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Protein lipidation dynamically controls protein localization and function within cellular membranes. A unique form of protein O-fatty acylation in Corynebacterium, termed protein O-mycoloylation, involves the attachment of mycolic acids─unusually large and hydrophobic fatty acids─to serine residues of proteins in these organisms outer mycomembrane. However, as with other forms of protein lipidation, the scope and functional consequences of protein O-mycoloylation are challenging to investigate due to the inherent difficulties of enriching and analyzing lipidated peptides. To facilitate the analysis of protein lipidation and enable the comprehensive profiling and site mapping of protein O-mycoloylation, we developed a chemical proteomics strategy integrating metabolic labeling, click chemistry, cleavable linkers, and a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) method employing LC separation and complementary fragmentation methods tailored to the analysis of lipophilic, MS-labile O-acylated peptides. Using these tools in the model organism Corynebacterium glutamicum, we identified approximately 30 candidate O-mycoloylated proteins, including porins, mycoloyltransferases, secreted hydrolases, and other proteins with cell envelope-related functions─consistent with a role for O-mycoloylation in targeting proteins to the mycomembrane. Site mapping revealed that many of the proteins contained multiple spatially proximal modification sites, which occurred predominantly at serine residues surrounded by conformationally flexible peptide motifs. Overall, this study (i) discloses the putative protein O-mycoloylome for the first time, (ii) yields new insights into the undercharacterized proteome of the mycomembrane, which is a hallmark of important pathogens (e.g., Corynebacterium diphtheriae, Mycobacterium tuberculosis), and (iii) provides generally applicable chemical strategies for the proteomic analysis of protein lipidation.

Methods to access chiral sulfur(VI) pharmacophores are of interest in medicinal and synthetic chemistry. We report the desymmetrization of unprotected sulfonimidamides via asymmetric acylation with a cinchona-phosphinate catalyst. The desired products are formed in excellent yield and enantioselectivity with no observed bis-acylation. A data-science-driven approach to substrate scope evaluation was coupled to high throughput experimentation (HTE) to facilitate statistical modeling in order to inform mechanistic studies. Reaction kinetics, catalyst structural studies, and density functional theory (DFT) transition state analysis elucidated the turnover-limiting step to be the collapse of the tetrahedral intermediate and provided key insights into the catalyst-substrate structure-activity relationships responsible for the origin of the enantioselectivity. This study offers a reliable method for accessing enantioenriched sulfonimidamides to propel their application as pharmacophores and serves as an example of the mechanistic insight that can be gleaned from integrating data science and traditional physical organic techniques.

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]

A general and highly enantioselective method for the preparation of tetra‐substituted 3‐hydroxyphthalide esters via isothiourea‐catalysed acylative dynamic kinetic resolution (DKR) is reported. Using (2S,3R)‐HyperBTM (5 mol %) as the catalyst, the scope and limitations of this methodology have been extensively probed, with high enantioselectivity and good to excellent yields observed (>40 examples, up to 99 %, 99 : 1 er). Substitution of the aromatic core within the 3‐hydroxyphthalide skeleton, as well as aliphatic and aromatic substitution at C(3), is readily tolerated. A diverse range of anhydrides, including those from bioactive and pharmaceutically relevant acids, can also be used. The high enantioselectivity observed in this DKR process has been probed computationally, with a key substrate heteroatom donor O⋅⋅⋅acyl‐isothiouronium interaction identified through DFT analysis as necessary for enantiodiscrimination. [ABSTRACT FROM AUTHOR]

The development of methods to allow the selective acylative dynamic kinetic resolution (DKR) of tetra‐substituted lactols is a recognised synthetic challenge. In this manuscript, a highly enantioselective isothiourea‐catalysed acylative DKR of tetra‐substituted morpholinone and benzoxazinone‐derived lactols is reported. The scope and limitations of this methodology have been developed, with high enantioselectivity and good to excellent yields (up to 89 %, 99 : 1 er) observed across a broad range of substrate derivatives incorporating substitution at N(4) and C(2), di‐ and spirocyclic substitution at C(5) and C(6), as well as benzannulation (>35 examples in total). The DKR process is amenable to scale‐up on a 1 g laboratory scale. The factors leading to high selectivity in this DKR process have been probed through computation, with an N−C=O⋅⋅⋅isothiouronium interaction identified as key to producing ester products in highly enantioenriched form. [ABSTRACT FROM AUTHOR]

The cross‐regulation of immunity and metabolism is currently a research hotspot in life sciences and immunology. Metabolic immunology plays an important role in cutting‐edge fields such as metabolic regulatory mechanisms in immune cell development and function, and metabolic targets and immune‐related disease pathways. Protein post‐translational modification (PTM) is a key epigenetic mechanism that regulates various biological processes and highlights metabolite functions. Currently, more than 400 PTM types have been identified to affect the functions of several proteins. Among these, metabolic PTMs, particularly various newly identified histone or non‐histone acylation modifications, can effectively regulate various functions, processes and diseases of the immune system, as well as immune‐related diseases. Thus, drugs aimed at targeted acylation modification can have substantial therapeutic potential in regulating immunity, indicating a new direction for further clinical translational research. This review summarises the characteristics and functions of seven novel lysine acylation modifications, including succinylation, S‐palmitoylation, lactylation, crotonylation, 2‐hydroxyisobutyrylation, β‐hydroxybutyrylation and malonylation, and their association with immunity, thereby providing valuable references for the diagnosis and treatment of immune disorders associated with new acylation modifications. [ABSTRACT FROM AUTHOR]

