Ester Method Research Articles

The Cytochalasins and Polyketides from a Mangrove Endophytic Fungus Xylaria arbuscula QYF.

Twelve compounds, including four undescribed cytochalasins, xylariachalasins A-D (1-4), four undescribed polyketides (5-8), and four known cytochalasins (9-12), were isolated from the mangrove endophytic fungus Xylaria arbuscula QYF. Their structures and absolute configurations were established by extensive spectroscopic analyses (1D and 2D NMR, HRESIMS), electronic circular dichroism (ECD) calculations, 13C NMR calculation and DP4+ analysis, single-crystal X-ray diffraction, and the modified Mosher ester method. Compounds 1 and 2 are rare cytochalasin hydroperoxides. In bioactivity assays, Compound 2 exhibited moderate antimicrobial activities against Staphylococcus aureus and Candida albicans with MIC values of 12.5 μM for both Compound 10 exhibited significant cytotoxic activity against MDA-MB-435 with an IC50 value of 3.61 ± 1.60 μM.

Experimental Device for the “Green” Synthesis of Unbranched Aliphatic Esters C4–C8 Using an Audio Frequency Electric Field

One of the most important reactions in organic synthesis is esterification, and the compounds generated using this process are esters with a wide range of applications in various industries. Numerous approaches have been employed to enhance the ester yield and reaction rate and establish equilibrium in esterification reactions. This study uses a non-catalytic thermal esterification method to obtain unbranched aliphatic esters C4–C8. The effect of an audio frequency electric field instead of a catalyst on the esterification reaction between acetic acid and linear C4–C8 aliphatic alcohols was studied. The main goal of this study was to design and implement a lab-scale device for the synthesis of aliphatic esters in an environmentally sustainable manner using only specific raw materials and an audio frequency electric field at 3 and 6 kHz at 20 °C and 50 °C. A mechanism for the esterification reaction using an audio frequency electric field is also suggested. The proposed experimental device is designed to produce esters in a green and cost-effective manner and could be used on a large scale in the food, cosmetics, and pharmaceutical industries.

Applied AMT machine learning and multi-objective optimization for enhanced performance and reduced environmental impact of sunflower oil biodiesel in compression ignition engine

Biodiesel has emerged as a compelling substitute for conventional diesel fuel, providing a sustainable and eco-friendly choice for fueling compression ignition engines. This comprehensive study investigates the influence of biodiesel, specifically derived from sunflower oil, through the esterification method, on crucial engine performance parameters and environmental effects. The study examines the impact of varying engine torque on the performance of a single-cylinder, four-stroke compression ignition engine, encompassing parameters such as brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC), as well as exhaust emissions, including unburned hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx). Four distinct biodiesel blends (B10, B20, B30, B40) with varying sunflower oil content are systematically compared to pure diesel (B0). The engine operates at a consistent speed of 1700 rpm, while the torque undergoes controlled adjustments from 0 to 10 Nm. Subsequently, this study explores the application of an alternating model tree (AMT) machine learning algorithm to establish relationships between independent factors, specifically torque and biodiesel volume (%vol), and dependent variables, including BTE, BSFC, CO, and NOx in a combustion engine. Additionally, the study employs a multi-objective ameliorative whale optimization algorithm (AWOA) to optimize the model's output. The objective is to identify optimal values for torque and%vol that maximize engine performance (BTE) while minimizing engine emissions (CO and NOx) and reducing fuel consumption (BSFC). The optimization process yields noteworthy results, with AWOA achieving peak BTE at 29.714 %, BSFC at 0.262 kg.kWh-1, and NOx emissions at 992 ppm at torque 7.3 N.m and 13% vol. In contrast, particle swarm optimization (PSO) secured the minimum CO level at 0.123 %, with torque set at 7.6 N.m and 26% vol. The AMT models demonstrate high prediction accuracy, with coefficient of determination (R2) values exceeding 0.98.

