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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]

The modulation of protein-protein interactions with small molecules is one of the most rapidly developing areas in drug discovery. In this review, we discuss advances over the past decade (2014-2023) focusing on molecular glues (MGs)-monovalent small molecules that induce proximity, either by stabilizing native interactions or by inducing neomorphic interactions. We include both serendipitous and rational discoveries and describe the different approaches that were used to identify them. We classify the compounds in three main categories: degradative MGs, non-degradative MGs or PPI stabilizers, and MGs that induce self-association. Diverse, illustrative examples with structural data are described in detail, emphasizing the elements of molecular recognition and cooperative binding at the interface that are fundamental for a MG mechanism of action.

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]

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]

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]

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]

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]

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]

Amidine‐substituted allosteric receptors 2 a and 2 b for benzenediols were synthesized. Receptor 2 a with five‐membered amidines exhibited greater allostericity than the amide‐substituted receptor 1, while 2 b with six‐membered amidines exhibited less allostericity. NMR titration experiments revealed that a significant enthalpic factor was involved in the allostericity of these receptors. X‐ray and DFT optimized structures of 2 a and 2 b revealed that 2 a adopted a coplanar conformation with π‐conjugation between the amidines and the phenylene ring of the hydrindacene framework, resulting in high allostericity due to inactivation of the initial binding. [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]

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]

AbstractDocosahexaenoic acid ethyl ester has an important role in the prevention of the neuropsychiatric and neurodegenerative diseases. Its extraction from fish such as the stingray as anoil creates a pharmaceutical formulation. Therefore it is essential to develop fast molecular recognition methods able to perform both qualitative and quantitative determination of docosahexaenoic in stingray meat and liver. A miniplatform incorporating a 3D stochastic microsensor was designed and validated for the molecular recognition of docosahexaenoic acid ethyl ester. The design of the microsensor was based on the modification of a graphene decorated with nitrogen and boron paste (NB-graphene paste) with 10−3mol L−1 alpha-cyclodextrin. A wide linear concentration range (5.0 × 10−14 − 5.0 × 10−7 g mL−1) and a low limit of quantitation (5.0 × 10−14 g mL−1) were obtained. High recovery values were determined when the miniplatform was used for the assay of docosahexaenoic acid ethyl ester from stingray liver and meat with recoveries higher than 99.20%. The relative standard deviation values were less than 0.05 (N = 10). [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]

Supramolecular macrocycles, renowned for their remarkable capabilities in molecular recognition and complexation, have emerged as pivotal elements driving advancements across various innovative research fields. Cocrystal materials, an important branch within the realm of crystalline organic materials, have garnered considerable attention owing to their simple preparation methods and diverse potential applications, particularly in optics, electronics, chemical sensing and photothermal conversion. In recent years, macrocyclic entitles have been successfully brought into this field, providing an essential and complementary channel to create novel functional materials, especially those with multiple functionalities and smart stimuli-responsiveness. In this Review, we present an overview of the research efforts on functional cocrystals constructed with macrocycles, covering their design principles, preparation strategies, assembly modes, and diverse functions and applications. Finally, the remaining challenges and perspectives are outlined. We anticipate that this review will serve as a valuable and timely reference for researchers interested in supramolecular crystalline materials and beyond, catalyzing the emergence of more original and innovative studies in related fields. [ABSTRACT FROM AUTHOR]

The active template synthesis of mechanically interlocked molecular architectures exploits the dual ability of various structural elements (metals or, in the case of metal-free active template synthesis, particular arrangements of functional groups) to serve as both a template for the organisation of building blocks and as a catalyst to facilitate the formation of covalent bonds between them. This enables the entwined or threaded intermediate structure to be covalently captured under kinetic control. Unlike classical passive template synthesis, the intercomponent interactions transiently used to promote the assembly typically do not 'live on' in the interlocked product, meaning that active template synthesis can be traceless and used for constructing mechanically interlocked molecules that do not feature strong binding interactions between the components. Since its introduction in 2006, active template synthesis has been used to prepare a variety of rotaxanes, catenanes and knots. Amongst the metal–ion-mediated versions of the strategy, the copper(I)-catalysed alkyne–azide cycloaddition (CuAAC) remains the most extensively used transformation, although a broad range of other catalytic reactions and transition metals also provide effective manifolds. In metal-free active template synthesis, the recent discovery of the acceleration of the reaction of primary amines with electrophiles through the cavity of crown ethers has proved effective for forming an array of rotaxanes without recognition elements, including compact rotaxane superbases, dissipatively assembled rotaxanes and molecular pumps. This Review details the active template concept, outlines its advantages and limitations for the synthesis of interlocked molecules, and charts the diverse set of reactions that have been used with this strategy to date. The application of active template synthesis in various domains is discussed, including molecular machinery, mechanical chirality, catalysis, molecular recognition and various aspects of materials science. [ABSTRACT FROM AUTHOR]

