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Chiral quantum dots (QDs) are promising materials applied in many areas, such as chiral molecular recognition and spin selective filter for charge transport, and can be prepared by facile ligand exchange approaches. However, ligand exchange leads to an increase in surface defects and reduces the efficiencies of radiative recombination and charge transport, which restricts further applications. Here, we investigate the light-induced photoluminescence (PL) enhancement in chiral L- and D-cysteine CdSe QD thin films, providing a strategy to increase the PL. The PL intensity of chiral CdSe QD films can be significantly enhanced over 100 times by continuous UV laser irradiation, indicating a strong passivation of surface defects upon laser irradiation. From the comparative measurements of the PL intensity evolutions in vacuum, dry oxygen, air, and humid nitrogen atmospheres, we conclude that the mechanism of PL enhancement is photo-induced surface passivation with the assistance of water molecules. [ABSTRACT FROM AUTHOR]

Ammonium and carboxylic moieties play a central role in proton-mediated processes of molecular recognition, charge transfer or chemical change in (bio)materials. Whereas both chemical groups constitute acid–base pairs in organic salt-bridge structures, they may as well host excess protons in acidic environments. The binding of excess protons often precedes proton transfer reactions and it is therefore of fundamental interest, though challenging from a quantum chemical perspective. As a benchmark for this process, we investigate proton storage in the amphoteric compound 5-aminovaleric acid (AV), within an intramolecular proton bond shared by its primary amine and carboxylic acid terminal groups. Infrared ion spectroscopy is combined with ab initio Molecular Dynamics (AIMD) calculations to expose and rationalize the spectral signatures of protonated AV and its deuterated isotopologues. The dynamic character of the proton bond confers a fluxional structure to the molecular framework, leading to wide-ranging bands in the vibrational spectrum. These features are reproduced with remarkable accuracy by AIMD computations, which serves to lay out microscopic insights into the excess proton binding scenario. [ABSTRACT FROM AUTHOR]

A one-pot synthetic protocol to access a diverse library of diamide–diester macrocycles from the same starting materials is reported. The molecular symmetry can be readily tuned based on the reaction sequence, while the core structure can be varied using amino acids and aromatic building blocks. The first class of macrocycles with C2 axes in their molecular plane were obtained in 24 h with 40–70% yield, while another class with C2 axes perpendicular to the plane were synthesized in 18 h in 10–30% yield. The phenyl- and serine-derived macrocycles of the first class could bind acetate, chloride, and phosphate ions. These macrocycles can be functionalized with hydrophobic groups and potentially be used as ion transporters. [ABSTRACT FROM AUTHOR]

The development of complex molecular scaffolds with defined folding properties represents a central challenge in chemical research. Proteins are natural scaffolds defined by a hierarchy of structural complexity and have evolved to manifest unique functional characteristics; for example, molecular recognition capabilities that facilitate the binding of target molecules with high affinity and selectivity. Utilizing these features, proteins have been used as a starting point for the design of synthetic foldamers and enhanced biocatalysts, as well as bioactive reagents in drug discovery. In this account, we describe the strategies used in our group to stabilize protein folds, ranging from the constraint of bioactive peptide conformations to chemical protein engineering. We discuss the evolution of peptides into peptidomimetics to inhibit protein–protein and protein–nucleic acid interactions, and the selective chemical modification of proteins to enhance their properties for biotechnological applications. The reported peptide- and proteomimetic structures cover a broad range of molecular sizes and they highlight the importance of structure stabilization for the design of functional biomimetics. 1 Introduction 2 Constraining the Conformation of Peptides 3 Peptide-Based Covalent Protein Modifiers 4 Chemical Protein Engineering 5 Conclusions [ABSTRACT FROM AUTHOR]

The aim of this work is the development of a biomimetic strategy involving a molecular recognition mechanism using aptamers immobilized on a solid support for the analysis of the mycotoxin zearalenone (ZEA) and two of its derivatives in human urine: alpha-zearelenol (α-ZEL) and beta-zearelenol (β-ZEL). Three oligonucleotide sequences reported in the literature as being specific to ZEA were thus covalently grafted onto activated sepharose, and a thorough study of the percolation and washing conditions was performed to promote the selective retention of the three targeted compounds. With the optimized extraction procedure, a strong and selective retention was obtained for ZEA and to a lesser extent α-ZEL and β-ZEL, with extraction recoveries of 88±9%, 77±15%, and 45±12% respectively, in standard solutions. Application of this procedure to spiked human urine strongly highlighted the efficiency of the clean-up effect resulting from the use of this selective sorbent. Limits of quantification of the whole analytical procedure including extraction on oligosorbent and LC-MS analysis were 0.18 and 0.24 ng mL−1, for ZEA and α-ZEL, respectively, thus demonstrating clearly the potential of the developed method for monitoring human dietary exposure to these compounds. [ABSTRACT FROM AUTHOR]

Angiotensin II (Ang II) is a peptide hormone that causes vasoconstriction and an increase in blood pressure. Due to its relationship with cardiovascular diseases, it is an important biomarker in blood serum. In this study, Ang II imprinted nanoparticles were synthesized by miniemulsion polymerization reaction for the determination of Ang II from human serum. Hydroxyethyl methacrylate (HEMA) based Ang II imprinted (Ang II‐MIPnp) and non‐imprinted nanoparticles (NIPnp) were synthesized, characterized by zeta size analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectrophotometer (FTIR‐ATR). The average particle size of the NPs was recorded as 50 nm. Ang II molecules were successfully removed from the Ang II‐MIPnp with a 98% success rate using 0.5 M NaCl solution to obtain template‐specific cavities. Then, the adsorption studies were achieved. The binding capacity was found as 4500 pg. g−1 at 700 pg. mL−1 Ang II concentration. The selectivity studies showed that Ang II‐MIPnp can recognize Ang II molecules 2.76 times and 3.23 times selectivity than Ang I and Vsp respectively. Reusability studies shows that the synthesized nanomaterial is reusable. [ABSTRACT FROM AUTHOR]

Receptors for carboxylate anions have many possible biomedical applications, including mimicry of the vancomycin group of antibiotics. However, binding carboxylates in water, the biological solvent, is highly challenging due to the hydrophilicity of these polar anions. Here we report, for the first time, the recognition of simple carboxylates such as acetate and formate in water by synthetic receptors with charge‐neutral binding sites. The receptors are solubilised by polyanionic side‐chains which, remarkably, do not preclude anion binding. The tricyclic structures feature two identical binding sites linked by polyaromatic bridges, capable of folding into closed, twisted conformations. This folding is hypothesised to preorganise the structures for anion recognition, mimicking the process which generates many protein binding sites. The architecture is suitable for elaboration into enclosed structures with potential for selective recognition of biologically relevant carboxylates. [ABSTRACT FROM AUTHOR]

