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Epoxyeicosatrienoic acids (EpETrEs) are bioactive lipid mediators of arachidonic acid cytochrome P450 oxidation. In vivo, the free (unbound) form of EpETrEs regulate multiple processes including blood flow, angiogenesis and inflammation resolution. Free EpETrEs are thought to rapidly degrade via soluble epoxide hydrolase (sEH); yet, in many tissues, the majority of EpETrEs are esterified to complex lipids (e.g. phospholipids) suggesting that esterification may play a major role in regulating free, bioactive EpETrE levels. This hypothesis was tested by quantifying the metabolism of intraperitoneally injected free d11-11(12)-Epoxyeicosatrienoic acid (d11-11(12)-EpETrE) in male and female rats. Plasma and tissues (liver, adipose and brain) were obtained 3 to 4 min later and assayed for d11-11(12)-EpETrE and its sEH metabolite, d11-11,12-dihydroxyeicosatrienoic acid (d11-11,12-diHETrE) in both the free and esterified lipid fractions. In both males and females, the majority of injected tracer was recovered in liver followed by plasma and adipose. No tracer was detected in the brain, indicating that brain levels are maintained by endogenous synthesis from precursor fatty acids. In plasma, liver, and adipose, the majority (>54 %) of d11-11(12)-EpETrE was found esterified to phospholipids or neutral lipids (triglycerides and cholesteryl esters). sEH-derived d11-11,12-diHETrE was not detected in plasma or tissues, suggesting negligible conversion within the 3-4 min period post tracer injection. This study shows that esterification is the main pathway regulating free 11(12)-EpETrE levels in vivo.

The reliance on wasteful stoichiometric reagents to accomplish dehydration reactions such as esterification, amidation, and alcohol substitution is a longstanding challenge in synthetic chemistry. To address this problem, an electrochemical approach has been developed as a new conceptual platform for dehydration reactions. As a proof-of-concept demonstration, an electrochemical esterification protocol has been described that proceeds at room temperature, without acid or base additives, and without consuming stoichiometric reagents. This approach therefore overcomes key complications of esterification chemistry, and we envision that it will similarly enable improvements to a range of important, related transformations. 1 Introduction 2 An Electrochemical Design for Catalytic Dehydration 3 Electrochemical Esterification 4 Conclusions [ABSTRACT FROM AUTHOR]

Carbohydrates are synthetically challenging molecules with vital biological roles in all living systems. To better understand the biological functions of this fundamentally important class of molecules, novel methodologies are needed, including site-selective functionalization and glycosylation reactions. This account describes our efforts toward the development of novel methodologies for site-selective functionalization of carbohydrates and stereoselective glycosylation through various acylation reactions. [ABSTRACT FROM AUTHOR]

Hyperpolarized13 C magnetic resonance spectroscopy can provide unique insights into metabolic activity in vivo. Despite the advantages of this technology, certain metabolic pathways such as the tricarboxylic acid (TCA) cycle are more challenging to examine due to the limitations associated with currently available hyperpolarized13 C probes. In this report, we systematically employ computational analyses, synthetic techniques, and in vitro studies to facilitate the design of new chemical probes for the TCA cycle. This platform allows for the rapid identification of probe scaffolds that are amenable to hyperpolarized13 C experimentation. Using these results, we have developed two13 C-labeled chemical probes, [1,4-13 C2 ]-dipropyl succinate and [1,4-13 C2 ]-diallyl succinate, which are employed in hyperpolarized13 C metabolic studies. [ABSTRACT FROM AUTHOR]

ABSTRACT Imidazole is one of the most important heterocyclic rings. This nucleus can be found in a plethora of substances in different knowledge areas such as medicinal, agrochemical, polymer, and dyestuff. N‐alkylation reactions involving N − 1 atom is a remarkable tool to synthesize many imidazole derivatives which can be attached to a great variety of functional groups. In this work, we synthesized 10 new intermediates 4‐chlorobutyl 1‐aryl‐1H‐pyrazole‐4‐carboxylates 3(a–j) from 1‐aryl‐1H‐pyrazole‐4‐carbonyl chlorides, obtained from 1‐aryl‐1H‐pyrazole‐4‐carboxylic acids 4(a–j), and 4‐chlorobutan‐1‐ol 1, generated by THF ring‐opening promoted by hydrochloric acid. Compounds 3(a–j) promoted N‐alkylation of 4(5)‐nitro‐1H‐imidazole to afford the targets 4‐(4‐nitro‐1H‐imidazol‐1‐yl)butyl 1‐aryl‐1H‐pyrazole‐4‐carboxylates 2(a–j) in 18%–85% yields. [ABSTRACT FROM AUTHOR]

Bioaromas can be produced by lipases either through their hydrolytic or (trans)esterifying activities. Therefore, this work reports the development of a lipase-catalyzed biotransformed licuri oil, forming volatile ethyl esters with odor notes resembling tropical fruits. Ethyl octanoate formation was promoted when 7.0 % (m/v) Lipozyme 435® was used to convert a grain alcohol:licuri oil mixture (51:49, v/v) at 58ºC and 70 rpm for 6 hours. The biotransformed oil has shown antimicrobial activity against Staphylococcus hominis , S. epidermidis, and Corynebacterium xerosis , bacteria associated with bad skin odor. Finally, this biotransformed oil was used without further treatments (e.g., recovery or purification procedures) to prepare two cosmetic formulations (in a dosage of 1.5 %), aiming for both fragrant and deodorant activity. • Odor-active ethyl esters were formed in lipase-biotransformed licuri oil. • 8.22 g/L ethyl octanoate was formed with 7 % lipase, 51:49 alcohol:oil ratio at 58°C. • Antibacterial activity of biotransformed oil could prevent bad skin odor. • Cosmetic formulations were prepared with 1.5 % biotransformed licuri oil. • No purification procedures were needed to use a natural fragrant mixture. [ABSTRACT FROM AUTHOR]

Alternating‐rich copolymer of vinylboronic acid pinacol ester (VBpin) and maleic anhydride (MAH) was found to catalyze direct dehydrative esterification of carboxylic acid and alcohol. The key to the catalytic function is the activation of the MAH unit by the neighboring Lewis acidic boron directly connected to the backbone through the formation of five‐membered ring. The effects of the side‐chain cooperation were clarified through comparisons with the polymers having similar structures and a conventional titanium catalyst as well as the analyses of reactions with carboxylic acid or alcohol. The catalytic activity was enhanced as the molecular weight was higher, which is owing to the structural feature that boron is directly attached to the backbone. The cooperative catalysis is of interest because of its conceptual similarity with enzyme. [ABSTRACT FROM AUTHOR]

