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Summary: Proteins are commonly used ingredients to impart certain non‐nutritional properties to foods. Consequently, the industry is constantly seeking to enhance proteins that provide these attributes to food products. Therefore, the aim of this research was to extract the protein from sesame seeds and evaluate the effect of chemical modification through acylation with lauroyl chloride and acetic anhydride on functional properties (solubility index, emulsifying, foaming, swelling and water‐holding and oil‐holding capacity). Chemical modification was successfully demonstrated using FTIR spectroscopy and X‐rays. It was found that acylation with lauroyl chloride or acetic anhydride altered the physicochemical and functional properties, particularly at pH 10. Both reactions exhibited substitution degrees exceeding 20%. Chemical modification via acylation resulted in significant improvements in water and oil retention capacity, emulsifying activity and foaming activity. Thermal analysis revealed significant changes in the modified samples, altering their denaturation temperature, leading to the conclusion that chemical modifications through acylation with lauroyl chloride or acetic anhydride offer benefits in certain functional properties relevant to the food industry. They also represent an opportunity to diversify the application of a by‐product obtained from sesame oil extraction. [ABSTRACT FROM AUTHOR]

This paper presents a novel and reliable approach for the determination of tilmicosin residues in poultry muscle and pork via gas chromatography–tandem mass spectrometry after precolumn derivatization. The samples were subjected to a quick, easy, cheap, effective, rugged, and safe preparation method, solid-phase extraction, hydrogenation, gel chromatography separation, acid hydrolysis, and derivatization with pyridine and acetic anhydride. For the blank spiked samples at the limit of quantification, 0.5 times the maximum residue limit (MRL), the MRL, and 2.0 times the MRL, the recoveries were from 76.91 to 87.99% with a precision of 2.04–5.47%. The limits of detection and quantification were 2.3–4.4 and 6.2–9.8 µg kg−1, respectively. The protocol was validated and real samples analyzed to demonstrate its practical application. [ABSTRACT FROM AUTHOR]

BACKGROUND: Collagen is a biomedical material with good biocompatibility, low toxicity, low immunoactivity, and high cellular affinity. However, the defects such as hydrophilicity and poor thermal stability are the key technical problems that need to be solved urgently in biomedical, tissue engineering, and other applications. OBJECTIVE: To elaborate on the preparation method, characterization, and application progress of acylated collagen. METHODS: PubMed, X-mol, and CNKI databases were used to search the literature on acylated collagen preparation methods, characterization, and application. The search time was from January 1992 to May 2023. The English search terms were “acylated collagen, modified collagen, water-soluble collagen, acetic anhydride”. Chinese search terms were “acylated collagen, modified collagen, water-soluble collagen”. After an initial screening of all articles according to inclusion and exclusion criteria, 53 articles with high relevance were retained for review. RESULTS AND CONCLUSION: (1) The preparation of acylated collagen is mainly obtained by the acylation reaction of acid anhydride, and the reaction sites are mainly ε-amino and N-terminus-amino of collagen, and the reaction environment of acylation reaction needs to be carried out in an alkaline environment. (2) Succinic anhydride is the preferred reactant of acylated collagen. Carbonic anhydride, citric anhydride, and bifunctional modifiers with acylation ability have been excavated in recent years to meet various requirements, but it is still limited to laboratory preparation; complex preparation process is difficult to industrialize, and follow-up research is needed to continuously improve. (3) The characterization methods of acylated collagen are similar to those of collagen, but there is still a lack of standards for the water-soluble characterization of acylated collagen. (4) In recent years, acylated collagen has been gradually used in the preparation of lenses, hydrogels, and dressings, as well as cosmetic raw materials. However, there is still little research on the application of acylated collagen, and there is a lack of complete in vivo experiments to verify the practicality of acylated collagen. [ABSTRACT FROM AUTHOR]

Diboradiazene compounds, derived in one step from the boron‐mediated reduction of dinitrogen (N2), were treated separately with sulfur and acetic anhydride, providing heterocyclic compounds that are BN isosteres of thiophene and 1,3‐oxazole, respectively. These simple reactions represent the final steps in two‐step routes to complex heterocycles from N2 that both circumvent the need for transition metal reagents and completely bypass the traditional intermediate ammonia. [ABSTRACT FROM AUTHOR]

BACKGROUND: Starch is the main component of quinoa seeds. However, quinoa starch has poor solubility in cold water and poor mechanical resistance and is easily aged, which limit its application. Therefore, modification of its structure to improve its functional properties is necessary. RESULTS: This research used acetic anhydride and sodium trimetaphosphate to modify the structure of starch molecules and investigated their influence on bread quality. The results showed that both esterification and crosslinking prevented the aggregation behavior of starch molecules. Moreover, they both decreased the gelatinization enthalpy change and relative crystallinity of the starch. Compared with native starch, modification significantly decreased the gelatinization temperature from 57.01 to 52.01 °C and the esterified starch exhibited the lowest enthalpy change with a 44.2% decrease. Modified starch increased the specific volume and decreased the hardness and chewiness of bread. Modification did not influence the moisture content in bread but impacted the water retention capacity, depending on the degree of modification. Low and medium degrees of modification improved the water retention capacity during storage. By contrast, a high degree of modification (10 g kg−1 crosslinking agent) decreased the water retention capacity. The dually modified quinoa starch (esterified and crosslinked) showed no influence on the textural properties of bread. CONCLUSION: This study demonstrated that both esterification and crosslinking significantly improved the functional properties of quinoa starch. Crosslinked or esterified quinoa starches have the potential to improve the textural properties of bakery products. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The mechanochemical hydrogenation of 4-nitrophenol was examined in a ball mill reactor. Hydrogen gas flows through the reactor at ambient temperature and pressure in the presence of Pd/C catalyst and acetic anhydride. Under optimized conditions, simultaneous hydrogenation and acetylation in one pot increased paracetamol selectivity by avoiding undesirable side reactions of 4-aminophenol. Side product formation was further reduced through a novel bubbler configuration allowing for the delivery of acetic anhydride vapor to the reaction vessel. Ball mill results were compared to traditional stirred tank hydrogenations in a Parr reactor and shown to have superior yield and process mass intensity. [ABSTRACT FROM AUTHOR]