An efficient strategy for high‐performance chiral materials is to design and synthesize host molecules with left‐ and right‐ (M‐ and P‐)twisted conformations and to control their twisted conformations. For this, a quantitative analysis is required to describe the chiroptical inversion, chiral transfer, and chiral recognition in the host‐guest systems, which is generally performed using circular dichroism (CD) and/or proton nuclear magnetic resonance (1H NMR) spectroscopies. However, the mass‐balance model that considers the M‐ and P‐twisted conformations has not yet been established. In this study, we derived the novel equations based on the mass‐balance model for the 1 : 1 host‐guest systems. Then, we further applied them to analyze the 1 : 1 host‐guest systems for the achiral calixarene‐based capsule molecule, achiral dimeric zinc porphyrin tweezer molecule, and chiral pillar[5]arene with the chiral and/or achiral guest molecules by using the data obtained from the CD titration, variable temperature CD (VT−CD), and 1H NMR experiments. The thermodynamic parameters (ΔH and ΔS), equilibrium constants (K), and molar CD (Δϵ) in the 1 : 1 host‐guest systems could be successfully determined by the theoretical analyses using the derived equations. [ABSTRACT FROM AUTHOR]

Receptors for carboxylate anions have many possible biomedical applications, including mimicry of the vancomycin group of antibiotics. However, binding carboxylates in water, the biological solvent, is highly challenging due to the hydrophilicity of these polar anions. Here we report, for the first time, the recognition of simple carboxylates such as acetate and formate in water by synthetic receptors with charge‐neutral binding sites. The receptors are solubilised by polyanionic side‐chains which, remarkably, do not preclude anion binding. The tricyclic structures feature two identical binding sites linked by polyaromatic bridges, capable of folding into closed, twisted conformations. This folding is hypothesised to preorganise the structures for anion recognition, mimicking the process which generates many protein binding sites. The architecture is suitable for elaboration into enclosed structures with potential for selective recognition of biologically relevant carboxylates. [ABSTRACT FROM AUTHOR]

An efficient strategy for high‐performance chiral materials is to design and synthesize host molecules with left‐ and right‐ (M‐ and P‐)twisted conformations and to control their twisted conformations. For this, a quantitative analysis is required to describe the chiroptical inversion, chiral transfer, and chiral recognition in the host‐guest systems, which is generally performed using circular dichroism (CD) and/or proton nuclear magnetic resonance (1H NMR) spectroscopies. However, the mass‐balance model that considers the M‐ and P‐twisted conformations has not yet been established. In this study, we derived the novel equations based on the mass‐balance model for the 1 : 1 host‐guest systems. Then, we further applied them to analyze the 1 : 1 host‐guest systems for the achiral calixarene‐based capsule molecule, achiral dimeric zinc porphyrin tweezer molecule, and chiral pillar[5]arene with the chiral and/or achiral guest molecules by using the data obtained from the CD titration, variable temperature CD (VT−CD), and 1H NMR experiments. The thermodynamic parameters (ΔH and ΔS), equilibrium constants (K), and molar CD (Δϵ) in the 1 : 1 host‐guest systems could be successfully determined by the theoretical analyses using the derived equations. [ABSTRACT FROM AUTHOR]

The importance of anions in various processes has led to a search for molecules that can effectively recognize and interact with these anions. This study explores how the tetraglycine [(Gly)4] peptide in its zwitterionic, neutral, and terminally capped forms acts as a receptor for H2PO4− and HSO4− anions within the framework of supramolecular host‐guest chemistry. Using molecular dynamics (MD) simulations, we obtained the conformations of the receptor‐anion complexes. Density functional theory (DFT), quantifies the complexes' interaction energies in both gas and solvent phases. Proton transfer within the zwitterionic complex with H2PO4− anion alters peptide charge distribution, affecting its conformation and binding site arrangement, as analysed by quantum mechanics/molecular mechanics (QM/MM) methods. Symmetry‐adapted perturbation theory (SAPT) and noncovalent interactions analysis highlight the role of electrostatic interactions in these receptor‐anion complexes. It emphasizes the key interactions such as N−H⋅⋅⋅⋅O and O−H⋅⋅⋅O=C between the peptide backbone and anions and elucidates the molecular recognition mechanism driven by crucial noncovalent interactions. The termination of the peptide's end groups modulates anion binding sites from the backbone to the charged N‐terminal, resulting in distinct binding sites. Our findings provide insights for designing peptides tailored to function as anion receptors in diverse supramolecular chemistry applications. [ABSTRACT FROM AUTHOR]

In this review, a summary of the precursors, processing conditions, and exogenous additions involved in the synthesis of ethyl carbamate (EC) in fermented alcoholic beverages is provided. The discussion then shifts to the inhibitory effect of molecularly imprinted polymers (MIPs) on EC development, with a focus on the molecular mechanism behind MIP effective recognition and elimination of EC. MIPs work well to extract EC and its precursors from alcoholic fermented drinks. To provide a comprehensive explanation of the structure-activity connections and molecular recognition mechanisms, the inhibition of EC is covered in detail. More information is provided on the health risks posed by MIPs, and it is imperative that green MIPs be developed in order to make up for their shortcomings in food processing applications. Additionally covered are the potential drawbacks and alluring possibilities of MIPs for EC inhibition. [ABSTRACT FROM AUTHOR]

Targeted therapy is an attractive approach for treating infectious diseases. Affibody molecules have similar capability to antibodies that facilitate molecular recognition in both diagnostic and therapeutic applications. Targeting major outer membrane protein (MOMP) for treating infection of Chlamydia trachomatis , one of the most common sexually transmitted pathogens, is a promising therapeutic approach. Previously, we have reported a MOMP-specific affibody (ZMOMP:461) from phage display library. Here, we first fused it with modified Pseudomonas exotoxin (PE38KDEL) and a cell-penetrating peptide (CPP) to develop an affitoxin, Z461X-CPP. We then verified the addition of both toxin and CPPs that did not affect the affinitive capability of ZMOMP:461 to MOMP. Upon uptake by C trachomatis –infected cells, Z461X-CPP induced cell apoptosis in vitro. In an animal model, Z461X significantly shortened the duration of C trachomatis infection and prevented pathological damage in the mouse reproductive system. These findings provide compelling evidence that the MOMP-specific affitoxin has great potential for targeting therapy of C trachomatis infection. [ABSTRACT FROM AUTHOR]

The advancement of synthetic host–guest chemistry has played a pivotal role in exploring and quantifying weak non-covalent interactions, unraveling the intricacies of molecular recognition in both chemical and biological systems. Macrocycles, particularly calix[4]resorcinarene-based cavitands, have demonstrated significant utility in receptor design, facilitating the creation of intricately organized architectures. Within the realm of macrocycles, these cavitands stand out as privileged scaffolds owing to their synthetic adaptability, excellent topological structures, and unique recognition properties. So far, extensive investigations have been conducted on various applications of calix[4]resorcinarene-based cavitands. In this review, we will elaborate on their diverse functions, including catalysis, separation and purification, polymeric materials, sensing, battery materials, as well as drug delivery. This review aims to provide a holistic understanding of the multifaceted roles of calix[4]resorcinarene-based cavitands across various applications, shedding light on their contributions to advancing the field of supramolecular chemistry. [ABSTRACT FROM AUTHOR]

