Grinding-induced supramolecular charge-transfer assemblies with switchable vapochromism toward haloalkane isomers.

Synthetic macrocycles have proved to be of great application value in functional charge-transfer systems in the solid state in recent years. Here we show a switchable on-off type vapochromic system toward 1-/2-bromoalkane isomers by constructing solid-state charge-transfer complexes between electron-rich perethylated pillar[5]arene and electron-deficient aromatic acceptors including 4-nitrobenzonitrile and 1,4-dinitrobenzene. These charge-transfer complexes with different colors show opposite color changes upon exposure to the vapors of 1-bromoalkanes (fading) and 2-bromoalkanes (deepening). Single-crystal structures incorporating X-ray powder diffraction and spectral analyses demonstrate that this on-off type vapochromic behavior is mainly attributed to the destruction (off) and reconstruction (on) of the charge-transfer interactions between perethylated pillar[5]arene and the acceptors, for which the competitive host-guest binding of 1-bromoalkanes and the solid-state structural transformation triggered by 2-bromoalkanes are respectively responsible. This work provides a simple colorimetric method for distinguishing positional isomers with similar physical and chemical properties.

[Hepatotoxicity and mechanism of Rhododendri Mollis Flos based on zebrafish model].

This study used the zebrafish model to explore the hepatotoxicity of Rhododendri Mollis Flos(RMF). The mortality was calculated according to the number of the survival of zebrafish larvae 4 days after fertilization under different concentration of RMF, and the dose-toxicity curve was fitted to preliminarily evaluate the toxicity of RMF. The liver phenotypes under the sublethal concentration of RMF in the treatment group and the blank control group were observed by hematoxylin-eosin(HE) staining and acridine orange(AO) staining. Meanwhile, the activities of alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were determined to confirm the hepatotoxicity of RMF. Real-time quantitative polymerase chain reaction(real-time PCR) and Western blot were used to determine the expressions of genes and proteins in zebrafish larvae. Gas chromatography time-of-flight mass spectrometry(GC-TOF-MS) was used to conduct untargeted metabolomics testing to explore the mechanism. The results showed that the toxicity of RMF to zebrafish larvae was dose-dependent, with 1 100 µg·mL~(-1) of the absolute lethal concentration and 448 µg·mL~(-1) of sublethal concentration. The hepatocyte apoptosis and degeneration appeared in the zebrafish larvae under the sublethal concentration of RMF. The content of ALT and AST in zebrafish larvae at the end of the experiment was significantly increased in a dose-dependent manner. Under the sublethal concentration, the expressions of genes and proteins related to apoptosis in zebrafish larvae were significantly increased as compared with the blank control group. The results of untargeted metabolomics showed that the important metabolites related to the he-patotoxicity of RMF were mainly enriched in alanine, aspartic acid, glutamic acid, and other pathways. In conclusion, it is inferred that RMF has certain hepatotoxicity to zebrafish larvae, and its mechanism may be related to apoptosis.

Macrocycle-Based Crystalline Supramolecular Assemblies Built with Intermolecular Charge-Transfer Interactions.

Synthetic macrocycles have served as principal tools for supramolecular chemistry, have greatly extended the scope of organic charge transfer (CT) complexes, and have proved to be of great practical value in the solid state during the past few years. In this Minireview, we summarize the research progress on the macrocycle-based crystalline supramolecular assemblies primarily driven by intermolecular CT interactions (a.k.a. macrocycle-based crystalline CT assemblies, MCCAs for short), which are classified by their donor-acceptor (D-A) constituent elements, including simplex macrocyclic hosts, heterogeneous macrocyclic hosts, and host-guest D-A pairs. Particular attention will be focused on their diverse functions and applications, as well as the underlying CT mechanisms from the perspective of crystal engineering. Finally, the remaining challenges and prospects are outlined.

A Water-Soluble Leggero Pillar[5]arene.

The study of aqueous-phase molecular recognition of artificial receptors is one of the frontiers in supramolecular chemistry since most biochemical processes and reactions take place in an aqueous medium and heavily rely on it. In this work, a water-soluble version of leggero pillar[5]arene bearing eight positively charged pyridinium moieties (CWP[5]L) was designed and synthesized, which exhibited good binding affinities with certain aliphatic sulfonate species in aqueous solutions. Significantly, control experiments demonstrate that the guest binding performance of CWP[5]L is superior to its counterpart water-soluble macrocyclic receptor in traditional pillararenes.

