectrometry (LC-HRMS/MS) is a gold standard approach. Nevertheless, the identification steps remain the bottleneck of such analyses. For this purpose, molecular network has been recently proposed as a suitable strategy to organize tandem mass spectrometry data, needed for a reliable identification of unknown compounds. To illustrate this statement, we report the identification of synthetic cannabinoids and their metabolites by a non-targeted approach using molecular network strategy, in an 18-year-old poisoned patient hospitalized for neuropsychiatric disorders related to recent synthetic cannabinoid withdrawal. Upon admission, this patient was suspected of using adulterated e-liquid containing synthetic cannabinoids. Sample preparation of the tainted e-liquid was based on a liquid-liquid extraction using acetonitrile and methyl tert-butyl-ether. The tainted e-liquid was subsequently analysed with LC-HRMS/MS using electrospray as ion source in polarity switching mode and a Q-Exactive Focus® Orbitrap mass spectrometer. Data dependant acquisition was used to acquire tandem mass spectra on the three most intense ions. Molecular network was then generated following data processing on MZmine. The e-liquid was also analysed using GC-MS. The urine samples were extracted using the same procedure as for the e-liquid and was then analysed by LC-HRMS/MS. A segmental hair analysis (2 × 2 cm-long hair segments) was carried out by the CHRU de Lille using LC-HRMS and LC-MS/MS. Molecules detected in the e-liquid included glycerol, propylene glycol and nicotine. As expected, the e-liquid was also adulterated with synthetic cannabinoids namely MDMB-4en-PINACA and MDMB-5F-PICA. These two molecules were identified thanks to molecular network generated using LC-HRMS/MS data as well as using GC-MS, through SWGDRUG 3.9 library querying. Interestingly, in the e-liquid, compounds corresponding to trans-esterification products of MDMB-4en-PINACA was identified. The trans-esterification reaction was performed between MDMB-4en-PINACA and glycerol or propylene glycol and led to the corresponding products. Regarding urine sample of the patient, additional metabolites of MDMB-4en-PINACA were identified, including MDMB-4en-PINACA butanoic acid, dihydroxylated MDMB-4en-PINACA butanoic acid and glucurono-conjugated MDMB-4en-PINACA butanoic acid. The hair analysis of the patient allowed detection of MDMB-4en-PINACA and MDMB-5F-PICA in the two investigated hair segments. Analysis of the e-liquid and biological samples from the poisoned patient provides information on the chemical structure of synthetic cannabinoids and confirmation of synthetic cannabinoid use, respectively. The complete characterization of synthetic cannabinoid-related molecules in adulterated e-liquid, as exemplified by the identification of trans-esterification products of MDMB-4en-PINACA, is a needed step for understanding the mechanisms of cannabinoid toxicity. In addition, the identification of several metabolites in the patient's urine was possible through molecular network and propagation of the annotation. Hair analysis was useful in confirming the exposure to the two synthetic cannabinoids in the two segments studied and suggested chronic consumption of these products by the patient. The non-targeted analysis approach used to study this case offers new insights into the identification of novel psychoactive substances, as demonstrated by the identification of synthetic cannabinoids belonging to the indazole and indole structural families and related structures in e-liquid, hair and urine. Molecular networks have proven essential for the identification of synthetic cannabinoids, their derivatives, and metabolites in numerous matrices, as shown in the example of adulterated e-liquid and patient urine samples.