The immobilization design strategy plays an important role in biosensor development and its sensing performance. Both adsorption (physisorption) and cross-linker functionalization (chemisorption) are common approaches for immobilizing a bioreceptor layer. In this work, these two approaches were studied and compared, envisaging a functional and strongly attached bioreceptor layer onto sputtered Au–TiO2 thin films. DSP cross-linker (Lomant's reagent) was used in the thin film's functionalization, and the effect of different concentrations on the development of an adhesion layer was investigated. Surface morphology analysis of functionalized thin films suggested the development of uniformly coated self-assembled layers. However, DSP islands with a fractal structure were found for a concentration of 4 mg ml−1. Infrared spectroscopy confirmed the cross-linker functionalization at the thin film's surface. Confocal microscopy of immobilized fluorescent antibodies revealed that DSP islands improve the chemical surface area available for bioreceptor immobilization. Moreover, an immunoassay using mouse IgG interaction with fluorescent anti-mouse IgG (Fab specific), working as capture and detection antibody, respectively, showed that DSP functionalization favors antibodies orientation and adhesion strength to the surface, when compared to physisorption. [ABSTRACT FROM AUTHOR]

The article "Whole Blood Transcriptomics Identifies Differences in Innate Immune Pathway Expression in Infants at Risk for Peanut Allergy" explores the differential gene expression in infants at risk for peanut allergy. The study aims to analyze the transcriptomic signature of infants at risk for peanut allergy using whole blood RNA sequencing. Results suggest that disruption of the innate immune response may play a role in peanut allergy development, highlighting the importance of understanding immune developmental defects associated with food allergies. Further investigation into the innate immune response in infants at high risk of peanut allergy may have implications for the development of clinical reactivity in sensitized individuals. [Extracted from the article]

Chemotherapy‐based combination regimens are recommended as first‐line treatment for colorectal cancer. However, multidrug resistance (MDR) and limited drug infiltration in tumor microenvironment remain critical challenges. Herein, a pH/redox dual activated supramolecular DAS@CD‐OxPt (IV) nanoparticles (NPs) via host‐guest molecular recognition to achieve relay drugs delivery of active oxaliplatin (OxPt (IV)) and Src inhibitor dasatinib (DAS) between tumor cells is developed. DAS@CD‐OxPt (IV) NPs exhibit prolonged circulation in the blood and intra‐tumoral retention. Triggered by the endo/lysosome (pH 5.0), flexible DAS@CD‐OxPt (IV) NPs exhibited proton‐driven in situ assembly to form nanofiber in tumor cells. Dual chemotherapeutic agents released from DAS@CD‐OxPt (IV) NPs synergistically cause irreversible DNA damage by blocking p53‐mediated DNA repair. Supramolecular nanofibers can further serve as the "ammunition depot" to continuously release drugs from dying cells and transport them into neighboring tumor cells, leading to domino‐like cell death and enhanced immunogenicity. Furthermore, DAS@CD‐OxPt (IV) NPs combined with immune checkpoint blockade (ICB) therapy strikingly suppress CT26 tumor growth and pulmonary metastasis. [ABSTRACT FROM AUTHOR]

Organic molecular cages with low symmetry are promising to generate complex chemical environments for molecular recognition and catalysis. Herein, a new triangular prism cage with three rigid 8‐aminoquinoline‐2‐carboxylic acid derivatives as edges were synthesized. This molecular cage possesses reduced symmetry and contains both secondary amine and amide as hydrogen donating groups for molecular recognition. It could bind anions, such as NO3−, AcO−, and F− with moderate affinity. [ABSTRACT FROM AUTHOR]

Nucleic acid‐based molecular recognition plays crucial roles in various fields like biosensing and disease diagnostics. To achieve optimal detection and analysis, it is essential to regulate the response performance of nucleic acid probes or switches to match specific application requirements by regulating thermodynamics and kinetics properties. However, the impacts of thermodynamics and kinetics theories on recognition performance are sometimes obscure and the relative conclusions are not intuitive. To promote the thorough understanding and rational utilization of thermodynamics and kinetics theories, this review focuses on the landmarks and recent advances of nucleic acid thermodynamics and kinetics and summarizes the nucleic acid thermodynamics and kinetics‐based strategies for regulation of nucleic acid‐based molecular recognition. This work hopes such a review can provide reference and guidance for the development and optimization of nucleic acid probes and switches in the future, as well as for advancements in other nucleic acid‐related fields. [ABSTRACT FROM AUTHOR]

In view of the existence of an optimal conformation for molecular recognition and bearing in mind that nucleosides exhibit a broad range of pharmaceutical properties, whereby their conformation has a key role in molecular recognition, the tendency of the pseudosugar moiety in carbanucleosides to adopt a boat‐like conformation has been studied on the basis of a bicyclo[3.1.0]hexane system, resulting in versatile drug‐like scaffolds to increase molecular recognition. It is already known that using this system as pseudosugar can fix the conformation in the Northern or Southern geometry, required for biological activity, according to the relative position of the three‐member cycle. By mapping their energy potential surface, we investigate the preference for boat‐like conformers in bicyclo[3.1.0]hexanes. DFT is utilized alongside NBO analysis to explore the enhanced stability of boat‐like conformers, also considering the influence of oxygen, sulfur, and selenium heteroatoms. Additionally, charge density distribution analysis using QTAIM identifie key atoms contributing to stability changes. These findings will help to comprehend this behavior in the drug discovery process when conformationally restricted nucleosides are involved. [ABSTRACT FROM AUTHOR]