Disposal of used oils as a prospective method of production of biodiesel

The article is devoted to the improvement of the production technology of diesel biofuel from waste oils, which are a significant source of environmental pollution. Environmental pollution is one of the biggest environmental problems of our time. Used oils that are not properly disposed of cause serious environmental problems, including water and soil pollution. The use of waste oils for the production of biofuel is a promising technology that allows reducing the amount of pollution and reducing dependence on fossil fuels. Biodiesel from waste oils has significant environmental, economic and sustainable advantages. The main goal of the article is a detailed analysis of modern technologies for the production of diesel biofuel from waste oils and an assessment of their improvements and impact on ecology, economy and society. The article discusses innovative approaches to the processing of used oils, their purification and preparation for further use. An analysis of the main methods of transesterification, hydrogenation, esterification and enzyme catalysis, as well as the latest technologies, such as ultrasonic and microwave intensification of biofuel production, was carried out. New technological solutions for the preliminary preparation of used oils with a high content of free fatty acids using a combination of acid catalysts are proposed, and a technological scheme of the full production cycle is developed. The rational parameters of the equipment for the preliminary preparation of used oils with a high content of free fatty acids have been determined. Recommended conditions include hydrogenation temperature not higher than 80°С, duration of the process not less than 40 minutes; separation of the water-protein part by centrifugation at a rotation frequency of the centrifuge rotor of 3000 rpm for 20 minutes; the esterification reaction temperature is no more than 60°C; molar ratio of alcohol to oil 9:1; acid catalyst concentration within 1-15%; the intensity of mixing in the reactor is 31.42 s-1; the duration of the process is not less than 120 minutes. It was established that it is advisable to use potassium hydroxide for the transesterification reaction. The use of potassium hydroxide is beneficial because the potassium salts formed during the technological process of diesel biofuel production can be used as mineral fertilizers. According to the results of the research, the optimal parameters for the transesterification reaction were chosen: the amount of methanol - 20% by mass. from the weight of the oil, the KOH 1 catalyst is 1.5%, the temperature of the process is 60°C and the duration is 60-70 minutes. Examples of successful implementation of these technologies in various countries of the world, in particular in Europe, the USA and Asia, are presented. Additionally, recommendations are provided for further research and technology development, including the need to improve waste oil purification methods, optimize transesterification processes, and integrate renewable energy sources. The prospects and challenges of the industry of biofuel production from waste oils are considered, in particular the issues of regulatory support, financial incentives and investment attraction.

Methyl Ester Production from Rice Bran Oil and Methanol with Calcium Carbonate Catalysts Using Esterification Method

Rice bran oil is a type of oil with high nutritional value from rice bran. However, the free fatty acid content in it can increase by more than 60% with sufficient storage time. Free fatty acids contained in rice bran have the potential to be produced into biodiesel (methyl ester). This research aimed to determine the effect of methanol volume and esterification process time on biodiesel yield and to compare methyl ester yield to standard biodiesel. This research was conducted in two stages, namely rice bran oil extraction and esterification. In the extraction stage, rice bran was extracted with n-hexane for 3 hours at an operating temperature of 65oC. The esterification process was carried out by mixing rice bran oil, methanol with a certain volume (100, 125, 150, 175, 200 mL), and calcium carbonate catalyst as much as 1% of the amount of methanol. Esterification was carried out with time variations of 1; 1.5; 2; 2.5 and 3 hours. The results in the form of rice bran oil were analyzed for the value of the biodiesel yield. The result of rice bran oil was analyzed for initial free fatty acid value. Pure biodiesel product in the form of methyl ester was obtained through separation with glycerol as a by-product. The optimum methyl ester yield was 81.70% at 175 ml methanol volume for 3 hours. The methyl ester results are in accordance with SNI biodiesel for density and kinematic viscosity values.