The significant medicinal and pharmacological facts about chromenes (benzopyran) nucleus prompted us to focus on constructing unique chromenes with biological value. New chromene derivatives 2–15 were synthesized, and their antibacterial effectiveness was studied. The reaction of the 2-amino-4H-chromene derivative 1 with a variety of reagents such as acetic anhydride, formic acid, chloroacetyl chloride, cyclopentanone, ethyl acetoacetate, diethyl malonate, aldehydes, and isatin produced derivatives 2–13. Compound 1 was also treated with aromatic amines such as p-toluidine and/or benzene-1,4-diamine with formaldehyde, yielding derivatives 14 and 15, respectively; spectral techniques were used to confirm the predicted structures of all compounds. The antibacterial activity of the recently synthesized compounds was assessed against two types of bacteria, Bacillus subtilis and Escherichia coli. There is encouraging antibacterial activity in compounds 5 and 7. [ABSTRACT FROM AUTHOR]

The objectives of this study are to investigate the structural and physicochemical properties of a novel acetylated lotus seed starch (LSA). LSA is successfully prepared using an aqueous phase method. Fourier transform infrared spectroscopy (FTIR) proves that a carbonyl C=O vibration at 1737 cm−1 are due to the introduced acetyl groups. X‐ray diffraction (XRD) indicates that the acetylation treatment does not change the crystal structure, but reduces the relative crystallinity of starch. Scanning electron microscopy (SEM) shows that the surface of LSA with 12% of acetic anhydride (LS‐12A) becomes the roughest. Moreover, compared with lotus seed starch (LS), the particle size, transparency, swelling power, and solubility of LSA are increased to 18.01 ± 0.66 µm, 15.30% ± 0.30%, 9.59 ± 1.78 g g−1, and 6.06% ± 0.99% at 55 °C with the additional content of acetic anhydride. However, differential scanning calorimetry (DSC) shows that the melting enthalpy of LSA decreases compared with LS. This work provides some theoretical basis for the study and development of acetylated starch. [ABSTRACT FROM AUTHOR]

A novel series of 1,3,4-oxadiazole derivatives of mefenamic acid was obtained by reacting hydrazones of mefenamic acid with anhydrous acetic anhydride. The mefenamic hydrazones were obtained by reacting different substituted aldehydes with mefenamic acid hydrazide. All the compounds were characterized by spectral data and elemental analysis. Molecular docking studies of all the compounds were performed against COX-1/COX-2 enzymes. Compound 4 and compound 10 were found to have the highest potential to bind with COX-1 while compound 3, compound 6, and compound 10 were found to have the highest potential to bind with COX-2 enzyme. [ABSTRACT FROM AUTHOR]

This report expresses a sustainable methodology for the in situ synthesis of Ag nanoparticles (NPs) adorned carboxymethyl lignin (CML) functionalized Fe3O4 nanocomposite (Fe3O4@CML/Ag) and its subsequent chemical and biological applications. Structural and physicochemical features of such novel material was evaluated through a number of analytical techniques like FT-IR, FE-SEM, TEM, EDS, XRD, ICP and VSM. The nanomaterial was a competent catalyst towards the N-acylation of diverse amines using acetic anhydride at solvent-free conditions. The material was isolated by magnet and reused for 8 consecutive times. Furthermore, the material was employed in the biological evaluation of anti-oxidant properties by DPPH method as well as the anticancer studies of against HT-29 and Caco-2 colon cell lines following MTT method. The DPPH assay afforded a significant IC50 value that suggested the material to have good anticancer properties. Interestingly, % cell viability of the malignant cell lines was found to decrease dose-dependently over Fe3O4@NaLS/Ag nanocomposite. MTT assay afforded the corresponding IC50 values to be 395.4 μg/ml and 287.3 μg/ml respectively against the two cell lines. The absorbance rate was evaluated at 545 nm, which represented toxicity on normal cell line (CHO) even up to 2000 μg/mL. [ABSTRACT FROM AUTHOR]

BACKGROUND: Wheat bran is rich in dietary fiber (DF), particularly insoluble dietary fiber (IDF). Although the benefits for human health following the consumption of these DFs have been documented, the lower water retention capacity (WRC) and other properties still limit the applications of DF. Therefore, the current research investigated the impact of acetylation on the changes in the corresponding physicochemical and functional properties of DF. RESULTS: The current results indicated the acetylated group restricted the alignment of the molecular chains, which led to an increased amorphous phase in the fiber structure, followed by an enhanced thermal sensitivity and a reduced crystallinity as evidenced by X‐ray diffraction (XRD). Moreover, the acetylation of the IDFs enhanced the cholesterol absorption capacity, but the corresponding antioxidant capacity and cation exchange capacity were reduced, which might be due to the partial loss of the phenolic compounds onto the polysaccharides during the modification. Interestingly, a lower degree of substitution (DS) of the IDF achieved from water‐acetic anhydride modification led to a higher WRC and water swelling capacity (WSC). In contrast, a higher DS from acetic anhydride modification demonstrated a greatly improved in vitro hypoglycemic performance of the IDF, including α‐amylase inhibitory activity and glucose dialysis retardation index (GDRI), compared to the other samples. CONCLUSION: This study highlights a new approach to modify the functionality of IDFs via acetylation and the design of a novel IDF with hypoglycemic activity. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A phosphine, base and additive free cross-coupling of arylboronic acid is reported via C–O bond cleavage of acetic anhydride using a switchable ferrocene functionalized n-heterocyclic carbene (NHC) palladium complex. The novel redox active catalytic system afforded the corresponding arylketones with good to excellent yields. [ABSTRACT FROM AUTHOR]