G‐quadruplexes (G4 s), as non‐canonical DNA structures, attract a great deal of research interest in the molecular biology as well as in the material science fields. The use of small molecules as ligands for G‐quadruplexes has emerged as a tool to regulate gene expression and telomeres maintenance. Meso‐tetrakis‐(N‐methyl‐4‐pyridyl) porphyrin (TMPyP4) was shown as one of the first ligands for G‐quadruplexes and it is still widely used. We report an investigation comprising molecular docking and dynamics, synthesis and multiple spectroscopic and spectrometric determinations on simple cationic porphyrins and their interaction with different DNA sequences. This study enabled the synthesis of tetracationic porphyrin derivatives that exhibited binding and stabilizing capacity against G‐quadruplex structures; the detailed characterization has shown that the presence of amide groups at the periphery improves selectivity for parallel G4 s binding over other structures. Taking into account the ease of synthesis, 5,10,15,20‐tetrakis‐(1‐acetamido‐4‐pyridyl) porphyrin bromide could be considered a better alternative to TMPyP4 in studies involving G4 binding. [ABSTRACT FROM AUTHOR]

Although biocatalysis has garnered widespread attention in both industrial and academic realms, the enzymatic synthesis of chiral oxetanes remains an underdeveloped field. Halohydrin dehalogenases (HHDHs) are industrially relevant enzymes that have been engineered to accomplish the reversible transformation of epoxides. In this study, a biocatalytic platform was constructed for the stereoselective kinetic resolution of chiral oxetanes and formation of 1,3‐disubstituted alcohols. HheC from Agrobacterium radiobacter AD1 was engineered to identify key variants capable of catalyzing the dehalogenation of γ‐haloalcohols (via HheC M1‐M3) and ring opening of oxetanes (via HheC M4‐M5) to access both (R)‐ and (S)‐configured products with high stereoselectivity and remarkable catalytic activity, yielding up to 49 % with enantioselectivities exceeding 99 % ee and E>200. The current strategy is broadly applicable as demonstrated by expansion of the substrate scope to include up to 18 examples for dehalogenation and 16 examples for ring opening. Additionally, the functionalized products are versatile building blocks for pharmaceutical applications. To shed light on the molecular recognition mechanisms for the relevant variants, molecular dynamic (MD) simulations were performed. The current strategy expands the scope of HHDH‐catalyzed chiral oxetane ring construction, offering efficient access to both enantiomers of chiral oxetanes and 1,3‐disubstituted alcohols. [ABSTRACT FROM AUTHOR]

Although biocatalysis has garnered widespread attention in both industrial and academic realms, the enzymatic synthesis of chiral oxetanes remains an underdeveloped field. Halohydrin dehalogenases (HHDHs) are industrially relevant enzymes that have been engineered to accomplish the reversible transformation of epoxides. In this study, a biocatalytic platform was constructed for the stereoselective kinetic resolution of chiral oxetanes and formation of 1,3‐disubstituted alcohols. HheC from Agrobacterium radiobacter AD1 was engineered to identify key variants capable of catalyzing the dehalogenation of γ‐haloalcohols (via HheC M1‐M3) and ring opening of oxetanes (via HheC M4‐M5) to access both (R)‐ and (S)‐configured products with high stereoselectivity and remarkable catalytic activity, yielding up to 49 % with enantioselectivities exceeding 99 % ee and E>200. The current strategy is broadly applicable as demonstrated by expansion of the substrate scope to include up to 18 examples for dehalogenation and 16 examples for ring opening. Additionally, the functionalized products are versatile building blocks for pharmaceutical applications. To shed light on the molecular recognition mechanisms for the relevant variants, molecular dynamic (MD) simulations were performed. The current strategy expands the scope of HHDH‐catalyzed chiral oxetane ring construction, offering efficient access to both enantiomers of chiral oxetanes and 1,3‐disubstituted alcohols. [ABSTRACT FROM AUTHOR]

The document titled "Contents list" from Chemical Society Reviews provides a comprehensive overview of various research articles in the field of chemistry. Topics covered include covalent organic frameworks for environmental pollution control, chemical strategies for antisense antibiotics, and light-driven nitrogen fixation routes for green ammonia production. The journal showcases exceptional research on solar energy, photovoltaics, and advanced catalysis, offering valuable insights into cutting-edge developments in the field. [Extracted from the article]

The development of methodology for attaching ligand binding sites to proteins of interest has accelerated biomedical science. Such protein tags have widespread applications as well as properties that significantly limit their utility. This review describes the mechanisms and applications of supramolecular systems comprising the synthetic receptors cucurbit[7]uril (Q7) or cucurbit[8]uril (Q8) and their polypeptide ligands. Molecular recognition of peptides and proteins occurs at sites of 1–3 amino acids with high selectivity and affinity via several distinct mechanisms, which are supported by extensive thermodynamic and structural studies in aqueous media. The commercial availability, low cost, high stability, and biocompatibility of these synthetic receptors has led to the development of myriad applications. This comprehensive review compiles the molecular recognition studies and the resulting applications with the goals of providing a valuable resource to the community and inspiring the next generation of innovation. [ABSTRACT FROM AUTHOR]

We developed a pyridine–acetylene–phenol macrocycle in which a fluorine atom was introduced in place of a hydroxy group, as a host for the selective binding to epimers of glucose. The fluorine atom was expected to work as a negatively charged infill repelling oxygen atoms of saccharides and prevent the efficient formation of a hydrogen‐bond network with a glucoside, whose cross‐section size is larger than those of the corresponding epimers, especially of a mannoside. UV–Vis and fluorescence titration experiments revealed that this host showed a higher affinity for a mannoside than a glucoside. 1H NMR and molecular modeling suggested that the fluorine atom acts as a moderate infill weakening the binding to a glucoside. This result indicates that selectivity for guest molecules can be modified by replacing a hydroxy group and a hydrogen atom in host molecules with a fluorine atom. [ABSTRACT FROM AUTHOR]

Metal nanoclusters (MNCs) are emerging as a novel class of luminescent nanomaterials with unique properties, bridging the gap between individual atoms and nanoparticles. Among these, DNA-templated MNCs have gained significant attention due to the synergistic combination of MNCs' properties (such as exceptional resistance to photostability, size-tunable emission, and excellent optical characteristics) with the inherent advantages of DNA, including programmability, functional modification, molecular recognition, biocompatibility, and water solubility. The programmability and biocompatibility of DNA offer precise control over the size, shape, and composition of MNCs, leading to tunable optical, electrical, and magnetic properties. This review delves into the complex relationship between DNA sequence, structure, and the resulting MNC properties. By adjusting parameters such as DNA sequence, length, and conformation, the size, morphology, and composition of the corresponding MNCs can be fine-tuned, enabling insights into how DNA structure influences the optical, electrical, and magnetic properties of MNCs. Finally, this review highlights the remarkable versatility and latest advancements of DNA-templated MNCs, particularly in biosensing and imaging, and explores their future potential to revolutionize biomedical applications. [ABSTRACT FROM AUTHOR]