Catalytic esterification in water has been achieved with the aid of a commercially available polymer-supported lipase, Novozym-435. Remarkably, this well-known biocatalyst demonstrates significant activity towards esterification using just water as the reaction medium. This methodology features representative esterifications of complex acids and alcohols, in the presence of unprotected amines. The work disclosed leading to esters typically requires only two equivalents of alcohol, although conversion for water-soluble alcohols appears to require increased loadings. Recycling of both the aqueous medium and catalyst are documented, highlighting the potential of this new technology, especially using directed evolution on the enzyme involved. Pharmaceutically relevant compounds are efficiently esterified (e.g., Ibuprofen, Tolmetin, and Ticagrelor) and multi-step, one-pot chemoenzymatic sequences can be performed to demonstrate the robustness of this catalytic aqueous system. [ABSTRACT FROM AUTHOR]

The inhibition of the hLDHA (human lactate dehydrogenase A) enzyme has been demonstrated to be of great importance in the treatment of cancer and other diseases, such as primary hyperoxalurias. In that regard, we have designed, using virtual docking screening, a novel family of ethyl pyrimidine-quinolinecarboxylate derivatives (13–18)(a–d) as enhanced hLDHA inhibitors. These inhibitors were synthesised through a convergent pathway by coupling the key ethyl 2-aminophenylquinoline-4-carboxylate scaffolds (7–12), which were prepared by Pfitzinger synthesis followed by a further esterification, to the different 4-aryl-2-chloropyrimidines (VIII(a–d)) under microwave irradiation at 150–170 °C in a green solvent. The values obtained from the hLDHA inhibition were in line with the preliminary of the preliminary docking results, the most potent ones being those with U-shaped disposition. Thirteen of them showed IC50 values lower than 5 μM, and for four of them (16a, 18b, 18c and 18d), IC50 ≈ 1 μM. Additionally, all compounds with IC50 < 10 μM were also tested against the hLDHB isoenzyme, resulting in three of them (15c, 15d and 16d) being selective to the A isoform, with their hLDHB IC50 > 100 μM, and the other thirteen behaving as double inhibitors. [ABSTRACT FROM AUTHOR]

Background Accurate determination of active pharmaceutical ingredients and impurities is essential for ensuring the safety and effectiveness of medications. This study focuses on the validation of a high-performance liquid chromatography (HPLC) method for quantifying atorvastatin and its impurities, addressing a critical aspect of pharmaceutical analysis. Objective The primary objective is to conduct a comprehensive validation study for the HPLC method, covering specificity assessment, response function establishment, and a detailed analysis of precision, trueness, and tolerance intervals. The emphasis is on demonstrating the method's precision, accuracy, and stability-indicating capabilities across various concentrations and compounds. Methods The HPLC method is validated through rigorous assessments, including specificity, response function establishment, and analyses of precision, trueness, and tolerance intervals. Induced degradation experiments are conducted to explore atorvastatin's behavior under extreme conditions. Insights into the compound's synthesis and degradation pathways are provided through a proposed mechanism for intramolecular esterification. Results The results affirm the precision, accuracy, and stability-indicating capabilities of the validated HPLC method. The method effectively differentiates between atorvastatin and its impurities, showcasing its suitability for pharmaceutical quality control. Conclusions The validated HPLC method emerges as a robust and reliable tool for atorvastatin analysis, contributing significantly to pharmaceutical research and quality control. Its application ensures the safety and efficacy of medications, reinforcing its role in pharmaceutical analysis. Highlights This study not only validates a crucial HPLC method for atorvastatin analysis but also provides insights into the compound's behavior under extreme conditions and its synthesis and degradation pathways. The validated method serves as a cornerstone in pharmaceutical research and quality control, ensuring medication safety and efficacy. [ABSTRACT FROM AUTHOR]

Petroleum-based food packaging causes environmental problems such as waste accumulation and microplastic generation. In this work, biobased films from stable polyelectrolyte complex suspensions (PECs) of xylan and chitosan (70 Xyl/30 Ch wt% mass ratio), at different concentrations of citric acid (CA) (0, 2.5, 5, 7.5 wt%), were prepared and characterized. Films were treated at two temperatures (135 °C, 155 °C) and times (30 min, 60 min) to promote covalent crosslinking. Esterification and amidation reactions were confirmed by Fourier Transform Infrared Spectroscopy and Confocal Raman Microscopy. Water resistance and dry and wet stress–strain results were markedly increased by thermal treatment, mainly at 155 °C. The presence of 5 wt% CA tended to increase dry and wet stress–strain values further, up to 88 MPa—10% (155 °C for 60 min), and 5.6 MPa—40% (155 °C for 30 min), respectively. The UV-blocking performance of the films was improved by all treatments, as was thermal stability (up to Tonset: 230 °C). Contact angle values were between 73 and 84°, indicating partly wettable surfaces. Thus, thermal treatment at low CA concentrations represents a good alternative for improving the performance of Xyl/Ch films. [ABSTRACT FROM AUTHOR]

Polyglyceryl polyricinoleate (PGPR) is an emulsifier produced by esterification of polyricinoleic acid and polyglycerol. Polyricinoleic acid is derived from ricinoleic acid, which is expensive compared to other fatty acids. Therefore, analogues of polyricinoleic acid should be made from less expensive fatty acids, such as oleic acid. Therefore, oleic acid was converted to polyhydroxy estolide (PE) by a reaction with hydrogen peroxide and acetic acid. The PE was used as a substitute for polyricinoleic acid to produce PGPR analogues by direct esterification with polyglycerol and various fatty acids. The direct reaction between polyglycerol and PE produced a polyglyceryl estolide (PGE) with high viscosity and hydroxyl value, which limited its suitability as an emulsifier for the isopropyl myristate (IPM) and water system. Conversely, PGE prepared from lauric acid, polyglycerol and PE showed lower viscosity and hydroxyl value, resulting in a broad region of emulsion stability on a phase diagram when evaluated as a water-in-oil emulsifier for the IPM/water system. Similarly, other PGE made with oleic acid also displayed good emulsion stability for systems with higher IPM concentrations. In contrast, PGE prepared with stearic acid was a semi-solid at room temperature. Most of the prepared PGEs showed promising potential as emulsifiers for water-in-oil emulsions. [ABSTRACT FROM AUTHOR]