Pillararene-Inspired Macrocycles: From Extended Pillar[n]arenes to Geminiarenes.

chemistry since their establishment due to their innate functional features of molecular recognition and complexation. The rapid development of modern supramolecular chemistry has also significantly benefited from creating new macrocycles with distinctive geometries and properties. For instance, pillar[n]arenes (pillarenes), a relatively young generation of star macrocyclic hosts among the well-established ones (e.g., crown ethers, cyclodextrins, cucurbiturils, and calixarenes), promoted a phenomenal research hotspot all over the world in the past decade. Although the synthesis, host-guest properties, and various supramolecular functions of pillarenes have been intensively studied, many objective limitations and challenges still cannot be ignored. For example, high-level pillar[n]arenes (n > 7) usually do not possess applicable large-sized cavities due to structural folding and cannot be synthesized on a large scale because of the uncompetitive cyclization process. Furthermore, two functional groups must be covalently para-connected to each repeating phenylene unit, which severely limits their structural diversity and flexibility. In this context, we have developed a series of pillarene-inspired macrocycles (PIMs) using a versatile and modular synthetic strategy during the past few years, aiming to break through the synthetic limitations in traditional pillarenes and find new opportunities and challenges in supramolecular chemistry and beyond. Specifically, by grafting biphenyl units into the pillarene backbones, extended pillar[n]arenes with rigid and nanometer-sized cavities could be obtained with reasonable synthetic yields by selectively removing hydroxy/alkoxy substitutes on pillarene backbones, leaning pillar[6]arenes and leggero pillar[n]arenes with enhanced structural flexibility and cavity adaptability were obtained. By combining the two types of bridging modes in pillarenes and calixarenes, a smart macrocyclic receptor with two different but interconvertible conformational features, namely geminiarene, was discovered. Benefiting from the synthetic accessibility, facile functionalization, and superior host-guest properties in solution or the solid state, this new family of macrocycles has exhibited a broad range of applications, including but not limited to supramolecular assembly/gelation/polymers, pollutant detection and separation, porous organic polymers, crystalline/amorphous molecular materials, hybrid materials, and controlled drug delivery. Thus, in this Account, we summarize our research efforts on these PIMs. We first present an overview of their design and modular synthesis and a summary of their derivatization strategies. Thereafter, particular attention is paid to their structural features, supramolecular functions, and application exploration. Finally, the remaining challenges and perspectives are outlined for their future development. We hope that this Account and our works can stimulate further advances in synthetic macrocyclic chemistry and supramolecular functional systems, leading to practical applications in various research areas.

Modulating Supramolecular Charge-Transfer Interactions in the Solid State using Compressible Macrocyclic Hosts.

Modulating intermolecular charge-transfer (ICT) interactions between specific donor and acceptor species in host-guest systems is a big challenge and full of research value in supramolecular chemistry and materials science. In this work, a strategy to modulate the supramolecular ICT interactions in the solid state is developed by compressing the binding cavity of a macrocyclic host named perethylated leaning pillar[6]arene (p-EtLP6). The solid-state ICT affinities of p-EtLP6 toward multi-types of electron-deficient planar guests could be significantly enhanced by transforming the macrocyclic backbone from the original para-bridged mode into a hybrid para- and meta-bridged isomeric form (m-EtLP6). X-ray single-crystal structural analyses incorporating theoretical calculation demonstrate that the improved ICT affinities are mainly attributed to the superior host-guest size fit arising from the compressed binding cavity in m-EtLP6 as compared with p-EtLP6.

Guest-induced amorphous-to-crystalline transformation enables sorting of haloalkane isomers with near-perfect selectivity.

The separation of haloalkane isomers with distillation-free strategies is one of the most challenging research topics in fundamental research and also gave high guiding values to practical industrial applications. Here, this contribution provides a previously unidentified solid supramolecular adsorption material based on a leggero pillararene derivative BrP[5]L, which can separate 1-/2-bromoalkane isomers with near-ideal selectivity. Activated solids of BrP[5]L with interesting amorphous and nonporous features could adsorb 1-bromopropane and 1-bromobutane from the corresponding equal volume mixtures of 1-/2-positional isomers with purities of 98.1 and 99.0%, respectively. Single-crystal structures incorporating theoretical calculation reveal that the high selectivity originates from the higher thermostability of 1-bromoalkane-loaded structures compared to its corresponding isomer-loaded structures, which could be further attributed to the perfect size/shape match between BrP[5]L and 1-bromoalkanes. Moreover, control experiments using its counterpart macrocycle of traditional pillararene demonstrate that BrP[5]L has better adsorptive selectivity, benefiting from the intrinsic free-rotation phenylene subunit on its backbone.