BACKGROUND: The present work describes the facile, fast and economic base‐catalyzed acylation of benzenediols with vinyl acetate. The Hirshfeld surface analysis of benzene‐1,4‐diol O,O′‐diacetate is also described. NaOH, KOH and K2CO3 were the bases used for the catalysis of the acylation of benzene‐1,x‐diols (x = 2, 3, 4) with vinyl acetate to obtain the corresponding O,O′‐diacetyl derivatives. RESULTS: The yields were quite good, up to 99% under solvent‐free conditions. This method represents an alternative 'green' process for the preparation of O‐acetyl derivatives of hydroxyaryls. The benzene‐1,4‐diol O,O′‐diacetate crystal structure was obtained and described using Hirshfeld surface analysis. A noticeable contribution of the C⋯H contacts is shown (16.7%), despite the insignificant area of the Hirshfeld surface occupied by the carbon atoms (9.4%). By using two‐dimensional fingerprint plots, it was proved that C⋯H contacts were due to the presence of π‐stacking. The O⋯H contacts (41.4%) were the most numerous ones, relating mainly to typical hydrogen bonds (de + di ≈ 2.6 Å). The high saturation of the C⋯H and O⋯H contacts (enrichment ratios (E) = 1.30 and 1.36, respectively), despite their smaller contribution to the overall surface as compared to the H⋯H contacts (E = 0.84), is shown. CONCLUSION: The novelty of this work is the development of a method based on an inexpensive, safe and easy‐to‐use catalyst (K2CO3). This method is fast with high yields. Besides, it may be used for acylation at an industrial scale. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Aldehyde dehydrogenases (ALDHs) represent a superfamily of enzymes, which oxidize aldehydes to the corresponding acids. Certain families, namely ALDH9 and ALDH10, are best active with ω-aminoaldehydes arising from the metabolism of polyamines such as 3-aminopropionaldehyde and 4-aminobutyraldehyde. Plant ALDH10s show broad specificity and accept many different aldehydes (aliphatic, aromatic and heterocyclic) as substrates. This work involved the above-mentioned aminoaldehydes acylated with dicarboxylic acids, phenylalanine, and tyrosine. The resulting products were then examined with native ALDH10 from pea and recombinant ALDH7s from pea and maize. This investigation aimed to find a common efficient substrate for the two plant ALDH families. One of the best natural substrates of ALDH7s is aminoadipic semialdehyde carrying a carboxylic group opposite the aldehyde group. The substrate properties of the new compounds were demonstrated by mass spectrometry of the reaction mixtures, spectrophotometric assays and molecular docking. The N-carboxyacyl derivatives were good substrates of pea ALDH10 but were only weakly oxidized by the two plant ALDH7s. The N-phenylalanyl and N-tyrosyl derivatives of 3-aminopropionaldehyde were good substrates of pea and maize ALDH7. Particularly the former compound was converted very efficiently (based on the kcat/Km ratio), but it was only weakly oxidized by pea ALDH10. Although no compound exhibited the same level of substrate properties for both ALDH families, we show that these enzymes may possess more common substrates than expected. [ABSTRACT FROM AUTHOR]

One‐pot synthetic procedures allow multiple chemical transformations circumventing the isolation of intermediates and thus saving time, energy and feedstocks. Within the scope of one‐pot processes, cascade, domino, or tandem procedures are even more efficient, as multiple reactions can occur in parallel. Hydroformylation is an industrially relevant reaction particularly suitable for this kind of methodology, as the primary products (aldehydes) are usually converted into compounds containing other functionalities. In addition to examples of transformations of the substrate before the hydroformylation step or the transformation of the aldehyde into other functionalities, we highlight a novel approach, in which an additional functionalization takes place in a remote site of the substrate molecule, along with the hydroformylation of the carbon‐carbon double bond. [ABSTRACT FROM AUTHOR]

Chemical reactivity and applications of 4-alkynylated pyrazol-3-ones are described. A facile access to the synthesis of novel pyrazol-4-yl furan- and/or thiophene-2-carboxylates through the ring transformation and subsequent acylation of 4-alkynylated pyrazol-3-ones as the key intermediates, which were prepared from pyrazole-4,5-dione and terminal alkynes, in moderate to good yields is achieved. All the synthesized compounds were characterized by spectroscopic analysis. [ABSTRACT FROM AUTHOR]

Ketones are ubiquitous patterns found in various biological molecules and natural products. In recent years, a number of acylation methods have been developed based on the use of α-oxocarboxylic acids as acyl-transfer reagents, with particular emphasis on the photoinduced decarboxylative acylation of α-keto acids. This review focuses on the latest advancements in acylation methodologies through the decarboxylation of α-keto acids over the past several years, highlighting their product diversity, selectivity, and applicability. Where possible, the mechanistic rationale is presented, providing a positive outlook for the promising future of this field. [ABSTRACT FROM AUTHOR]

Acyl-1,4-dihydropyridines have recently emerged as universal acylation reagents. These easy-to-make and bench-stable NADH biomimetics play the dual role of single-electron reductants and sources of acyl radicals. This review article discusses applications of acyl-1,4-dihydropyridines in organic synthesis since their introduction in 2019. Acyl-1,4-dihydropyridines, activated by photochemical, thermal or electrochemical methods, have been successfully applied as radical sources in multiple diverse organic transformations such as acyl radical addition to olefins, alkynes, imines and other acceptors, as well as in the late-stage functionalisation of natural products and APIs. Release of acyl radicals and an electron can be performed under mild conditions—in green solvents, under air and sunlight, and without the use of photocatalysts, photosensitizers or external oxidants—which makes them ideal reagents for organic chemists. [ABSTRACT FROM AUTHOR]

