Aggregation caused quenching to aggregation induced emission transformation: a precise tuning based on BN-doped polycyclic aromatic hydrocarbons toward subcellular organelle specific imaging

Examining the adsorption and sensing characteristics of cytosine (CTE) on Y9N9 (Y = Al, B, Ga) nanorings using solvent effects, DFT, AIM and SERS analyses

Nucleobases are nitrogenous biological compounds that are more significant in a range of biological and in medical applications. They are constituents of nucleotides in deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Therefore, we assessed the sensing applicability by studying the cytosine (CTE)-Y9N9 (Y = Al, B, Ga) nanoring interaction using density functional theory. It was evident that CTE interacted strongly with each ring. Due to charge transfer between the nanoring and CTE, a dipole moment (DM) is generated. All complexes have band gaps less than that of CTE. Complexes' band gap energies are lower in aqueous phase and vacuum than they are in pristine rings. All complexes exhibit higher adsorption energies in solvent medium in comparison with that in vacuum. Changes in the frontier molecular orbitals (FMOs) energies of nanorings after interaction have a major impact on their electrical conductivity and work function. In addition to being an electrical sensor, the Y9N9 nanorings for CTE can also be utilized as a work function-based sensor. But Y9N9's CTE recovery time indicates that it can be used to extract or store CTE depending on the environment. The current work can be expanded to examine the impact of Ag/Au/Cu doping using Y9N9 in order to examine the characteristics of drug delivery carriers and the consequence of doping. The interaction between the analyte and substrate was further studied using reduced density gradient (RDG) analysis, comparing the nature and strength of the interaction in both vacuum and aqueous medium. The observations revealed a stronger interaction in the presence of an aqueous medium, which aligns with the higher adsorption energy values.

Frozen-Pair-Type pCCD-Based Methods and Their Double Ionization Variants to Predict Properties of Prototypical BN-Doped Light Emitters

Novel, robust, computationally efficient, and reliable theoretical methods are indispensable for the large-scale modeling of desired molecular properties. One such example is the orbital optimized pair coupled-cluster doubles (oo-pCCD) ansatz and its various CC extensions, which range from closed-shell ground- and excited-state models to open-shell variants. Specifically, the ionization-potential equation-of-motion frozen-pair (IP-EOM-fp)CC methods proved to be competitive with standard CC-type methods for modeling the ionization potentials of organic electronics. In this work, we extend the existing IP-EOM-pCCD-based methods to their double ionization potential (DIP) variants, resulting in various DIP-EOM-fpCC models, including up to double excitations. These methods open the way to reach open-shell singlet, triplet, and quintet states using various pCCD reference functions. Their accuracy is tested for the singlet-triplet gaps of the ortho-, meta-, and para-benzynes. Then, the most accurate models are applied to study the effects of boron and nitrogen doping on designing prototypical naphthalene-based donors and acceptors. Our results demonstrate consistent and reliable outcomes with standard methods and available experimental data. Most importantly, fpCC-type methods show slightly better performance than DIP-EOM-CCSD for strongly-correlated cases and similar performance for systems dominated by dynamical correlation when determining singlet-triplet gaps.

BN-embedded aromatic hydrocarbons: synthesis, functionalization and applications

Substituting CC double bonds with B-N bonds in polycyclic aromatic hydrocarbons (PAHs) has emerged as a promising approach to advance and diversify organic functional materials. This structural modification not only imparts unique electronic and optical properties, but also enhances chemical stability, thereby opening new avenues for material design and applications. However, the widespread adoption of BN-fused aromatic hydrocarbons in practical applications is still in its nascent phase. This constraint stems primarily from the challenges in precisely tailoring molecular structures to optimize photophysical and electronic properties, thereby influencing their efficacy in targeted applications. Consequently, a comprehensive evaluation of historical, current, and prospective developments in BN-fused aromatic hydrocarbons is deemed essential. This review offers an in-depth overview of recent advancements in BN-fused aromatic hydrocarbons, focusing on synthetic strategies, fundamental properties, and emerging applications. Additionally, we elucidate the pivotal role of computational chemistry in directing the design, discovery, and optimization of these materials. Our objective is to foster interdisciplinary collaboration and stimulate innovative approaches to fully harness the potential of azaborinine chemistry across various fields, including organic optoelectronics, biomedicine, and related disciplines.

Domain-Based Charge-Transfer Decomposition and Its Application to Explore the Charge-Transfer Character in Prototypical Dyes

We introduce a new domain-based charge-transfer analysis tool exploiting the locality of pair Coupled Cluster Doubles orbitals. Unique features of the proposed model include the ability to monitor the direction of the charge flow between different parts or moieties of the system and its quantitative evaluation. We assess the predictive power of our new method for selected dye candidates of dye-sensitized solar cells with different doping and structural arrangements and compare our results for excitation and orbital energies to various density functional approximations and the domain-based local pair natural orbital variant of coupled cluster singles doubles. Our work confirms that the dyes with S-doped bridges are the most promising candidates for dye-sensitized solar cells applications, featuring the largest donor → bridge → acceptor directed charge transfer and the most favorable electrodonating and electroaccepting powers.

Multi-stimuli-responsive aggregation-induced emission of boryl substituted phenothiazine

Stimuli-responsive materials, especially multi-stimuli-responsive ones, represent a kind of intelligent materials with significant potential in high-tech innovations, owing to their ability to undergo physical property changes in response to external stimuli. This investigation produced three new functionalized donor-acceptor (D-A) fluorophores, specifically aminoboranes incorporating phenothiazyl groups (4a, 4b, and 4c), featuring analogous structural components. These aminoborane derivatives demonstrated excellent resistance to air/moisture degradation, along with reduced HOMO energy states compared to a CN-containing analog, 4d. Analysis indicated that these aminoborane compounds displayed fascinating photophysical characteristics, encompassing aggregation-induced emission (AIE). Notably, the diarylboryl-phenothiazines show case reversible and distinct multi-stimuli-responsive luminescence upon exposure to fluoride ions, voltage, and mechanical force. This investigation enhances understanding of molecular interaction mechanisms and structural modifications essential for developing advanced stimuli-responsive luminescent compounds.