[Construction of a high-throughput screening model for mitochondrial function of Aconiti Lateralis Radix Praeparata by machine learning algorithm and mechanism analysis].

A high-throughput screening machine learning model for mitochondrial function was constructed, and compounds of Aco-niti Lateralis Radix Praeparata were predicted. Deoxyaconitine with the highest score and benzoylmesaconine with the lowest score among the compounds screened by the model were selected for mitochondrial mechanism analysis. Mitochondrial function data were collected from PubChem and Tox21 databases. Random forest and gradient boosted decision tree algorithms were separately used for mo-deling, and ECFP4(extended connectivity fingerprint, up to four bonds) and Mordred descriptors were employed for training, respectively. Cross-validation test was carried out, and balanced accuracy(BA) and overall accuracy were determined to evaluate the performance of different combinations of models and obtain the optimal algorithm and hyperparameters for modeling. The data of Aconiti Lateralis Radix Praeparata compounds in TCMSP database were collected, and after prediction and screening by the constructed high-throughput screening machine learning model, deoxyaconitine and benzoylmesaconine were selected to measure mitochondrial membrane potential, reactive oxygen species(ROS) level and protein expression of B-cell lymphoma 2(Bcl-2), Bcl-2-associated X protein(Bax) and peroxisome proliferator-activated receptor-γ-coactivator 1α(PGC-1α). The results showed that the model constructed using gradient boosted decision tree+Mordred algorithm performed better, with a cross-validation BA of 0.825 and a test set accuracy of 0.811. Deoxyaconitine and benzoylmesaconine changed the ROS level(P<0.001), mitochondrial membrane potential(P<0.001), and protein expression of Bcl-2(P<0.001, P<0.01) and Bax(P<0.001), and deoxyaconitine increased the expression of PGC-1α protein(P<0.01). The high-throughput screening model for mitochondrial function constructed by gradient boosted decision tree+Mordred algorithm was more accurate than that by random forest+ECFP4 algorithm, which could be used to build an algorithm model for subsequent research. Deoxyaconitine and benzoylmesaconine affected mitochondrial function. However, deoxyaconitine with higher score also affected mitochondrial biosynthesis by regulating PGC-1α protein.

Gene co-expression network based on part mutual information for gene-to-gene relationship and gene-cancer correlation analysis.

BACKGROUND: Finding correlation patterns is an important goal of analyzing biological data. Currently available methods for correlation analysis mainly use non-direct associations, such as the Pearson correlation coefficient, and focus on the interpretation of networks at the level of modules. For biological objects such as genes, their collective function depends on pairwise gene-to-gene interactions. However, a large amount of redundant results from module level methods often necessitate further detailed analysis of gene interactions. New approaches of measuring direct associations among variables, such as the part mutual information (PMI), may help us better interpret the correlation pattern of biological data at the level of variable pairs. RESULTS: We use PMI to calculate gene co-expression networks of cancer mRNA transcriptome data. Our results show that the PMI-based networks with fewer edges could represent the correlation pattern and are robust across biological conditions. The PMI-based networks recall significantly more important parts of omics defined gene-pair relationships than the Pearson Correlation Coefficient (PCC)-based networks. Based on the scores derived from PMI-recalled copy number variation or DNA methylation gene-pairs, the patients with cancer can be divided into groups with significant differences on disease specific survival. CONCLUSIONS: PMI, measuring direct associations between variables, extracts more important biological relationships at the level of gene pairs than conventional indirect association measures do. It can be used to refine module level results from other correlation methods. Particularly, PMI is beneficial to analysis of biological data of the complicated systems, for example, cancer transcriptome data.

Mechanosensitive Piezo1 channel in rat epididymal epithelial cells promotes transepithelial K+ secretion.

