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This work deals with the synthesis, characterization of hybrid ethylene propylene diene monomer (EPDM) composites loaded with nano‐boron nitride (nano‐BN)/nano‐titanium dioxide (nano‐TiO2) and micro Mg(OH)2 particles for its suitability towards high‐voltage insulation application. The elastomer samples were prepared by carefully dispersing the micro and nano fillers during the mastication process of EPDM polymer using a two roll mill, followed by vulcanization. The samples were characterized for mechanical, morphological, thermal, and electrical insulation properties. The highest tensile strength among the composite samples was noted for 1 phr nanoparticles loaded samples. Fourier Transform Infrared (FTIR) results show no change in the chemical moiety upon addition of nano‐BN/nano‐TiO2 in EPDM composites. Enhancement in hydrophobicity is observed for 3 phr nano‐TiO2 loaded composites, which shows a maximum static contact angle of 110°. Meanwhile remarkable enhancement in the thermal conductivity and volume resistance of the composites are contributed to the addition of nano‐BN, thereby achieving maximum dielectric breakdown voltage (i.e., ~21 kV/mm for EMB3). Scanning electron microscope images and atomic force microscopy (AFM) topography highlight that low concentration (i.e., 1 phr) based composites have homogeneous dispersion in matrix and excessive nano filler addition deteriorates properties by forming filler aggregates and increasing surface roughness. [ABSTRACT FROM AUTHOR]

Oligo(para‐phenylene) (PPn) is a compound composed of directly connected 1,4‐phenylene moieties. The synthesis of PPn composed of six or more phenylene moieties with no substituent at the internal phenylene moiety has been challenging because of its low solubility. Herein we synthesized oligo(para‐phenylene)[2]rotaxanes, including a deca(para‐phenylene)[2]rotaxane, with a defined number of phenylene moieties. Biaryl coupling of iodoarenes mediated by macrocyclic dibenzodihydrophenanthroline‐Ni complex was utilized for the first time to synthesize the [2]rotaxanes. Compared to the non‐interlocked deca(para‐phenylene), the deca(para‐phenylene)[2]rotaxane showed higher solubility. The properties of the oligo(para‐phenylene)[2]rotaxanes and non‐interlocked oligo(para‐phenylene)s were analyzed by spectroscopic methods. [ABSTRACT FROM AUTHOR]

Two new fully π-conjugated ethylene-linked COFs containing benzotrithiophene as functional group by Knoevenagel polycondensation reaction were sythesized to explore their differences in H 2 photogeneration activity. The donor-acceptor (D-A) type BTT-BpyDAN-COF exhibited the approximately enhanced 2.6-folds hydrogen evolution rate of 10.1 mmol g-1h−1 compared to a non-D-A COF (BTT-PDAN-COF) and gained an excellent apparent quantum efficiency of 4.83% under visible light irradiation. [Display omitted] Covalent organic frameworks (COFs) have a broad prospect to be used as a photocatalytic platform to convert solar energy into valuable chemicals due to their tunable structures and rich active catalytic sites. However, constructing COFs with tuned sp2 -carbon donor-acceptor moiety remains an enormous challenge. Herein, we synthesized two new fully π-conjugated cyano-ethylene-linked COFs containing benzotrithiophene as functional group by Knoevenagel polycondensation reaction. The accetpor 2,2′-bipyridine unit in BTT-BpyDAN-COF skeleton favored the formation of a intermolecular specific electron transport pathway with the donor benzotrithiophene, and thereby promoted charge separation and transfer efficiency. Specifically, a donor-acceptor (D-A) type BTT-BpyDAN-COF exhibited high hydrogen evolution rate of 10.1 mmol g-1h−1 and an excellent apparent quantum efficiency of 4.83 % under visible light irradiation. [ABSTRACT FROM AUTHOR]

ABA types triblock copolymers, specifically poly(L‐lactide)‐co‐poly(ethylene glycol)‐co‐poly(L‐lactide) (PLLA‐PEG‐PLLA) and poly(D‐lactide)‐co‐poly(ethylene glycol)‐co‐poly(D‐lactide) (PDLA‐PEG‐PDLA), are employed for stereocomplexes (SCs) formation. These SCs are subsequently utilized as axles, in conjunction with various cyclodextrins (CDs) as ring moieties to create pseudo‐polyrotaxane (PPRX). The authors referred to this new construct as "SC PPRX", to distinguish it from the earlier study, denoted as "PPRX SC", which primarily focuses on SC within the PPRX. When attempting to form PPRXs in aqueous solutions, the authors encountered challenges related to the inclusion of CDs due to the robust presence of the SC structure. However, by using mixed solvents, such as water/acetone (10/1, v/v), a partial relaxation of the SC structure is observed. This allows for the successful inclusion of CDs, thereby facilitating the PPRX formation. These observations highlight the significance of axle–axle interaction, which, in this case, prevailed over axle–ring interactions in determining the outcome of the formation process. The authors propose the term, 'SC pseudo‐capping effect' to describe this unique phenomenon, underscoring the role of interactions among polymer chains, including polymer–polymer and axle–axle interactions, in shaping the architecture of rotaxanes. This study thus unveils a novel dimension of polymer‐polymer interactions within the realm of rotaxane. [ABSTRACT FROM AUTHOR]