Quantitative analysis of loxoprofen sodium loaded microspheres comprising pectin and its thiolated conjugates: In-vivo evaluation of their sustained release behavior

Continuous use of oral NSAIDs can damage mucosal membrane, which results in decreased bioavailability and non-compliance with the therapy. But the use of sustained release drug delivery systems might offer a solution. Objective was to synthesize mucoadhesive SR microspheres by using different combinations of pectin (PEC) and its thiolated derivative (T-PEC3100) for improved loxoprofen (LS) permeation. Thiolated pectin (T-PEC) was synthesized by the esterification method using thioglycolic acid. Thiolation was confirmed by thiol group quantification and charring point determination. Further characterization was done by Fourier Transform Infrared spectroscopy (FTIR), and Scanning electron microscopy (SEM). Ex-vivo mucoadhesion study was performed to confirm the improved characteristics. Microspheres (MS) were prepared using different ratios of PEC/T-PEC by solvent evaporation method and their particle size and surface morphology were evaluated. Mucus permeation study was carried out using the trans-well plate method. Sustained release behavior of prepared microspheres was investigated through the edema inhibition method in albino rats. T-PEC3100 was considered the optimum formulation for further evaluation and contained maximum thiol group content. FTIR spectra showed a characteristic peak of –SH and charring point was also changed considerably confirming the successful thiolation of PEC. SEM results showed spherical microspheres in the size range of 2–10 μm. Thiol-rich formulation of MS exhibited more than 80 % release after 12 h and maximum absorbable dose (MAD) was calculated as 400 μg % inhibition of edema in MS treated group was slowly attained initially but the reduction in inflammation was detected even after 24 h as compared to control group. Promising results from In-vivo edema inhibition study suggest the possible use of these thiolated MS in formulating sustained release formulation for arthritis.

Poly(Butylene Succinate) Copolyesters Modified with Linear‐Chain Diols toward Adjustable Thermal, Mechanical, and Biodegradable Properties

AbstractThe production and application of poly(butylene succinate) (PBS) still face challenges such as high production costs, insufficient toughness, and slow biodegradation. This study utilizes the ring‐opening condensation polymerization method to prepare PBS copolyesters using succinic anhydride (SAA) and 1,4‐butanediol (BDO) as raw materials, with 20 moL% different lengths of linear‐chain diols as third monomers (carbon numbers are 3, 5, 6, 8, 9,10, and 12). Both PBS and its copolyesters exhibit high weight average molecular weights (18.8 × 104–26.1 × 104 g moL−1), much higher than those obtained through the traditional conventional direct esterification method. Incorporating the third monomer reduces the glass transition temperature (Tg), crystallinity, and melting point (Tm) of the copolyesters. As the chain length of the third monomer increases, the copolyesters show improved toughness, with the elongation at break and notch impact strength of poly(butylene succinate‐ran‐dodecylene succinate) (P(BS‐ran‐DoS)) increasing from 374.1% and 5.6 KJ m−2 of PBS to 723.2% and 64.8 KJ m−2, respectively. The degradation rate of the copolyesters modified with short‐chain diols increases significantly, and as the chain length of the third monomer increases, the degradation rate of the copolyesters slows down. Therefore, the selection of the third monomer can be used to adjust the properties of the polymer.

Difluorocarbene-Promoted O-O Bond Activation of Peroxy Acids for Electrophilic Carboxylation of Boronic Acids.

In this study, a difluorocarbene-promoted O-O bond activation of peroxy acids is developed through the insertion of difluorocarbene into O-H bond. This activation strategy in synergy with O-B coordination with boronic acids/ester greatly polarizes the O-O bond for in-situ generation of carboxylium species that reacts with the nucleophilic part of boronic acids in a concerted way to produce carboxylic esters. Good efficiency and functional group tolerance are demonstrated. Application of this method to the functionalization of a boronic acid drug used as HSL enzyme inhibitor produces smoothly the ester derivative. This difluorocarbene-mediated O-O bond activation strategy is conceptually different from traditional radical type methods, and is also complementary to conventional esterification methods with a distinct retro-synthetic disconnection.