The Piezo1 channel, a mechanosensitive channel that exhibit a preference for Ca2+, play multifarious physiological and pathological roles in the endothelium and epithelium of various tissues. However, the functional expression of Piezo1 channel in the epithelium of the male reproductive tract remains unknown. In the present study, the expression of Piezo1 channel in the rat epididymis was determined by real-time quantitative PCR, western blot and immunohistochemical analysis. Our data revealed that Piezo1 channel was located in the epithelial layer of the rat epididymis, with higher expression levels in the corpus and cauda regions. The pro-secretion function of Piezo1 channel was then investigated using short circuit current (ISC) and intracellular Ca2+ imaging techniques. Application of Yoda1, a selective Piezo1 channel activator, stimulated a remarkable decrease in the ISC of the epididymal epithelium. Pharmacological experiments revealed that the ISC response induced by Piezo1 channel activation was abolished by pretreating epithelial cells with the Yoda1 analogue, Dooku1, the selective mechanosensitive cation channel blocker, GsMTx4, or removal of basolateral K+. Meanwhile, we demonstrated that activation of Piezo1 channel triggered a robust Ca2+ influx in epididymal epithelial cells. The possible involvement of Ca2+- activated K+channels (KCa) in transepithelial K+ secretion was then evaluated. And that big conductance KCa (BK), but not small conductance or intermediate conductance KCa, mediated Piezo1-elicited transepithelial K+ secretion. Moreover, we demonstrated that NKCC and NKA were responsible for supplying substrate K+ during transepithelial K+ secretion. These data demonstrate that the activation of Piezo1 channel promotes BK-mediated transepithelial K+ secretion, and thus may plays an important role in the formation of a high K+ concentration in epididymal intraluminal fluid.

Toxicities of amyloid-beta and tau protein are reciprocally enhanced in the Drosophila model.

Extracellular aggregation of amyloid-beta (Aß) and intracellular tau tangles are two major pathogenic hallmarks and critical factors of Alzheimer's disease. A linear interaction between Aß and tau protein has been characterized in several models. Aß induces tau hyperphosphorylation through a complex mechanism; however, the master regulators involved in this linear process are still unclear. In our study with Drosophila melanogaster, we found that Aß regulated tau hyperphosphorylation and toxicity by activating c-Jun N-terminal kinase. Importantly, Aß toxicity was dependent on tau hyperphosphorylation, and flies with hypophosphorylated tau were insulated against Aß-induced toxicity. Strikingly, tau accumulation reciprocally interfered with Aß degradation and correlated with the reduction in mRNA expression of genes encoding Aß-degrading enzymes, including dNep1, dNep3, dMmp2, dNep4, and dIDE. Our results indicate that Aß and tau protein work synergistically to further accelerate Alzheimer's disease progression and may be considered as a combined target for future development of Alzheimer's disease therapeutics.

Activation of TRPV4 stimulates transepithelial K+ secretion in rat epididymal epithelium.

The maturation of sperms is dependent on the coordinated interactions between sperm and the unique epididymal luminal milieu, which is characterized by high K+ content. This study investigated the involvement of transient receptor potential vanilloid 4 (TRPV4) in the K+ secretion of epididymal epithelium. The expression level and cellular localization of TRPV4 and Ca2+-activated K+ channels (KCa) were analyzed via RT-PCR, real-time quantitative PCR, western blot and immunofluorescence. The functional role of TRPV4 was investigated using short-circuit current (ISC) and intracellular Ca2+ imaging techniques. We found a predominant expression of TRPV4 in the corpus and cauda epididymal epithelium. Activation of TRPV4 with a selective agonist, GSK1016790A, stimulated a transient decrease in the ISC of the epididymal epithelium. The ISC response was abolished by either the TRPV4 antagonists, HC067047 and RN-1734, or the removal of basolateral K+. Simultaneously, the application of GSK1016790A triggered Ca2+ influx in epididymal epithelial cells. Our data also indicated that the big conductance KCa (BK), small conductance KCa (SK) and intermediate conductance KCa (IK) were all expressed in rat epididymis. Pharmacological studies revealed that BK, but not SK and IK, mediated TRPV4-elicited transepithelial K+ secretion. Finally, we demonstrated that TRPV4 and BK were localized in the epididymal epithelium, which showed an increased expression level from caput to cauda regions of rat epididymis. This study implicates that TRPV4 plays an important role in the formation of high K+ concentration in epididymal intraluminal fluid via promoting transepithelial K+ secretion mediated by BK.

A network pharmacology approach to reveal the pharmacological targets and biological mechanism of compound kushen injection for treating pancreatic cancer based on WGCNA and in vitro experiment validation.