Macrocycles are key tools for molecular recognition and self‐assembly. However, traditionally prevalent macrocyclic compounds exhibit specific cavities with diameters usually less than 1 nm, limiting their range of applications in supramolecular chemistry. The efficient synthesis of giant macrocycles remains a significant challenge because an increase in the monomer number results in cyclization‐entropy loss. In this study, we developed a low‐entropy‐penalty synthesis strategy for producing giant macrocycles in high yields. In this process, long and rigid monomers possessing two reaction modules were condensed with paraformaldehyde via Friedel–Crafts reaction. A series of giant macrocycles with cavities of sizes ranging from 2.0 to 4.7 nm were successfully synthesized with cyclization yields of up to 72%. Experimental results and theoretical calculations revealed that extending the monomer length rather than increasing the monomer numbers could notably reduce the cyclization‐entropy penalty and avoid configuration twists, thereby favoring the formation of giant macrocycles with large cavities. Significantly, the excellent self‐assembly capacity of these giant macrocycles promoted their assembly into organogels. The xerogels exhibited enhanced photoluminescence quantum efficiencies of up to 83.1%. Mechanism investigation revealed the excellent assembly capacity originated from the abundant π–π interactions sites of the giant macrocycles. The outstanding emission enhancement resulted from the restricted nonradiative decay processes of rotation/vibration and improved radiative decay process of fluorescence. This study provides an effective and general method for achieving giant macrocycles, thereby expanding the supramolecular toolbox for host–guest chemistry and assembly applications. Moreover, the intriguing assembly and photophysical properties demonstrate the feasibility of developing novel and unique properties by expanding the macrocycle size. [ABSTRACT FROM AUTHOR]

In this study, unconventional C—Hlg···H–C (Hlg = Cl, Br, and I) interactions involving sp, sp2, and sp3 organic halides were investigated at the RI-MP2/aug-cc-pVQZ level of theory. Energy Decomposition Analyses (EDA) and Natural Bonding Orbital (NBO) studies showed that these intermolecular contacts are mainly supported by orbital and dispersion contributions, which counteracted the unfavorable/slightly favorable electrostatics due to the halogen–hydrogen σ-hole facing. In addition, the Bader's Quantum Theory of Atoms in Molecules (QTAIM) and the Noncovalent Interaction plot (NCIplot) visual index methodologies were used to further characterize the interactions discussed herein. We expect that the results reported herein will be useful in the fields of supramolecular chemistry, crystal engineering, and rational drug design, where the fine tuning of noncovalent interactions is crucial to achieve molecular recognition or a specific solid-state architecture. [ABSTRACT FROM AUTHOR]

Catalysis plays a crucial role in modern chemistry, with macrocyclic compounds like calixarenes serving as key players in organic transformations through supramolecular chemistry. These macrocycles, synthesized from phenol and formaldehyde condensation, exhibit a variety of conformations, such as cone and partial‐cone, due to their flexible structures. Their effectiveness as catalysts arises from their lipophilic cavities and the ease of functionalization on both the upper and lower rims. Water‐soluble calixarenes, in particular, have gained attention for their ability to interact with hydrophobic cavities, facilitating molecular recognition in aqueous environments. A landmark achievement in this field was Shinkai's synthesis of water‐soluble calix[4]arene in 1984, which involved sulphonation using tert‐butyl groups, resulting in compounds known for their low toxicity and encapsulation capabilities. This review provides a comprehensive overview of the advancements in sulphonated calixarenes as catalysts, emphasizing their diverse applications and potential for future development. Key catalytic reactions and their substrate scopes are discussed, along with future perspectives on how these compounds can further revolutionize catalytic processes. [ABSTRACT FROM AUTHOR]

The three isomers of the tetraoxa[4]arene derivative, C24H16O4, which consist of two m-phenylenes and two phenylenes (meta 1, para 2, ortho 3), represent not only intriguing fundamental structures that induce molecular recognition toward non-porous adaptive crystals, but also attractive candidates for crystallographic polymorphism. In this study, we crystallized isomers 2 and 3, in comparison to isomer 1, in order to understand their stable orientations and the corresponding intermolecular interactions in the crystalline state. For example, m-phenylene derivative 1 exhibits polymorphism with both prismatic and block-shaped crystals. Therefore, we prepared p-phenylene derivative 2 and o-phenylene derivative 3, and their structures were fully characterized by SC-XRD, revealing two polymorphs of derivative 2, namely prismatic crystal 2-I and block-shaped crystal 2-II, along with changes to the crystal lattice parameters (2-Ia, 2-Ib, and 2-Ic) based on temperature dependence. In all of its crystal forms, derivative 2 adopts an O-shaped planar structure, where the p-phenylene units face each other. This suggests that the packing mode during the early stages of crystallization, rather than due to any remarkable changes in the molecular structure, directly affects the bulk crystal morphology. On the other hand, derivative 3 adopts a U-shaped vent structure and, to the best of our knowledge, does not form polymorphs. The Platon and Hirshfeld surface analyses indicated that the contributions to the crystal packing were C···C (av. 37.3% for 2-Ia, av. 38.2% for 2-II, and 18.7% for 3), C···H/H···C (av. 37.3% for 2-Ia, av. 38.2% for 2-II, and 18.7% for 3), and O···H/H···O (av. 17.8% for 2-Ia, av. 19.6% for 2-II, and 19.4% for 3), highlighting significant intermolecular CH···π interactions and pseudo-hydrogen bonding forms for derivative 2 and π···π interactions for derivative 3. [ABSTRACT FROM AUTHOR]

Cage‐type structures based on coordination and dynamic covalent chemistry have the characteristics of facile and efficient preparation but poor stability. Chemically stable organic cages, generally involving fragment coupling and multi‐step reactions, are relatively difficult to synthesize. Herein, we offer a general and modular strategy to customize covalent organic cages with diverse skeletons and sizes. First, one skeleton (S) module with three extension (E) modules and three reaction (R) modules are connected by one‐ or two‐step coupling to get the triangular monomer bearing three reaction sites. Then one‐pot Friedel‐Crafts condensation of the monomer and linking module of paraformaldehyde produces the designed organic cages. The cage forming could be regulated by the geometrical configuration of monomeric blocks. The S−E−R angles in the monomer is crucial; only 120° (2,4‐dimethoxyphen as reaction module) or 60° (2,5‐dimethoxyphen as reaction module) angle between S−E−R successfully affords the resulting cages. By the rational design of the three modules, a series of organic cages have been constructed. In addition, the host‐guest properties show that the representative cages could strongly encapsulate neutral aromatic diimide guests driven by solvophobic interactions in polar solvents, giving the highest association constant of (2.58±0.18)×105 M−1. [ABSTRACT FROM AUTHOR]