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Catalytic methods to couple alcohol and alkene feedstocks are highly valuable in synthetic chemistry. The direct oxidative coupling of primary alcohols and alkenes offers a streamlined approach to ketone synthesis. Currently, available methods are based on transition metal-catalyzed alkene hydroacylation, which involves the generation of an electrophilic aldehyde intermediate from primary alcohol dehydrogenation. These methods generally require high reaction temperatures and a high loading of precious metal catalysts and are predominantly effective for branch-selective reactions with electron-rich alkenes. Herein, we designed a dual photo/cobalt-catalytic method to manipulate the reactivity of nucleophilic ketyl radicals for the synthesis of ketones from primary alcohols and alkenes in complementary reactivity and selectivity. This protocol exhibits exceptional scope across both primary alcohols and alkenes with high chemo- and regio-selectivity under mild reaction conditions. Mechanism investigations reveal the essential role of cobalt catalysis in enabling efficient catalysis and broad substrate scope. Catalytic methods to couple alcohol and alkene feedstocks are highly valuable in synthetic chemistry but available methods typically rely on transition metal-catalyzed alkene hydroacylation. Here the authors design a dual photo/cobalt-catalytic method to manipulate the reactivity of nucleophilic ketyl radicals for the synthesis of ketones from primary alcohols and alkenes in complementary reactivity and selectivity. [ABSTRACT FROM AUTHOR]

Chiral guanidine-catalyzed acylative and silylative dynamic kinetic resolutions of 6-hydroxy-2 H -pyran-3(6 H)-one were achieved. We succeeded in developing a non-enzymatic acylative dynamic kinetic resolution of 6-hydroxy-2 H -pyran-3(6 H)-one with high enantioselectivity, which could be improved by recrystallization. In contrast, the non-enzymatic silylative dynamic kinetic resolution of 6-hydroxy-2 H -pyran-3(6 H)-one was accomplished with a moderate selectivity for the first time. [ABSTRACT FROM AUTHOR]

Delivering nucleic acid therapeutics across cell membranes is a significant challenge. Cell-penetrating peptides (CPPs) containing arginine (R), tryptophan (W), and histidine (H) show promise for siRNA delivery. To improve siRNA delivery and silence a model STAT3 gene, we hypothesized that oleyl acylation to CPPs, specifically (WRH)n, would enhance STAT3 silencing efficiency in breast and ovarian cancer cells. Using Fmoc/tBu solid-phase peptide chemistry, we synthesized, purified, and characterized the oleyl-conjugated (WRH)n (n = 1–4) peptides. The peptide/siRNA complexes were non-cytotoxic at N/P 40 (~20 μM) against MDA-MB-231, MCF-7, SK-OV-3, and HEK-293 cells after 72 h incubation. All peptide/siRNA complexes showed serum stability at N/P ≥ 40. The synthesized conjugates, with a diameter of <100 nm, formed nano-complexes with siRNA and exhibited a stable range of zeta potential values (13–18 mV at N/P = 40). Confocal microscopy and flow cytometry analysis provided qualitative and quantitative evidence of a successful cellular internalization of siRNA. The peptides oleyl-(WRH)3 and oleyl-(WRH)4 showed ~60% and ~75% cellular uptake of siRNA, respectively, in both MDA-MB-231 and SK-OV-3 cells. Western blot analysis of oleyl-(WRH)4 demonstrated effective silencing of the STAT-3 gene, with ~75% silencing in MDA-MB-231 cells and ~45% in SK-OV-3 cells. [ABSTRACT FROM AUTHOR]

Metabolic syndrome (MetS) comprises a cluster of metabolic risk factors, which include obesity, hypertriglyceridemia, high blood pressure, and insulin resistance. The purpose of this study was to evaluate the effects of laurate-bioconjugated fructans on pro- and anti-inflammatory cytokines in Wistar rats with MetS induced by a high-fat diet. Laurate-bioconjugated fructans were synthesized with agave fructans, immobilized lipase B, and vinyl laureate as the acylant. Groups were fed a standard diet (NORMAL), a high-fat diet (HFD), or a high-fat diet plus laurate-bioconjugated fructans (FL PREV) for 9 weeks. A fourth group received a high-fat diet for 6 weeks, followed by simultaneous exposure to a high-fat diet and laurate-bioconjugated fructans for 3 additional weeks (FL REV). The dose of laurate-bioconjugated fructans was 130 mg/kg. Laurate-bioconjugated fructans reduced food and energy intake, body weight, body mass index, abdominal circumference, adipose tissue, adipocyte area, serum triglycerides, insulin, insulin resistance, and C-reactive protein but they increased IL-10 protein serum levels and mRNA expression. The impact of laurate-bioconjugated fructans on zoometric and metabolic parameters supports their potential as therapeutic agents to improve obesity, obesity comorbidities, insulin resistance, type 2 diabetes mellitus, and MetS. [ABSTRACT FROM AUTHOR]

Phosphoglycerylation is a non-enzymatic protein modification in which a phosphoglyceryl moiety is covalently bound to the ε-amino group of lysine. It is enriched in glycolytic enzymes from humans and mice and is thought to provide a feedback mechanism for regulating glycolytic flux. We report the first proteomic analysis of this post-translational modification in bacteria by profiling phosphoglyceryl-lysine during the growth of Streptococcus pyogenes in different culture media. The identity of phosphoglyceryl-lysine was confirmed by a previously unknown diagnostic cyclic immonium ion generated during MS/MS. We identified 370 lysine phosphoglycerylation sites in 123 proteins of S. pyogenes. Growth in a defined medium on 1% fructose caused a significant accumulation of phosphoglycerylation compared to growth in a rich medium containing 0.2% glucose. Re-analysis of phosphoproteomes from 14 bacterial species revealed that phosphoglycerylation is generally widespread in bacteria. Many phosphoglycerylation sites were conserved in several bacteria, including S. pyogenes. There was considerable overlap between phosphoglycerylation, acetylation, succinylation, and other acylations on the same lysine residues. Despite some exceptions, most lysine phosphoglycerylations in S. pyogenes occurred with low stoichiometry. Such modifications may be meaningless, but it is also conceivable that phosphoglycerylation, acetylation, and other acylations jointly contribute to the overall regulation of metabolism. [ABSTRACT FROM AUTHOR]