Glycan recognition by lectins mediates important biological events. This Tutorial Review aims to introduce lectin–ligand interactions and show how these molecular recognition events inspire innovations such as: (i) glycomimetic ligands; (ii) multivalent ligand agonists/antagonists; (iii) ligands for precision delivery of therapies to cells, where therapies include vaccines, siRNA and LYTACs (iv) development of diagnostics. A small number of case studies are selected to demonstrate principles for development of new ligands for applications inspired by knowledge of natural glycan ligand structure and function. [ABSTRACT FROM AUTHOR]

Aptamers are molecular recognition elements that have been extensively deployed in a wide array of applications ranging from diagnostics to therapeutics. Due to their unique properties as compared to antibodies, aptamers were also largely isolated during the COVID-19 pandemic for multiple purposes. Typically generated by conventional SELEX, the inherent drawbacks of the process including the time-consuming, cumbersome and resource-intensive nature catalysed the move to adopt in silico approaches to isolate aptamers. Impressive performances of these in silico-derived aptamers in their respective assays have been documented thus far, bearing testimony to the huge potential of the in silico approaches, akin to the traditional SELEX in isolating aptamers. In this study, we provide an overview of the in silico selection of aptamers against SARS-CoV-2 by providing insights into the basic steps involved, which comprise the selection of the initial single-stranded nucleic acids, determination of the secondary and tertiary structures and in silico approaches that include both rigid docking and molecular dynamics simulations. The different approaches involving aptamers against SARS-CoV-2 were illuminated and the need to verify these aptamers by experimental validation was also emphasized. Cognizant of the need to continuously improve aptamers, the strategies embraced thus far for post-in silico selection modifications were enumerated. Shedding light on the steps involved in the in silico selection can set the stage for further improvisation to augment the functionalities of the aptamers in the future. [ABSTRACT FROM AUTHOR]

Many chemoreceptors contain a C‐terminal pentapeptide at the end of a linker. In Escherichia coli, this pentapeptide forms a high‐affinity binding site for CheR and phosphorylated CheB, and its removal interferes with chemoreceptor adaptation. Analysis of chemoreceptors revealed significant variation in their pentapeptide sequences, and bacteria often possess multiple chemoreceptors with differing pentapeptides. To assess whether this sequence variation alters CheR affinity and chemotaxis, we used Pectobacterium atrosepticum SCRI1043 as a model. SCRI1043 has 36 chemoreceptors, with 19 of them containing a C‐terminal pentapeptide. We show that the affinity of CheR for the different pentapeptides varies up to 11‐fold (KD 90 nM to 1 μM). Pentapeptides with the highest and lowest affinities differ only in a single amino acid. Deletion of the cheR gene abolishes chemotaxis. The replacement of the pentapeptide in the PacC chemoreceptor with those of the highest and lowest affinities significantly reduced chemotaxis to its cognate chemoeffector, L‐Asp. Altering the PacC pentapeptide also reduced chemotaxis to L‐Ser, but not to nitrate, which are responses mediated by the nontethered PacB and PacN chemoreceptors, respectively. Changes in the pentapeptide sequence thus modulate the response of the cognate receptor and that of another chemoreceptor. [ABSTRACT FROM AUTHOR]

Background: Continuous breakthroughs in computational algorithms have positioned AI-based models as some of the most sophisticated technologies in the healthcare system. AI shows dynamic contributions in advancing various medical fields involving data interpretation and monitoring, imaging screening and diagnosis, and treatment response and survival prediction. Despite advances in clinical oncology, more effort must be employed to tailor therapeutic plans based on each patient's unique transcriptomic profile within the precision/personalized oncology frame. Furthermore, the standard analysis method is not compatible with the comprehensive deciphering of significant data streams, thus precluding the prediction of accurate treatment options. Methodology: We proposed a novel approach that includes obtaining different tumour tissues and preparing RNA samples for comprehensive transcriptomic interpretation using specifically trained, programmed, and optimized AI-based models for extracting large data volumes, refining, and analyzing them. Next, the transcriptomic results will be scanned against an expansive drug library to predict the response of each target to the tested drugs. The obtained target-drug combination/s will be then validated using in vitro and in vivo experimental models. Finally, the best treatment combination option/s will be introduced to the patient. We also provided a comprehensive review discussing AI models' recent innovations and implementations to aid in molecular diagnosis and treatment planning. Results: The expected transcriptomic analysis generated by the AI-based algorithms will provide an inclusive genomic profile for each patient, containing statistical and bioinformatics analyses, identification of the dysregulated pathways, detection of the targeted genes, and recognition of molecular biomarkers. Subjecting these results to the prediction and pairing AI-based processes will result in statistical graphs presenting each target's likely response rate to various treatment options. Different in vitro and in vivo investigations will further validate the selection of the target drug/s pairs. Conclusions: Leveraging AI models will provide more rigorous manipulation of large-scale datasets on specific cancer care paths. Such a strategy would shape treatment according to each patient's demand, thus fortifying the avenue of personalized/precision medicine. Undoubtedly, this will assist in improving the oncology domain and alleviate the burden of clinicians in the coming decade. [ABSTRACT FROM AUTHOR]