Cage‐type structures based on coordination and dynamic covalent chemistry have the characteristics of facile and efficient preparation but poor stability. Chemically stable organic cages, generally involving fragment coupling and multi‐step reactions, are relatively difficult to synthesize. Herein, we offer a general and modular strategy to customize covalent organic cages with diverse skeletons and sizes. First, one skeleton (S) module with three extension (E) modules and three reaction (R) modules are connected by one‐ or two‐step coupling to get the triangular monomer bearing three reaction sites. Then one‐pot Friedel‐Crafts condensation of the monomer and linking module of paraformaldehyde produces the designed organic cages. The cage forming could be regulated by the geometrical configuration of monomeric blocks. The S−E−R angles in the monomer is crucial; only 120° (2,4‐dimethoxyphen as reaction module) or 60° (2,5‐dimethoxyphen as reaction module) angle between S−E−R successfully affords the resulting cages. By the rational design of the three modules, a series of organic cages have been constructed. In addition, the host‐guest properties show that the representative cages could strongly encapsulate neutral aromatic diimide guests driven by solvophobic interactions in polar solvents, giving the highest association constant of (2.58±0.18)×105 M−1. [ABSTRACT FROM AUTHOR]

Molecular recognition is a fundamental function of natural systems that ensures biological activity. This is achieved through the sieving effect, host-guest interactions, or both in biological environments. Recent advancements in multifunctional proteins reveal a new dimension of functional organization that goes beyond single-function molecular recognition, emphasizing the need for artificial multifunctional materials in industrial applications. Herein, we have designed a porous Ni4O4-cubane squarate coordination polymer as an artificial molecular recognition host, drawing inspiration from the structural and functional features of natural enzymes. A comprehensive assessment of the material's ability to distinguish target species under different operating conditions was carried out. The results confirm its sieving function through hexane isomers separation, host-guest interaction function via xenon/krypton separation, and dual presence of sieving and interaction through carbon dioxide/nitrogen separation. Additionally, the material demonstrates good stability and feasibility for large-scale production, indicating its practical potential. Our findings provide a bio-inspired multifunctional recognition material for chemical separations as proof-of-concept while offering solutions to advance artificial multifunctional materials adaptable to other applications beyond chemical separations. Materials for multifunctional molecular recognition are essential in industry. Here, the authors present a cost-effective, stable and multifunctional Ni-cubane MOF that effectively separates hexane isomers, xenon/krypton, and carbon dioxide/nitrogen. [ABSTRACT FROM AUTHOR]

PANoptosis is a newly identified inflammatory programmed cell death (PCD) that involves the interplay of apoptosis, necrosis, and pyroptosis. However, its overall biological effects cannot be attributed to any one type of PCD alone. PANoptosis is regulated by a signaling cascade triggered by the recognition of pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) by various sensors. This triggers the assembly of the PANoptosome, which integrates key components from other PCD pathways via adapters and ultimately activates downstream execution molecules, resulting in cell death with necrotic, apoptotic, and pyroptotic features. Autoimmune diseases are characterized by reduced immune tolerance to self-antigens, leading to abnormal immune responses, often accompanied by systemic chronic inflammation. Consequently, PANoptosis, as a unique innate immune-inflammatory PCD pathway, has significant pathophysiological relevance to inflammation and autoimmunity. However, most previous research on PANoptosis has focused on tumors and infectious diseases, leaving its activation and role in autoimmune diseases unclear. This review briefly outlines the characteristics of PANoptosis and summarizes several newly identified PANoptosome complexes, their activation mechanisms, and key components. We also explored the dual role of PANoptosis in diseases and potential therapeutic approaches targeting PANoptosis. Additionally, we review the existing evidence for PANoptosis in several autoimmune diseases and explore the potential regulatory mechanisms involved. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Carbohelicenes have garnered considerable attention for their inherent chirality and structural flexibility. Increasing multi‐helicity and incorporating non‐six‐membered rings to substitute benzenoid rings within helicenes are effective strategies for introducing unique photoelectric properties. Despite the disclosure of numerous helicenes, the inaccessible precursors and the lack of synthetic routes pose a challenge in achieving desired helicene structures fused with non‐benzenoid rings. Herein, we report the synthesis of multiple non‐benzenoid carbohelicenes fused with fluorene unit(s) through intramolecular cyclodehydrogenation of 9,10‐di(naphthalen‐1‐ yl)anthracene on Au(111) surface. Two potential cyclodehydrogenation manners between naphthyl and anthracene lead to the formation of fluorene‐fused [5]helicene and [4]helicene moiety. Consequently, a total of four stable products were observed. The atomic topographies of products are characterized by bond‐resolving scanning tunneling microscopy. The chiral helicity of targeted products can be switched by tip manipulation. Density‐functional‐theory calculations unveils the reaction pathway of four products. The comparative analysis of their respective energy barriers exhibits a correlation with the experimentally determined yields. Furthermore, we synthesize the polymer chains incorporating non‐benzenoid carbohelicenes via the Ullmann reaction of 2,6‐dibromo‐9,10‐di(1‐naphthyl)anthracene precursors. Our work proposes a synthetic methodology for several novel helicene‐like structures fused with fluorene units and the polymer bearing helicene subunits, thus highlighting the immense potential of these compounds in the application fields of luminescent electronic devices. [ABSTRACT FROM AUTHOR]

GTP-binding proteins are essential molecular switches that regulate a wide range of cellular processes. Their function relies on the specific recognition and binding of guanine within their binding pockets. This study aims to elucidate the molecular determinants underlying this recognition. A large-scale data mining of the Protein Data Bank yielded 298 GTP-binding protein complexes, which provided a structural foundation for a systematic analysis of the intermolecular interactions that are responsible for the molecular recognition of guanine in proteins. It was found that multiple modes of non-bonded interactions including hydrogen bonding, cation–π interactions, and π–π stacking interactions are employed by GTP-binding proteins for binding. Subsequently, the strengths of non-bonded interaction energies between guanine and its surrounding protein residues were quantified by means of the double-hybrid DFT method B2PLYP-D3/cc-pVDZ. Hydrogen bonds, particularly those involving the N2 and O6 atoms of guanine, confer specificity to guanine recognition. Cation–π interactions between the guanine ring and basic residues (Lys and Arg) provide significant electrostatic stabilization. π–π stacking interactions with aromatic residues (Phe, Tyr, and Trp) further contribute to the overall binding affinity. This synergistic interplay of multiple interaction modes enables GTP-binding proteins to achieve high specificity and stability in guanine recognition, ultimately underpinning their crucial roles in cellular signaling and regulation. Notably, the NKXD motif, while historically considered crucial for guanine binding in GTP-binding proteins, is not universally required. Our study revealed significant variability in hydrogen bonding patterns, with many proteins lacking the NKXD motif but still effectively binding guanine through alternative arrangements of interacting residues. [ABSTRACT FROM AUTHOR]