Optimization of biodiesel production via transesterification of soybean oil using α-MoO3 catalyst obtained by the combustion method

A catalyst based on MoO3 was synthesized by a simple and fast pilot-scale combustion reaction method and applied to the conversion of soybean oil to biodiesel via transesterification. For that, the statistical analysis of the catalyst amount and temperature, factors that influence the process, was evaluated by means of central composite design 22. MoO3 was characterized in terms of structure by X-ray diffraction (XRD), textural characterization Brunauer-Emmett-Teller (BET), density by helium pycnometry (DE), particle size analysis (DG) and acidity tests by temperature-programmed desorption of ammonia (NH3-TPD), chemical analysis by X-ray fluorescence (EDX), morphology by scanning electron microscopy (SEM) and catalytic properties. The transesterification products were characterized by gas chromatography (GC), acidity index (AI) and kinematic viscosity (KV). The results indicate the catalyst formation with a surface area of 1.36 m2g−1, and density of 4.5 g/cm3 which consists of a single crystalline phase of orthorhombic configuration, with total NH3 acidity of 33.61 μ.mol/g. Morphological characterization revealed that the catalyst is formed by irregular plates of various sizes and shapes, with a wide sizes range of agglomerated particles. In the soybean oil transesterification reactions, the catalyst was active showing 96.9% conversion to ethyl esters. The experimental design was meaningful and predictive, with a reliability level of 95%. The statistical analysis identified temperature as a significant variable for the adopted planning. To conclude, a new single-phase catalyst (α-MoO3) has been developed and successfully applied to the biodiesel Synthesis from soybean oil. These results have a positive and promising impact for biodiesel production by transesterification of soybean oil against ethanol.

Anti-COVID-19 and antidiabetic activities of new oleanane and ursane-type triterpenoids from Salvia grossheimii: an in-silico approach

Salvia grossheimii is a perennial herb with antidiabetic and cytotoxic constituents. In continuation of our study on S. grosshiemii to identify the bioactive phytochemicals, we have reported the characterization of seven undescribed triterpenoids. The aerial parts of the plant were extracted in dichloromethane and its constituents were isolated using chromatography techniques. The structures of compounds were identified using 1D, 2D NMR, and ESI-MS spectral data. Seven new oleanane- and ursane-type triterpenoids (1–7) were identified in S. grossheimii. The structures of 1–7 were characterized as; 2α-hydroxy-3β-acetoxy-olean-9(11),12-diene (1), 2α-acetoxy-3β-hydroxy-olean-9(11),12-diene (2), 3β-acetoxy-olean-18-ene,2α,11α-diol (3), 2α-hydroxy-3β-acetoxy-urs-9(11),12-diene (4), 2α-acetoxy-3β-hydroxy-urs-9(11),12-diene (5), 2α,3β-diacetoxy-urs-12-ene-11α,20β-diol (6), 2α,3β-diacetoxy-urs-9(11),12-diene-20β-ol (7). Triterpenoids (2, 5, and 7) were intramolecular transesterification or dehydration products of their corresponding isomers or allylic alcohol in the C rings, respectively, produced in-situ during NMR spectroscopy. Virtual screening of 1–7 was performed with molecular docking analysis to identify the potential SARS-CoV-2 and α-glucosidase inhibitors using the smina molecular docking algorithm. The best binding energy values (kcal/mol) against COVID-19 main protease Mpro were calculated for 6 (-8.77) and 7 (-8.68), and the higher binding affinities toward human α-glucosidase were obtained for 2 (-9.39) and 6 (-8.63). This study suggests S. grossheimii as a rich source of bioactive triterpenoids and introduces new natural compounds. Considering the high binding energy values of 2, 6, and 7, these structures could be candidates for anti-COVID-19 and antidiabetic drug development in the future.

Biodiesel Production of Palm Oil Mill Effluent by Using Hydrotalcite Catalyst

Biodiesel is currently preferred for consumption and has been widely used as a substitute for diesel. This study aimed to determine the effect of various methanol-to-oil ratios in the esterification process and also the effect of hydrotalcite catalyst weight on the transesterification product. The catalyst was characterized with SEM, XRD, FTIR, and TG-DTG-DTA. The esterification process was operated at various oil-to-methanol ratios, i.e., 1:12-1:36 and the transesterification was performed using several catalyst weights, 0.5%-2.5%. The results showed that the optimum conditions of esterification were at the 1:30 molar ratio of oil-to-methanol, which decreased the amount of acid number by 95.75%, while the optimum condition of transesterification was at 1.5% catalyst weight. The characteristics of biodiesel using 0.5-2% hydrotalcite catalyst (acid number, total glycerol, free glycerol, ester levels, viscosity, density, oxidation stability) have met the Indonesian biodiesel standard of SNI-04-7182-2012.