Aromatic Amines in Organic Synthesis Part III; p-Aminocinnamic Acids and Their Methyl Esters

Fifteen amine derivatives of cinnamic acid were synthesized by reaction of the corresponding benzaldehydes and malonic acid. The selected acids were then converted into methyl esters. Three esterification methods were tested with (1) thionyl chloride in methanol, (2) sulfuric acid in methanol, and (3) dimethyl sulfate in acetone. The latter method turned out to be the best, both in terms of reaction efficiency and product purity. The chemical structure and purity of all the synthesized compounds were verified by elemental analysis, 1H and 13C NMR, and IR spectroscopy. The cinnamic acids and their esters, thanks to an extensive system of conjugated double bonds compared to analogous benzoic acids, can be used to obtain dyes for various applications, including non-linear optics and optoelectronics. Therefore, their basic spectroscopic properties are presented as well.

A color-changed fluorescence sensor for pesticide triclopyr 2-butoxyethyl ester based on naphthalimide Schiff-base

Triclopyr 2-butoxyethyl ester is a usual pesticide, however, its excessive use might pose risks to environmental safety. The rapid, simple and in-situ detecting method for triclopyr 2-butoxyethyl ester is of great importance but rarely reported. In this work, the first fluorescent sensor for triclopyr 2-butoxyethyl ester was developed based on a derivative of n-butyl-1,8-naphthimide Schiff-base (NSB). NSB is a typical AIE molecule with good green fluorescence in DMSO-H2O (5:95). The green fluorescence of NSB was transferred into strong blue fluorescence on sensing triclopyr 2-butoxyethyl ester. The high selective detection of NSB for triclopyr 2-butoxyethyl ester was observed among 26 kinds of normal metallic ions and pesticide molecules. The detecting limitation was as low as 2.89 × 10−7 M. The sensing mechanism was confirmed as 1:1 stoichiometric ratio based on the multiple hydrogen bonding and hydrophobic interactions. NSB was applied on sensing triclopyr 2-butoxyethyl ester in real samples of wheat seedlings, sugarcane and broadleaf weedane and water samples, suggesting the excellent application potential on simple, rapid and in-situ detection of triclopyr 2-butoxyethyl ester in daily environments.

Incorporating mannose-functionalized hydroxyapatite/metal-organic framework into the hyaluronic acid hydrogel film: A potential dual-targeted oral anticancer delivery system

The recent challenge in enhancing the targeted delivery of anticancer drugs to cancer cells is improving the bioavailability and therapeutic efficacy of drug delivery systems while minimizing their systemic side effects. In this study, the MIL-88(Fe) metal-organic framework was synthesized using the in situ method in the presence of hydroxyapatite nanoparticles (HAP) toward the HAP/MIL-88(Fe) (HM) nanocomposite preparation. It was then functionalized with mannose (M) as an anticancer receptor through the Steglich esterification method. Various analyses confirmed the successful synthesis of MHM. For drug release investigation, 5-Fu was loaded into the MHM, which was then coated with a hyaluronic acid (HA) hydrogel film. Characterization analyses verified the structure of the resulting HA/5-Fu-MHM hydrogel film. In vitro drug release experiments showed that the release of 5-Fu drug from HA/5-Fu-MHM could be controlled with pH, reducing its release rate in the acidic environment of the stomach while increasing it in the intestinal environment. Cytotoxicity results of the HA/5-Fu-MHM hydrogel film against HT29 cancer cells showed enhanced cytotoxicity due to the mannose and hyaluronic acid in its structure, which triggers a dual-targeted drug delivery system. The obtained results indicate that the prepared hydrogel films can be a promising bio-platform for colon cancer treatment.

Reversed-Phase Medium-Pressure Liquid Chromatography Purification of Omega-3 Fatty Acid Ethyl Esters Using AQ-C18.