Development in hemoglobin-based oxygen carriers (HBOCs) that may be used as alternatives to donated blood requires an extensive supply of highly pure hemoglobin (Hb) preparations. Therefore, it is essential to fabricate inexpensive, stable and highly selective absorbents for Hb purification. Molecular imprinting is an attractive technology for preparing such materials for targeted molecular recognition and rapid separations. In this case study, we developed human fetal hemoglobin (HbF)-imprinted polymer beads through the fusion of surface imprinting and Pickering emulsion polymerization. HbF was firstly covalently coupled to silica nanoparticles through its surface-exposed amino groups. The particle-supported HbF molecules were subsequently employed as templates for the synthesis of molecularly imprinted polymers (MIPs) with high selectivity for Hb. After removing the silica support and HbF, the resulting MIPs underwent equilibrium and kinetic binding experiments with both adult Hb (HbA) and HbF. These surface-imprinted MIPs exhibited excellent selectivity for both HbA and HbF, facilitating the one-step isolation of recombinant Hb from crude biological samples. The saturation capacities of HbA and HbF were found to be 15.4 and 17.1 mg/g polymer, respectively. The present study opens new possibilities for designed resins for tailored protein purification, separation and analysis. [ABSTRACT FROM AUTHOR]

Small‐molecule receptors are increasingly employed to probe various functional groups for (bio)chemical analysis. However, differentiation of polyfunctional analogs sharing multiple functional groups remains challenging for conventional mono‐ and bidentate receptors because their insufficient number of binding sites limits interactions with the least reactive yet property‐determining functional group. Herein, we introduce 6‐thioguanine (TG) as a supramolecular receptor for unique tridentate receptor‐analyte complexation, achieving ≥97 % identification accuracy among 16 polyfunctional analogs across three classes: glycerol derivatives, disubstituted propane, and vicinal diols. Crucially, we demonstrate distinct spectral changes induced by the tridentate interaction between TG's three anchoring points and all the analyte's functional groups, even the least reactive ones. Notably, hydrogen bond (H‐bond) networks formed in the TG‐analyte complexes demonstrate additive effects in binding strength originating from good bond linearity, cooperativity, and resonance, thus strengthening complexation events and amplifying the differences in spectral changes induced among analytes. It also enhances spectral consistency by selectively forming a sole configuration that is stronger than the respective analyte‐analyte interaction. Finally, we achieve 95.4 % accuracy for multiplex identification of a mixture consisting of multiple polyfunctional analogs. We envisage that extension to other multidentate non‐covalent interactions enables the development of interference‐free small molecule‐based sensors for various (bio)chemical analysis applications. [ABSTRACT FROM AUTHOR]

Multivalency is a fundamental principle in nature that leads to high‐affinity intermolecular recognition through multiple cooperative interactions that overcome the weak binding of individual constituents. For example, multivalency plays a critical role in lectin‐carbohydrate interactions that participate in many essential biological processes. Designing high‐affinity multivalent glycoconjugates that engage lectins results in systems with the potential to disrupt these biological processes, offering promising applications in therapeutic design and bioengineering. Here, a versatile and tunable synthetic platform for the synthesis of metallosupramolecular glycoassemblies is presented that leverages subcomponent self‐assembly, which employs metal ion templates to generate complex supramolecular architectures from simple precursors in one pot. Through ligand design, this approach provides precise control over molecular parameters such as size, shape, flexibility, valency, and charge, which afforded a diverse family of well‐defined hybrid glyconanoassemblies. Evaluation of these complexes as multivalent binders to Concanavalin A (Con A) by isothermal titration calorimetry (ITC) demonstrates the optimal saccharide tether length and the effect of electrostatics on protein affinity, revealing insights into the impact of synthetic design on molecular recognition. The presented studies offer an enhanced understanding of structure‐function relationships governing lectin‐saccharide interactions at the molecular level and guide a systematic approach towards optimizing glyconanoassembly binding parameters. [ABSTRACT FROM AUTHOR]

[Display omitted] Over the past decades, advances in lipid nanotechnology have shown that self-assembled lipid structures providing ease of preparation, chemical stability, and biocompatibility represent a landmark on the development of multidisciplinary technologies. Lipid nanotubes (LNTs) are a unique class of lipid self-assembled structures, bearing unique properties such as high-aspect ratio, tunable diameter size, and precise molecular recognition. They can be obtained either by the action of external factors to already formed vesicles or spontaneously, the latter depending strongly on subtle molecular features. Here, we report on the spontaneous formation of supported lipid nanotubes of a particular type of glycolipid, ohmline, whose hydrophobic core displays remarkable asymmetry. The combination of bulk and surface-sensitive techniques indicates that below its main transition, ohmline displays an interdigitated gel phase, likely driven by the unique asymmetry in its hydrophobic core. Enhanced order packing by interdigitation favors the formation of ohmline nanotubes in agreement with chiral-based models of nanotube formation. The findings presented in this work call for additional studies to link lipid molecular structure-assembly relationships, whose understanding is relevant for the controlled design of lipid nanotubes networks in particular and controlled design of soft-matter nanomaterials in general. [ABSTRACT FROM AUTHOR]