Biodiesel, a promising alternative to traditional petroleum fuels, is a green energy solution. Photocatalysis is a facile, novel, economic, and efficient approach to biodiesel synthesis. Metal sulfides have been used extensively for various photocatalytic applications. The present study demonstrates, for the first time, the photocatalytic production of biodiesel using a novel metal sulfide‐based heterogeneous photocatalyst under visible light irradiation. A nano zero‐valent silver doped hydroxyapatite (Ag/HAp) was synthesized using a green bio‐reductant technique and decorated with tin sulfide nanoparticles (SnS2/Ag/HAp or SAH) for photocatalytic biodiesel synthesis. The hydroxyapatite (HAp) was extracted from waste fish scales to minimize the use of chemicals and to utilize waste for useful applications. The prepared SAH photocatalyst was characterized through X‐ray diffraction, UV‐visible diffuse reflectance spectroscopy, photoluminescence spectroscopy, Fourier transform infrared analysis, energy dispersive X‐ray analysis, scanning electron microscopy, high‐resolution transmission electron microscopy and X‐ray photoelectron spectroscopy analysis. The effect of reaction parameters was optimized, and under optimum conditions of 1 wt% photocatalyst loading, and 8:1 methanol‐to‐oleic‐acid ratio, for 60 min, a high yield of 98.0 ± 0.61% could be achieved using a SAH photocatalyst. Scavenger tests indicated the simultaneous generation of photoinduced electrons and holes necessary for photocatalytic biodiesel synthesis. A mechanism for the photocatalytic esterification reaction of oleic acid is proposed. The synthesized SnS2‐based photocatalyst could be easily recoverable and reusable for five consecutive runs, which can replace traditional industrial heterogeneous catalysts in the near future. [ABSTRACT FROM AUTHOR]

Zeolite imidazolate frameworks (ZIFs) were composited with NaY zeolite using two different approaches to the ship‐in‐bottle method. The two synthesized nanocatalysts showed that the ZIF‐8 composite with NaY zeolite could stabilize their structure as catalysts in an acidic environment. The NaY@ZIF‐8 nanocomposites that were prepared were investigated using Fourier transform infrared (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), elemental mapping (MAP), thermogravimetric (TGA), temperature‐programmed desorption of ammonia (NH3‐TPD), and inductively coupled plasma analyses. The synthesized composites were used as catalysts for the esterification reaction of acetic acid with four different alcohols and the transesterification reaction of animal fats, vegetable oils, and waste oils. The results show that the efficiency of the esterification reactions for the two catalytic composites was 98.5% and 94.3%, respectively, and 78.1% for the transesterification reaction. [ABSTRACT FROM AUTHOR]

Two new compounds, cladospolides I (1) and J (2), together with two new naturally occurring ones, methyl 11-hydroxy-4-oxododecanoate (3) and 11-hydroxy-4-oxododecanoic acid (4), were isolated from the culture extract of the cold-seep sediment-derived fungus Cladosporium cladosporioides 8-1. Their structures and configurations were established by analysis of 1D/2D NMR, MS, ECD, and specific optical rotation data. Compound 3 was possibly formed by methyl esterification of 4 during the purification process due to the utilization of methanol. All compounds were evaluated for inhibition of four marine phytoplankton species and five marine-derived bacteria. [ABSTRACT FROM AUTHOR]

Bio-oil contains many oxygenated compounds, as well as high acid and water content, which can reduce the stability of its components and have poor overall physicochemical properties. In this study, the quality of bio-oil produced from the pyrolysis of oil palm fronds was enhanced through a hydrodeoxygenation (HDO) reaction that was preceded by esterification as a pre-treatment. The catalyst used in the HDO reaction is mixed metal oxide (Fe2O3-CoO) anchored within zeolite mordenite (Fe2O3-CoO/Mor). The catalysts were characterized using XRD, SEM-EDX, and BET methods. The presence of metal oxides on the surface of mordenite increases the activity of the catalyst in producing liquid products while reducing the formation of coke. Upgrading of bio-oil has improved the physicochemical properties of bio-oil compared to the one-stage upgrading process. The analysis of product showed that the C and H content increased from 11.5 to 23.5 wt% and from 9.76 to 11.2 wt%, respectively. On the other hand, the O content decreased from 78.7 to 65.2 wt% with a degree of deoxygenation of 59.8%. Moreover, higher heating value (HHV) of the bio-oil increased by 38% from 11.6 to 16.0 MJ/kg. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study aimed to address the significant challenges associated with agricultural and cocoa waste disposal within the context of global food waste concerns. The magnitude of global food waste is staggering, estimated at 1.6 Gt of primary product equivalents, with 1.3 Gt attributed specifically to the edible parts of food. Focusing on cocoa waste, which constitutes around 80% of total cocoa production, management poses a considerable environmental challenge, with over 60% of this waste either burnt or left to rot in plantations. METHOD: Ultrasound‐assisted extraction of pectin from cocoa pulp mucilage (CPM), cocoa pod husk (CPH), and cocoa bean shell (CBS) was achieved with a central composite design (CCD) using response surface methodology (RSM). RESULTS: Ultrasound‐assisted extraction takes into consideration independent factors such as temperature, sonication time, pH, solid–liquid ratio, and ultrasonic power intensity. This study achieved the highest yield, anhydrouronic acid content, and degree of esterification under optimum conditions – sonication time of 20 min, pH of 2.5, solid‐solvent ratio of 1:40 g mL−1, and ultrasonic power intensity of 64 W cm−2. The composition and characterization of pectin showed that its anhydrouronic acid content was 68.59 ± 0.2% when extracted from CPH, 50.7 ± 0.5% when extracted from CBS, and 43.97 ± 0.17% when extracted from CPM with citric acid. CONCLUSION: This study underscored the potential to reduce the environmental impact of cocoa waste, offering improved pectin extraction and sustainable methods for handling agricultural by‐products. It is relevant for individuals interested in waste reduction and resource efficiency within the broader agricultural industry, showcasing the potential for practical and sustainable solutions in cocoa waste management. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A facile esterification of α,β-unsaturated aldehydes with alcohols has been developed for the synthesis of esters by using bulky N-heterocyclic (NHC) carbene as a metal-free and eco-friendly organocatalyst. This new protocol has been proved to be effective with a wide substrate scope, giving selective esters in yields greater than 84% under mild conditions. Moreover, proposed synthetic strategy enables modification of various types of silsesquioxanes (SQ) which cannot or are technically difficult to be carried out with known protocols. For the first time, a one-pot sequential esterification/hydrosilylation has been successfully carried out. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: An asymmetric isomerization/intramolecular coupling reaction of allylic alcohols to synthesize chiral dihydrocoumarins was successfully accomplished through ruthenium catalysis. This method demonstrates a wide substrate applicability, excellent tolerance for various functional groups, and good enantioselectivities (up to 90% ee). It provides a convenient pathway to produce a diverse range of structurally distinct chiral dihydrocoumarins in good efficiency. [ABSTRACT FROM AUTHOR]