Omega-3 fatty acids are in high demand due to their efficacy in treating hypertriglyceridemia and preventing cardiovascular diseases. However, the growth of the industry is hampered by low purity and insufficient productivity. This study aims to develop an efficient RP-MPLC purification method for omega-3 fatty acid ethyl esters with high purity and capacity. The results indicate that the AQ-C18 featuring polar end-capped silanol groups outperformed C18 and others in retention time and impurity separation. By injecting pure fish oil esters with a volume equivalent to a 1.25% bed volume on an AQ-C18 MPLC column using a binary isocratic methanol-water (90:10, v:v) mobile phase at 30 mL/min, optimal omega-3 fatty acid ethyl esters were obtained, with the notable purity of 90.34% and a recovery rate of 74.30%. The total content of EPA and DHA produced increased from 67.91% to 85.27%, meeting the acceptance criteria of no less than 84% set by the 2020 edition of the Pharmacopoeia of the People's Republic of China. In contrast, RP-MPLC significantly enhanced the production efficiency per unit output compared to RP-HPLC. This study demonstrates a pioneering approach to producing omega-3 fatty acid ethyl esters with high purity and of greater quantity using AQ-C18 RP-MPLC, showing this method's significant potential for use in industrial-scale manufacturing.

Tailored design of NHS–SS–NHS cross-linked chitosan nano-hydrogels for enhanced anti-tumor efficacy by GSH-responsive drug release

The traditional chemotherapeutic agents’ disadvantages such as high toxicity, untargeting and poor water solubility lead to disappointing chemotherapy effects, which restricts its clinical application. In this work, novel size-appropriate and glutathione (GSH)-responsive nano-hydrogels were successfully prepared via the active ester method between chitosan (containing –NH2) and cross-linker (containing NHS). Especially, the cross-linker was elaborately designed to possess a disulfide linkage (SS) as well as two terminal NHS groups, namely NHS–SS–NHS. These functionalities endowed chitosan-based cross-linked scaffolds with capabilities for drug loading and delivery, as well as a GSH-responsive mechanism for drug release. The prepared nano-hydrogels demonstrated excellent performance applicable morphology, excellent drug loading efficiency (∼22.5%), suitable size (∼100 nm) and long-term stability. The prepared nano-hydrogels released over 80% doxorubicin (DOX) after incubation in 10 mM GSH while a minimal DOX release less than 25% was tested in normal physiological buffer (pH = 7.4). The unloaded nano-hydrogels did not show any apparent cytotoxicity to A 549 cells. In contrast, DOX-loaded nano-hydrogels exhibited marked anti-tumor activity against A 549 cells, especially in high GSH environment. Finally, through fluorescent imaging and flow cytometry analysis, fluorescein isothiocyanate-labeled nano-hydrogels show obvious specific binding to the GSH high-expressing A549 cells and nonspecific binding to the GSH low-expressing A549 cells. Therefore, with this cross-linking approach, our present finding suggests that cross-linked chitosan nano-hydrogel drug carrier improves the anti-tumor effect of the A 549 cells and may serve as a potential injectable delivery carrier.

Efficient delivery of anticancer drugs using functionalized-Ag-decorated Fe3O4@SiO2 nanocarrier with folic acid and β-cyclodextrin

Nanocarrier surface functionalization has been widely regarded as a promising approach for achieving precise and targeted drug delivery systems. In this work, the fabrication of functionalized-Ag-decorated Fe3O4@SiO2 (Fe3O4@SiO2-Ag) nanocarriers with folic acid (FA) and β-cyclodextrin (BCD) exhibit a remarkable capacity for delivering two types of anticancer drugs, i.e., doxorubicin (DOX) and epirubicin (EPI), into cancer cells. The effective functionalization of Fe3O4@SiO2-Ag nanoparticles has been achieved through the use of cysteine (Cys) as an anchor for attaching FA and BCD via EDC-NHS coupling and Steglich esterification methods, respectively. The findings indicate that surface functionalization had no significant impact on the physicochemical characteristics of the nanoparticles. However, it notably affected DOX and EPI loading and release efficiency. The electrostatic conjugation of DOX/EPI onto the surface of Fe3O4@SiO2-Ag/Cys/FA and Fe3O4@SiO2-Ag/Cys/BCD exhibited maximum loading efficiency of 50–60% at concentration ratio of DOX/EPI to nanoparticles of 1:14. These nanocarriers also achieved an 40–47% DOX/EPI release over 36 days. Furthermore, the drug-loaded functionalized-nanocarrier showed cytotoxic effects on SK-MEL-2 cells, as demonstrated by an in vitro MTT assay. This suggests that the as-prepared functionalized-nanoparticles have promise as a carrier for the efficient anticancer drugs.