Direct and selective installation of two different functional groups into the unsaturated bonds of alkenes constitutes a long-standing goal in organic synthesis. Herein, we first report a photoelectrochemical approach for the carboacylation/silanoylation of alkenes with unactivated alkanes/hydrosilanes via the LMCT process. A number of ketones with high complexity and diversity were rapidly obtained from commercially available materials in an economical and sustainable manner. Furthermore, this protocol can be scaled up to the gram-level. This paired electrocatalysis strategy features excellent regioselectivity, and ample substrate scope, is external-oxidant-free, and features a high resource economy. A series of mechanistic experiments were performed to determine the preferred pathway for the photoelectrochemical Ni(I)/Ni(II)/Ni(III) cycles in these transformations. [ABSTRACT FROM AUTHOR]

The complex and diverse molecular architectures along with broad biological activities of ent-kauranoids natural products make them an excellent testing ground for the invention of synthetic methods and strategies. Recent efforts notwithstanding, synthetic access to the highly oxidized enmein-type ent-kauranoids still presents considerable challenges to synthetic chemists. Here, we report the enantioselective total syntheses of C-19 oxygenated enmein-type ent-kauranoids, including (–)-macrocalyxoformins A and B and (–)-ludongnin C, along with discussion and study of synthetic strategies. The enabling feature in our synthesis is a devised Ni-catalyzed decarboxylative cyclization/radical-polar crossover/C-acylation cascade that forges a THF ring concomitantly with the β-keto ester group. Mechanistic studies reveal that the C-acylation process in this cascade reaction is achieved through a carboxylation followed by an in situ esterification. Biological evaluation of these synthetic natural products reveals the indispensable role of the ketone on the D ring in their anti-tumor efficacy. The complex and diverse molecular architectures along with broad biological activities of ent-kauranoids natural products attract increasing interest from synthetic chemists. Herein, the authors report the enantioselective total syntheses of C-19 oxygenated enmein-type ent-kauranoids, including (–)-macrocalyxoformins A and B and (–)-ludongnin C. [ABSTRACT FROM AUTHOR]

Acremolactone B is a pyridine‐containing azaphilone‐type polyketide. The first total synthesis of this molecule was achieved on a gram scale, based on an aza‐6π electrocyclization–aromatization strategy for construction of the tetra‐substituted pyridine ring. A bicyclic intermediate was expeditiously prepared by using [2+2] photocycloaddition and chemoselective Baeyer–Villiger oxidation, which was further elaborated to a densely substituted aza‐triene. An electrocyclization–aromatization cascade was utilized to forge the tetracyclic core of this natural product, and the side chain was introduced through diastereoselective acylation and reduction. [ABSTRACT FROM AUTHOR]

An electrochemical method with high faradaic efficiency was developed for the ruthenium‐catalyzed C8‐regioselective aroylation of quinoline N‐oxides under oxidant‐free conditions by using aryl α‐ketoacids as the aroylation reagent. A series of 8‐aroylquinoline N‐oxides were effectively synthesized in moderate‐to‐excellent yields. Furthermore, the proposed method was successfully applied to the gram‐scale synthesis of a tubulin polymerization inhibitor. Additionally, a plausible reaction mechanism for the decarboxylation radical acylation was proposed on the basis of the results of cyclic voltammetry and control experiments. Overall, this method provides a novel solution for the C8‐regioselective aroylation of quinoline N‐oxides. [ABSTRACT FROM AUTHOR]

We employed an amide photo‐Fries rearrangement for the synthesis benzoheterocyclic compounds and found that direct acylation of the α‐carbon atom in an arene ring can occur upon exposure to ultraviolet (UV) light. In this reaction, the N‐acetyl group of amides underwent rearrangement to the α‐position across the bridgehead carbon atom under UV−C light. The reaction conditions were gentle and safe. Moreover, this reaction proves to be more convenient for selectively manipulating benzoheterocyclic compounds in comparison to traditional approaches involving Lewis acid catalysts or anionic reagents. [ABSTRACT FROM AUTHOR]

In the present work, synthesis of 4,5-dehydrospiulosine and its chain analogues (7-9) as potential Sphingosine Kinase I inhibitors has been achieved via the diastereoselective Grignard reaction and stereoselective cross-metathesis reaction followed by N-acylation with p-nitrophenyl butyrate to give the corresponding butyrate ceramides (10-12). All compounds were obtained in high yield and purity. Molecular docking simulation studies were performed for the synthesized compounds that indicated their varying binding affinities with the Sphingosine Kinase 1 (SPHK1) protein. Following, molecular dynamics simulations were performed for the SPHK1-compound (10) complex that indicated compound (10) to be structurally and energetically stable within the binding pocket of SPHK1. Further, the biological evaluation studies, as potential anti-prostate cancer agents and as anti-colon cancer agents by inhibiting the SPHK1 of all synthesized compounds (7-12) on PC-3 cell lines and HCT-116 cell lines by the SRB method were done. Compound N-((2S,3S,E)-3-hydroxyheptadec-4-en-2-yl) butyramide (10) exhibited remarkable cytotoxicity with an IC50 value of 0.018 μM against PC-3 cell lines and 0.076 μM against HCT-116 cell lines, whereas compound (11) showed best cytotoxicity with an IC50 value of 0.062 μM against HCT-116 cell lines. [ABSTRACT FROM AUTHOR]