Background: The yeast Starmerella bombicola is renowned for its highly efficient sophorolipid production, reaching titers and productivities of (over) 200 g/L and 2 g/(L h), respectively. This inherent efficiency has led to the commercialization of sophorolipids. While the sophorolipid biosynthetic pathway has been elucidated a few years ago, in this study, it is revisited and true key intermediates are revealed. Results: Recently, Starmerella bombicola strains developed and evaluated in the past were reevaluated unveiling unexpected findings. The AT enzyme encoded in the sophorolipid biosynthetic gene cluster is the only described enzyme known to acetylate sophorolipids, while the SBLE enzyme encoded by the SBLE gene is described to catalyze the conversion of (acetylated) acidic sophorolipids into lactonic sophorolipids. A double knockout of both genes was described to result in the generation of bolaform sophorolipids. However, new experiments performed with respective S. bombicola strains Δsble, Δat Δsble, and ∆at revealed inconsistencies with the current understanding of the SL pathway. It was observed that the ∆sble strain produces mainly bolaform sophorolipids with higher acetylation degrees instead of acidic sophorolipids. Furthermore, the ∆at strain produces predominantly bolaform sophorolipids and lactonic sophorolipids with lower acetylation degrees, while the ∆at ∆sble strain predominantly produces bolaform sophorolipids with lower acetylation degrees. These results indicate that the AT enzyme is not the only enzyme responsible for acetylation of sophorolipids, while the SBLE enzyme performs an intramolecular transesterification reaction on bolaform glycolipids instead of an esterification reaction on acidic sophorolipids. These findings, together with recent in vitro data, led us to revise the sophorolipid biosynthetic pathway. Conclusions: Bolaform sophorolipids instead of acidic sophorolipids are the key intermediates in the biosynthetic pathway towards lactonic sophorolipids. Bolaform sophorolipids are found in very small amounts in extracellular S. bombicola wild type broths as they are very efficiently converted into lactonic sophorolipids, while acidic sophorolipids build up as they cannot be converted. Furthermore, acetylation of sophorolipids is not exclusively performed by the AT enzyme encoded in the sophorolipid biosynthetic gene cluster and acetylation of bolaform sophorolipids promotes their transesterification. These findings led to the revision of the industrially relevant sophorolipid biosynthetic pathway. [ABSTRACT FROM AUTHOR]

The multifunctional derivatization of alcohols has been achieved by the bipyridinium‐based conjugated small molecule photocatalysts with redox center and Lewis acid site. Besides exhibiting high activity in the selective generation of aldehydes/ketones, acids from alcohols through solvent modulation, this system renders the first selective synthesis of esters via an attractive cross‐coupling pattern, whose reaction route is significantly different from the traditional condensation of alcohols and acids or esterification from hemiacetals. Following the oxidization of alcohol to aldehyde via bipyridinium‐mediated electron and energy transfer, the Lewis acid site of bipyridinium then activates the aldehyde and methanol to obtain the acetal, which further reacts with methanol to generate ester. This method not only demonstrates a clear advantage of bipyridinium in diverse catalytic activities, but also paves the way for designing efficient multifunctional small molecule photocatalysts. This metal‐ and additive‐free photocatalytic esterification reaction marks a significant advancement towards a more environmentally friendly, cost‐effective and green sustainable approach, attributed to the utilization of renewable substrate alcohol and the abundant, low‐cost air as the oxidant. The mildness of this esterification reaction condition provides a more suitable alternative for large‐scale industrial production of esters. [ABSTRACT FROM AUTHOR]

Co3O4 was prepared as a precursor for Co catalysts for hydrodeoxygenation of n-octanoic acid, with four precipitants applied to modulate the surface acidity distribution. It was observed that medium acidity facilitated esterification, medium–strong acidity promoted partial hydrogenation to alcohols, and strong acidity produced alkanes with one carbon loss. [ABSTRACT FROM AUTHOR]

A catalytic asymmetric vinylogous aldol reaction between β,γ-unsaturated amides and isatins has been developed. In the presence of 10 mol% of tertiary amine-thiourea C7, the vinylogous reaction has been achieved in up to 98% yield and up to 99% ee (26 examples). This methodology provides an efficient approach to construct chiral multifunctional 3-hydroxy-2-oxindoles. Moreover, the transformations of the chiral products, including the esterification of amides, the hydrogenation of the C–C double bond and further conversion to spirolactones, have been investigated. [ABSTRACT FROM AUTHOR]

This study presents a short communication on exploring, for the first time, a simple approach for the selective and highly effective synthesis of tricaproin by synergistically combining silicon tripolyphosphate and phosphoric acid in the catalytic esterification of glycerol with caproic acid. Results reveal that within the initial hour of the synthesis, the conversion in the presence of the proposed mixture achieved an efficiency of 62.99 %, whereas this figure for individual catalysts only modestly stopped at 27.50 and 11.74 %, respectively. Furthermore, the inherent shortcomings in the tricaprion synthesis, such as catalyst deactivation, resinification of the reaction solution, and generation of numerous by-products, were successfully addressed. The structure of the resultant tricaproin and the possible absence of undesired by-products were confirmed by NMR, mass spectrometry, FT-IR, and TLC. The optimal conditions for the synthesis were also investigated. The study not only contributes a practical and selective synthetic approach for tricaproin but also paves the way for exploring novel avenues to enhance the efficiency of the catalytic esterification. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. 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. [Display omitted] [ABSTRACT FROM AUTHOR]

A stereoselective synthesis of the C1–C13 segment of poecillastrin C has been achieved. The C1–C4 moiety was derived from diallyl l -tartrate, and the amide group at the C3 position was constructed by means of a traceless Staudinger reaction. The C1–C13 segment was submitted to model studies, including esterification with a bulky alcohol at the C1 position and Stille coupling with vinyl iodide at the C13 position. The reactivity of the C1 position was affected by the neighboring C2-protective group. When the C2 hydroxy group was protected as a TBS ether, the C1 carboxylic acid did not undergo esterification with a bulky secondary alcohol, whereas the p -methoxybenzylidene N , O -acetal afforded a 2,4-dimethyl-3-pentyl ester. Stille coupling of the C1–C13 segment with 1-iodohept-1-ene gave the southern part of the poecillastrin C macrolactam attached to simplified eastern and western parts. [ABSTRACT FROM AUTHOR]

Poly(ester amide)s (PEAs) attract much attention as a new kind of biodegradable polymers. However, the synthesis of PEAs with sequence-regulated chain structures is still complicated due to the multistep polymerization, high monomer purity, as well as the usage of organic solvents, which greatly inhibits its development and applications. Herein, a one-pot strategy without solvent was developed to synthesize the alternating PEA from α,ω-amino alcohol and dicarboxylic acid by sequential polycondensation, where water was used as the controlling agent for amidation and esterification. Specifically, the amidation and esterification were controlled to proceed in turn by adding or removing water, realizing the one-pot preparation of alternating PEAs. The resultant PEA is characterized by 1H- and 13C-NMR, and its chain structure is confirmed to be highly quasi-alternating similar to alternating PEAs prepared by classical methods The evaluations from DSC and DMA demonstrate that the properties of quasi-alternating PEA (Tm=102 °C, ΔHm=30 J·g−1) are far superior to those of random PEA (Tm=72 °C, ΔHm<1 J·g−1). [ABSTRACT FROM AUTHOR]