Various sets of thiazole, thiophene, and 2-pyridone ring structures containing a dimethylaniline component were synthesized. Substituted thiazoles 2–3 and thiophenes 5–7 were produced by reacting thiocarbamoyl compound 4 with α-halogenated reagents in different basic conditions. Also, a series of 2-pyridone derivatives 9a–f substituted with dimethylaniline was synthesized through Michael addition of malononitrile to α,β-unsaturated nitrile derivatives 8a–f. The synthesized products were structurally proven by spectroscopic methods such as IR, 1H NMR, 13C NMR, and MS data. Furthermore, the anti-cancer efficacy of the compounds was assessed using the MTT assay on two cell lines: hepatocellular carcinoma (HepG-2) and breast cancer (MDA-MB-231). The results showed the highest growth inhibition for derivatives 2, 6, 7, and 9c, which were further examined for their IC50 values. The IC50 for compound 2 showed equipotent activity (IC50 = 1.2 µM) against the HepG-2 cell line compared to Doxorubicin (IC50 = 1.1 µM). Compounds 2, 6, 7 and 9c showed very good ADME assessments for further drug administration. Moreover, the PASS theoretical prediction for the compounds showed high antimitotic and antineoplastic activities for compounds 2, 6, 7, and 9c, as well as potent inhibition activity for the insulysin enzyme (IDE). Molecular docking stimulations were performed on CDK1/CyclinB1/CKS2 (PDB ID: 4y72) and BPTI (PDB ID: 2ra3). When docked into (PDB ID: 4y72), all of the tested compounds showed considerable inhibition, and the 2-pyridone derivative 9d had the maximum binding affinity (− 8.1223 kcal/mol). While thiophene derivative 6 offered the maximum binding affinity (− 7.5094 kcal/mol) when docked into (PDB ID: 2ra3). [ABSTRACT FROM AUTHOR]

Glycosyl aryl sulfones have gained significant attention due to their diverse range of biological activities. However, a straightforward synthesis under mild conditions remains a challenging endeavor. This work presents the first transition-metal-free glycosyl sulfonation, employing a readily prepared sodium glycosyl sulfinate in conjunction with diaryliodonium salts. The method is compatible with various sugar substrates including unprotected sugar derivatives. Notably, the transfer of an aryl moiety in unsymmetric diaryl iodonium salts is chemoselectively achieved by utilizing an anisyl or TMP fragment as a dummy ligand. Preliminary mechanistic studies suggest that the reaction may proceed through an intramolecular SNAr process with a four-membered ring transition state. [ABSTRACT FROM AUTHOR]

Rare examples of trinuclear [Ni–N2–M–N2–Ni] core (M = Ca, Mg) with linear bridged dinitrogen ligands are reported in this work. The reduction of [iPr2NN]Ni(μ-Br)2Li(thf)2 (1) (iPr2NN = 2,4-bis-(2,6-diisopropylphenylimido)pentyl) with elemental Mg or Ca in THF under an atmosphere of dinitrogen yields the complex {iPr2NNNi(μ-N2)}2M (thf)4 (M = Mg, complex 2 and M = Ca, complex 3). The bridging end-on (μ-N2)2M(thf)4 moiety connects the two [iPr2NNNi]− nickelate fragments. A combination of X-ray crystallography, solution and solid-state spectroscopy have been applied to characterize complexes 2 and 3, and DFT studies have been used to help explain the bonding and electronic structure in these unique Ni–N2–Mg and Ni–N2–Ca complexes. [ABSTRACT FROM AUTHOR]

Seven new glycosides (1 − 7) with galloyl groups and two known kaempferol glycosides (8 and 9) were obtained from the overground parts of Balakata baccata. The structures of the new compounds were determined by comprehensive spectroscopic analyses. The rarely seen allene moiety in compounds 6 and 7 were described by detailed analysis of 1D and 2D NMR data. The antineuroinflammatory effect of all the isolates was assessed through inhibiting nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Compounds 1, 2, 6, and 7 showed potent inhibitory activities with IC50 values of 25.7, 17.2, 15.5 and 24.4 μM, respectively, compared with the positive control minocycline (IC50 = 16.1 μM). [ABSTRACT FROM AUTHOR]

In this concept, we showcase the upsurge in the studies of dynamic ultralong room‐temperature phosphorescence (RTP) materials containing inorganic and/or organic components as versatile photo‐responsive platforms. The goal is to provide a comprehensive analysis of photo‐controllable RTP, and meanwhile delve into the underlying RTP properties of various classes of photochromic materials including metal‐organic complexes, organic‐inorganic co‐crystals, purely organic small molecules and organic polymers. In particular, the design principles governing the integration of the photochromic and RTP moieties within a single material system, and the tuning of dynamic RTP in response to light are emphasized. As such, this concept sheds light on the challenges and opportunities of using these tunable RTP materials for potential applications in optoelectronics, particularly highlighting their use of reversible information encryption, erasable light printing and rewritable smart paper. [ABSTRACT FROM AUTHOR]

A major hindrance in the commercialization of alkaline polyelectrolyte‐based electrochemical energy conversion devices is the development of durable anion exchange membranes (AEMs). Despite many alkali‐stable cations that have been explored, the stability of these cationic moieties at the membrane scale is in the blind. Herein, we present a molecularly designed polyaromatic AEM with cationic moieties in an alternating manner to unbiasedly compare the alkaline stability of piperidinium and ammonium groups at the membrane state. Using nuclear magnetic resonance spectroscopy, we demonstrate that the pentyltrimethyl group is about 2‐fold more stable than piperidinium within a polyaromatic scaffold, either in ex‐situ alkaline soaking or in‐situ cell operation. This finding challenges the judgment extrapolated from the stability trend of cations, that is, the piperidinium‐functionalized AEM is more alkali‐stable than the counterparts based on quaternary ammoniums. Moreover, the deterioration mechanism of piperidinium moiety after being embedded in polyaromatic backbone is rationalized by density functional theory. [ABSTRACT FROM AUTHOR]

Since 1993, it has been known that 13C chemical shift tensor (i.e., δ11, δ22, and δ33) provides information sufficient to distinguish between COOH and COO− sites. Herein, four previously unreported metrics are proposed for differentiating COOH/COO− moieties. A new relationship is also introduced that correlates the asymmetry (i.e., δ11–δ22) of COOH sites to the proximity of hydrogen bond donating partners within 2.6 Å with high accuracy (±0.05 Å). Conversely, a limitation to all proposed metrics is that they fail to distinguish between COO− and hydrogen disordered COOH sites. To reconcile this omission, a new approach is proposed based on T1 measurements of both 1H and 13C. The 13C T1 values are particularly sensitive with the T1 for hydrogen disordered COOH moieties found to be nearly six times smaller than T1's from COO− sites. [ABSTRACT FROM AUTHOR]