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]

Oxidative degradation is a common issue of commercial edible oils that results in rancidity, downgrading the organoleptic characteristics of food matrices. The aim of this study was the enzymatic modification of common vegetable oils (pomace olive and sunflower oil) with polyphenolic extract to prepare functional oils enriched with bioactive phenolipids. Under that scope, an agro‐industrial effluent, olive mill wastewater, was used as source to recover phenolic compounds. The recovery of hydroxytyrosol and tyrosol reached up to 81.2% ± 0.3% and 98.3% ± 0.2%, respectively. Further, immobilized lipase was used to catalyze the one‐step acylation of these phenolic antioxidants into the oils with the aim of enhancing their stability under accelerated oxidation conditions. The optimum parameters of the bioconversion were found to be 0.1% (w/w) immobilized lipase, 24h of incubation at 50°C under orbital shaking reaching high conversion yields for both phenolic compounds (≥94%). The results also highlighted that the extract‐modified oils presented notable thermooxidative stability at 60°C for 28 days compared to the control and synthetic antioxidant‐enriched oils, as demonstrated by several analytical (conjugated dienes, thiobarbituric reactive substances), chromatographic (solid‐phase microextraction gas chromatography/mass spectroscopy), and spectroscopic (fluorescence, attenuated total reflectance) techniques, giving new insights regarding the preservation of edible oils. Practical Application: Htyr has recently gained much attention as an active ingredient of food matrices for industrial applications due to its high antioxidant/antiradical activity. A major drawback of Htyr exploitation is the high market price and its solubility. Meanwhile, several edible oils are prone to autooxidation during transport, stock management, and household storage. The proposed one‐step biocatalytic process aims to enhance the lipophilicity and bioactivity of Htyr in bulk oil systems, making the use of this potent antioxidant compound feasible. This approach shows promise in extending the shelf life of common oils and highlights the advantages of by‐product management. Moreover, these functional oils can be applied for the preparation of sauces, bakery products, food supplements, and so on, as the bioactive ingredients that are present in them can delay the oxidative cascade reactions and, thus, the spoilage of the products, whereas the whole process meets the requirements of circular economy and green chemistry. [ABSTRACT FROM AUTHOR]

Non-annulated tetrazole-containing polynuclear compounds, in which heterocyclic fragments are bound by an acetamide linker were synthesized. The synthesis was accomplished by acylation of 2-hydrazinyl-4,6-dimethylpyrimidine, 4-amino-4H-1,2,4-triazol-3-thiol, 2-[(1-amino-1H-tetrazol-5-yl)thio]-N-tert-butylacetamide, 1-methyl-1H-tetrazol-5-amine, and 2-methyl-2H-tetrazol-5-amine with one key reagent, (5-phenyltetrazol-2-yl)acetyl chloride. Preliminary in silico studies showed the presence of the in vivo antidiabetic (diabetes 2 type) activity in N′-(4,6-dimethylpyrimidin-2-yl)-2-(5-phenyl-2H-tetrazol-2-yl)acetohydrazide. N-(3-Mercapto-4H-1,2,4-triazol-4-yl)-2-(5-phenyl-2H-tetrazol-2-yl)acetamide demonstrated minimal hypoglycemic activity in in vivo studies, at the same time, it showed pronounced activity as a drug for combating obesity. [ABSTRACT FROM AUTHOR]

In the title compound, C19H18BrFN2O, the pyrrolidine ring adopts an envelope conformation. In the crystal, molecules are linked by intermolecular N—H...O, C—H...O, C—H...F and C—H...Br hydrogen bonds, forming a three-dimensional network. In addition, C—H...π interactions connect molecules into ribbons along the b-axis direction, consolidating the molecular packing. The intermolecular interactions in the crystal structure were quantified and analysed using Hirshfeld surface analysis.

Metal triflate-catalyzed acylation of sulfonamides and direct transacylation of N-acylsulfonamides have been investigated. The acylation of sulfonamides proceeds efficiently in the presence of a catalytic amount of Cu(OTf)2 (0.001 equiv) using either carboxylic anhydrides or acyl chlorides as the acylating agents. Alternative catalysts suitable for this transformation include Al(OTf)3, Fe(OTf)3, Ga(OTf)3, In(OTf)3, and Er(OTf)3. In the presence of Cu(OTf)2 (0.2 equiv), N-acylsulfonamides undergo direct transacylation in excess acyl chlorides (10 equiv) to furnish new N-acylsulfonamides through exchange of N-acyl groups. Ga(OTf)3, Fe(OTf)3, and In(OTf)3 are similarly reactive in catalyzing such transacylation transformations. The reaction conditions are mild and operationally convenient. A variety of functional groups including halogeno, keto, nitro, cyano, ether, and carboxylic ester are tolerated, providing the corresponding monoacylated N-acylsulfonamides in good to excellent yields. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Phthalides serve as core structures pervasive in a wide array of natural products and drug molecules, which display a diverse array of biological activities. We report herein a highly efficient dynamic kinetic resolution of 3‐hydroxyphthalides by chiral isothioureas (ITUs) catalyzed asymmetric acylation, facilitating the effective synthesis of a variety of chiral phthalidyl esters with good yields and enantioselectivities. Notably, this reaction features mild reaction conditions, expansive substrate scope as well as good functional group compatibility. In addition, the practicality of this method is underscored by the large‐scale synthesis, reduced catalyst loading experiment and the synthesis of the chiral phthalidyl ester prodrug. [ABSTRACT FROM AUTHOR]