In this paper, we present the synthesis of new selenoloquinoxaline derivatives starting from 2‐chloroquinoxaline‐3‐carbonitrile 1. The compound 1 was subjected to a reaction with selenium metal in the presence of NaBH4 as a reducing agent in ethanol, under a nitrogen atmosphere. This reaction resulted in the formation of the sodium salt of 3‐cyanoquinoxaline‐2‐selenolate, which was subsequently reacted with α‐halogenated carbonyl compounds in situ. This reaction produced a series of newly synthesized 3‐aminoselenolo[2,3‐b]quinoxaline‐2‐substituents. Ethyl 3‐aminoselenolo[2,3‐b]quinoxaline‐2‐carboxylate 3a was hydrolyzed by sodium hydroxide to give the corresponding sodium salt 9. This salt was then refluxed with acetic anhydride to produce oxazinone compound 10. The reaction of compound 10 with ammonium acetate afforded pyrimidoselenolo[2,3‐b]quinoxaline derivative 11. Compound 11 was then chlorinated using phosphorous oxychloride to give the corresponding chlorocompound. [ABSTRACT FROM AUTHOR]

Functionalized ionic liquids (FILs) are efficient ILs for the protection of various functionalities such as aldehydes, phenol, and alcohols with acetic anhydride under neat conditions. The attracted rising interest and the subject of active research in the field of catalysis is the variety of expanded applications and yet reports on ILs are still quickly increasing. This work reports a sulfonic acid functionalized ionic liquid is an environmentally friendly, easy handling, and reusable ionic liquid catalyst for the protection of aldehydes and phenols. The catalyst was characterized with different spectroscopic techniques which indicates the fabricated IL is matching with the reported methods. The catalyst can be recycled up to eight times without substantial loss in activity. Furthermore, no chromatographic separations were needed to obtain the desired products. [ABSTRACT FROM AUTHOR]

This study was the first-ever attempt to apply MIL-68 (Ga) in developing an analytical method. The method extracts and preconcentrates some parabens from mouthwash and hydrating gel samples. The variable extraction parameters were optimized, and the figures of merit were documented. Avogadro software was used besides discussing intermolecular interactions to clarify the absorption process. ComplexGAPI software was also exploited to assess the greenness of the method. After the derivatization of the parabens using acetic anhydride in the presence of sodium carbonate, sodium chloride was added to the solution and vortexed to dissolve. A few milligrams of MIL-68 (Ga) were added into the solution and vortexed. Centrifugation separated the analyte-loaded absorbent, which was treated with mL volume of methanol through vortexing for desorption aim. A few microliters of 1,2-dibromoethane were merged with the methanolic phase and injected into a sodium chloride solution. One microliter of the extracted phase was injected into a gas chromatograph equipped with a flame ionization detector. High enrichment factors (200–330), reasonable extraction recoveries (40–66%), wide linear ranges (265–30,000 µg L−1), and appreciable coefficients of determination (0.996–0.999) were documented. The applicability of dispersive solid phase extraction for extracting polar analytes, imposing no additional step for performing derivatization, the capability of MIL-68 (Ga) for the absorption of both derivatized and non-derivatized parabens, the use of only 10 mg absorbent, and one-pot synthesis besides no high temperature or long reaction time in the sorbent provision are the highlights of the method. [ABSTRACT FROM AUTHOR]

A new series of benzoquinoline-based heterocycles was synthesized utilizing the building block synthon, 2-((3-chlorobenzo[f]quinolin-2-yl)methylene)hydrazine-1-carbothioamide via the condensation of 3-chlorobenzo[f]quinoline-2-carbaldehyde with thiosemicarbazide. The titled thiosemicarbazone scaffold was conducted with some carbon-centered electrophilic reagents such as acetic anhydride, chloroacetyl chloride, chloroacetic acid, 2-bromo-1-(3-nitrophenyl)ethan-1-one, 2-chloro-N-phenylacetamide, and dimethyl but-2-ynedioate to achieve triazolethione, imidazolone, thiazolidinone, and thiazole derivatives. In turn, the hydrazinolysis of this substrate did not proceed as expected but it afforded the azine derivative. The antioxidant activity screening of the produced compounds revealed that thiazole and triazolethione derivatives were the most potent. [ABSTRACT FROM AUTHOR]

Hierarchical Beta zeolites with interconnected intracrystalline mesopores and high structural stability are highly attractive for catalytic applications involving bulky reactants. Here, by introducing a suitable amount of polydiallyldimethylammonium chloride into the initial synthesis system, micron-sized Beta zeolite crystals with abundant hierarchical porosity (Beta-H) were hydrothermally synthesized. The sample named Beta-H_1 exhibited very high catalytic activity and durability for the Friedel–Crafts acylation of anisole with acetic anhydride. A 92% conversion rate of acetic anhydride could be achieved after 1 h of reaction in a fixed bed reactor, and 71% conversion still remained after 10 h, much better than the rate for conventional Beta zeolite (which decreased rapidly from 85% to 37% within 10 h). The enhanced catalytic performance of Beta-H zeolites could be mainly attributed to the relatively lower strong acid density and the faster transport rate of the hierarchical zeolites. In addition, Beta-H showed high structural stability and could be easily regenerated via high-temperature calcination without obvious loss in catalytic activity, demonstrating its great potential for catalytic applications in the industrially important Friedel–Crafts acylation process. [ABSTRACT FROM AUTHOR]

In order to improve process safety, product purity, and production efficiency in the synthesis of N-n-butyl-N-(2-nitroxy-ethyl)nitramine (BuNENA), a two-stage continuous flow microreactor system was constructed by sequentially connecting the self-designed heart-shaped channel microreactor and the caterpillar microreactor. n-Butylethanolamine was used as the raw material, nitric acid and acetic anhydride were used as the nitrating agents. The results showed that when the flow rate of n-butylethanolamine was 1.00 mL.min− 1, the temperature of the heart-shaped channel microreactor was 10 ℃, the temperature of the caterpillar microreactor was 35 ℃, the molar ratio of ZnCl2 to n-butylethanolamine was 2%, the molar ratio of nitric acid to n-butylethanolamine was 2.4, and the molar ratio of ZnCl2 to n-butylethanolamine was 2.4, the result was best. Under the conditions, the reaction time was shortened to 300 s, the purity of BuNENA was up to 98.1%, and the yield was 87.1%. [ABSTRACT FROM AUTHOR]