Herein, a series of novel 4-chromanone-derived compounds incorporating an acylhydrazone moiety was synthesized and their structures were confirmed using 1H NMR, 13C NMR, and HRMS technologies. Bioassay results demonstrated that some of the target compounds exhibited moderate to good antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicolaby (Xoc), as well as antifungal activities against Lasiodiplodia theobromae (L. theobromae) and Fusarium proliferatum (F. proliferatum). [ABSTRACT FROM AUTHOR]

Sila[1]ferrocenophane bearing a 9-silafluorenylidene moiety (1) as a bridging unit was synthesized and isolated as a stable crystalline compound. Sila[1]ferrocenophane 1, which was newly obtained in this study, was characterized by spectroscopic analyses, a single-crystal X-ray diffraction (SC-XRD) analysis, and electrochemical measurements. Due to the characteristic 9-silafluorenyl moiety, 1 exhibited large electron affinity and a slightly higher oxidation potential relative to that of ferrocene. In addition, 1 was found to undergo ring-opening polymerization (ROP) triggered by thermolysis at a lower temperature relative to that of Ph2Sifc (1′, fc = 1,1′-ferrocenylidene). It also underwent ROP through reduction by KC8 to give the corresponding polymeric compound. The DFT calculations suggested that one-electron reduction of 1 would promote ring-opening polymerization, as shown in the experimental results. [ABSTRACT FROM AUTHOR]

In main group chemistry, the BDI ligand ([HC(C(Me)N(R))2]), more commonly known as NacNac, has proved indispensable over the last two decades. Within this work, we are introducing the hybrid NacNac‐akin ligand 3,3‐dimethyl‐2‐[2‐methyl‐2‐(2,6‐diisopropyl‐aniline)ethenyl]‐3H‐indolenine (DNI). On the basis of this novel ligand, alkali metal complexes [DNI(M1)] [M1=Li (3(OEt2)), Na (4(THF)3), and K (5(THF)3)] have been synthesized by facile deprotonation of the ligand's backbone. The reaction of DNI with AlH3 ⋅ NMe2Et led to the aluminium dihydride compound [DNI‐AlH2] (6) in excellent yield (90 %). Further synthesis of [DNI‐AlI2] (7), which is seen as a potential precursor for the aluminium(I) complex, was realized in the presence of 1.0 equiv. iodine with 6. All products 2–7 were completely characterized by 2D‐NMR, mass spectrometry, elemental analysis and SC‐XRD. Density functional theory calculations were performed to provide better understanding of their bonding characteristics and electronic structures. [ABSTRACT FROM AUTHOR]

Utilizing rhodium complexes to catalyze 2‐vinylbenzaldehyde derivatives has proven to be a valuable strategy in constructing indanone moieties. In this study, the stoichiometric reactions of Wilkinson's catalyst RhCl(PPh3)3 with 2‐vinylbenzaldehyde derivatives were investigated, leading to the formation of rhodaindanone complexes (2). Notably, the transformation of of rhoda‐1‐indanone (2 a) to rhoda‐2‐indanone (3) was achieved for the first time. In comparision, the reactivity of IrCl(PPh3)3 and Ir(CO)(CH3CN)(PPh3)2 ⋅ BF4 towards 2‐vinylbenzaldehyde derivatives affords irida‐2‐indanone complexes (4) and fused iridacycles (5), respectively. These newly prepared coumpounds represent the first metellacycles resulting from the reactions between 2‐vinylbenzaldehyde derivatives and rhodium/iridium complexes and may provide further insights into the catalytic processes involving 2‐vinylbenzaldehyde derivatives for synthesizing indanone compounds. [ABSTRACT FROM AUTHOR]

New cadmium 2,3,4,5-tetrafluorobenzoate (6HTfb) and 2,3,5,6-tetrafluorobenzoate (4Htfb) complexes, [Cd(6HTfb)(H2O)3]n·(6HTfb)·2nH2O (I), [Cd3(Phen)2(6HTfb)6] (II, Phen = 1,10-phenanthroline), [Cd2(Phen)2(4Htfb)4]n·2nH2O (III), and [Cd(Phen)2(4Htfb)2] (IV), were synthesized. Analysis of the obtained results and published data demonstrated that a decrease in the number of fluorine substituents is unfavorable for the formation of coordination polymers comprising stacked alternating fluorinated and non-fluorinated aromatic moieties. In the case of 2,4,5-trifluorobenzoate complex, a typical trivial structure of the binuclear cadmium complex with ligand-shielded metal core is formed. The synthesis of 2,3,4,5- and 2,3,5,6-tetrafluorobenzoate complexes produced an intermediate situation and demonstrated that the structure of complex formation products is affected by not only the number, but also the positions of fluorine substituents. Using quantum chemical calculations, it was shown that the formation of coordination polymers requires a molecular precursor with a Chinese lantern structure stable in solutions, while the formation of unusual flattened binuclear complexes with additionally coordinated water molecules requires doubly bridged binuclear complexes able to switch to a conformation with exposed coordinatively unsaturated metal centers. [ABSTRACT FROM AUTHOR]

A series of substituted ethyl 5-phenyl-1,2-oxazole-3-carboxylates were synthesized in good to excellent yields in one step using hydroxylamine base and ethyl 2,4-dioxo-4-(4-R-phenyl)butanoates bearing both electron-donating and electron-withdrawing moieties on the benzene ring, and antioxidant properties of the products were investigated by the DPPH method. The proposed method is suitable for the large-scale production of isoxazole derivatives. [ABSTRACT FROM AUTHOR]

Several ortho‐carboranes bearing a phenoxy or a phenylamino group in the B9 position were prepared employing various protection and deprotection strategies. Following established protocols, dendritic compounds were synthesized from a hexachlorocyclotriphosphazene or thiophosphoryl chloride core, and possible anchoring options for the B9‐substituted ortho‐carboranes were investigated experimentally and theoretically (DFT). Furthermore, 1‐ or 1,2‐phosphanyl‐substituted carborane derivatives were obtained. The resulting diethyl‐, diisopropyl‐, di‐tert‐butyl‐, diphenyl‐ or diethoxyphosphines bearing a tunable ortho‐carborane moiety are intriguing ligands for future applications in homogeneous catalysis or the medicinal sector. [ABSTRACT FROM AUTHOR]