Geraniol and citronellol are monoterpenoid alcohols with diverse pharmacological activities. This research focuses on synthesized of geranyl laurate and citronellyl laurate using silica gel as an esterification catalyst. The FTIR peak spectra of silica gel showed that Si-OH, Si-O-Si group were observed. XRD showed that the silica gel is an amorphous phase. The reaction was conducted under reflux using a Dean-Stark trap. The reaction was monitored by TLC and then the product was purified using column chromatography. This work reported that silica gel can be utilized as a catalyst for preparing geranyl laurate and citronellyl laurate which proven by the spectra of FTIR, ¹H-NMR, and 13CNMR of the geranyl laurate and citronellyl laurate formed. The IR spectra of geranyl laurate and citronellyl laurate showed the presence of a carbonyl group (C=O) at 1744-1745 cm-1 and C-O from ester at 1170-1176 cm-1. The peak number and its chemical shift on ¹H-NMR and 13C-NMR spectra further verified the structure of geranyl laurate and citronellyl laurate. In conclusion, silica gel can be utilised as a catalyst for preparing geranyl laurat and citronellyl laurate. Therefore, a silica gel-based catalyst is promising to be developed for esterification applications. [ABSTRACT FROM AUTHOR]

Microstructured reactors offer fast chemical engineering transfer and precise microfluidic control, enabling the determination of reactions' kinetic parameters. This review examines recent advancements in measuring microreaction kinetics. It explores kinetic modeling, reaction mechanisms, and intrinsic kinetic equations pertaining to two types of microreaction: esterification and transesterification reactions involving acids, bases, or biocatalysts. The utilization of a micro packed-bed reactor successfully achieves a harmonious combination of the micro-dispersion state and the reaction kinetic characteristics. Additionally, this review presents micro-process simulation software and explores the advanced integration of microreactors with spectroscopic analyses for reaction monitoring and data acquisition. Furthermore, it elaborates on the control principles of the micro platform. The superiority of online measurement, automation, and the digitalization of the microreaction process for kinetic measurements is highlighted, showcasing the vast prospects of artificial intelligence applications. [ABSTRACT FROM AUTHOR]

A series of activated carbons (YMBC) obtained from yerba mate twig residue (YMT) were prepared by chemical (H3PO4) and thermal activation. Five materials were synthesized, varying the carbonization temperature (400–600 °C under N2 atmosphere) and H3PO4:YMT ratio (60–80 wt%). They were physicochemically and texturally characterized by SEM-EDX, BET, FT-IR, and 31P MAS-NMR. Potentiometric titration with the n-butylamine technique was used to evaluate their acidic properties. The materials exhibited a high specific surface area (572 m2 g−1 < SBET < 1031 m2 g−1) and mesoporosity (67% < Smeso/SBET < 93%). The results showed that the acid strength and the number of acid sites increased with the H3PO4:YMT ratio and decreased with the calcination temperature increment. The FT-IR and 31P characterization revealed the presence of Hn+2PnO3n+1 species firmly (via P-O-C linkages) and loosely attached (by electrostatic interaction). The latter were successfully removed by refluxing the material in water or n-propanol. The optimal reaction conditions were applied to the synthesis of other levulinic acid esters using YMBC-500-70NP as a catalyst. Furthermore, the effective separation of the product combined with the use of a recyclable catalyst resulted in a clean and environmentally friendly strategy for the synthesis of alkyl levulinates, bioproducts of relevance to the biorefinery industry, which can be applied as fragrances, flavoring agents, as well as fuel additives. [ABSTRACT FROM AUTHOR]

In this paper, porous Brønsted acidic ionic liquid modified catalyst ILs-AB-8 was successfully synthesized by using 3 steps of Friedel–Crafts hyper-crosslinking synchronous chloromethylation, imidazlole grafting and sulfonic functionalization using macroporous polystyrene AB-8 resin as a raw material. The porous ionic liquid immobilized catalyst ILs-AB-8 exhibits a hierarchical pore structure by the coexistence of abundant macropore, mesopore, and micropore. The catalyst IL2-AB-8 with dual Brønsted acid sites(-SO3H acid site and p-methylbenzenesulfonic acid site), large surface area (327.19 m2/g), high ionic liquid loading amount (IEC 2.03 mmol/g) displayed excellent catalytic activity, with methyl oleate yield up to 95.65% at 338 K in 100 min. The enhanced catalytic performance of IL2-AB-8 can be ascribed to the novel Friedel–Crafts hyper-crosslinking process in conjunction with chloromethylation, coupled with th in situ generated activating chloromethyl group incorporated onto the surface of the AB-8 carrier. The hyper-crosslinking approach also effectively transforms the macroporous AB-8 carrier into a multi-level pore structure. This work highlights that IL2-AB-8 with high specific surface area, ionic liquid loading content, and strong covalent connection with carrier was coordinated to provide an efficient metal-free heterogeneous catalyst for biodiesel production. [ABSTRACT FROM AUTHOR]

Lignin is a complex of organic polymers that are abundantly present in the plant cell wall which considered of emerging substrates for various kinds of value-added industrial products. Lignin has potential use for the production of green nanomaterials, which exhibit improved or different properties corresponding to their parent polymers. Nano lignin has received significant interest in recent years due to its applications in numerous fields. Lignin, the abundant and limited functionality has challenges for its potential uses. Creating advanced functional lignin-derived material like lignin nanoparticles (LNPs) which significantly alter the biological process has great potential for its applications. In the fields of biotechnology, several lignin extraction processes from various raw materials and diverse synthesis techniques, including acid precipitation, dialysis, solvent shifting/solvent exchange, antisolvent precipitation, homogenization, water-in-oil (W/O) microemulsion, ultra-sonication, interfacial crosslinking, polymerization, and biological pathway can be employed to produce LNPs. The scientific community has recently become more concerned about the transformation of lignin to lignin nanomaterials, including nanoparticles, nanocapsules, nanofibers, nanotubes, and nanofilms. Recent research has shown that lignin nanoparticles (LNPs) are: non-toxic at adequate amounts (both in vitro and in vivo), are economical, and can be biodegradable by bacteria and fungi. In promising studies, LNPs have been investigated for their potential applications in gene delivery systems, drug carriers, biocatalysts, tissue engineering, heavy metal absorbers, encapsulation of molecules, supercapacitors, hybrid nanocomposites, and other applications. This current review addresses the recent advances in the synthesis of LNPs, their advanced application in different areas, future perspectives, and challenges associated with lignin-based nanomaterials. [ABSTRACT FROM AUTHOR]