Twenty 3-acyloxymaltol/ethyl maltol derivatives (7a-j and 8a-j) were synthesized and evaluated in vitro for their anti-oomycete activity against Phytophthora capsici, respectively. Among all of twenty derivatives, more than half of the compounds 7f, 7h, 8a-h and 8j had anti-oomycete activity higher than the positive control zoxamide (EC50 = 22.23 mg/L), and the EC50 values of 18.66, 20.32, 12.80, 16.18, 10.59, 14.98, 16.80, 10.36, 15.32, 12.64, and 13.59 mg/L, respectively. Especially, compounds 8c and 8f exhibited the best anti-oomycete activity against P. capsici with EC50 values of 10.59 and 10.36 mg/L, respectively. Overall, hydroxyl group of maltol/ethyl maltol is important active modification site. [ABSTRACT FROM AUTHOR]

In the title compound, C24H21NO3S, the cyclopentene ring adopts an envelope conformation. In the crystal, molecules are linked by C—H...π interactions, forming ribbons along the a axis. Intermolecular C—H...O hydrogen bonds connect these ribbons to each other, forming layers parallel to the (0\overline{1}1) plane. The molecular packing is strengthened by van der Waals interactions between the layers. The intermolecular contacts were quantified using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be H...H 46.0%, C...H/H...C 21.1%, O...H/H...O 20.6% and S...H/H...S 9.0%.

The possible catalytic mechanism was proposed and studied comprehensively at the M062X/6-31G(d,p) level of theory for a reported chemoselective intermolecular SN2 nucleophilic substitution of aldehydes with alkanolamine. The calculated results show that the catalytic cycle occurs through six stages, namely, the nucleophilic attack of active N-heterocyclic carbene (NHC) on the substrate, generation of the Breslow intermediate, oxidative addition of NBS and alkanolamine, SN2 nucleophilic substitution, Et3N-assisted debromination, and finally regeneration of the NHC along with the release of the product. The results show that TSs of the C–N or C–O bond formation is the key transition state that determines the chemoselectivity of the title reaction. Moreover, our results demonstrated that the N-bromoamine intermediate is more favorable both thermodynamically and kinetically than hypobromite by 14.2 kcal mol−1, which is consistent with the fact that only the N-acylation product was observed in the experiment. In addition, we found that alkanolamine not only acts as a reactant but also as a proton-shuttle and stabilizer to stabilize the structure of the favored chemoselective transition state by multiple N–H⋯N, N–H⋯O and C–H⋯Br− noncovalent interactions. Et3N firstly acts as a base to promote the formation of the active catalyst NHC, then the protonated Et3N acts as a proton-shuttle to accelerate the Breslow intermediate formation and decrease the activation barrier. The Parr functions and frontier molecular orbital analyses of key species indicate that NHC remarkably enhances the nucleophilicity of the substrate aldehyde, leading to a significant increase of the HOMO energy and a moderate increase of the LUMO energy. We hope this work could provide deeper insights into the fundamental mechanisms of the Et3N-assisted NHC-catalyzed SN2 substitution reactions. [ABSTRACT FROM AUTHOR]

Pig liver is a high-quality source of animal protein, but natural pig liver protein is poorly emulsified. To improve its properties and enhance the added value of pig liver processing, this experiment prepared pig liver protein solution, measured the index of acylation, and investigated the effects on the emulsification properties, protein particle state, and molecular structure of pig liver protein with the addition amount of succinic anhydride as the variable. Results showed that with the increase of succinic anhydride addition, the acylation degree and emulsification activity of porcine liver protein showed an overall increasing trend, the emulsion zeta potential and the protein adsorption on the surface of emulsion oil droplets showed an increasing trend and then a decreasing trend, the emulsion particle size and protein surface hydrophobicity showed a decreasing trend, and the advanced structure of the protein were changed. The optimal addition of succinic anhydride for acylation treatment of porcine liver protein solution (10 mg/mL of concentration) was 0.10 g/g Pro. The emulsification activity of the porcine liver protein increased from 9.550 m²/g to 64.135 m²/g under this condition. Succinic anhydride reacted with porcine liver protein through covalent binding, causing changes in protein structure and significantly improving the emulsifying activity of the porcine liver protein. [ABSTRACT FROM AUTHOR]

A novel photocatalytic acylation strategy was developed harnessing tetrabutylammonium decatungstate (TBADT) as a hydrogen atom transfer (HAT) photocatalyst to facilitate the direct coupling of aldehydes with N-heterocycles at ambient temperature. This approach realizes the direct acylation of N-hetrerocycles without the need for noble metals, acids, or external oxidants, thereby marking a significant advance in green chemistry protocols. Utilizing this photocatalyzed method, we successfully synthesized a diverse array of 3-acylated azauracils and quinoxalin-2(1H)-ones, adorned with a variety of functional groups, achieving yields ranging from good to excellent. This research opens avenues for the rapid and efficient modification of heterocyclic compounds, which are foundational structures in medicinal chemistry and materials science. [ABSTRACT FROM AUTHOR]

Small‐molecule reactions at the 2′‐OH groups of RNA enable useful applications for transcriptome technology and biology. To date, all reactions have involved carbonyl acylation and mechanistically related sulfonylation, limiting the types of modifications and properties that can be achieved. Here we report that electron‐deficient heteroaryl species selectively react with 2′‐OH groups of RNA in water via SNAr chemistry. In particular, trialkyl‐ammonium (TAA)‐activated aromatic heterocycles, prepared in one step from aryl chloride precursors, give high conversions to aryl ether adducts with RNAs in aqueous buffer in ~2–3 h. Remarkably, a TAA triazine previously used only for reaction with carboxylic acids, shows unprecedented selectivity for RNA over water, reacting rapidly with 2′‐OH groups while exhibiting a half‐life in water of >10 days. We further show that a triazine aryl species can be used as a probe at trace‐level yields to map RNA structure in vitro. Finally, we prepare a number of functionalized trialkylammonium triazine reagents and show that they can be used to covalently label RNA efficiently for use in vitro and in living cells. This direct arylation chemistry offers a simple and distinct structural scaffold for post‐synthetic RNA modification, with potential utility in multiple applications in transcriptome research. [ABSTRACT FROM AUTHOR]