Physicochemical Study of Ethanol Ratio in the Transesterification Process for Biodiesel Synthesis from Kesambi (Schleichera Oleosa) Seed Oil

The demand for energy, particularly for fossil fuels, has been increasing in line with the growing number of transportation units. However, natural resource conditions such as fossil fuels are not always fulfilled. This is because fossil fuels are categorized as non-renewable resources. Moreover, all countries in the world are required to reduce the use of fossil resources and increase the use of green energy. Therefore, alternative green energy sources are needed to replace fossil fuels. Biodiesel is a green energy source that could be produced from renewable resources. Biodiesel could be obtained from non-food sources such as kesambi oil. In this research, the biodiesel production process was carried out by esterification and transesterification methods. The transesterification process was performed by varying the molar ratio between ethanol and kesambi oil. The molar ratio used in the transesterification process were 4:1, 6:1, 8:1, 10:1, and 12:1. The results showed that the molar ratio of 12:1 produced the lowest values of density, viscosity, and flash point, which were 0.839 g/ml, 3.98 CST, and 109.4°C, respectively, but the highest values of calorific value and yield, which were 9,040 cal/g and 91.30%, respectively.

Comprehensive Review of EGCG Modification: Esterification Methods and Their Impacts on Biological Activities.

Epigallocatechin gallate (EGCG), the key constituent of tea polyphenols, presents challenges in terms of its lipid solubility, stability, and bioavailability because of its polyhydroxy structure. Consequently, structural modifications are imperative to enhance its efficacy. This paper comprehensively reviews the esterification techniques applied to EGCG over the past two decades and their impacts on bioactivities. Both chemical and enzymatic esterification methods involve catalysts, solvents, and hydrophobic groups as critical factors. Although the chemical method is cost-efficient, it poses challenges in purification; on the other hand, the enzymatic approach offers improved selectivity and simplified purification processes. The biological functions of EGCG are inevitably influenced by the structural changes incurred through esterification. The antioxidant capacity of EGCG derivatives can be compromised under certain conditions by reducing hydroxyl groups, while enhancing lipid solubility and stability can strengthen their antiviral, antibacterial, and anticancer properties. Additionally, esterification broadens the utility of EGCG in food applications. This review provides critical insights into developing cost-effective and environmentally sustainable selective esterification methods, as well as emphasizes the elucidation of the bioactive mechanisms of EGCG derivatives to facilitate their widespread adoption in food processing, healthcare products, and pharmaceuticals.

A new isopropyl esterification method for quantitative profiling of short-chain fatty acids in human and cow milk by gas chromatograph-mass spectrometer

Short-chain fatty acids (SCFA) content in milk may have been underestimated due to the neglect of the esterified SCFA content and the lack of an accurate detection method, especially for C1:0, C2:0, and C3:0 SCFA. In this study, an accurate GC-MS profiling method was established for 10 SCFA. A 2-step esterification, including alkaline saponification (60°C for 30 min) and acid-catalyzed esterification (80°C for 150 min) in water/isopropyl/hexane (1:2:1, volume ratio), was found to be the most suitable for the quantification of esterified and nonesterified SCFA analysis. The validation results demonstrate satisfactory linearity, sensitivity, matrix effects, precision, and accuracy. The recoveries of nonesterified and esterified SCFA ranged from 82.78% to 112.49%, respectively. Human milk is distinguished from cow milk by its higher C1:0 and C2:0 content and lower C4:0 and C6:0 content. This method successfully accomplished qualitative and quantitative estimation of all 10 SCFA in milk, including both nonesterified and esterified SCFA. Furthermore, whether our method is applicable for the determination of SCFA in serum, rumen fluid, and feces remains to be explored.