In this study, we successfully prepare solid acid catalysts using plastic as the starting material for the production of methyl 2-hydroxyisobutyrate (HBM) through the esterification of 2-hydroxyisobutyric acid (HBA) and methanol. Polyethylene (PE) and polyvinyl chloride (PVC) are sulfonated at different temperatures (X) to obtain sulfonated polymer catalysts (SPE_X and SPVC_X). Various characterizations clearly confirm the introduction of sulfonic acid groups (–SO3H groups), which serve as active sites in this reaction, on the PE and PVC surfaces via sulfonation. For the SPVC_X catalysts, an excessively high sulfonation temperature facilitate the loss of chlorine groups (–Cl groups) via dehydrochlorination, resulting in a decrease in catalytic activity. In particular, the –Cl groups improve the acidic properties and accessibility of reactants to the –SO3H groups of the SPVC_X catalysts, leading to a high HBM yield. Therefore, the SPVC_120 catalyst show the highest HBM yield (ca. 75%) because of the abundant –SO3H and –Cl groups on the catalyst surface. Furthermore, the catalytic performance of the SPVC_120 catalyst surpassed those of commercial ion-exchange resins such as Amberlyst-15 and Nafion NR50, which are representative solid acid catalysts for esterification. [ABSTRACT FROM AUTHOR]

In the present work, the sulphonated nanocomposite of titanium and tungsten oxide (TiO2/WO3/SO42−) is used as a heterogeneous catalyst for the esterification of levulinic acid (LA) and butanol (BOH) to produce butyl levulinate (BL). The characterisation results showed the presence of a nanocrystalline structure and sulphonated active sites. A full factorial design space was generated to study the effect of mole ratio, temperature, and catalyst loading for the conversion of LA. The experimental data was analysed by the response surface methodology and fitted to a full quadratic regression model. The best optimization conditions are 8:1 mol ratio (BOH:LA), 120 °C, and 1.5 wt% catalyst loading resulting in conversion of 93.1% subjected to a mole ratio constraint of 8:1 (BOH:LA). The data at the optimum conditions was used to determine the kinetic parameters by fitting it to a pseudo-homogeneous model and the activation energy was computed to be 27.5 ± 1.1 kJ mol−1. [ABSTRACT FROM AUTHOR]

The fines fraction in mechanical pulp, produced during wood processing can impact the mechanical properties of the resulting paper positively or negatively, making them potential additives for paper strength improvement at the right loading level. To enhance fines' effectiveness as paper strength additives that have heterogeneous surface chemistries, this work employed a regioselective surface esterification method conducted under mild conditions in acetone, with the addition of succinic anhydride and imidazole. This approach converted surface hydroxyl groups of fines into carboxylic acid groups, resulting in a final content of near 0.5 mmol g−1. This modification increased fines' hydrophilicity, as evidenced by enhanced moisture absorption capacity in dynamic vapor sorption analysis. These fines with additional functionality strengthened intermolecular bonding, leading to over 150% enhancement in tensile strength and Young's modulus when cast into thin films. Fines were substituted at 10–20 wt.% concentration to the fiber fraction of softwood thermomechanical pulp (TMP) and bleached chemi-thermomechanical pulp (BCTMP) forming handsheets. It was observed that fines modified with succinic anhydride and imidazole were more effective in enhancing paper strength, including tensile (up to 30%), burst (up to 39%) and tear (up to 4%) indices. This improvement was likely due to enhanced intermolecular bonding between modified fines and the fiber surfaces. By modifying mechanical pulp fines with succinic anhydride and imidazole, we have converted a potential heterogeneous waste product from the industry into a valuable by-product to enhance paper performance. [ABSTRACT FROM AUTHOR]

This study explores the esterification of levulinic acid with 1-pentanol, employing Dowex® 50WX8 as a catalyst under microwave irradiation. Key parameters such as the pentanol/acid molar ratio, temperature, and catalyst loading were evaluated and utilized for kinetic modeling. The kinetic behavior of the reaction was investigated using a dual-model approach: a pseudo-homogeneous model to account for the microwave effect and catalytic contributions modeled through LHHW and Eley–Rideal mechanisms. The best model was chosen based on statistical results obtained from Markov Chain Monte Carlo (MCMC) analysis, which involved an LHHW model with the surface reaction as the limiting step, resulting in an activation energy of 50.6 kJ mol−1 for the catalytic synthesis of pentyl levulinate. The role of the alcohol in the esterification route was explained, and catalytic stability was confirmed, with the catalyst maintaining activity over multiple cycles. The absence of mass transfer limitations was proved using the Weisz–Prater criterion. A plausible reaction pathway was proposed for the levulinic acid esterification over the 50WX8 catalyst. [ABSTRACT FROM AUTHOR]

Catalytic performance of zirconyl hydrogen tellurate (ZrOHTe) and hafnium hydrogen tellurate (HfHTe) was studied for the first time. A process of butyl acetate synthesis was used as a test reaction. A number of physicochemical techniques (XRD, SEM, TGA/DSC and XPS) was applied for catalyst characterization. Using molecular electrostatic potential and net atomic charges, both the electronic structure and the chemical reactivity of ZrOHTe and HfHTe were considered. Kinetic (activation energy, pre-exponential factor) and thermodynamic (enthalpy, entropy, Gibbs free energy barrier) parameters were calculated. A plausible reaction mechanism for esterification was offered. Particles of a low crystallinity degree or small-sized crystallites were found to form ZrOHTe and HfHTe. The fragments in ZrOHTe/HfHTe are prismatic/layered in shape with an average size around 160 μm. XPS exposed that HTeO 4 - managed the surface phenomena for ZrOHTe and HfHTe. A higher butyl acetate yield using ZrOHTe than HfHTe due to higher surface acidity of the former was generated. [ABSTRACT FROM AUTHOR]

Macrocyclic conformations play a crucial role in regulating their properties. Our understanding of the determinants to control macrocyclic conformation interconversion is still in its infancy. Here we present a macrocycle, octamethyl cyclo[4](1,3-(4,6)-dimethylbenzene)[4]((4,6-benzene)(1,3-dicarboxylate) (OC-4), that can exist at 298 K as two stable atropisomers with C2v and C4v symmetry denoted as C2v-OC-4 and C4v-OC-4, respectively. Heating induces the efficient stepwise conversion of C2v- to C4v-OC-4 via a Cs-symmetric intermediate (Cs-OC-4). It differs from the typical transition state-mediated processes of simple C–C single bond rotations. Hydrolysis and further esterification with a countercation dependence promote the generation of C2v- and Cs-OC-4 from C4v-OC-4. In contrast to C2v-OC-4, C4v-OC-4 can bind linear guests to form pseudo-rotaxans, or bind C60 or C70 efficiently. The present study highlights the differences in recognition behavior that can result from conformational interconversion, as well as providing insights into the basic parameters that govern coupled molecular rotations. The three-dimensional conformation of macrocycles determine their chemical and recognition properties and the factors that influence the interconversion between macrocyclic forms are poorly understood. Here the authors describe a macrocycle existing as two stable atropisomers and the mechanism behind the thermally-induced transition between them. [ABSTRACT FROM AUTHOR]