Using salicylic acid and acetic anhydride as raw materials, silica gel as a catalyst, and microwave technology as an optimization method, the university organic chemistry teaching experiment of 'Preparation and Characterization of Acetylsalicylic Acid' was improved. Through the experiment, the impact of factors such as microwave power, reaction time, and raw material ratio on the final yield was explored. The optimal experimental conditions were determined as follows: silica gel with a particle size of 100-200 mesh, 0.25 g in quantity, 60 s reaction time, 70 °C reaction temperature, 500 W microwave power, and a molar ratio of acetic anhydride to salicylic acid of 2 : 1. The average yield was approximately 68.0%. Compared to the conventional heating method for the preparation of acetylsalicylic acid, microwave-assisted synthesis offers advantages such as simplicity, shorter reaction time, higher product yield, fewer impurities, and environmental friendliness. Introducing this microwave experiment into undergraduate organic chemistry laboratory teaching can broaden students' horizons, enrich experimental teaching content, and further improve the teaching level. [ABSTRACT FROM AUTHOR]

In this research, the ionic liquid 4-methylpyridinium chloride grafted on nanoporous Ni/zeolite-Y was fabricated in several steps. Firstly, the nanocomposite of nickel-zeolite–Y (Ni@ZY) was prepared from the exchange-metal reaction of nickel (II) chloride with zeolite-NaY. This nanomaterial was then reacted consecutively with trimethoxysilyl propyl chloride and 4-methylpyridine to obtain nanocomposite of Ni/[(MPy)+Cl−]@ZY. Then, Fe3O4 nanoparticles were produced inside the functionalized zeolite pores with the use of ultrasonic waves to prepare a multi-functional and magnetically 4-methylpyridinium ionic liquid-nickel nanosystem (Ni/[(MPy)+Cl−]@ZY-Fe3O4). Its structure was identified and confirmed by various analyses including: FT-IR, FE-SEM, TEM, EDX, XRD, TGA, VSM and N2 adsorption–desorption (BET). To evaluate the catalytic performance, it has been successfully employed as a nanocatalyst, in facile Erlenmeyer synthesis of 4-arylidene-2-phenyl-5(4H) oxazolones (azlactones) through the multi-component reaction of benzoyl chloride, glycine, arylaldehydes and acetic anhydride under mild conditions. The presence of basic ionic liquid (4-methylpyridinium chloride), Lewis acid (Ni2+) on the solid surface of nanoporous (multifunctional) and the easy separation of the nanocatalyst from the reaction medium by an external magnet are the most distinguished advantages of this procedure. These points can be beneficial and effective in the catalytic processes. Some other advantages of the present process are high product yields, high-speed reaction rate, application of nanotechnology in the catalytic process, catalyst recyclability, low cost and non-toxicity. [ABSTRACT FROM AUTHOR]

To alleviate the global warming, it is necessary to transform carbon dioxide (CO2) into carbon monoxide (CO) through an expedient and resultful approach. In this work, a novel kind of Schiff base-cobalt ion complexes (CHE-Co) was constructed with 5-chorosalicylaldehyde, acetylglycine, acetic anhydride and CoCl3·6H2O as raw materials. It was discovered that CHE-Co exhibits outstanding photocatalytic activity to reduce CO2 to CO (selectivity: 91%) in an H2O/CH3CN solution (V:V = 1:4) under the irradiation of a LED-simulated solar lamp (λ > 400 nm, 90 mW cm–2). Under the optimized conditions, the yield of CO photo-catalytically reduced from CO2 can reach 15.92 μmol, with TON value of 1592 and TOF value of 159.2 h−1. The photo-catalytic mechanism of CHE-Co was proposed that CHE-Co with a positive Eonset can drive electrons shift from excited-state photosensitizer [Ru(phen)3]2+* to CHE-Co via a single-molecule rate control reaction. [ABSTRACT FROM AUTHOR]

Chemical modification of starch from the chayote root (Sechium edule Jacq) is carried out with lauric acid and acetic anhydride. The modified starch is characterized by Fourier‐transform infrared spectrometry (FTIR), X‐ray diffraction (XRD), and Differential Scanning Calorimetry (DSC) and used to formulate edible films. The developed edible films are characterized based on their physicochemical and mechanical properties. The physicochemical and functional properties of starch are affected by the incorporation of the acyl and acetyl group. Both starches exhibit a significant decrease in solubility. Starch modified by the incorporation of the acyl group (lauroyl) has higher thermal stability than starch modified by the incorporation of the acetyl group. The first shows an increase in emulsifying and foaming capacity, as well as water‐ and oil‐retention capacity, while the second exhibits adequate edible film‐forming properties. The edible films develop with modified starch with acetyl group has a homogeneous surface and exhibit a higher percentage of elongation at break when they are stored at a water activity of 0.561. In accordance with the above, it is concluded that the chayote root starch modified has physicochemical and functional properties that indicate their potential utility in the food industry. [ABSTRACT FROM AUTHOR]

The present work describes an efficient and convenient synthesis of a library of novel 1, 2-bis- (tetrasubstituted-benzylidene) hydrazine an analogue (3-7) 1,2-bis (3-methoxy-2-hydroxybenzlidene) hydrazine (3) and 1,2-bis (6-bromo-3-methoxy 2-hydroxybenzylidene) hydrazine (4), were obtained via opening of ester coumarin derivatives (1 and 2) with hydrazine hydrate under reflux. Diazotization of compound 4 with aryldiazonium chloride led to the formation of 1,2-bis (6-bromo-5-arylazo-3-methoxy-2-hydroxybenzylidene) hydrazine (6a,b). Acetylation of compounds 4 and 6a with acetic anhydride afforded the corresponding 1,2-bis (6-bromo-5-substituted-3-methoxy-2-acetoxy benzylidene) hydrazines (5 and 7). The cytotoxicity screening of some synthesized 1,2-bis (tetra substituted benzylidene) hydrazines (4-7) against breast cancer cell lines (MCF-7), and it was found several active compounds. Meanwhile compound 5 exhibited cytotoxic activity compared to reference drug. The DNA flow cytometry on MCF-7 cells of compound 5 was determined, it was found to cause G2/M phase arrest and induce apoptosis in all G1/M phases. In addition, compound 5 has been tested in other trials against aromatase inhibitors and tyrosinase inhibitors. [ABSTRACT FROM AUTHOR]