A convenient and versatile approach to important 1‐azaspirocyclic systems relevant to medicinal chemistry and natural products is reported herein. The main strategy relies on a reductive decarboxylative cyclization of redox‐active esters which can be rapidly assembled from abundant cyclic azaacids and tailored acceptor sidechains, with a focus on alkyne acceptors enabling the generation of useful exo‐alkene moieties. Diastereoconvergent variants were studied and could be achieved either through remote stereocontrol or conformational restriction in bicyclic carbamate substrates. Two sets of metal‐free photocatalytic conditions employing inexpensive eosin Y were disclosed and studied experimentally to highlight key mechanistic divergences. [ABSTRACT FROM AUTHOR]

Due to their favorable chemical features, Re and Tc complexes have been widely used for the development of new therapeutic agents and imaging probes to solve problems of biomedical relevance. This review provides an update of the most relevant research efforts towards the development of novel cancer theranostic agents using Re and Tc‐based compounds interacting with specific DNA structures. This includes a variety of homometallic complexes, namely those containing M(CO)3 (M=Re, Tc) moieties, that exhibit different modes of interaction with DNA, such as covalent binding, intercalation, groove binding or G‐quadruplex DNA binding. Additionally, heterometallic complexes, designed to potentiate synergistic effects of different metal centers to improve DNA‐targeting, cytotoxicity and fluorescence properties, are also reviewed. Particular attention is also given to 99mTc‐ and 188Re‐labeled oligonucleotides that have been widely explored to develop imaging and therapeutic radiopharmaceuticals through the in vivo hybridization with a specific complementary DNA or RNA target sequence to provide useful molecular tools in precision medicine for cancer diagnosis and treatment. Finally, the need for further improvement of DNA‐targeted Re and Tc‐based compounds as potential therapeutic and diagnostic agents is highlighted, and future directions are discussed. [ABSTRACT FROM AUTHOR]

A convenient protocol for the synthesis of 25,26,27-tribenzoyl-28-[((S)-1-diphenylphos- phanyl-propan-2-yl)oxy]-calix[4]arene via stereospecific methylation on Evans' oxazolidinone moiety was reported. According to the 13C NMR analysis of this phosphine, the calix[4]arene skeleton adopted a 1,3-alternate conformation. The latter conformation of the macrocycle and the (S)-chirality of the carbon atom bearing the methyl substituent were confirmed by a single-crystal X-ray diffraction study. After coordination of the phosphinated ligand to the dimeric [RuCl2(p-cymene)]2 organometallic precursor, the resulting arene–ruthenium complex was tested in the asymmetric reduction of acetophenone and alcohol was obtained with modest enantiomeric excess. [ABSTRACT FROM AUTHOR]

Molecular hybridization represents a new approach in drug discovery in which specific chromophores are strategically combined to create novel drugs with enhanced therapeutic effects. This innovative strategy leverages the strengths of individual chromophores to address complex biological challenges, synergize beneficial properties, optimize pharmacokinetics, and overcome limitations associated with single-agent therapies. Coumarins are documented to possess several bioactivities and have therefore been targeted for combination with other active moieties to create molecular hybrids. This review summarizes recent (2013–2023) trends in the synthesis of coumarins, as well as coumarin–chalcone and coumarin–triazole molecular hybrids. To cover the wide aspects of this area, we have included differently substituted coumarins, chalcones, 1,2,3– and 1,2,4–triazoles in this review and considered the point of fusion/attachment with coumarin to show the diversity of these hybrids. The reported syntheses mainly relied on well-established chemistry without the need for strict reaction conditions and usually produced high yields. Additionally, we discussed the bioactivities of the reported compounds, including antioxidative, antimicrobial, anticancer, antidiabetic, and anti-cholinesterase activities and commented on their IC50 where possible. Promising bioactivity results have been obtained so far. It is noted that mechanistic studies are infrequently found in the published work, which was also mentioned in this review to give the reader a better understanding. This review aims to provide valuable information to enable further developments in this field. [ABSTRACT FROM AUTHOR]

A series of new disulfides incorporating naphthalimide moiety were designed, synthesized and biologically evaluated against three human cancer cell lines (MCF-7, SMMC-7721 and Hela). Most of target compounds exhibited some degrees of anticancer activities, and some compounds displayed better effects than reference drugs PX-12 and 5-FU against the tested three cancer cells. Especially, compound 7d showed the most potent antiproliferative activity against MCF-7 cell lines with IC50 value of 3.19 μM. Compound 8a displayed prominent anticancer property against SMMC-7721 cell lines with IC50 value of 1.84 μM. Compound 6c possessed the most effective proliferation inhibitory activity against Hela cell lines with IC50 value of 2.14 μM. In addition, cytotoxicity evaluation indicated that most of the compounds had weak cytotoxicity to L929 cell lines. [ABSTRACT FROM AUTHOR]

A total of eighteen novel 2-(1H-indol-1-yl)-N-(5-phenyl-1,3,4-thiadiazol-2-yl) acetamide derivatives were synthesized through the condensation reaction of 2-(1H-indol-1-yl) acetic acid and 5-phenyl1,3,4-thiadiazol-2-amine via fragment-based design strategy. The target compounds were subjected to screening for antibacterial activity against Xanthomonas oryzae pv. Oryzae, Xanthomonas axonopodis pv. Citri and Pseudomonas syringae pv. Actinidiae. The preliminary antibacterial evaluation of the target compounds showed that some target compounds possessed moderate to good activities against Xoo and Xac. Among them, compound 3p exhibited best inhibition effects against Xoo (77.85% and 62.15%, respectively) and Xac (52.51% and 36.48%, respectively) at 100 lg/mL and 50 lg/mL, which were superior to Thiodiazole-copper and Bismerthiazol. To the best of our knowledge, it is the first report on the design, synthesis, and antibacterial evaluation of novel indole-derived compounds containing 1,3,4-thiadiazole and amide moieties. [ABSTRACT FROM AUTHOR]