The KSF-clay is a material that presents a high density of acidic active sites, ideal for being a heterogeneous acid catalyst with outstanding activity. For this study, KSF-clay was characterized by X-ray photoelectron spectroscopy and temperature-programmed desorption of ammonia. Additionally, studies of the adsorption of ethanol, propan-2-ol, and acetic acid molecules over KSF-clay surface to establish their thermal stability species were studied by diffuse reflectance infrared Fourier transform spectroscopy. The relationship between the properties of KSF-clay and the adsorption-interaction process with organic molecules is related to its performance as an acid catalyst. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION The preparation of malic acid starch ester (MSE) is mostly carried out using a high temperature method, but there are problems such as high energy consumption, long preparation time, and uneven heating. Microwave technology can be used to overcome these limitations. The semi‐crystalline structure of starch granules hinders the modifier's access to the matrix, thus limiting the esterification reaction. Physical techniques can act on the interior of the starch to create a number of active sites, thereby facilitating the reaction of the starch with esterification reagents. Therefore, this study investigated the effect of starch pretreatment by microwave, heat‐moisture, and ultrasonic techniques on the degree of substitution (DS), structure, and physicochemical properties of MSE synthesized by the microwave method.The DS of MSE was increased after pretreatments. The modified starch obtained by different pretreatment methods did not show new characteristic peaks, while the MSE synthesized showed new absorption peaks near 1735 cm−1. The granular structure and morphology of the modified starch obtained by microwave and heat‐moisture pretreatment were gelatinized and aggregated, while some of the starch particles of the modified starch obtained by ultrasonic pretreatment appeared pore‐sized. The relative crystallinity and gelatinization enthalpy of the MSE were reduced, but the crystallization pattern remained as A‐type.Overall, the results suggest that various pretreatment methods can enhance the DS of MSE by disrupting the structure of starch. The findings of this study provide theoretical support for improving the DS of esterified starch. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) advanced in the past decade as the new generation of green and sustainable extraction and reaction media in biorefineries and in a multitude of chemical and biotechnological processes. Particularly, enzyme catalyzed reactions benefit from the specific properties of DESs, which not only ensure good substrate solubility but also enhance enzyme stability and operational efficiency. Recent studies showed that natural deep eutectic solvents (NADESs) comprising choline chloride or betaine as hydrogen bond acceptor and a large spectrum of natural compounds, such as carbohydrates, polyols carboxylic acids, as hydrogen bond donors, can have multiple functions, acting simultaneously as extraction solvent, reaction medium, source of substrate and source as catalyst. This novel approach for the utilization of multifunctional reactive natural deep eutectic solvents (R‐NADESs) in catalytic conversions opens the way to the development of greener biocatalytic and chemo‐catalytic processes, with simpler downstream processing and minimal discarded wastes, which will speed up their durable implementation in industry. This paper reviews the innovative applications of R‐NADESs in biocatalytic reactions for the synthesis of a large diversity of high value chemicals and materials, including biosurfactants, flavors, biobased building blocks and biobased polymers, with highlight on esterification, transesterification, glycerolysis, polymerization, and redox reactions. [ABSTRACT FROM AUTHOR]

This study describes the Casson (a non-Newtonian fluid) nanofluid bioconvection flow across a spinning disc in the presence of gyrotactic microorganisms, many slips and thermal radiation. Also, the flow is considered as a reversible flow. The esterification process is taken into account. Using the proper variables, a system of extremely nonlinear PDEs is converted into a system of ODEs. To arrive to the solution of such equations, a numerical approach is used. Using the bvp4c approach, nonlinear flow equations can be numerically solved. Investigated are the effects of different numbers on the thermal field, volumetric concentration of nanoparticles and microbiological field. The key characteristics of the parameters in relation to the profiles of the velocity, temperature, concentration and microorganisms are graphically assessed with appropriate physical effects. A graphical explanation is provided for the wall shear stress, local Nusselt number, local Sherwood number and local motile density number. Rate of motile density number shows a prominent difference between reversible and irreversible flows for Brownian motion and Peclet number. The results of the theoretical simulations have dynamic applications in the fields of biotechnology and thermal engineering. [ABSTRACT FROM AUTHOR]

The emergence and spread of antibiotic resistance represent a growing threat to public health. Of particular concern is the appearance of β-lactamases, which are capable to hydrolyze and inactivate the most important class of antibiotics, the β-lactams. Effective β-lactamase inhibitors and mechanistic insights into their action are central in overcoming this type of resistance, and in this context boronate-based β-lactamase inhibitors were just recently approved to treat multidrug-resistant bacteria. Using boric acid as a simplified inhibitor model, time-resolved serial crystallography was employed to obtain mechanistic insights into binding to the active site serine of β-lactamase CTX-M-14, identifying a reaction time frame of 80–100 ms. In a next step, the subsequent 1,2-diol boric ester formation with glycerol in the active site was monitored proceeding in a time frame of 100–150 ms. Furthermore, the displacement of the crucial anion in the active site of the β-lactamase was verified as an essential part of the binding mechanism of substrates and inhibitors. In total, 22 datasets of β-lactamase intermediate complexes with high spatial resolution of 1.40–2.04 Å and high temporal resolution range of 50–10,000 ms were obtained, allowing a detailed analysis of the studied processes. Mechanistic details captured here contribute to the understanding of molecular processes and their time frames in enzymatic reactions. Moreover, we could demonstrate that time-resolved crystallography can serve as an additional tool for identifying and investigating enzymatic reactions. Boronate-based ß-lactamase inhibitors play an important role in treating multidrug-resistant bacteria infection, however, the molecular mechanism of inhibition remains unclear. Here, the authors use time-resolved serial crystallography to investigate the binding process by using boric acid as a model against β-lactamase CTX-M-14, revealing the binding to the active site serine within 80–100 ms, a subsequent 1,2-diol boric ester formation with glycerol within 100–150 ms, as well as the displacement of the sulfate anion in the active site. [ABSTRACT FROM AUTHOR]