The document is the contents list for an issue of the journal Chemical Communications. It includes a range of articles on various topics, such as nanopesticides, molecular dynamics simulations, radical qubits, enzymatic activity, and electrochemical reactions. The journal is published by The Royal Society of Chemistry and aims to connect the world with the chemical sciences. The document provides a snapshot of the articles included in the issue, allowing library patrons to quickly identify relevant research topics. [Extracted from the article]

The electro-generation of acyl radicals from both aromatic and aliphatic aldehydes remains an unmet challenge. We provide a solution to this challenge by merging electro-oxidation and a quinuclidine-mediated hydrogen atom transfer strategy. The generation of acyl radicals at decreased applied potentials compared to that of formyl oxidation exhibits excellent functional group compatibility. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A general and convenient photoredox‐catalyzed acylation and alkylcyanation of MBH acetates has been established, enabling the assembly of the C(sp2)–C(sp3) bond by a nitrogen‐centered radical strategy for the synthesis of trisubstituted alkenes in moderate to excellent chemical yields (48 examples in total). The reaction of MBH acetates with acyl (indanone) oxime esters afforded trisubstituted alkenes containing 1,4‐dicarbonyl groups. Interestingly, the use of Eosin Y as a photocatalyst in the catalytic system resulted in the formation of distal cyano group‐anchored trisubstituted alkenes via deconstructive functionalization of cycloketone oxime esters. Notably, these resulting 1,4‐dicarbonyl compounds could be applied to late‐stage transformations, providing important methods for the synthesis of dihydropyridazin‐3(2H)‐one. [ABSTRACT FROM AUTHOR]

An investigation of phenolic glycosides extracted from Salix germplasm revealed that arbusculoidin (benzyl 1-O-β-d-glucopyranosyl-1-hydroxy-6-oxo-2-cyclohexenyl carboxylate) and its enolic 6-glycoside isomer, isoarbusculoidin, are widespread across the Salix family. An analysis of natural hybrid species and progeny from a willow breeding programme demonstrated that the putative biosynthetic pathway leading to the salicinoid family of phenolic glycosides runs in parallel to a "benzyl"-based pathway to arbusculoidin. The introduction of a known Diels–Alder reaction trait from Salix dasyclados, as well as an acylation trait, into progeny containing both salicyl- and benzyl- pathways caused the formation of all possible hetero-cyclodimers from mixtures of reactive dienone (acyl)glycosides that participated in cross-over reactions. In addition to providing access to new analogues of the anti-cancer dimer miyabeacin, the analysis of the breeding progeny also indicated that these dienone (acyl)glycosides are stable in planta. Although the immediate biosynthetic precursors of these compounds remain to be defined, the results suggest that the (acyl)glycosylation reactions may occur later in the pathway than previously suggested by in vitro work on cloned UGT enzymes. [ABSTRACT FROM AUTHOR]

A selective, mild, convenient, and green protocol for the preparation of S‐acyl and N‐acyl glutathiones is described involving the chemical modification of glutathione (GSH) with N‐acyl imidazoles at room temperature in water. The syntheses of S‐acyl glutathiones were achieved in very high yields using 1 equiv. of an N‐acyl imidazole in water at room temperature, without the need of a base. Double acylation of GSH with various N‐acyl imidazoles in weakly basic aqueous media in the presence of N‐hydroxysuccinimide (HOSu) as the activating reagent followed by selective deprotection of the S‐acyl group with aqueous ammonia at room temperature gave high yields of N‐acyl glutathiones. Moreover, the reaction could accommodate a diverse range of carboxylic acids such as (hetero)benzoic acids, phenylacetic acids, aliphatic acids from short‐chain fatty acids (including acetic acid), long‐chain polyunsaturated fatty acids, secondary or tertiary amino acids, and carboxylic acids containing clickable functional groups, fluorescent probes, or drugs. [ABSTRACT FROM AUTHOR]

Spatiotemporal regulation of clustered regularly interspaced short palindromic repeats (CRISPR) system is attractive for precise gene editing and accurate molecular diagnosis. Although many efforts have been made, versatile and efficient strategies to control CRISPR system are still desirable. Here, we proposed a universal and accessible acylation strategy to regulate the CRISPR–Cas12a system by efficient acylation of 2′‐hydroxyls (2′‐OH) on crRNA strand with photolabile agents (PLGs). The introduction of PLGs confers efficient suppression of crRNA function and rapid restoration of CRISPR–Cas12a reaction upon short light exposure regardless of crRNA sequences. Based on this strategy, we constructed a universal PhotO‐Initiated CRISPR–Cas12a system for Robust One‐pot Testing (POIROT) platform integrated with recombinase polymerase amplification (RPA), which showed two orders of magnitude more sensitive than the conventional one‐step assay and comparable to the two‐step assay. For clinical sample testing, POIROT achieved high‐efficiency detection performance comparable to the gold‐standard quantitative PCR (qPCR) in sensitivity and specificity, but faster than the qPCR method. Overall, we believe the proposed strategy will promote the development of many other universal photo‐controlled CRISPR technologies for one‐pot assay, and even expand applications in the fields of controllable CRISPR‐based genomic editing, disease therapy, and cell imaging. [ABSTRACT FROM AUTHOR]