Congenital heart defects (CHDs) rank among the most common birth defects, presenting diverse phenotypes. Genetic and environmental factors are critical in molding the process of cardiogenesis. However, these factors' interactions are not fully comprehended. Hence, this study aimed to identify and characterize differentially expressed genes involved in CHD development through bioinformatics pipelines. We analyzed experimental datasets available in genomic databases, using transcriptome, gene enrichment, and systems biology strategies. Network analysis based on genetic and phenotypic ontologies revealed that EP300, CALM3, and EGFR genes facilitate rapid information flow, while NOTCH1, TNNI3, and SMAD4 genes are significant mediators within the network. Differential gene expression (DGE) analysis identified 2513 genes across three study types, (1) Tetralogy of Fallot (ToF); (2) Hypoplastic Left Heart Syndrome (HLHS); and (3) Trisomy 21/CHD, with LYVE1, PLA2G2A, and SDR42E1 genes found in three of the six studies. Interaction networks between genes from ontology searches and the DGE analysis were evaluated, revealing interactions in ToF and HLHS groups, but none in Trisomy 21/CHD. Through enrichment analysis, we identified immune response and energy generation as some of the relevant ontologies. This integrative approach revealed genes not previously associated with CHD, along with their interactions and underlying biological processes. [ABSTRACT FROM AUTHOR]

Non‐natural building blocks (BBs) present a vast reservoir of chemical diversity for molecular recognition and drug discovery. However, leveraging evolutionary principles to efficiently generate bioactive molecules with a larger number of diverse BBs poses challenges within current laboratory evolution systems. Here, we introduce programmable chemical evolution (PCEvo) by integrating chemoinformatic classification and high‐throughput array synthesis/screening. PCEvo initiates evolution by constructing a diversely combinatorial library to create ancestral molecules, streamlines the molecular evolution process and identifies high‐affinity binders within 2–4 cycles. By employing PCEvo with 108 BBs and exploring >1017 chemical space, we identify bicyclic peptidomimetic binders against targets SAR‐CoV‐2 RBD and Claudin18.2, achieving nanomolar affinity. Remarkably, Claudin18.2 binders selectively stain gastric adenocarcinoma cell lines and patient samples. PCEvo achieves expedited evolution in a few rounds, marking a significant advance in utilizing non‐natural building blocks for rapid chemical evolution applicable to targets with or without prior structural information and ligand preference. [ABSTRACT FROM AUTHOR]

Non‐natural building blocks (BBs) present a vast reservoir of chemical diversity for molecular recognition and drug discovery. However, leveraging evolutionary principles to efficiently generate bioactive molecules with a larger number of diverse BBs poses challenges within current laboratory evolution systems. Here, we introduce programmable chemical evolution (PCEvo) by integrating chemoinformatic classification and high‐throughput array synthesis/screening. PCEvo initiates evolution by constructing a diversely combinatorial library to create ancestral molecules, streamlines the molecular evolution process and identifies high‐affinity binders within 2–4 cycles. By employing PCEvo with 108 BBs and exploring >1017 chemical space, we identify bicyclic peptidomimetic binders against targets SAR‐CoV‐2 RBD and Claudin18.2, achieving nanomolar affinity. Remarkably, Claudin18.2 binders selectively stain gastric adenocarcinoma cell lines and patient samples. PCEvo achieves expedited evolution in a few rounds, marking a significant advance in utilizing non‐natural building blocks for rapid chemical evolution applicable to targets with or without prior structural information and ligand preference. [ABSTRACT FROM AUTHOR]

PANoptosis is a newly identified inflammatory programmed cell death (PCD) that involves the interplay of apoptosis, necrosis, and pyroptosis. However, its overall biological effects cannot be attributed to any one type of PCD alone. PANoptosis is regulated by a signaling cascade triggered by the recognition of pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) by various sensors. This triggers the assembly of the PANoptosome, which integrates key components from other PCD pathways via adapters and ultimately activates downstream execution molecules, resulting in cell death with necrotic, apoptotic, and pyroptotic features. Autoimmune diseases are characterized by reduced immune tolerance to self-antigens, leading to abnormal immune responses, often accompanied by systemic chronic inflammation. Consequently, PANoptosis, as a unique innate immune-inflammatory PCD pathway, has significant pathophysiological relevance to inflammation and autoimmunity. However, most previous research on PANoptosis has focused on tumors and infectious diseases, leaving its activation and role in autoimmune diseases unclear. This review briefly outlines the characteristics of PANoptosis and summarizes several newly identified PANoptosome complexes, their activation mechanisms, and key components. We also explored the dual role of PANoptosis in diseases and potential therapeutic approaches targeting PANoptosis. Additionally, we review the existing evidence for PANoptosis in several autoimmune diseases and explore the potential regulatory mechanisms involved. [ABSTRACT FROM AUTHOR]

This compound is a synthetic macrocycle comprising three pivaloyl‐protected resorcinarene units connected by six pentylene chains. We conducted a conformational study using 1H‐NMR, X‐ray diffraction (XRD), and computational analyses. The macrocycle adopts two conformers, one open, the other closed. The ratio of the open to closed forms depended on the solvent used. Only the open form existed in [D8]toluene, both forms coexisted in [D6]benzene, and the closed form was the major conformer in [D1]chloroform. The benzene‐solvated open form observed in the solid state suggests that cavity solvation by solvent molecules directs the open form. The open form was the major or only conformer in [D10]o‐ and [D10]m‐xylene and [D12]mesitylene, whereas the closed form was the major conformer in [D6]acetone. The open and closed forms were equally populated in [D10]p‐xylene, suggesting that the size, shape, and dimensions of the solvent molecules most likely influenced the conformation of the protected trisresocinarene. [ABSTRACT FROM AUTHOR]

Protein surfaces have pivotal roles in interactions between proteins and other biological molecules. However, the structural dynamics of protein surfaces have rarely been explored and are poorly understood. Here, the surface of a single‐stranded DNA (ssDNA) binding protein (SSB) with four DNA binding domains that bind ssDNA in binding site sizes of 35, 56, and 65 nucleotides per tetramer is investigated. Using oligonucleotides as probes to sense the charged surface, NaCl induces a two‐state structural transition on the SSB surface even at moderate concentrations. Chelation of sodium ions with charged amino acids alters the network of hydrogen bonds and/or salt bridges on the surface. Such changes are associated with changes in the electrostatic potential landscape and interaction mode. These findings advance the understanding of the molecular mechanism underlying the enigmatic salt‐induced transitions between different DNA binding site sizes of SSBs. This work demonstrates that monovalent salt is a key regulator of biomolecular interactions that not only play roles in non‐specific electrostatic screening effects as usually assumed but also may configure the surface of proteins to contribute to the effective regulation of biomolecular recognition and other downstream events. [ABSTRACT FROM AUTHOR]