Acremosides A-G, Sugar Alcohol-Conjugated Acyclic Sesquiterpenes from a Sponge-Derived Acremonium Species.

Seven new sugar alcohol-conjugated acyclic sesquiterpenes, acremosides A-G (1-7), were isolated from the cultures of the sponge-associated fungus Acremonium sp. IMB18-086 cultivated with heat-killed Pseudomonas aeruginosa. The structures were determined by comprehensive analyses of 1D and 2D NMR spectroscopic data. The relative configurations were established by J-based configuration analysis and acetonide derivatization. The absolute configurations were elucidated by the Mosher ester method and ECD calculations. The structures of acremosides E-G (5-7) featured the linear sesquiterpene skeleton with a tetrahydrofuran moiety attached to a sugar alcohol. Acremosides A (1) and C-E (3-5) showed significant inhibitory activities against hepatitis C virus (EC50 values of 4.8-8.8 μM) with no cytotoxicity (CC50 of >200 μM).

Synthesis, characterization and performance evaluation of a nontoxic functional plasticizer for poly(vinyl chloride) derived from sustainable lactic acid

The use of plasticizers is crucial in enhancing the flexibility of engineering plastics. Currently, the primary plasticizers employed in poly(vinyl chloride) materials are nonrenewable phthalates. These exhibit a detrimental impact on the environment and human health owing to their toxic benzene ring structure. Consequently, the development of easily synthesizable, green plasticizers with excellent properties using biobased resources has been a long-standing objective in the field of resin plasticizing. Herein, we synthesized a branched lactic acid ester (BLAE) plasticizer using esterification and acid anhydride end-capping methods. Further, we investigated its application performance and oral toxicity. The abundance of polar ester groups in the oligolactic acid structure enables them to form secondary bonds with polymer chains. This results in a glass transition temperature is 59% less than that of pure poly(vinyl chloride), thereby improving the mechanical properties of the material. The addition of the BLAE plasticizer not only improved the thermal stability of the compound film but also effectively reduced the self-catalytic dehydrochlorination reaction of poly(vinyl chloride). This overcomes the limitations of unmodified poly(vinyl chloride), such as performance deterioration and color variation due to light exposure. Furthermore, the hydrophobicity of the compound film was substantially enhanced, resulting in outstanding antifouling and self-cleaning properties. These findings suggest that lactic acid-based plasticizer exhibits comparable or even superior overall performance when compared to commercially available plasticizers such as dioctyl phthalate and acetyl tributyl citrate. This work not only addresses the gap in the toxicity assessment of lactic acid plasticizers but also demonstrates their nontoxic characteristics in acute oral toxicity tests. This research offers novel insights into the green synthesis and functional development of biobased plasticizers, showcasing considerable potential for the substituting of dioctyl phthalate.

Microwave-assisted esterification and electro-enhanced solid-phase microextraction of omega-3 polyunsaturated fatty acids in eggs

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs), a type of fatty acid that has many health benefits, are of increasing concern. Herein, we developed a method for the rapid esterification and enrichment of ω-3 PUFAs in eggs, which includes microwave-assisted esterification (MAE) and electrically enhanced solid-phase microextraction (EE-SPME). Combined with gas chromatographic, efficient detection of ω-3 PUFAs was achieved in eggs. Under microwave radiation, the esterification efficiency exhibited a significant increase ranging from 5.06 to 10.65 times. The EE-SPME method reduced extraction time from 50 to 15 min. In addition, improvements in extractive fiber coating materials were explored, which ensured efficient extraction of ω-3 PUFAs. Under the optimal conditions, the method displayed a low detection limit (1.01–1.54 μg L−1), good recoveries (85.82%–106.01%), and wide linear range (7.5–1000 μg L−1), which was successfully applied to determine ω-3 PUFAs in real egg samples.