BACKGROUND: Compound kushen injection (CKI), a Chinese patent drug, is widely used in the treatment of various cancers, especially neoplasms of the digestive system. However, the underlying mechanism of CKI in pancreatic cancer (PC) treatment has not been totally elucidated. METHODS: Here, to overcome the limitation of conventional network pharmacology methods with a weak combination with clinical information, this study proposes a network pharmacology approach of integrated bioinformatics that applies a weighted gene co-expression network analysis (WGCNA) to conventional network pharmacology, and then integrates molecular docking technology and biological experiments to verify the results of this network pharmacology analysis. RESULTS: The WGCNA analysis revealed 2 gene modules closely associated with classification, staging and survival status of PC. Further CytoHubba analysis revealed 10 hub genes (NCAPG, BUB1, CDK1, TPX2, DLGAP5, INAVA, MST1R, TMPRSS4, TMEM92 and SFN) associated with the development of PC, and survival analysis found 5 genes (TSPOAP1, ADGRG6, GPR87, FAM111B and MMP28) associated with the prognosis and survival of PC. By integrating these results into the conventional network pharmacology study of CKI treating PC, we found that the mechanism of CKI for PC treatment was related to cell cycle, JAK-STAT, ErbB, PI3K-Akt and mTOR signalling pathways. Finally, we found that CDK1, JAK1, EGFR, MAPK1 and MAPK3 served as core genes regulated by CKI in PC treatment, and were further verified by molecular docking, cell proliferation assay, RT-qPCR and western blot analysis. CONCLUSIONS: Overall, this study suggests that the optimized network pharmacology approach is suitable to explore the molecular mechanism of CKI in the treatment of PC, which provides a reference for further investigating biomarkers for diagnosis and prognosis of PC and even the clinical rational application of CKI.

Bottom-Up Solid-State Molecular Assembly via Guest-Induced Intermolecular Interactions.

The manipulation of molecular motions to construct highly ordered supramolecular architectures from chaos in the solid state is considered to be far more complex and challenging in comparison to that in solution. In this work, a bottom-up molecular assembly approach based on a newly designed skeleton-trimmed pillar[5]arene analogue, namely the permethylated leggero pillar[5]arene MeP[5]L, is developed in the solid state. An amorphous powder of MeP[5]L can take up certain guest vapors to form various ordered linker-containing solid-state molecular assemblies, which can be further used to construct a thermodynamically favored linker-free superstructure upon heating. These approaches are driven by vapor-induced solid-state molecular motions followed by a thermally triggered phase-to-phase transformation. The intermolecular interactions play a crucial role in controlling the molecular arrangements in the resulting assemblies. This research will open new insights into exploring controllable molecular motions and assemblies in the solid state, providing new perspectives in supramolecular chemistry and materials.

Inhibition of a Novel CLK1-THRAP3-PPARγ Axis Improves Insulin Sensitivity.

Increasing energy expenditure by promoting "browning" in adipose tissues is a promising strategy to prevent obesity and associated diabetes. To uncover potential targets of cold exposure, which induces energy expenditure, we performed phosphoproteomics profiling in brown adipose tissue of mice housed in mild cold environment at 16°C. We identified CDC2-like kinase 1 (CLK1) as one of the kinases that were significantly downregulated by mild cold exposure. In addition, genetic knockout of CLK1 or chemical inhibition in mice ameliorated diet-induced obesity and insulin resistance at 22°C. Through proteomics, we uncovered thyroid hormone receptor-associated protein 3 (THRAP3) as an interacting partner of CLK1, further confirmed by co-immunoprecipitation assays. We further demonstrated that CLK1 phosphorylates THRAP3 at Ser243, which is required for its regulatory interaction with phosphorylated peroxisome proliferator-activated receptor gamma (PPARγ), resulting in impaired adipose tissue browning and insulin sensitivity. These data suggest that CLK1 plays a critical role in controlling energy expenditure through the CLK1-THRAP3-PPARγ axis.

FIGS: Featured Ion-Guided Stoichiometry for Data-Independent Proteomics through Dynamic Deconvolution.

Data-independent acquisition (DIA) has significant advantages for mass spectrometry (MS)-based peptide quantification, while mixed spectra remain challenging for precise stoichiometry. We here choose to analyze the library spectra in specific sets preferentially and locally. Accordingly, the featured ions are defined as the fragment ions uniquely assigned to corresponding precursors in a given spectrum set, which are generated by dynamic deconvolution of the mixed mass spectra. Then, we present featured ion-guided stoichiometry (FIGS), a universal method for accurate and robust peptide quantification for the DIA-MS data. We validate the high performance on the quantification sensitivity, accuracy, and efficiency of FIGS. Notably, our FIGS dramatically improves the quantification accuracy for the full dynamic range, especially for low-abundance peptides.