Formic acid, activated by acetic anhydride and a base, was employed as a CO surrogate to deoxygenate nitroarenes to nitrosoarenes, a reaction catalyzed by a palladium/phenanthroline complex in the homogeneous phase. Nitrosoarenes were trapped by conjugated dienes to give 3,6‐dihydro‐2H‐[1,2]‐oxazines. The latter were then transformed into N‐arylpyrroles employing CuCl as the catalyst. The reaction was designed to give the best results for pyrroles lacking any substituent in the 2 and 5 positions, which are difficult to produce employing most pyrrole syntheses. [ABSTRACT FROM AUTHOR]

Among oxygen-containing heterocyclic compounds such as coumarin and azacoumarin derivatives, the scaffold has become an important construction motif for developing new drugs. Coumarin and its derivatives possess many types of biological activities and have been reported to show significant cytotoxic activity. N-(6,8-disubstituted coumarin-3-yl)benzamides (8a-c) namely (3-N-(benzoyl) aminocoumarin-6-ylmethyl acetate (8a); N-[6-(1-acetylpyrazol-3-yldiazineyl) coumarin-3-yl] benzamide (8b); N-(8-methoxy-6-bromo-coumarin-3-yl) benzamide (8c), were synthesized via a cyclocondensation reaction of 5-(chloromethyl)-2-hydroxybenzaldehyde (3), 5-(pyrazol-3-yl-diazineyl)-2-hydroxybenzaldehyde (4), and 5-bromo-3-methoxy-2-hydroxybenzaldehyde (5) with N-benzoylglycine (7), in good yield. Treatment of compound 8c with ammonia in the presence of anhydrous potassium carbonate to yield N-(5-bromo-8-methoxy-1-azocoumarin-3-yl) benzamide (9). Compound (9) was acetylated with acetic anhydride to give N-(2-acetoxy-5-bromo-8-methoxyquinolin-3-yl) benzamide (10). N-(substituted coumarin and azacoumarin-3-yl) benzamides (8-10) were tested for their in vitro cytotoxic activity against (HepG2) cell line. Furthermore, DNA flow cytometry investigation over HepG2 cells indicated that compound 8a demonstrated arrest at G1/S stages of the cell cycle and induction of apoptosis by rising pre-G1 stage. Compound 8a displayed a significant tubulin polymerization inhibition. [ABSTRACT FROM AUTHOR]

The 2-[2-(1-(4-chlorophenyl)ethylidene]hydrazineyl-1,3-thiazolidin-4-one (V) compound was synthesized via the condensation of thiosemicarbazone derivatives (III) with chloroacetyl chloride which gave a 1,3-disubstituted thiourea derivative (IV) as an intermediate compound, this was followed by cyclization of (IV) in situ boiling ethanol solvent in the presence of anhydrous potassium carbonate. The treatment of thiazole derivative (V) with 4-hydroxybenzaldehyde yielded the corresponding 2,5-disubstituted-1,3-thiazolidin-4-one (VI). Compound (VI) was reacted with 4-chlorophenacyl bromide that afforded 5-(4-hydroxybenzylidene)-2-(1,2-disubstituted) hydrazineyl-1,3-thiazolid-in-4-one (VIII). Acetylation of compounds (VI) and (VIII) with acetic anhydride formed acetyl derivatives (VII) and (IX). The structures of synthesized compounds were characterized and confirmed based on spectroscopic methods and microanalytical method (elemental analysis). It was found that most of the 1,3-thiazole derivatives (V–IX) showed enzyme activity, while compound (VIII) exhibited an excellent activity with IC50 value (4.22 μM) for α-amylase. Also, compound (VIII) gave a good inhibitory activity against free radical scavenging (DPPH), DPP-4, and human breast cancer (MCF-7). Based on the achieved results, it was suggested that compound (VIII) acts as a vital structure for the development of the most potent α-amylase inhibitors. [ABSTRACT FROM AUTHOR]

Application of bioisostere plays an important role in drug discovery. α‐Aminoboronic acid is the familiar bioisostere of α‐amino acid. Developing reactions for the synthesis of a wide variety of α‐aminoboronic acid is one important task for synthetic chemistry. Herein, we report the development of nucleophilic C‐borylation chemistry for N‐arylimines catalyzed by nickel. The reaction proceeds through the insertion of a borylnickel species into the C=N bond to afford the corresponding α‐aminoboronate, which was isolated as acetamide after trapping with acetic anhydride. N‐Benzyl imine is also tolerated by the developed reaction. [ABSTRACT FROM AUTHOR]

A flexible chitin nanofiber (ChNF) film with a thin fiber morphology, named, scaled-down (SD)-ChNF film, was previously found to be formed via successive partial deacetylation of the parent self-assembled ChNFs, cationization/dispersion via electrostatic repulsion in aqueous acetic acid, and suction filtration/drying. In this study, acetylation of a SD-ChNF film using acetic anhydride in pyridine was carried out to improve the mechanical properties. The FT-IR spectra of the acetylated SD-ChNF films suggested that acetylation progressed from the surface to the interior of the films with the increasing amounts of pyridine and elevating temperatures. The degrees of acetylation (DA) strongly affected the chitin crystallinity and surface morphology of the acetylated SD-ChNF films. Tensile testing of the acetylated SD-ChNF films indicated that the mechanical properties were improved by adjusting the DA values of the films. For example, the acetylated SD-ChNF film with an 1.84 DA value on surface showed values of 44.1 MPa and 24.9% for tensile strength and elongation at break, respectively. [ABSTRACT FROM AUTHOR]