Stemming from early seminal notions of molecular recognition and encapsulation, three-dimensional, cavity-containing capsular compounds and assemblies have attracted intense interest due to the ability to modulate chemical and physical properties of species encapsulated within these confined spaces compared to bulk environments. With such a diverse range of covalent motifs and non-covalent (supramolecular) interactions available to assemble building blocks, an incredibly wide-range of capsular-type architectures have been developed. Furthermore, synthetic tunability of the internal environments gives chemists the opportunity to engineer systems for uses in sensing, sequestration, catalysis and transport of molecules, just to name a few. In this tutorial review, an overview is provided into the design principles, synthesis, characterisation, structural facets and properties of coordination cages, porous organic cages, supramolecular capsules, foldamers and mechanically interlocked molecules. Using seminal and recent examples, the advantages and limitations of each system are explored, highlighting their application in various tasks and functions. [ABSTRACT FROM AUTHOR]

Solvent competition for London dispersion attenuates its energetic significance in molecular recognition processes. By varying both the stacked contact area and the solvent, here we experimentally deconvolute solvent attenuation using molecular balances. Experimental stacking energies (phenyl to pyrene) correlated strongly with calculations only when dispersion was considered. Such calculations favoured stacking by up to −27 kJ mol−1 in the gas phase, but it was weakly disfavoured in our solution‐phase experiments (+0.5 to +4.6 kJ mol−1). Nonetheless, the propensity for stacking increased with contact area and in solvents with lower bulk polarisabilities that compete less for dispersion. Experimental stacking energies per unit change in solvent accessible area ranged from −0.02 kJ mol−1 Å−2 in CS2, to −0.05 kJ mol−1 Å−2 in CD2Cl2, but were dwarfed by the calculated gas‐phase energy of −0.6 kJ mol−1 Å−2. The results underscore the challenge facing the exploitation of dispersion in solution. Solvent competition strongly but imperfectly cancels dispersion at molecular recognition interfaces, making the energetic benefits difficult to realise. [ABSTRACT FROM AUTHOR]

Solvent competition for London dispersion attenuates its energetic significance in molecular recognition processes. By varying both the stacked contact area and the solvent, here we experimentally deconvolute solvent attenuation using molecular balances. Experimental stacking energies (phenyl to pyrene) correlated strongly with calculations only when dispersion was considered. Such calculations favoured stacking by up to −27 kJ mol−1 in the gas phase, but it was weakly disfavoured in our solution‐phase experiments (+0.5 to +4.6 kJ mol−1). Nonetheless, the propensity for stacking increased with contact area and in solvents with lower bulk polarisabilities that compete less for dispersion. Experimental stacking energies per unit change in solvent accessible area ranged from −0.02 kJ mol−1 Å−2 in CS2, to −0.05 kJ mol−1 Å−2 in CD2Cl2, but were dwarfed by the calculated gas‐phase energy of −0.6 kJ mol−1 Å−2. The results underscore the challenge facing the exploitation of dispersion in solution. Solvent competition strongly but imperfectly cancels dispersion at molecular recognition interfaces, making the energetic benefits difficult to realise. [ABSTRACT FROM AUTHOR]

Purpose: In recent decades, advancements in biosensors technology have made fluorescent biosensor pivotal for biomolecular recognition. This paper aims to provide an in-depth analysis of polymerase chain reaction (PCR) fluorescent biosensor detection technology for identifying Escherichia coli (E. coli), setting the stage for future developments in the field. Design/methodology/approach: The review of literature on PCR fluorescent biosensor detection technology for E. coli over the past decades includes discussions on traditional biological fluorescent detection, quantitative PCR fluorescent detection and digital fluorescent detection technology. Findings: Advancements in fluorescent biosensor technology enable precise measurement of fluorescent signals, and when integrated with microfluidic technology, produce compact, reagent-efficient digital sensor devices. Originality/value: This paper provides a comprehensive review of recent fluorescent detection technology for pathogenic E. coli, assessing method efficiencies and offering insights to advance the field. [ABSTRACT FROM AUTHOR]

The present study assesses the phylogenetic position of certain Thai members of Gymnema, Gymnemopsis, and Sarcolobus in relation to other known Marsdenieae species. Fifteen accessions newly sequenced from Thailand were added to the dataset of the homologous sequences of 125 accessions of Marsdenieae downloaded from GenBank. In our molecular phylogeny, almost all the delimited major clades and their relationships are largely congruent with those revealed in previous studies. The monophyly of Gymnema (including the former Jasminanthes species) and that of Sarcolobus, as presently circumscribed, are confirmed. The new accessions of these two genera from Thailand are well grouped with the members of their respective genera. Our analyses provide the first molecular evidence for recognition of Gymnemopsis, a small Asian genus that has never been included in the previous phylogenetic studies, as a distinct genus. All elements of Gymnemopsis are retrieved as a well-supported monophyletic group that is strongly supported as sister to Lygisma, another small Asian genus that most closely resembles it in growth habit, color of latex, indumentum on plant parts, corona structure and follicle traits. Combined molecular phylogenetic, morphological and ecological data also support recognition of two new Sarcolobus species from Thailand, Sarcolobus busbanianus sp. nov. and S. flavus sp. nov. Similarities and differences between these new species and their close relative, S. carinatus, are discussed. In addition, this study also reveals the first record for Thailand of Gymnema lacei. Keys to the species of Gymnemopsis (for all members of the genus), Gymnema and Sarcolobus (for Thai members of these genera) are provided. [ABSTRACT FROM AUTHOR]

This study aims to statistically compare two methods for determining 210Pb in tobacco: the molecular recognition sorbent method (AnaLig Sr01) and the extraction chromatography sorbent method (Sr Resin). The TriCarb 3100 TR liquid scintillation spectrometer was used to measure and determine 210Pb activity in the tobacco solution. Statistical analysis confirmed the accuracy and precision of the 210Pb measurements, with high detection efficiencies of 82% for both AnaLig Sr01 and Sr Resin. The linear model demonstrated that the residuals followed the Gaussian model, without any autocorrelation or trend. Paired t tests showed consistent results across all methods, and all solid-phase extraction methods proved efficient for 210Pb separations in tobacco samples. These findings provide support for the suitability of both methods and lay a foundation for future articles on tobacco and cigarette samples. [ABSTRACT FROM AUTHOR]