Inherently chiral medium-ring derivatives have important applications in many research fields, such as materials science, molecular recognition, and asymmetric catalysis. However, the enantioselective assembly of these molecules, especially by organocatalytic strategies, remains a formidable challenge, and few methods are available. Here, we report the enantioselective NHC-catalyzed (NHC: N-heterocyclic carbenes) formal high-order (5 + 3) annulation of 1-(2-indolyl)naphthalen-2-ols with ynals. In the presence of an NHC pre-catalyst, base, Lewis acid and oxidant, this protocol enables the catalytic formation of C–C and C-O bonds, providing practical and facile access to an array of inherently chiral saddle-shaped eight-membered lactones featuring an oxocin-2-one scaffold with structural diversity in good efficiency and excellent enantiocontrol. Moreover, the scale-up preparation and representative late-stage transformations of the eight-membered lactones further demonstrate the application potential of this synthetic technology. Inherently chiral medium-ring derivatives have important applications in many research fields, but few enantioselective methods are available. Herein, the authors report the enantioselective N-heterocyclic carbenes-catalyzed formal (5 + 3) annulation of 1-(2-indolyl)naphthalen-2-ols with ynals for the synthesis of eight-membered lactones. [ABSTRACT FROM AUTHOR]

Millions of years of evolution have optimized many biosynthetic pathways by use of multi‐step catalysis. In addition, multi‐step metabolic pathways are commonly found in and on membrane‐bound organelles in eukaryotic biochemistry. The fundamental mechanisms that facilitate these reaction processes provide strategies to bioengineer metabolic pathways in synthetic chemistry. Using Brownian dynamics simulations, here we modeled intermediate substrate transportation of colocalized yeast–ester biosynthesis enzymes on the membrane. The substrate acetate ion traveled from the pocket of aldehyde dehydrogenase to its target enzyme acetyl‐CoA synthetase, then the substrate acetyl CoA diffused from Acs1 to the active site of the next enzyme, alcohol‐O‐acetyltransferase. Arranging two enzymes with the smallest inter‐enzyme distance of 60 Å had the fastest average substrate association time as compared with anchoring enzymes with larger inter‐enzyme distances. When the off‐target side reactions were turned on, most substrates were lost, which suggests that native localization is necessary for efficient final product synthesis. We also evaluated the effects of intermolecular interactions, local substrate concentrations, and membrane environment to bring mechanistic insights into the colocalization pathways. The computation work demonstrates that creating spatially organized multi‐enzymes on membranes can be an effective strategy to increase final product synthesis in bioengineering systems. [ABSTRACT FROM AUTHOR]

The intricate molecular architecture of ESIPT salicylaldehyde Schiff bases facilitates dynamic processes, inducing tunable photoluminescent properties. Notably, their halochromic nature, exhibiting colour changes in response to external stimuli, adds a vibrant dimension to their molecular repertoire. This sensitivity extends to environmental factors, making them valuable indicators for alterations in surroundings. The compound (E)-N’-(3,5-dibromo-2-hydroxybenzylidene)-4-methylbenzohydrazide (PTBH) demonstrates exceptional sensitivity to ammonia, enabling real-time detection (LOD = 0.14 nM) in both solution (ratiometric) and the solid state. Moreover, their metal chelation capability allows simultaneous sensing of Mg2+ and Fe2+ ions, addressing environmental hazards. Exploiting molecular recognition, the fluorescent probe serves as sensors for amino acids, opening new avenues in biomedical diagnostics. The study introduces a novel solid-state emissive Schiff base, highlighting its stimuli-responsive photoluminescent properties and diverse applications, emphasising its potential in intelligent fluorescent materials for analytical and sensing technologies. [ABSTRACT FROM AUTHOR]

Bowl-shaped, nitrogen-doped polycyclic aromatic hydrocarbons were examined for the first time as molecular receptors for the recognition of metal cations. Potentiometric and spectrofluorimetric assays, supported with density functional theory computations, revealed that the title compounds recognise metal cations with a special focus on caesium (Cs+) cations. [ABSTRACT FROM AUTHOR]

The rational design and synthesis of a novel contorted calix[2]phyrin(2.2.1.1.1) structure has been achieved, utilizing a terphenyl unit as a key building component. This terphenyl unit serves as a segment of the armchair periphery in a π-extended two-dimensional architecture. The resulting molecule exhibits remarkable properties, including the ability to self-assemble into solid-state supramolecular nanotubes. Additionally, it has demonstrated an affinity for complexation with fluoride anions, highlighting its potential for applications in molecular recognition and sensor technology. The incorporation of the terphenyl unit not only enhances the structural rigidity but also contributes to the unique electronic characteristics of the calix[2]phyrin. [ABSTRACT FROM AUTHOR]