The reaction of nicotinic and isonicotinic acid hydrazides with o-formyl benzoic acid in ethanol led to the formation of the corresponding hydrazones. It was found that o-formyl benzoic acid reacted in aldehyde form with hydrazides to form hydrazones. When heated in acetic anhydride, the latter are smoothly cyclized into 3-acetoxyisoindolin-1-ones. Structure of the synthesized compounds was proved by 1H and 13C NMR spectroscopy data. Antiradical and antiviral activity of the synthesized hydrazones and 3-acetoxyisoindolin-1-ones was studied. A compound with a wide spectrum of virus-inhibiting action against strains of the A virus was identified. [ABSTRACT FROM AUTHOR]

The efficacy of human recombinant insulin can be affected by its aggregation. Effects of acetylation were observed on insulin structure, stability, and aggregation at 37 and 50 °C and pH of 5.0 and 7.4 with the use of spectroscopy, circular dichroism (CD), dynamic light scattering (DLS), and atomic force microscopy (AFM). Raman and FTIR results were indicative of structural changes in AC-INS, and CD analyses showed a slight increase in β-sheet content in AC-INS. Melting temperature (Tm) measurements indicated an overall more stable structure and spectroscopic assessment showed a more compact one. Formation of amorphous aggregates was followed over time and kinetics parameters showed a longer nucleation phase (higher t* amount) and lower aggregates amount (lower Alim) for acetylated insulin (AC-INS) compared to native (N-INS) in all tested conditions. The results of amyloid-specific probes approved the formation of amorphous aggregates. Size particle and microscopic analysis suggested that AC-INS was less prone to form aggregates, which were smaller if formed. In conclusion, this study has demonstrated that controlled acetylation of insulin may lead to its higher stability and lower propensity toward amorphous aggregation and has provided insight into the result of this type of post-translational protein modification. [ABSTRACT FROM AUTHOR]

4-Quinolones are the structural elements of many pharmaceutically active compounds. Although several approaches are known for their synthesis, the introduction of an aryl ring in position 2 is problematic with most of them. The reductive cyclization of o-nitrochalcones by pressurized CO, catalyzed by ruthenium or palladium complexes, has been previously reported to be a viable synthetic strategy for this aim, but the need for pressurized CO lines and autoclaves has prevented its widespread use. In this paper, we describe the use of the formic acid/acetic anhydride mixture as a CO surrogate, which allows us to perform the reaction in a cheap and commercially available thick-walled glass tube without adding any gaseous reagent. The obtained yields are often high and compare favorably with those previously reported by the use of pressurized CO. The procedure was applied to a three-step synthesis from commercially available and cheap reagents of the alkaloid Graveoline. [ABSTRACT FROM AUTHOR]

The method for obtaining alkoxycarbonylmethyl esters of thioacetic acid, based on the interaction of mercaptoacetic acid esters with acetic anhydride in an alkaline medium was proposed. It showed that an alternative way to obtain alkoxycarbonylmethyl esters of thioacetic acid is the reaction of mercaptoacetic acid esters with acetyl chloride in the presence of equimolar quantities of triethylamine. The interaction of mercaptoacetic acid esters with benzoyl chloride in the presence of equimolar amounts of triethylamine was used to synthesize appropriate alkoxycarbonylmethyl esters of thioacetic and thiobenzoic acids. Study into synthesized compounds as additives to lubricating oils revealed that addition of butoxycarbonyl methyl ester of thioacetic acid at a concentration of 1% in M-8 oil practically eliminated its corrodibility, while butoxycarbonyl methyl esters of thioacetic and thiobenzoic acids also had some lubricating and antimicrobial properties. [ABSTRACT FROM AUTHOR]

Feasible, scalable, and cost-effective method for the synthesis of low-molecular 2-(trifluoroacetyl)oxazoles from the corresponding oxazoles and trifluoroacetic anhydride was elaborated. The procedure was scaled up to 70 g of the desired ketones in a single run. Tolerance of the oxazole core to various functional group transformations was demonstrated. Thus, synthesis of various building blocks approved the possibility of using 2-(trifluoroacetyl)oxazoles as a starting materials for medicinal chemistry. [ABSTRACT FROM AUTHOR]

Camptothecin-like compounds are actively employed as anticancer drugs in clinical treatments. The aromathecin family of compounds, which contains the same indazolidine core structure as the camptothecin family of compounds, is also expected to display promising anticancer activity. Therefore, the development of a suitable and scalable synthetic method of aromathecin synthesis is of great research interest. In this study, we report the development of a new synthetic approach for constructing the pentacyclic scaffold of the aromathecin family by forming the indolizidine moiety after synthesizing the isoquinolone moiety. Thermal cyclization of 2-alkynylbenzaldehyde oxime to the isoquinoline N-oxide, followed by a Reissert–Henze-type reaction, forms the key strategy in this isoquinolone synthesis. Under the optimum reaction conditions for the Reissert–Henze-type reaction step, microwave irradiation-assisted heating of the purified N-oxide in acetic anhydride at 50 °C reduced the formation of the 4-acetoxyisoquinoline byproduct to deliver the desired isoquinolone at a 73% yield after just 3.5 h. The eight-step sequence employed afforded rosettacin (simplest member of the aromathecin family) at a 23.8% overall yield. The synthesis of rosettacin analogs was achieved by applying the developed strategy and may be generally applicable to the production of other fused indolizidine compounds. [ABSTRACT FROM AUTHOR]