Compared to ubiquitous functional groups such as alcohols, carboxylic acids, amines, and amides, which serve as central "actors" in most organic reactions, sulfamates, phosphoramidates, and di‐tert‐butyl silanols have historically been viewed as "extras". Largely considered functional group curiosities rather than launch‐points of vital reactivity, the chemistry of these moieties is under‐developed. Our research program has uncovered new facets of reactivity of each of these functional groups, and we are optimistic that the chemistry of these fascinating molecules can be developed into truly general transformations, useful for chemists across multiple disciplines. In the ensuing sections, I will describe our efforts to develop new reactions with these "unusual" functional groups, namely sulfamates, phosphoramidates, and di‐tert‐butyl silanols. [ABSTRACT FROM AUTHOR]

The tendency of two pinane derivatives of fluoroquinolone to crystallize with two independent molecules in the unit cell is revealed. In these molecules, the geometry of achiral fluoroquinolone moieties is mirror symmetric at the identical configuration of the pinnae core. Prostereogenic groups in the bridge between the bicycloheptene and fluoroquinolone fragments support the mirror symmetry of the achiral moiety. They are organized by intra- and intermolecular interactions, oppositely to independent molecules. [ABSTRACT FROM AUTHOR]

Recent and intriguing research demonstrates that post-translational modification (PTM) events can act in a local-dependent manner in addition to the traditional sequence-dependent manner. We propose the spray-type PTM concept and describe a mechanism that focuses on the exposure level of reactive electrophilic substrate molecules at the active sites of PTM enzymes. Spray-type PTMs involve chemical interactions between electrophilic groups and nucleophilic moieties that are in close proximity, resembling the principles behind contemporary proximity labeling techniques. We further propose that spray-type PTMs play crucial roles in the simultaneous regulation of proteins within the same location, which are crucial for efficient responses to various stressors such as DNA breaks, heat shock stress, or viral infection. A post-translational modification (PTM) occurs when a nucleophilic residue (e.g., lysine of a target protein) attacks electrophilic substrate molecules (e.g., acyl-AMP), involving writer enzymes or even occurring spontaneously. Traditionally, this phenomenon was thought to be sequence specific; however, recent research suggests that PTMs can also occur in a non-sequence-specific manner confined to a specific location in a cell. In this Opinion, we compile the accumulated evidence of spray-type PTMs and propose a mechanism for this phenomenon based on the exposure level of reactive electrophilic substrate molecules at the active site of the PTM writers. Overall, a spray-type PTM conceptual framework is useful for comprehending the promiscuous PTM writer events that cannot be adequately explained by the traditional concept of sequence-dependent PTM events. [ABSTRACT FROM AUTHOR]

The simple, economic, and conventional diazo-coupling method was developed for the synthesis of five different scaffolds of sulfadiazine incorporated azo dyes in acidic medium at chilled condition. The structural aspects of the prepared azo dyes were confirmed by various physical and spectroscopic techniques such as elemental analysis, electronic absorption studies, infrared, nuclear magnetic resonance (1H and 13C), and mass spectrometry. The electronic absorption study indicates that all the prepared azo dyes possess excellent coloring properties and it is supported by its molar absorptivity values. Further, these azo colorants were examined for different biological studies such as antimicrobial assay, radical scavenging, antituberculosis, anti-inflammatory, and DNA cleavage studies. From the results, all the studied azo dyes showed provoked and proficient biological efficacy against the tested assays. [ABSTRACT FROM AUTHOR]

Glioma stem cell/glioma-initiating cell (GIC) and their niches are considered responsible for the therapeutic resistance and recurrence of malignant glioma. To clarify the molecular mechanisms of GIC maintenance/differentiation, we performed a unique integrated proteogenomics utilizing GIC clones established from patient tumors having the potential to develop glioblastoma. After the integration and extraction of the transcriptomics/proteomics data, we found that chondroitin sulfate proteoglycan 4 (CSPG4) and its glycobiosynthetic enzymes were significantly upregulated in GICs. Glyco-quantitative PCR array revealed that chondroitin sulfate (CS) biosynthetic enzymes, such as xylosyltransferase 1 (XYLT1) and carbohydrate sulfotransferase 11, were significantly downregulated during serum-induced GIC differentiation. Simultaneously, the CS modification on CSPG4 was characteristically decreased during the differentiation and also downregulated by XYLT1 knockdown. Notably, the CS degradation on CSPG4 by ChondroitinaseABC treatment dramatically induced GIC differentiation, which was significantly inhibited by the addition of CS. GIC growth and differentiation ability were significantly suppressed by CSPG4 knockdown, suggesting that CS-CSPG4 is an important factor in GIC maintenance/differentiation. To understand the molecular function of CS-CSPG4, we analyzed its associating proteins in GICs and found that CSPG4, but not CS-CSPG4, interacts with integrin aV during GIC differentiation. This event sequentially upregulates integrin-extracellular signal-regulated kinase signaling, which can be inhibited by cyclic-RGD (Arg-Gly-Asp) integrin aV inhibitor. These results indicate that CS-CSPG4 regulates the GIC microenvironment for GIC maintenance/differentiation via the CS moiety, which controls integrin signaling. This study demonstrates a novel function of CS on CSPG4 as a niche factor, so-called "glyco-niche" for GICs, and suggests that CS-CSPG4 could be a potential target for malignant glioma. [ABSTRACT FROM AUTHOR]

Azobenzenes are a series of compounds that can be isomerized upon irradiation with light. These molecules can modify the physical, chemical, and biological properties of a diverse range of materials. They can control protein structure and function with temporal and spatial precision. In this work, we investigated the possible interaction between azobenzene and aromatic amino acids. We hypothesized that aromatic amino acids, such as tryptophan, would show altered photochemical properties when conjugated with azobenzene. When irradiated at either 365 nm or 465 nm, the molecule now lacks the usually characteristic photoswitch capabilities and is visibly fluorescent at 365 nm. To our knowledge, this is the first evidence to suggest that primary protein structure could affect photoswitch activity. The knowledge gained from this research will help to further the understanding of azobenzenes as they are used in biomolecules. [ABSTRACT FROM AUTHOR]