Catalyst‐controlled diversity‐oriented synthesis (CatDOS) is an important research area for expanding molecular complexities and achieving high atomic economics. Many regiodivergent syntheses have been achieved through metal catalysis, covalent organocatalysis, and non‐covalent organocatalysis by controlling the molecular recognition function of the catalysts. However, the development of regiodivergent CatDOS through Brønsted base organocatalysis was relatively less developed than others so far. Numerous studies about Brønsted base organocatalysis have demonstrated the powerful molecular recognition abilities of their cationic conjugate acids mainly in controlling the stereoselectivity instead of the regioselectivity. This concept review aims to conceptualize a new perspective to consider the potential role of the cationic conjugate acid of Brønsted bases for regiodivergent CatDOS. Recent representative examples are selected to demonstrate the potential of cationic conjugate acids in site‐selectivity control in single bond and multiple bonds formation reactions. The summarized results show that even the conjugate acid of common tertiary amines, protic ammonium ions, could affect the regioselectivity in the early‐ or late‐stage step during multiple bonds formation after initial deprotonation. The results also suggested that the properties and ion‐pairing interactions of conjugate acid could be more important than the basicity of the base in controlling regioselectivity. Perspectives and hypotheses for explaining the mechanism of regioselectivity are also included in this review. [ABSTRACT FROM AUTHOR]

Hydrogels, water-filled networks that can adapt to external stimuli by altering their volume, are known for their high flexibility and biocompatibility. DNA, a critical biomolecule renowned for its exceptional characteristics including information transmission, molecular recognition, and editability, has found widespread applications in the biosensing field as well. The integration of these two biomaterials offers promising opportunities for the development of novel biosensors with enhanced sensitivity, specificity, and adaptability. Therefore, by virtue of the collective features, researchers have recently focused on the construction of responsive DNA hydrogel systems. This feature article describes recent developments in fabricating DNA hydrogels and their applications in the biosensing area. Initially, it focuses on the design strategies employed in preparing DNA hydrogels, encompassing both pure DNA hydrogels and hybridized DNA hydrogels. Subsequently, it summarizes the use of DNA hydrogels in biosensing applications, highlighting their applications in visual detection, electrochemical sensing, and optical biosensing analyses. Furthermore, the underlying responsive mechanisms within these biosensing systems are also described. Lastly, this article presents a comprehensive discussion on the existing challenges and prospects of responsive DNA hydrogels, offering insights into their potential to revolutionize the field of biosensing. [ABSTRACT FROM AUTHOR]

Introduction: Lectins are carbohydrate-binding proteins that are extremely selective for sugar groups in the other molecules. As a result, they perform a variety of roles in biological processes involving cell, carbohydrate, and protein recognition at the cellular and molecular levels. Because lectins can bind to carbohydrates, they may play a role in determining the rate of carbohydrate digestion. They also bind to some proteins involved in diabetes mellitus (DM) pathophysiology. The present review aims to summarize the efficiency of lectins from different sources as potential antihyperglycemic agents. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were employed for the drafting. In this regard, published scientific articles on the effects of different lectins on blood glucose (BG), glucose tolerance, hormonal effects, carbohydrate-digesting enzymes, oxidative stress, and insulin production process were collected from reputed journals using electronic databases. Furthermore, the toxicity effects of lectins from different sources were collected. A specific keyword search was completed to collect numerous articles with unique experimental designs and significant results. This was followed by the selection of the requisite articles based on the criteria designed by the authors. Data extraction was based on the common research elements included in the articles. Results and Discussion: Of 13 identified studies, 11 studies were considered after double screening based on the inclusion criteria. All 11 pharmacological investigations were considered for review. Subsequent studies reflected on the pharmacological properties of lectins on the levels of BG, oxidative stress, ß-cell proliferation, insulin resistance, inhibition of carbohydrate digesting enzymes, body weight, food and water intake, lipid profile, and other parameters. This review highlights lectins as potential anti-diabetic agents. Conclusion: However, due to limited research, systematic evaluation is recommended for their development and promotion as effective potential antihyperglycemic agents. The clinical efficacy and safety of lectins against diabetes mellitus must also be evaluated. [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]