In this research, quinoa starch samples were evaluated in 9 treatments with different proportions of adipic acid and acetic anhydride mixture (ratio 1 to 30), along with a control sample in terms of physicochemical and functional characteristics and determining the optimal conditions for chemical modification. The mentioned treatments were designed by 3 independent variables affecting chemical modification, including chemical modifier concentration (2%, 4% and 6%), suspension pH (8, 8.5 and 9) and reaction time (60, 90, 120 minutes) by Taguchi method. became The swelling power and water absorption capacity of sample T2 (modifier concentration 2%, suspension pH 9 and reaction time 120 minutes) significantly increased compared to the control sample, which is a sign of the formation of crosslinks along with the formation of stable three - dimensional gel networks. Spectroscopy results showed that except for T2 sample, the rest of the samples had a slight tendency to retrogradation, which was a sign of the high stability of the said sample during the retention period to syneresis (p<0.05). Acetylation significantly improved the solubility characteristics compared to the control sample due to the better dispersion of starch in the aqueous medium. With the increase in the modifier concentration, the stability of the samples against the freeze -thaw cycle decreased significantly (p<0.05). The investigated parameters in measuring the thermal characteristics of modified quinoa starch were evaluated with a significant difference more than the control sample. The apparent viscosity of the T2 sample at the shear speed of 20, 50 and 100 rpm increased significantly compared to the control sample, but the other samples showed a lower viscosity. Also, using Taguchi analysis, the optimal treatment of modified quinoa starch with 2% modifier concentration, suspension pH 9 and reaction time 120 minutes was determined. [ABSTRACT FROM AUTHOR]

An efficient and convenient palladium-catalyzed reductive system by employing sodium hydride as the hydrogen donor and acetic anhydride as an activator has been developed for transfer hydrogenation and acetylation of a wide range of N -heteroarenes including quinoline, phthalazine, quinoxaline, phenazine, phenanthridine, and indole. Moreover, acridine substrates could be directly reduced without the use of acetic anhydride. This protocol provides a simple method for the preparation of various saturated N -heterocycles. [ABSTRACT FROM AUTHOR]

The essential oils of Lavender (Lavandula angustifolia) and Tropical Basil (Ocimum basilicum) are characteristically high in both linalool and linalyl acetate esters, key constituents determining essential oil (EO) quality and activity. The enrichment of these products in linalyl acetate has a great interest in the industry. Herein, we report the production of linalyl acetate using the free lipase PPL as a catalyst in a solvent‐free medium. Parametric studies referring response surface methodology (RSM) were applied to optimize the conversion. The optimal experimental condition for (R)‐linalool acylation (temperature at 60°C, catalyst amount at 150 mg, volume of acetic anhydride at 1 mL, and reaction time at 5 days) was obtained from an experimental design analysis. Under these conditions, the enzymatic acylation was carried out for both pure linalool, Lavandula angustifolia and O. basilicum essential oils as substrates. 24.94% conversion of pure linalool to linalyl acetate was obtained; however, essential oils gave lower conversions (conv = 13%). [ABSTRACT FROM AUTHOR]

A novel precolumn derivatization–GC-MS/MS method was developed for the determination of decoquinate residues in chicken tissues (muscle, liver, and kidney). The samples were extracted and purified by liquid–liquid extraction combined with solid-phase extraction and derivatized with acetic anhydride and pyridine. The recovery rates for decoquinate were 77.38~89.65%, and the intra-day and inter-day RSDs were 1.63~5.74% and 2.27~8.06%, respectively. The technique parameters meet the necessities for veterinary drug residue detection in China, the US, and the EU. Finally, the method was applied to analyze tissues of 60 chickens bought from a neighborhood supermarket, and solely one sample of chicken muscle contained 15.6 μg/kg decoquinate residue. [ABSTRACT FROM AUTHOR]

It is very important to identify the thermal behaviors of semi-batch reactors (SBRs) in isoperibolic operating mode. First, a default bilayered back propagation neural network (BPNN) is selected from multiple recognition algorithms to achieve this task, which is suitable for three kinds of reactions with arbitrary reaction orders: homogenous, kinetically−controlled, and diffusion−controlled liquid−liquid heterogeneous reactions. Then, it is further optimized by Bayesian regularization and genetic algorithm (GA). The result shows that the optimal bilayered BPNN undoubtedly has better recognition accuracy and generalization performance. It is found that the accuracy of the two test sets are 98.8% and 100%, respectively. Subsequently, a simple and user-friendly standalone desktop application program (app) is designed to easily use the developed optimal bilayered BPNN. Finally, a case of acetic anhydride hydrolysis reaction with acetic acid solvent is studied to prove the good validity of the bilayered BPNN and the great reliability of the standalone desktop app. [ABSTRACT FROM AUTHOR]

The industry has pursued efforts to minimize the use of fossil fuel-based processing oils in favor of naturally occurring nontoxic oils from renewable sources, such as vegetable oils. In this study, the feasibility of replacing naphthenic oil (NAPH)-based plasticizers in natural rubber (NR) compounds with oil originating from cashew nut shells was evaluated. Cardanol oil (Cdn), which is derived from decarboxylated cashew nut shell liquid, a byproduct of cashew nut production, was chemically modified by acetylation and named Cdn-A. The successful acetylation of Cdn with acetic anhydride was confirmed. The effects of Cdn and Cdn-A as plasticizers on the curing characteristics, thermal aging, and physical, mechanical, and dynamic properties of carbon black-filled NR compounds were then evaluated. Cdn acted as a co-activator for rubber vulcanization; by contrast, Cdn-A showed negligible effects on this process. Vulcanized Cdn- and Cdn-A-containing NR compounds exhibited improved abrasion and tear resistance compared with the reference compound containing NAPH, as well as antioxidant activity. The Cdn-added NR compound also demonstrated high elongation at break and toughness. The results collectively suggest that NR compounds containing Cdn exhibit properties suitable for tire tread applications requiring high grip characteristics. [ABSTRACT FROM AUTHOR]