Enantioselective Synthesis of Quaternary Carbon Stereocenters by Asymmetric Allylic Alkylation: A Review.

Quaternary stereocenters are of great importance to the three-dimensionality and enhanced properties of new molecules, but the synthetic challenges in creating quaternary stereocenters greatly hinder their wide use in drug discovery, organic material design, and natural product synthesis. The asymmetric allylic alkylation (AAA) of allylic substrates has proven to be a powerful methodology for enantioselective formation of structure skeletons bearing single or more quaternary carbon centers in modern asymmetric organocatalysis. AAA has certain advantages in constructing the tetrasubstituted stereocenters, including but not limited to mild reactive conditions, effective reaction rates, new functional group introduction, and carbon chains length extension. This review outlines the key considerations in the application of AAA reactions and summarizes the recent progress of AAA reactions in the enantioselective synthesis of products containing quaternary stereocenters. Meanwhile, a detailed discussion of the AAA reactions such as ligands, scope of substrates, transformations and the general reaction mechanisms is also provided. We hope this review could stimulate further advances in much broader areas, including organic synthesis, asymmetric catalysis, C-H activation, and symmetrical pharmaceutical chemistry.

Recyclable Supramolecular Assembly-Induced Emission System for Selective Detection and Efficient Removal of Mercury(II).

An efficient strategy for simultaneously detecting and removing Hg2+ from water is vital to address mercury pollution. Herein a supramolecular assembly G⊂H with photoluminescent properties is facilely constructed through the self-assembly of a functional pillar[5]arene bearing two N,N-dimethyldithiocarbamoyl binding sites (H) and an AIE-active tetraphenylethene derivative (G). Remarkably, the fluorescence of G⊂H can be exclusively quenched by Hg2+ among the 30 cations due to the formation of non-luminous ground state complex and only L-cysteine can restore fluorescence in the common 20 amino acids. Meanwhile, the probe G⊂H has a considerable thermal and pH stability, a good anti-interference property from various cations, and a satisfactory sensitivity. More importantly, G⊂H exhibits a prominent capability of Hg2+ removal with rapid capture rate (within 1 h) and excellent adsorption efficiency (98 %), as well as a highly efficient recyclability without losing any adsorption activity.

Macrocyclic Arenes-Based Conjugated Macrocycle Polymers for Highly Selective CO2 Capture and Iodine Adsorption.

Incorporating synthetic macrocycles with unique structures and distinct conformations into conjugated macrocycle polymers (CMPs) can endow the resulting materials with great potentials in gas uptake and pollutant adsorption. Here, four CMPs (CMP-n, n=1-4) capable of reversibly capturing iodine and efficiently separating carbon dioxide are constructed from per-triflate functionalized leaning tower[6]arene (LT6-OTf) and [2]biphenyl-extended pillar[6]arene (BpP6-OTf) via Pd-catalyzed Sonogashira-Hagihara cross-coupling reaction. Intriguingly, owing to the appropriate cavity size of LT6-OTf and the numerous aromatic rings in the framework, the newly designed CMP-4 possesses an outstanding I2 affinity with a large uptake capacity of 208 wt % in vapor and a great removal efficiency of 94 % in aqueous solutions. To our surprise, with no capacity to accommodate nitrogen, CMP-2 constructed from BpP6-OTf is able to specifically capture carbon dioxide at ambient conditions.

Synthetic Macrocycle-Based Nonporous Adaptive Crystals for Molecular Separation.

The exploitation of new materials for adsorptive separation of industrially important hydrocarbons is of great importance in both scientific research and petrochemical industry. Nonporous adaptive crystals (NACs) as a robust class of synthetic materials have drawn much attention during the past five years for their superior performance in adsorption and separation. Pillararenes are the main family of macrocyclic arenes used for NACs construction, where the structure-function relationship has been intensively studied. In the past two years, some emerging types of synthetic macrocyclic arenes have been successfully brought into this research field, showing the gradual enrichment and diversification of NACs materials. This Minireview summarizes the recent advances of synthetic macrocycle-based NACs, which are categorized by various practical applications in molecular separation. Besides, NACs-based vapochromic supramolecular systems are also discussed. Finally, future perspectives and challenges of NACs are given. We envisage that this Minireview will be a useful and timely reference for those who are interested in new molecular and supramolecular crystals for storage and separation applications.