Background: The study aims to comprehensively combine colorectal cancer data cohorts in order to analyze the effects of various DNA methylation-coding genes on colorectal cancer patients. The annual incidence and mortality of colorectal cancer are very high, and there are no effective treatments for advanced colorectal cancer. DNA methylation is a method widely used to regulate epigenetics in the molecular mechanism study of tumors. Method: Three single-cell cohorts GSE166555, GSE146771, and EMTAB8107, and five transcriptome cohorts GSE17536, GSE39582, GSE72970, and TCGA-CRC (TCGA-COAD and TCGA-READ) were applied in this study. 2 erasers (ALKBH5 and FTO), There are 7 writers (METTL3, METTL14, WTAP, VIRMA, RBM15, RBM15B, and ZC3H13) and 11 readers (YTHDC1, IGF2BP1, IGF2BP2, IGF2BP3, YTHDF1, YTHDF3, YTHDC2, and HNRNPA2B1, YTHDF2, HNRNPC and RBMX), a total of 20 M6A regulators, were used as the basis of the dataset in this study and were applied to the construction of molecular typing and prognostic models. Drugs that are differentially sensitive in methylation-regulated gene-related prognostic models were identified using the ConsensusClusterPlus package, which was also used to identify distinct methylation regulatory expression patterns in colorectal cancer and to model the relationship between tissue gene expression profiles and drug IC50 values. Finally, TISCH2 assessed which immune cells were significantly expressed with M6A scores. The immunosuppression of M6A methylation is spatially explained. Results: This study used data from 583 CRC patients in the TCGA-CRC cohort. Firstly, the mutation frequency and CNV variation frequency of 20 m6A modification-related factors were analyzed, and the corresponding histogram and heat map were drawn. The study next analyzed the expression variations between mutant and wild forms of the VIRMA gene and explored differences in the expression of these variables in tumor and normal tissues. In addition, the samples were divided into different subgroups by molecular clustering method based on m6A modification, and each subgroup's expression and clinicopathological characteristics were analyzed. Finally, we compared prognostic differences, tumor microenvironment (TME) characteristics, immune cell infiltration, and gene function enrichment among different subpopulations. We also developed a colorectal cancer m6A-associated gene signature and validated its prognostic effects across multiple cohorts. Finally, using single-cell RNA sequencing data, we confirmed that tumor cells show elevated expression of m6A-related gene signatures. Discussion: This study explored the mutation frequency, expression differences, interactions, molecular clustering, prognostic effect, and association with tumor characteristics of m6A modification-related factors in CRC and validated them at the single-cell level. These results clarify the association between m6A alteration and colorectal cancer (CRC) and offer important insights into the molecular recognition and management of cancer. [ABSTRACT FROM AUTHOR]

Despite advancements in the sensitivity and performance of analytical instruments, sample preparation remains a bottleneck in the analytical process. Currently, solid-phase extraction is more widely used than traditional organic solvent extraction due to its ease of use and lower solvent requirements. Moreover, various microextraction techniques such as micro solid-phase extraction, dispersive micro solid-phase extraction, solid-phase microextraction, stir bar sorptive extraction, liquid-phase microextraction, and magnetic bead extraction have been developed to minimize sample size, reduce solvent usage, and enable automation. Among these, in-tube solid-phase microextraction (IT-SPME) using capillaries as extraction devices has gained attention as an advanced "green extraction technique" that combines miniaturization, on-line automation, and reduced solvent consumption. Capillary tubes in IT-SPME are categorized into configurations: inner-wall-coated, particle-packed, fiber-packed, and rod monolith, operating either in a draw/eject system or a flow-through system. Additionally, the developments of novel adsorbents such as monoliths, ionic liquids, restricted-access materials, molecularly imprinted polymers (MIPs), graphene, carbon nanotubes, inorganic nanoparticles, and organometallic frameworks have improved extraction efficiency and selectivity. MIPs, in particular, are stable, custom-made polymers with molecular recognition capabilities formed during synthesis, making them exceptional "smart adsorbents" for selective sample preparation. The MIP fabrication process involves three main stages: pre-arrangement for recognition capability, polymerization, and template removal. After forming the template-monomer complex, polymerization creates a polymer network where the template molecules are anchored, and the final step involves removing the template to produce an MIP with cavities complementary to the template molecules. This review is the first paper to focus on advanced MIP-based IT-SPME, which integrates the selectivity of MIPs into efficient IT-SPME, and summarizes its recent developments and applications. [ABSTRACT FROM AUTHOR]

Oligoamines in cellular metabolism carry extremely diverse biological functions (i.e., regulating Ca2+-influx, neuronal nitric oxide synthase, membrane potential, Na+, K+-ATPase activity in synaptosomes, etc.). Furthermore, they also act as longevity agents and have a determinative role in autophagy, cell growth, proliferation, and death, while oligoamines dysregulation is a key in a variety of cancers. However, many of their mechanisms of actions have just begun to be understood. In addition to the numerous biosensing methods, only a very few simple small molecule-based tests are available for their selective but reversible tracking or fluorescent labeling. Motivated by this, we present herein a new fluorescent bis(acridino)-crown ether as a sensor molecule for biogenic oligoamines. The sensor molecule can selectively distinguish oligoamines from aliphatic mono- and diamino-analogues, while showing a reversible 1:2 (host:guest) complexation with a stepwise binding process accompanied by a turn-on fluorescence response. Both computational simulations on molecular docking and regression methods on titration experiments were carried out to reveal the oligoamine-recognition properties of the sensor molecule. The new fluorescent chemosensor molecule has a high potential for molecular-level functional studies on the oligoamine systems in cell processes (cellular uptake, transport, progression in cancers, etc.). [ABSTRACT FROM AUTHOR]