This article discusses the challenges of developing new antibiotics, particularly for the gram-negative bacteria Pseudomonas aeruginosa. The lack of therapeutic options for this bacteria is concerning, as it is classified as a "serious threat" by the CDC and has high rates of antibiotic resistance. The article presents permeation guidelines for P. aeruginosa, which can help in designing small molecules that can effectively penetrate the bacteria and gain intracellular access. These guidelines differ from those for another gram-negative bacteria, Escherichia coli, and provide insights into the physiological differences between the two bacteria. The article suggests that these permeation guidelines can aid in the development of new antibiotics by enhancing the accumulation of candidate drugs. [Extracted from the article]

Sulfur-containing oligomers comprising C—S—C and C—S—S—C moieties were syntesized via the condensation of 1,2-dichloroethane with a mixture of potassium sulfide and disulfide. Cleavage of disulfide bonds in these oligomers with the hydrazine hydrate–KOH system led to the formation of α,ω-potassium dithiolates containing several ethylene sulfide S—C—C—S moieties in the chain. Alkylation of the dithiolates with iodomethane allowed obtaining compounds containing monosulfide moieties. Such compounds can be used as extractants, sorbents, and catalysts and can find applications in various fields, including microbiology, biotechnology, medicine, and agriculture. [ABSTRACT FROM AUTHOR]

Among various catalysts for the alkylation of aniline with camphene, aluminum phenolate was found to be the most effective for the synthesis of N-isobornylaniline. Studies of the antioxidant properties of terpenylanilines on various in vitro models revealed a significant dependence of their activity on the position and structure of the terpene moiety, the choice of the method for assessing the antioxidant properties being also dependent on their structure. [ABSTRACT FROM AUTHOR]

Diarylethene (DAE) molecular photoswitches draw attention as building units in the preparation of diverse photoactive molecules. An interesting class of these molecules are photoactive peptides. A way to build DAE moiety into peptides/peptidomimetics is via DAE amino acids, an example of which has been demonstrated in bioactive cyclic peptides, wherein the DAE Fmoc-amino acid was prepared and used. Herein, the preparation of DAE Boc-amino acid is presented using a modified method of synthesis. This contribution to the DAE amino acid collection could be useful in the further enhancement of diversity in designing different routes to photoactive peptides. [ABSTRACT FROM AUTHOR]

The present paper describes the preparation and characterization of a new dinuclear ligand based on terpyridine featuring a diselenide unit. This new compound was synthesized in a two-step procedure that first involved the insertion of the diselenide moiety on a carboxylic acid and was followed by a Steglich esterification reaction between the biscarboxylic acid containing the diselenide unit and 2,6-di(pyridin-2-yl)pyridin-4-ol (tpyOH). The title compound was characterized via FT-IR, Raman, NMR (1D and 2D), and UV-Vis spectroscopies and elemental analysis. Emission properties were investigated. [ABSTRACT FROM AUTHOR]

Activation of nuclear factor erythroid 2-related factor 2 (Nrf2) by Kelch-like ECH-associated protein 1 (Keap1) alkylation plays a central role in anti-inflammatory therapy. However, activators of Nrf2 through alkylation of Keap1-Kelch domain have not been identified. Deoxynyboquinone (DNQ) is a natural small molecule discovered from marine actinomycetes. The current study was designed to investigate the anti-inflammatory effects and molecular mechanisms of DNQ via alkylation of Keap1. DNQ exhibited significant anti-inflammatory properties both in vitro and in vivo. The pharmacophore responsible for the anti-inflammatory properties of DNQ was determined to be the α, β-unsaturated amides moieties by a chemical reaction between DNQ and N -acetylcysteine. DNQ exerted anti-inflammatory effects through activation of Nrf2/ARE pathway. Keap1 was demonstrated to be the direct target of DNQ and bound with DNQ through conjugate addition reaction involving alkylation. The specific alkylation site of DNQ on Keap1 for Nrf2 activation was elucidated with a synthesized probe in conjunction with liquid chromatography-tandem mass spectrometry. DNQ triggered the ubiquitination and subsequent degradation of Keap1 by alkylation of the cysteine residue 489 (Cys489) on Keap1-Kelch domain, ultimately enabling the activation of Nrf2. Our findings revealed that DNQ exhibited potent anti-inflammatory capacity through α, β-unsaturated amides moieties active group which specifically activated Nrf2 signal pathway via alkylation/ubiquitination of Keap1-Kelch domain, suggesting the potential values of targeting Cys489 on Keap1-Kelch domain by DNQ-like small molecules in inflammatory therapies. [Display omitted] • Small molecule DNQ exhibits potent anti-inflammatory effects via activation of Nrf2. • Target of DNQ was elucidated with a synthesized probe combined with Click Chemistry. • DNQ activates Nrf2 through alkylation and ubiquitination of Keap1-Kelch domain. • DNQ loses the anti-inflammatory capacity when site mutation of Keap1 at Cys489. [ABSTRACT FROM AUTHOR]

BACKGROUND: Plant bacterial infections and plant viruses seriously affect the yield and quality of crops. Based on the various activities of tryptanthrin, a series of tryptanthrin analogues bearing F and piperazine moieties were designed, synthesized, and evaluated for their biological activities against three plant bacteria and tobacco mosaic virus (TMV). RESULTS: Bioassay results indicated that compounds 6a–6l displayed excellent antibacterial activities in vitro and 6a–6c and 6g exhibited better antiviral activities against TMV than commercial ribavirin. In particular, 6b showed the most effect on Xanthomonas oryzae pv. oryzae (Xoo) with a half‐maximal effective concentration (EC50) of 1.26 μg mL−1, compared with the commercial pesticide bismerthiazol (BT; EC50 = 34.3 μg mL−1) and thiodiazole copper (TC; EC50 = 73.3 μg mL−1). Meanwhile, 6a also had the best antiviral activity at 500 μg mL−1 for curative, protection, and inactivation purposes, compared with ribavirin in vivo. CONCLUSION: Compound 6b could cause changes in bacterial morphology, induce the accumulation of reactive oxygen species, promote apoptosis of bacterial cells, inhibit the formation of biofilm, and block the growth of Xoo cells. Proteomic analysis revealed major differences in the bacterial secretory system pathways T2SS and T6SS, which inhibited membrane transport. Molecular docking revealed that 6a and 6g could interact with TMV coat protein preventing virus assembly. These results suggest that tryptanthrin analogues bearing F and piperazine moieties could be promising candidate agents for antibacterial and antiviral use in agricultural production. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Machine learning models have found numerous successful applications in computational drug discovery. A large body of these models represents molecules as sequences since molecular sequences are easily available, simple, and informative. The sequence‐based models often segment molecular sequences into pieces called chemical words, analogous to the words that make up sentences in human languages, and then apply advanced natural language processing techniques for tasks such as de novo drug design, property prediction, and binding affinity prediction. However, the chemical characteristics and significance of these building blocks, chemical words, remain unexplored. To address this gap, we employ data‐driven SMILES tokenization techniques such as Byte Pair Encoding, WordPiece, and Unigram to identify chemical words and compare the resulting vocabularies. To understand the chemical significance of these words, we build a language‐inspired pipeline that treats high affinity ligands of protein targets as documents and selects key chemical words making up those ligands based on tf–idf weighting. The experiments on multiple protein–ligand affinity datasets show that despite differences in words, lengths, and validity among the vocabularies generated by different subword tokenization algorithms, the identified key chemical words exhibit similarity. Further, we conduct case studies on a number of target to analyze the impact of key chemical words on binding. We find that these key chemical words are specific to protein targets and correspond to known pharmacophores and functional groups. Our approach elucidates chemical properties of the words identified by machine learning models and can be used in drug discovery studies to determine significant chemical moieties. [ABSTRACT FROM AUTHOR]