Receptor-interacting serine/threonine protein kinase 2 (RIPK2) is a kinase that is essential in modulating innate and adaptive immune responses. As a downstream signaling molecule for nucleotide-binding oligomerization domain 1 (NOD1), NOD2, and Toll-like receptors (TLRs), it is implicated in the signaling triggered by recognition of microbe-associated molecular patterns by NOD1/2 and TLRs. Upon activation of these innate immune receptors, RIPK2 mediates the release of pro-inflammatory factors by activating mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB). However, whether RIPK2 is essential for downstream inflammatory signaling following the activation of NOD1/2, TLRs, or both remains controversial. In this study, we examined the role of RIPK2 in NOD2- and TLR4-dependent signaling cascades following stimulation of microglial cells with bacterial muramyl dipeptide (MDP), a NOD2 agonist, or lipopolysaccharide (LPS), a TLR4 agonist. We utilized a highly specific proteolysis targeting chimera (PROTAC) molecule, GSK3728857A, and found dramatic degradation of RIPK2 in a concentration- and time-dependent manner. Importantly, the PROTAC completely abolished MDP-induced increases in iNOS and COX-2 protein levels and pro-inflammatory gene transcription of Nos2, Ptgs2, Il-1β, Tnfα, Il6, Ccl2, and Mmp9. However, increases in iNOS and COX-2 proteins and pro-inflammatory gene transcription induced by the TLR4 agonist, LPS, were only slightly attenuated with the GSK3728857A pretreatment. Further findings revealed that the RIPK2 PROTAC completely blocked the phosphorylation and activation of p65 NF-κB and p38 MAPK induced by MDP, but it had no effects on the phosphorylation of these two mediators triggered by LPS. Collectively, our findings strongly suggest that RIPK2 plays an essential role in the inflammatory responses of microglia to bacterial MDP but not to LPS. [ABSTRACT FROM AUTHOR]

There are many problems in biochemistry that are difficult to study experimentally. Simulation methods are appealing due to direct availability of atomic coordinates as a function of time. However, direct molecular simulations are challenged by the size of systems and the time scales needed to describe relevant motions. In theory, enhanced sampling algorithms can help to overcome some of the limitations of molecular simulations. Here, we discuss a problem in biochemistry that offers a significant challenge for enhanced sampling methods and that could, therefore, serve as a benchmark for comparing approaches that use machine learning to find suitable collective variables. In particular, we study the transitions LacI undergoes upon moving between being non-specifically and specifically bound to DNA. Many degrees of freedom change during this transition and that the transition does not occur reversibly in simulations if only a subset of these degrees of freedom are biased. We also explain why this problem is so important to biologists and the transformative impact that a simulation of it would have on the understanding of DNA regulation. [ABSTRACT FROM AUTHOR]

Supramolecular polymers possess great potential in catalysis owing to their distinctive molecular recognition and dynamic crosslinking features. However, investigating supramolecular electrocatalysts with high efficiency in oxygen reduction reaction to hydrogen peroxide (ORHP) remains an unexplored frontier. Herein, we present organic polymers for ORHP by introducing cyclodextrin-containing noncovalent building blocks, affording these supramolecules with abundant dynamic bonds. The electronic states and reaction kinetics are further well-modulated via a host-guest strategy, resulting in appropriate regional electron binding force and controllable chemical activity. Notably, integrating supramolecular units into phenyl group-containing model covalent polymer achieves a production rate of 9.14 mol g−1cat h−1, with 98.01% Faraday efficiency, surpassing most reported metal-free electrocatalysts. Moreover, the dynamic bonds in supramolecular catalysts can effectively regulate the binding ability of oxygen intermediates, leading to high reactivity and selectivity for the 2e− pathway. Supported by theory calculation and in situ experiment, C atoms (site–1) adjacent to the –C = N (N) group are potential active sites. This work pioneers host-guest strategy and provides inspiring ideas for the ORHP process. Dynamic bonds offer unique advantages of adaptability and selectivity, yet, supramolecular electrocatalysts specifically tailored for 2e− pathway remain unexplored. Here, the authors report a host-guest strategy that employs dynamic bonds to adjust electronic states through dual-channel regulation. [ABSTRACT FROM AUTHOR]

Macrocyclic receptors have emerged as versatile and efficient molecular tools for the recognition and sensing of anions, playing a pivotal role in molecular recognition and supramolecular chemistry. The following review provides an overview of the recent advances in the design, synthesis, and applications of macrocyclic receptors specifically tailored for anion recognition. The unique structural features of macrocycles, such as their well-defined structures and pre-organised binding sites, contribute to their exceptional anion-binding capabilities that have led to their application across a broad range of the chemical and biological sciences. [ABSTRACT FROM AUTHOR]

Mastering of analytical methods for accurate quantitative determinations of enantiomeric excess is a crucial aspect in asymmetric catalysis, chiral synthesis, and pharmaceutical applications. In this context, the phenomenon of Self‐Induced Diastereomeric Anisochronism (SIDA) can be exploited in NMR spectroscopy for accurate determinations of enantiomeric composition, without using a chiral auxiliary that could interfere with the spectroscopic investigation. This phenomenon can be particularly useful for improving the quantitative analysis of mixtures with low enantiomeric excesses, where direct integration of signals can be tricky. Here, we describe a novel analysis protocol to correctly determine the enantiomeric composition of scalemic mixtures and investigate the thermodynamic and stereochemical features at the basis of SIDA. Dipeptide derivatives were chosen as substrates for this study, given their central role in drug design. By integrating the experiments with a conformational stochastic search that includes entropic contributions, we provide valuable information on the dimerization thermodynamics, the nature of non‐covalent interactions leading to self‐association, and the differences in the chemical environment responsible for the anisochronism, highlighting the importance of different stereochemical arrangement and tight association for the distinction between homochiral and heterochiral adducts. An important role played by the counterion was pointed out by computational studies. [ABSTRACT FROM AUTHOR]

Molecular‐recognition events are highly relevant in biology and chemistry. In the present study, we investigated such processes in the solid state under mechanochemical conditions using the formation of racemic phases upon reacting enantiopure entities as example. As test systems, α‐(trifluoromethyl)lactic acid (TFLA) and the amino acids serine and alanine were used. The effects of ball‐milling and resonant acoustic mixing (RAM) on the formation of racemic phases were probed by using solid‐state Nuclear Magnetic Resonance (NMR) spectroscopy. In a mixer mill, a highly efficient and fast racemic phase formation occurred for both TFLA and the two amino acids. RAM led to the racemic phase for TFLA also, and this process was facilitated upon employing pre‐milled enantiopure entities. In contrast, under comparable conditions RAM did not result in the formation of racemic phases for serine and alanine. [ABSTRACT FROM AUTHOR]

Molecular‐recognition events are highly relevant in biology and chemistry. In the present study, we investigated such processes in the solid state under mechanochemical conditions using the formation of racemic phases upon reacting enantiopure entities as example. As test systems, α‐(trifluoromethyl)lactic acid (TFLA) and the amino acids serine and alanine were used. The effects of ball‐milling and resonant acoustic mixing (RAM) on the formation of racemic phases were probed by using solid‐state Nuclear Magnetic Resonance (NMR) spectroscopy. In a mixer mill, a highly efficient and fast racemic phase formation occurred for both TFLA and the two amino acids. RAM led to the racemic phase for TFLA also, and this process was facilitated upon employing pre‐milled enantiopure entities. In contrast, under comparable conditions RAM did not result in the formation of racemic phases for serine and alanine. [ABSTRACT FROM AUTHOR]