Constructing organic composite materials through molecular recognition has emerged as an important theme in materials science. Here we report an ion‐pair recognition system involving the use of a propoxylated pillar[5]arene (PrP5) to modulate the solid‐state photophysical properties of dye trans‐4'‐(dimethylamino)‐N‐methyl‐4‐stilbazolium hexafluorophosphate (DMASP). Single crystal X‐ray diffraction analysis reveals that the dye guest DMASP is encapsulated by PrP5 to form a 2 : 1 host−guest complex 2PrP5⸧DMASP in the crystalline state. The macrocyclic skeleton of PrP5 imposes restrictions on the intramolecular motions of the dye guest, leading to a significant enhancement of its fluorescence emission. Additionally, within the 2PrP5⸧DMASP complex crystal structure, DMASP molecules are found to display two possible opposite orientations in the one‐dimensional channels formed by PrP5 molecules. This arrangement is believed to alter the overall solid‐state packing structure of DMASP, thereby activating its nonlinear optical activity. This work not only reports a novel ion‐pair molecular recognition system based on pillararenes but also provides valuable insights into the modulation of the crystalline state photophysical properties of organic dyes via cocrystal engineering. [ABSTRACT FROM AUTHOR]

Lys48‐linked ubiquitin chains, regulating proteasomal protein degradation, are known to include cyclized forms. This cyclization hinders recognition by many downstream proteins by occluding the Ile44‐centered patch. In contrast, the A20‐like Znf domain of ZNF216 (a ubiquitin‐binding protein, A20 Znf) is expected to bind to cyclic ubiquitin chains via constitutively solvent‐exposed surfaces. However, the underlying interaction mechanism remains unclear. Here, our ITC and NMR experiments collectively showed that cyclization did not interfere with and even slightly enhance the molecular recognition of diubiquitin by A20 Znf. This effect is explained by the cyclization‐induced repression of conformational dynamics in diubiquitin and an enlarged molecular interface in the complex. Thus, these results suggest that cyclic ubiquitin chains can be involved in regulation of ZNF216‐dependent proteasomal protein degradation. [ABSTRACT FROM AUTHOR]

Recombinant proteins hold significant importance in numerous disciplines. As the demand for expressing and purifying these proteins grows, the scientific community is in dire need of a simple yet versatile methodology that can efficiently purify these proteins. Aptamers as synthetic nucleic acid–based ligands with high affinity have shown promise in this regard, as they can capture targets through molecular recognition. In this study, novel aptamer‐functionalized polydopamine‐coated magnetic graphene oxide nanocomposites were facilely prepared, achieving an impressive average aptamer coverage density (45 nmol/mg). These nanocomposites exhibited a uniform structure and robust magnetic responsiveness. The findings indicated that they possess several advantages, such as rapid adsorption, substantial capacity (171.4 mg/g), and excellent reusability. Notably, due to the inherent properties of nucleic acids, the immobilized aptamer‐magnetic beads can be utilized repeatedly with high purification efficiency. Finally, the nanocomposites were further employed to purify His‐tagged proteins from actual samples. Remarkably, they were able to selectively and efficiently isolate His‐tagged retinoid X receptor alpha protein from complex Escherichia coli lysate. The purified His‐tagged retinoid X receptor alpha protein was analyzed using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. This confirmed the efficacy of developed nanocomposites, reinforcing their vast potential for purification of His‐tagged recombinant proteins. [ABSTRACT FROM AUTHOR]

Supramolecular chemistry focuses on the study of species joined by non-covalent interactions, and therefore on dynamic and relatively ill-defined structures. Despite being a well-developed field, it has to face important challenges when dealing with the selective recognition of biomolecules in highly competitive biomimetic media. However, supramolecular interactions reside at the core of chemical biology systems, since many processes in nature are governed by weak, non-covalent, strongly dynamic contacts. Therefore, there is a natural connection between these two research fields, which are not frequently related or share interests. In this feature article, I will highlight our most recent results in the molecular recognition of biologically relevant species, following different conceptual approaches from the most conventional design of elaborated receptors to the less popular dynamic combinatorial chemistry methodology. Selected illustrative examples from other groups will be also included. The discussion has been focused mainly on systems with potential biomedical applications. [ABSTRACT FROM AUTHOR]

The enzymatic atroposelective synthesis of biaryl compounds is relatively rare, despite considerable attention received by biocatalysis in the academic and industrial sectors. Imine reductases (IREDs) are an important class of enzymes that have been applied in the asymmetric synthesis of chiral amine building blocks. In this study, two IREDs (IR140 and IR189) were identified to catalyze the efficient desymmetrization of biaryls utilizing various amine donors. Further protein engineering enabled the identification of variants (IR189 M8–M9 and IR189 M13–M14) that are able to catalyze the formation of both (R) and (S) atropisomers in excellent yields and atroposelectivities (24 examples, up to 99 % ee and yield). The absolute configuration and rotational barriers were confirmed, and the reactions were readily scaled up to allow isolation of the atropisomeric product in 99 % ee and 82 % yield. The optically pure biaryl amines were further derivatized into various synthetically useful atropisomers. To shed light on the molecular recognition mechanisms, molecular dynamics (MD) simulations were performed, offering plausible explanations for the improved atroposelectivity and enzymatic activity. The current strategy expands the scope of the IRED‐catalyzed synthesis of axially chiral biaryl amines, contributing significantly to the field of atroposelective biocatalysis. [ABSTRACT FROM AUTHOR]