SWI/SNF enzymes are heterogeneous multi-subunit complexes that utilize the energy from ATP hydrolysis to remodel chromatin structure, facilitating transcription, DNA replication, and repair. In mammalian cells, distinct sub-complexes, including cBAF, ncBAF, and PBAF exhibit varying subunit compositions and have different genomic functions. Alterations in the SWI/SNF complex and sub-complex functions are a prominent feature in cancer, making them attractive targets for therapeutic intervention. Current strategies in cancer therapeutics involve the use of pharmacological agents designed to bind and disrupt the activity of SWI/SNF complexes or specific sub-complexes. Inhibitors targeting the catalytic subunits, SMARCA4/2, and small molecules binding SWI/SNF bromodomains are the primary approaches for suppressing SWI/SNF function. Proteolysis-targeting chimeras (PROTACs) were generated by the covalent linkage of the bromodomain or ATPase-binding ligand to an E3 ligase-binding moiety. This engineered connection promotes the degradation of specific SWI/SNF subunits, enhancing and extending the impact of this pharmacological intervention in some cases. Extensive preclinical studies have underscored the therapeutic potential of these drugs across diverse cancer types. Encouragingly, some of these agents have progressed from preclinical research to clinical trials, indicating a promising stride toward the development of effective cancer therapeutics targeting SWI/SNF complex and sub-complex functions. [ABSTRACT FROM AUTHOR]

A degradable acetal‐backboned polymer was developed via palladium‐catalyzed hydroalkoxylation of dialkoxyallenes with diols. Dialkoxyallenes were easily prepared from the corresponding diols through propargylation, followed by isomerization. Polymers were synthesized from the various combinations of diols and dialkoxyallens in the presence of a palladium catalyst to produce the acrolein acetal linkages. While the acetal backbones were completely degraded into the corresponding diols, the recycling of the polymer with 1,4‐benzenedimethanol was also demonstrated. The vinyl moiety in the newly generated acrolein acetals allowed for the thiol‐ene reaction, thereby providing a promising approach for the further applications of the polymer. [ABSTRACT FROM AUTHOR]

A method has been developed for synthesizing [FeFe]-H2ase mimics with diverse structures and properties, employing cross-metathesis of olefins. Vinylmetallocenes (5 and 6) and vinyl half-sandwich complexes (10 and 11) have been used as cross-metathesis partners with [FeFe]-H2ase mimics (4, 8, and 9) bearing a double bond in the moiety attached to the ADT-bridge nitrogen. Electrochemical studies of these complexes, encompassing metallocene-type (7a–b, 12a–b, and 13a–b) as well as half-sandwich derivatives (12c and 13c–d), have demonstrated that the introduction of a redox unit has a marginal impact on the reduction potential of these [FeFe]-H2ase mimics. The application of this cross-metathesis approach has allowed the synthesis of [FeFe]-H2ase mimics featuring an Ir(III) electrochemical antenna (16–18) as well as systems having an electron-donor-photosensitizer structure (ED-PS) (23). The electrocatalytic properties of these complexes have been elucidated through electrochemical studies. [ABSTRACT FROM AUTHOR]

A general synthesis and the characterization of novel alkyl‐substituted NHC‐stabilized pnictogenylboranes NHC ⋅ BH2ER2 (NHC=N‐heterocyclic carbene, E=P, As; R2=Me2, Ph2, tBuH, Cy2, (SiMe3)2) are reported. These compounds were reacted with Ni(CO)4 to the corresponding complexes of the type [(NHC ⋅ BH2ER2)Ni(CO)3] to determine their donor strength by Tolman Electronic Parameters (TEPs) and their steric demand as ligands compared to classical phosphines, superbasic phosphines and other commonly applied donor systems. The results show that the NHC‐stabilized pnictogenyltrielanes can be considered as being highly basic, while their steric influence depends strongly on the organic residues as well as the donor attached to the {BH2} moiety. Although weaker than commonly used superbasic phosphines, the donor strength of pnictogenyltrielanes in general can be classified as of similar strength as NHCs. The steric and electronic properties can easily be modified by alkyl substitution as evident from the TEP trends. [ABSTRACT FROM AUTHOR]

Organic thiocyanates are an important class of compounds because they are present in several bioactive molecules and can be used as key synthetic intermediates to access biorelevant sulfur‐containing scaffolds. Although the chemistry of organothiocyanates has been studied for decades, a recent resurgence of interest in the field has led to major advances in the synthesis of new molecules bearing a thiocyanate moiety. An emerging and powerful strategy consists in the selective functionalization of C(sp3)‐H bonds through the formation of a key C‐centered radical intermediate. This review highlights the recent work that has been reported to access novel alkylthiocyanate scaffolds through this promising approach. [ABSTRACT FROM AUTHOR]