Over the past decade, significant progress has been made in the direct C-H acylation of naphthalenes, occurring at the α or β positions to yield valuable ketones through Friedel-Crafts acylation or transition-metal-catalysed carbonylative coupling reactions. Nevertheless, highly regioselective acylation of naphthalenes remains a formidable challenge. Herein, we developed a nickel-catalysed reductive ring-opening reaction of 7-oxabenzonorbornadienes with acyl chlorides as the electrophilic coupling partner, providing a new method for the exclusive preparation of β-acyl naphthalenes. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A visible‐light‐enabled, photocatalyst‐free hydroacylation reaction of azodicarboxylic acid derivatives was described. This radical conjugate addition (RCA) protocol relied on the dual role of 4‐acyl‐1,4‐dihydropyridine (acyl‐DHP) reagents that besides being as radical reservoirs, they also enabled the conversion of radical adducts to anion intermediates via reduction. Under "catalyst‐oxidant‐additive free" conditions, a wide range of structurally different acyl hydrazide products were readily obtained in 56%—99% yields. The utility of this transformation was further demonstrated by the scale‐up synthesis and downstream derivatization. [ABSTRACT FROM AUTHOR]

An important mechanism of gene expression regulation is the epigenetic modification of histones. The cofactors and substrates for these modifications are often intermediary metabolites, and it is becoming increasingly clear that the metabolic and nutritional state of cells can influence these marks. These connections between the balance of metabolites, histone modifications and downstream transcriptional changes comprise a metabolic signaling program that can enable cells to adapt to changes in nutrient availability. Beyond acetylation, there is evidence now that histones can be modified by other acyl groups. In this Cell Science at a Glance article and the accompanying poster, we focus on these histone acylation modifications and provide an overview of the players that govern these acylations and their connections with metabolism. [ABSTRACT FROM AUTHOR]

Protein acetylation, which is dynamically maintained by histone acetyltransferases (HATs) and deacetylases (HDACs), might play essential roles in hippocampal exercise physiology. However, whether HATs/HDACs are imbalanced during the recovery phase following acute exercise has not been determined. Groups of exercised mice with different recovery periods after acute exercise (0 h, 0.5 h, 1 h, 4 h, 7 h, and 24 h) were constructed, and a group of sham-exercised mice was used as the control. The mRNA levels of HATs and HDACs were detected via real-time quantitative polymerase chain reaction. Lysine acetylation on the total proteins and some specific locations on histones were detected via western blotting, as were various acylation modifications on the total proteins. Except for four unaffected genes (Hdac4, Ncoa1, Ncoa2, and Sirt1), the mRNA expression trajectories of 21 other HATs or HDACs affected by exercise could be categorized into three clusters. The genes in Cluster 1 increased quickly following exercise, with a peak at 0.5 h and/or 1 h, and remained at high levels until 24 h. Cluster 2 genes presented a gradual increase with a delayed peak at 4 h or 7 h postexercise before returning to baseline. The expression of Cluster 3 genes decreased at 0.5 h and/or 1 h, with some returning to overexpression (Hdac1 and Sirt3). Although most HATs were upregulated and half of the affected HDACs were downregulated at 0.5 h postexercise, the global or residue-specific histone acetylation levels were unchanged. In contrast, the levels of several metabolism-related acylation products of total proteins, including acetylation, succinylation, 2-hydroxyisobutyryllysine, β-hydroxybutyryllysine, and lactylation, decreased and mainly occurred on nonhistones immediately after exercise. During the 24-h recovery phase after acute exercise, the transcriptional trajectory of HATs or the same class of HDACs in the hippocampus exhibited heterogeneity. Although acute exercise did not affect the selected sites on histone lysine residues, it possibly incurred changes in acetylation and other acylation on nonhistone proteins. [ABSTRACT FROM AUTHOR]

An intramolecular electrochemical dehydration reaction of dicarboxylic acids to their cyclic anhydrides is presented. This electrolysis allows dicarboxylic acids as naturally abundant, inexpensive, safe, and readily available starting materials to be transformed into carboxylic anhydrides under mild reaction conditions. No conventional dehydration reagent is required. The obtained cyclic anhydrides are highly valuable reagents in organic synthesis, and in this report, we use them in‐situ for acylation reactions of amines to synthesize amides. This work is part of the recent progress in electrochemical dehydration, which – in contrast to electrochemical dehydrogenative reactions for example – is an underexplored field of research. The reaction mechanism was investigated by 18O isotope labeling, revealing the formation of sulfate by electrochemical oxidation and hydrolysis of the thiocyanate‐supporting electrolyte. This transformation is not a classical Kolbe electrolysis, because it is non‐decarboxylative, and all carbon atoms of the carboxylic acid starting material are contained in the carboxylic anhydride. In total, 20 examples are shown with NMR yields up to 71 %. [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]

Incorporating stimuli‐responsive components into RNA constructs provides precise spatiotemporal control over RNA structures and functions. Despite considerable advancements, the utilization of redox‐responsive stimuli for the activation of caged RNAs remains scarce. In this context, we present a novel strategy that leverages post‐synthetic acylation coupled with redox‐responsive chemistry to exert control over RNA. To achieve this, we design and synthesize a series of acylating reagents specifically tailored for introducing disulfide‐containing acyl adducts into the 2′‐OH groups of RNA ("cloaking"). Our data reveal that these acyl moieties can be readily appended, effectively blocking RNA catalytic activity and folding. We also demonstrate the traceless release and reactivation of caged RNAs ("uncloaking") through reducing stimuli. By employing this strategy, RNA exhibits rapid cellular uptake, effective distribution and activation in the cytosol without lysosomal entrapment. We anticipate that our methodology will be accessible to laboratories engaged in RNA biology and holds promise as a versatile platform for RNA‐based applications. [ABSTRACT FROM AUTHOR]