Residual behaviors and metabolic pathway of ethylparaben in Drosophila melanogaster

ObjectiveParabens are commonly used as preservatives in foodstuffs, cosmetics, and pharmaceutical products. The widespread use of parabens has led to their leaking into the environment. Concerns about the safety of parabens have recently increased due to their potential endocrine–disrupting effects as an emerging contaminant. Thus, it is necessary to study the metabolism of parabens in vivo. MethodsIn this study, Drosophila melanogaster in males and females were exposed to ethylparaben (EP) concentration group (300 mg/L, 700 mg/L, and 1000 mg/L), and control group (0 mg/L) by the capillary feeding assay (CAFE). We quantified the activity of the detoxification-related carboxylesterase (CarE). The contents of EP metabolites in D. melanogaster, including p-hydroxybenzoic acid (PHBA), methylparaben (MP), and intact EP were carried out by high-performance liquid chromatography (HPLC). The regression model between EP metabolites (PHBA and MP) and CarE was developed using the Fourier series fitting method. ResultsThe general level of EP metabolites (PHBA, MP, and intact EP) accumulation was accounted for 5.6−11.5% in D. melanogaster. As EP accumulated, the activity of CarE increased, and the activity of CarE in females was higher than males, which is inconsistent with the result of EP intake dose. Additionally, there were significant differences in the proportion of EP metabolites between female and male flies, and the results of sex comparison were different depending on the EP treated groups and EP metabolites. In general, PHBA of EP hydrolytic product and MP of EP transesterification product in D. melanogaster were 41.4−63.9% and 10.4−24.6%, respectively. In terms of the rest of the EP existed in intact form and ranged from 22.4% to 34.0%. Moreover, the EP metabolites in the conjugated form were higher than those in the free form. The regression model between EP metabolites and CarE was established, showing that the CarE activity can be used to estimate the content of PHBA and MP. ConclusionThe result indicates that the EP can accumulate in the body through food. Hydrolysis is the main metabolic pathway of EP in D. melanogaster, and transesterification is another metabolic pathway of EP. Additionally, the EP metabolites in flies mainly exist in conjugated form. Furthermore, the Fourier series fitting method model between EP metabolites and CarE, providing theoretical support to study the dose–effect relationship between metabolites of parabens and CarE. This study not only provides a mathematical basis for the safety evaluation of parabens, but also provides support for the further study of the toxicological effects of parabens.

Biolubricant production via esterification and transesterification processes: Current updates and perspectives

The growing concern and limitations for existing lubricants have driven the need for biolubricants, extensively proposed as the most suitable and sustainable lubricating oils. Biolubricants are generally synthesized from various bio-based sources, including vegetable oils, microbially derived oils, waste cooking oil, etc. They are promising commodities and advantageous to mineral-based analogues due to their exceptional properties like their lubricity, biodegradability, reduced toxicity, and reduced volatility. Yet, their utilization as lubricants is constrained due to their relatively poor cold-flow and thermo-oxidative stability uncertainties even after being chemically modified. Hence, many chemical modification pathways have been reported to overcome this limitation, with the most exploited approaches being esterification and transesterification. This modification pathway enhanced the thermo-oxidative stability and the cold-flow properties of these bio-based oils, increased the yield, and enhanced the quality of the lubricants. With this in mind, this paper reviews up-to-date works conducted in this area and critically report the advancement in esterification and transesterification production of biolubricants. The study further reviews the latest published literature, current updates, and future perspectives related to the synthesis of biolubricants. Also, the review highlights the significant factors that govern the entire reaction process, selection criteria of renewable feedstocks, and the tribological performance of biolubricants.