A lipid cubic phase encompassing a cross-linked siloxane structure was formed by the self-assembly of a synthetic organoalkoxysilane lipid in water. The spontaneous sol–gel reaction of the alkoxysilane moiety on the lipid head group produced an organic–inorganic hybrid material with a double gyroid Ia3d cubic structure. [ABSTRACT FROM AUTHOR]

Exploring unique single‐atom sites capable of efficiently reducing O2 to H2O2 while being inert to H2O2 decomposition under light conditions is significant for H2O2 photosynthesis, but it remains challenging. Herein, we report the facile design and fabrication of polymeric carbon nitride (CN) decorated with single‐Zn sites that have tailorable local coordination environments, which is enabled by utilizing different Zn salt anions. Specifically, the O atom from acetate (OAc) anion participates in the coordination of single‐Zn sites on CN, forming asymmetric Zn−N3O moiety on CN (denoted as CN/Zn−OAc), in contrast to the obtained Zn−N4 sites when sulfate (SO4) is adopted (CN/Zn−SO4). Both experimental and theoretical investigations demonstrate that the Zn−N3O moiety exhibits higher intrinsic activity for O2 reduction to H2O2 than the Zn−N4 moiety. This is attributed to the asymmetric N/O coordination, which promotes the adsorption of O2 and the formation of the key intermediate *OOH on Zn sites due to their modulated electronic structure. Moreover, it is inactive for H2O2 decomposition under both dark and light conditions. As a result, the optimized CN/Zn−OAc catalyst exhibits significantly improved photocatalytic H2O2 production activity under visible light irradiation. [ABSTRACT FROM AUTHOR]

Enantio‐ and diastereoselective dearomative [4+2]‐cycloaddition reaction between N,N‐dimethylhydrazone derived from 9‐anthracenecarboxaldehyde and α,β‐unsaturated aldehydes is reported. The developed strategy utilizes HOMO‐rising activation of diene (via hydrazone formation) and aminocatalytic LUMO‐lowering activation of dienophile (via iminium ion formation). High chemical and stereochemical efficiency have been obtained owing to the application of Jørgensen catalyst. Target cycloadducts were subjected to selected transformations aiming at unmasking the hydrazone moiety that proceeded with preservation of optical purity introduced in the organocatalytic step. [ABSTRACT FROM AUTHOR]

An array of enantioenriched vinyl boronates bearing an allylic carbonate moiety have been prepared through selective hydroboration of propargyl carbonates. Treatment of these vinyl boronates with TBAF in THF affords enantioenriched 1,3‐disubstituted allenes through a novel 1,2‐anti elimination in good yields and high enantiospecificities. [ABSTRACT FROM AUTHOR]

A new polyamide bearing vinylcyclopropane (VCP) moieties in the main chain was synthesized from a diamine bearing a VCP moiety. Thermal properties of the resulting polyamide were evaluated by thermogravimetry (TG) and differential scanning calorimetry. TG clarified that the polyamide was much more heat resistant than that of the analogous linear polyurea reported previously, implying that the VCP moieties in the polyamide underwent thermally induced ring-opening reaction to enable cross-linking of the polyamide. The polyamide was cross-linked also by ring-opening reaction triggered by addition of thiyl radical to the vinyl group, demonstrating the usefulness of VCP structure for designing cross-linkable polymers. Polycondensation of diamine bearing a vinylcyclopropane moiety with an acid dichloride proceeded smoothly, affording a novel reactive polyamide bearing vinylcyclopropane moieties in the main chain. The synthesized linear polyamide exhibited much higher thermal resistance compared to the analogous linear polyurea. In addition, the linear polymer underwent cross-linking reaction with a dithiol via ring-opening reactions to produce a cross-linked polymer, suggesting that the introduction of vinylcyclopropane moiety into polymer structure enable an application for polymer reactions. [ABSTRACT FROM AUTHOR]

Herein, we present that the radicals [Ph3PC(Me)EMes2]˙ (2Si and 2Ge) can be generated from the α-silylated and α-germylated phosphorus ylides Ph3PC(Me)E(Cl)Mes2 (1Si and 1Ge) through one-electron reduction with Jones' dimer (MesNacNacMg)2 in benzene. Although isolation of the free radicals was not possible, the products of the intramolecular addition of the radicals to a phenyl substituent of the phosphorus moiety, followed by subsequent reaction with 2Si or 2Ge to the isolated species 3Si and 3Ge, respectively, were observed. This transformation witnesses a dearomative 1,4-addition of tetryl radical species to the phenyl scaffold in a stereoselective anti-fashion. [ABSTRACT FROM AUTHOR]

A series of novel azepine derivatives based on quinazolinone moiety was synthesized through the reaction of quinazolinone chalcones (2a–d) either with 2-amino aniline in acidic medium to give diazepines (3a–d) or with 2-aminophenol to offer oxazepine (4a–d). The structure of the synthesized compounds was confirmed via melting points, elemental analyses, and different spectroscopic techniques. Moreover, these newly compounds mode of action was investigated in-silico using molecular docking against the outer membrane protein A (OMPA), exo-1,3-beta-glucanase for their antimicrobial activity, and against Smoothened (SMO), transcription factor glioma-associated homology (SUFU/GLI-1), the main proteins of Hedgehog signaling pathway to inspect their anticancer potential. Our results showed that, diazepine (3a) and oxazepine (4a) offered the highest binding energy against the target OMPA/ exo-1,3-beta-glucanase proteins and exhibited the potent antimicrobial activities against E. coli, P. aeruginosa, S. aureus, B. subtilis, C. Albicans and A. flavus. As well, diazepine (3a) and oxazepine (4a) achieved the best results among the other compounds, in their binding energy against the target SMO, SUFU/GLI-1 proteins. The in-vitro cytotoxic study was done for them on panel of cancer cell lines HCT-116, HepG2, and MCF-7 and normal cell line WI-38. Conclusively, it was revealed that molecular docking in-silico simulations and the in-vitro experiments were agreed. As a result, our findings elucidated that diazepine (3a) and oxazepine (4a), have the potential to be used as antimicrobial agents and as possible cancer treatment medications. [ABSTRACT FROM AUTHOR]