Angiogenesis is a normal physiological process that also contributes to diabetic retinopathy-related complications and facilitates tumor metastasis by promoting the hematogenic dissemination of malignant cells from solid tumors. Here, we investigated the in vitro, ex vivo, and in vivo anti-angiogenic activity of phloridzin docosahexaenoate (PZ-DHA), a novel ω-3 fatty acid ester of a flavonoid precursor. Human umbilical vein endothelial cells (HUVEC) and human dermal microvascular endothelial cells (HMVEC) treated with a sub-cytotoxic concentration of PZ-DHA to assess in vitro anti-angiogenic activity showed impaired tubule formation on a Matrigel matrix. Ex vivo angiogenesis was measured using rat thoracic aortas, which exhibited reduced vessel sprouting and tubule formation in the presence of PZ-DHA. Female BALB/c mice bearing VEGF165- and basic fibroblast growth factor-containing Matrigel plugs showed a significant reduction in blood vessel development following PZ-DHA treatment. PZ-DHA inhibited HUVEC and HMVEC proliferation, as well as the migration of HUVECs in gap closure and trans-well cell migration assays. PZ-DHA inhibited upstream and downstream components of the Akt pathway and vascular endothelial growth factor (VEGF165)-induced overexpression of small molecular Rho GTPases in HUVECs, suggesting a decrease in actin cytoskeletal-mediated stress fiber formation and migration. Taken together, these findings reveal the potential of combined food biomolecules in PZ-DHA to inhibit angiogenesis. [ABSTRACT FROM AUTHOR]

A series of fatty aeid polyethylene glycol esters were synthesized by esterification reaction of fatty acids with different carbon chain lengths and polyethylene glycol. The content of monoesters and diesters in the products was determined by measuring the acid value, hydroxyl value, and polyethylene glycol content. Its flow state was observed, and its wetting, emulsification, foam and decontamination performance were measured. The results showed that as the feed ratio of C12 acid to polyethylene glycol 400 increased, the polyethylene glycol content of the product decreased, the monoester content decreased, and the diester content increased. The freezing point of fatty acid polyethylene glycol 600 ester is higher than that of fatty acid PEG400 ester. Fatty acid carbon chains grow, wetting deteriorates, and foaming ability weakens. The em unification ability of fatty acid PEG600 ester is stronger than that of fatty acid PEG400 ester. C12 Acid PEG600 has the strongest emulsifying power of soybean oil and paraffin. The detergency of fatty acid PEG400 ester and fatty acid PEG600 ester on carbon black is equivalent, while C18 acid PEG600 ester has the strongest detergency on sebum. [ABSTRACT FROM AUTHOR]

In this research, the preparation of lipoamide through direct amidation of fatty acid and via amidation of fatty acid methyl ester (FAME) was compared. The reactivity of aromatic amines and cyclohexylamine for the synthesis of lipoamide was investigated in this research. The performance of saturated and unsaturated fatty acids was also compared. The synthesis of lipoamides via direct amidation was conducted under reflux using a Dean-Stark trap and silica gel as the catalyst. On the other hand, the amidation of FAME was carried out without catalysts and solvent. Both reactions were run simultaneously for 18 hours at the same temperature. The reaction was monitored using TLC, and then the product was purified using column chromatography and characterized using FTIR and ¹H NMR. The TLC data, FTIR, and ¹H NMR spectra confirmed that both reaction pathways produced the same lipoamide as the product. Both reaction pathways were compatible with aromatic and nonaromatic amines and saturated and unsaturated fatty acids. The reaction yield of lipoamide from direct amidation was around 70-80% and two-fold higher than lipoamide synthesis via amidation of FAME. Therefore, direct amidation of fatty acid was preferred for the synthesis of lipoamides compared to via amidation of FAME. [ABSTRACT FROM AUTHOR]

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β‐Sitosteryl oleate, renowned for its diverse beneficial bioactivities, holds significant promise as a potential ingredient in functional foods. This study reports the superior performance of β‐sitosteryl oleate facilitated by lipase UM1 (lipase from marine Streptomyces sp. W007, immobilized on XAD1180 resin) as a biocatalyst in a solvent‐free system, in comparison to commercial enzymes Novozym 435 (lipase B from Candida antarctica, immobilized on a macroporous acrylic resin), Lipozyme TL IM (lipase from Thermomyces lanuginosus, immobilized on a non‐compressible silica gel carrier), and Lipozyme RM IM (lipase from Rhizomucor miehei, immobilized on a macroporous acrylic resin). Remarkably, an over 98% yield was achieved under the optimal conditions: a substrate molar ratio of β‐sitosterol to oleic acid of 1:4, lipase loading of 150 U, and a reaction temperature of 60°C. The process exhibited substantial resilience and effectiveness, maintaining a degree of esterification above 95% even after five recycles. Following this, the synthesis was successfully scaled up by 100‐fold, with the product isolated through molecular distillation and confirmed using ultra‐performance liquid chromatography mass spectrometry (UPLC‐MS) and Fourier transform infrared spectroscopy (FT‐IR) analytical techniques. These results underscore lipase UM1 as a promising catalyst for the industrial‐scale synthesis of β‐sitosteryl oleate, fostering expanded avenues for its utilization in the functional food industry. [ABSTRACT FROM AUTHOR]

Au‐Pd alloy particles supported on TiO2 were synthesized by the sol‐immobilized method and their confirmation was achieved through transmission electron microscope (TEM) and energy dispersive spectrometer (EDS) mapping. The samples were subjected to oxidative esterification of methacrolein with methanol to methyl methacrylate (MMA). Notably, a remarkable enhancement of catalytic performance was found in the presence of Pd. Among the samples tested, the sample Au0.25Pd0.75/TiO2 exhibited the highest catalytic performance. The interaction between Au and Pd demonstrated a synergistic effect, with Pd contributing to the stability of Au nanoparticles and strengthening the production of active oxygen species, which facilitated the efficient removal of hydrogen from intermediate hemiacetal. Furthermore, a probable reaction mechanism was proposed to explain these observations. [ABSTRACT FROM AUTHOR]

Sago starch is a locally abundant starch indigenous of Indonesia. Despite its abundance, it is underutilized and restricted to food and packaging applications due to its limited functional characteristics. The value of native sago starch can be increased through modifications that improve its functionality, such as dual chemical modification. This sophisticated approach is more effective than single modification and makes the starch suitable for wider applications. Our study aimed to determine if dual chemical modification involving hydroxypropylation and succinylation would optimize the functional properties of sago starch. The sago starch was first modified by hydroxypropylation with 7 % (w/w) propylene oxide under alkaline conditions for 3 hours. This process resulted in hydroxypropylated starch with a substitution degree of 0.107. We then subjected the starch to succinylation using succinic anhydride at 1 % to 5 % of the starch weight in an alkaline solution for 2 hours. We achieved optimal functional characteristics of the dual-modified sago starch in the sample modified with 3 % (w/w) of succinic anhydride. The succinyl degree of substitution, water holding capacity, oil holding capacity, swelling power, and solubility of the dual-modified starch were 0.093, 4.16 g g􀀀1, 7.20 g g􀀀1, 34.25 g g􀀀1, and 16:55 %, respectively. We conducted pasting properties analyses, infrared spectroscopy, and morphological structure analysis to determine the changes in the characteristics of the sago starch after hydroxypropylation and succinylation. The dual chemical modification successfully enhanced the functional characteristics of sago starch, particularly, its amphiphilic ability and swelling power. These results warrant further research and development in commercial applications.