The effect of the chemical treatment of paper mill sludge fibers and polypropylene molecular weight were studied relative to the physical, mechanical, and morphological properties of a novel cellulosic biocomposite. Paper mill sludge fibers were treated with acetic anhydride, and succinic anhydride was mixed with maleic anhydride polypropylene (MAPP) and coupling agent (0 and 3%). The ratio of fibers and polymer materials was considered 30 to 70, which was manufactured by the hotpressing method at 180 °C. Water absorption, volume swelling, and contact angle were examined on each specimen according to ASTM standards, while Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) explored the efficiency of chemical modification of fibers and the morphology of biocomposites, respectively. The results showed that chemical treatment of fibers reduced the water absorption and volumetric swelling. Both tensile and flexural strength were increased with chemical treatment using the coupling agent. Comparison of fibers treated with succinic acid and acetic acid showed that the succinic acid enhanced the mechanical properties better than the acetic acid treatment. Finally, FTIR analysis showed that the hydroxyl groups decreased, and SEM images indicated the interface between fibers and polypropylene improved via chemical treatment of sludge fibers. [ABSTRACT FROM AUTHOR]

A greener method for synthesizing azlactone has been described by using a highly efficient, selective, biodegradable and recyclable Choline hydroxide (ChOH) catalyst in an aqueous media. This approach has several advantages, including mild reaction conditions, high yields, short reaction time, and a simple set-up, making it a convenient and smart choice for Azlactone synthesis. Furthermore, the proposed methodology has the distinct advantage of not requiring the acetic anhydride, which is a corrosive and controlled ingredient. [ABSTRACT FROM AUTHOR]

A series of new ethyl 7-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylates and their halogenated derivatives were synthesized. Ethyl 7-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylate (2) was obtained by the condensation of 2-amino-4-hydroxybenzaldehyde and diethyl malonate. Halogenation of compound 2 with bromine led to the formation of 6,8-dibromo derivative 5, and the acylation and alkylation of 2 and 5 with acetic anhydride and p-chlorophenacyl bromide gave the corresponding acetoxy derivatives 3 and 6 and alkoxy derivatives 4 and 7. Compounds 2–7 were evaluated for their in vitro antiproliferative activity against MCF-7 and HepG2 cancer cell lines. The cell cycle analysis of compound 4 demonstrated cell cycle arrest at the G2/M phase and pre-G1 apoptosis. [ABSTRACT FROM AUTHOR]

Some pyrazole-based heterocycles, such as pyrrolone, pyridazinone, and imidazole derivatives were synthesized utilizing the pyrazolyl-2(3H)-furanone derivative 3, which was obtained in a good yield via Perkin condensation of 5-chloro-4-formyl-3-methyl-1-phenylpyrazole with 3-(4-methylbenzoyl)propionic acid in the presence of cyclo-dehydrating agent (sodium acetate and acetic anhydride). Also, the acid hydrazide obtained was reacted with some carbonyl reagents like acetic anhydride, benzoyl chloride, 4-chlorobenzaldehyde, and 1,3-diphenyl-4-formylpyrazole, aiming to achieve new pyrrolone derivatives. The antioxidant activity screening of some synthesized compounds demonstrated that pyridazinone and N-phenylhydrazide derivatives showed the most exceptional potencies. [ABSTRACT FROM AUTHOR]

This research presents the synthesis of new quinazolinone-based Mannich bases in good yields via a three-step procedure. The first step is the reaction of 6-hydroxyanthranilic acid 1 with an excess of acetic anhydride at 150°C for 2 h to afford benzoxazinone 2 in 87% yield. Compound 2 is then reacted with 4-aminophenol in DMSO at reflux for 7 h to give compound 3 in 75% yield. Finally, the reaction of 3 with paraformadehyde and secondary amines in ethanol affords new quinazolinone-based Mannich bases 4a-c and 5a-e in 55-70% yields. The structure of Mannich bases have been characterized by NMR and MS spectra. The bio-assay results show that some new Mannich bases exhibited weak to moderate cytotoxic activity against SKLu-1 and MCF-7 cell lines. [ABSTRACT FROM AUTHOR]

This work describes a simple and efficient alternative method for obtaining 1,3,4‐thiadialzolinic spirocompounds, combining the use of deep eutectic solvents (DES) with microwave irradiation in a one‐pot process. A series of DES based on different acids was explored as a solvent in a three‐component reaction including isatin derivatives (monomeric and dimeric), thiosemicarbazide, and acetic anhydride. Choline chloride and oxalic acid (1:1) showed better results concerning the other solvents evaluated, reaching yields of up to 79% when applied to the other compounds of the proposed series. For most of the monomeric compounds, the yields were very close to or higher than those reported in the literature for two‐step synthesis. These results demonstrate the possibility of using one‐pot synthesis as a faster, cleaner, and more efficient alternative method for obtaining thiadiazolines with expressive cytotoxic activity. [ABSTRACT FROM AUTHOR]

A new series of 4-methyl-2-{2-[(aryl)methylidene]hydrazinyl}-1,3-thiazole (2a-i), N-(4-acetyl-5-aryl)4,5-dihydro-1,3,4-thiadiazol-2-yl)acetamides (3a-b) and N-(5-(4-(substituted phenyl)-1,3,4-thiadiazol-2-yl)acetamides (3c-i) were synthesized by the reaction of 2-((aryl)methylene)hydrazine-1-carbothioamides (1a-i) and acetic anhydride or chloroacetone. The cytotoxic activities of the products were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay against Hela cervical cancer, MCF-7 breast carcinoma and HT-29 colorectal cancer cell lines. Thiazole based compounds 2a, 2b, 2f and 2i, bearing 4-bromothiophen-2-yl, naphthalen-2-yl, 2,5-difluorophenyl and 4-(trifluoromethoxy)phenyl moieties, respectively; also N-(4-acetyl-5-(naphthalen-2-yl)-4,5-dihydro-1,3,4-thiadiazol-2-yl)acetamide (3b) and N-(5-(2,6-difluorophenyl)-1,3,4-thiadiazol-2-yl)acetamide (3d) exhibited significant anticancer activity against three cancer cell lines. Moreover, these active compounds were further evaluated by apoptotic protein levels. The results showed that these thiazole and thiadiazole compounds induced apoptosis of cancer cells. [ABSTRACT FROM AUTHOR]