A phenanthroline-based erbium (III) complex: molecular docking, DNA/BSA -binding and biological evaluation

With the help of both theoretical as well as experimental research, in vitro binding research with CT-DNA (calf thymus) and BSA (bovine serum albumin) were carefully examined to figure out the chemotherapeutic and pharmacokinetic facets of the Erbium complex, which contains 1,10-phenanthroline (Phen). The binding characteristics and the mechanism of complex's interaction with DNA as well as the protein were determined utilizing fluorescence quenching method. Findings indicated that the complex's interaction with DNA via groove binding into DNA's minor grooves, with their binding constants falling within the 104 M-1 range. Furthermore, thermodynamic characteristics and the fluorescence emission of the tryptophan residues of the protein were obtained through fluorescence quenching studies at different temperatures. According to the results of the binding constants, the protein's interactions with the Er- complex were moderate, demonstrating that the compound may be transported effectively by the protein. Molecular docking results supported that of the experimental research. The HeLa and MCF-7 cancer cell lines, along with the normal human fibroblast cell line, were used in an MTT assay evaluation of the Er-complex cytotoxicity. The Er-complex displayed a selective inhibitory effect on the proliferation of different cancer cells.

A strategy of extracting and purifying the α-terpineol obtained from the Penicillium digitatum biotransformation of limonene

α-Terpineol, an abundant oxygenated monoterpene compound, shows a varied range of beneficial bioactivities. This study focused on the efficient extraction and purification of α-terpineol from the biotransformation of limonene using Penicillium digitatum DSM 62840 mutant (PdTP1-overexpressed OE2 strain). The α-terpineol was primarily distributed in the supernatant, with minimal association with the biomass. And the optimal extraction was achieved using ethyl acetate as the extractant, which can directly obtain the highest recovery of α-terpineol without sequential extractions. The equilibrium of mass transfer was quickly reached (≤20 s in vortex). Additionally, the purification method of α-terpineol using column chromatography was described, further improving the purity of product to 96.86% in gas chromatography. Structural identification of purified α-terpineol was confirmed using gas chromatography-mass spectrometry, Fourier-transform infrared spectroscopy, and nuclear magnetic resonance. This simplified and efficient strategy for the extraction and purification of α-terpineol not only provides a solid theoretical basis for the final step in the relevant study of microbial synthesis of α-terpineol but also is of great significance for its industrial application.

Dimethylacridine Based Emitters for Non-Doped Organic Light-Emitting Diodes with Improved Efficiency

Organic light-emitting diodes (OLEDs) has been attracting much extensive interest owing to their advantages of high-definition and flexible displays. Many advances have been focused on boosting the efficiency and stability. Two innovative dimethylacridine-based emitters, 1,1,2,2-tetrakis(4- (2,7-di-tert-butyl-9,9-dimethylacridin-10(9H)-yl)phenyl ethene (AcTPE), and bis(4-(2,7-di-tert-butyl-9,9-dimethylacridin-10(9H)-yl)phenyl)methanone (Ac2BP) were designed and synthesized, in which TPE-baesed AcTPE presents AIE properties, and with the phenyl as spacer between the DMAC and carbony, aryl-ketone-based Ac2BP doesn't show AIE properties due to the absence of restriction of intramolecular rotations. As the electron-withdrawing ability of carbonyl, well-matched energy levels of the Ac2BP improve carriers transfer and hole injecting process in devices, resulting an efficient green emission with a maximum PE of of 5.64 lm W-1, a EQE of 10.56 % and a maximum CE of 18.27 cd A-1. They are much higher than that of AcTPE-based devices (3.45 cd A-1, 1.18 lm W-1, and 1.46 %). This study provides a promising design strategy for efficient OLED emitters of aryl-ketone-architecture.

Mechanistic investigation on cellular internalization triggering structure-induced conformational modulation of boron-nitrogen luminogens

Exploring the effects of electron donor (D) and acceptor (A) functional groups in tuning the condensed state properties has been a challenging yet efficient approach to reveal promising materials for cutting-edge applications. Herein, a series of boron-nitrogen (BN) incorporated organic congeners (NBNMe2, NBOMe, NBF, NBCl, NBBr, NBCN, NBPy) appended with functional groups having various degrees of D/A characteristics were developed and their potential in controlling supramolecular assembly and condensed state luminescence features (>90 nm redshift in λ em,max) was explored. Despite the minor structural engineering in BN-based small molecules, they effectively modulated conformational orientation and molecular packing, leading to the directed growth of distinct and highly ordered self-assembly patterns, i.e., nanosheets, nanospheres, nanowires, and nanorods. The structure-property correlation investigation also highlighted the time-dependent fluorescence enhancement for NBPy owing to morphological growth via the fusion of nanospheres into nanowire conformation. Further, these nano-architectures with distinct conformations were employed to examine the mechanistic aspects as well as the influence of morphologies in cellular uptake and imaging, where all the nano-aggregates exhibited lysosomal localization following multiple endocytosis pathways and the nanorods possessed the highest uptakes (CTCF4h/0.5h = 3.11) with respect to other conformations. The in-depth inspection of the structural impact in single crystal X-ray diffraction (SCXRD) analysis disclosed the decisive role of boron atoms and functional group tuning that built a conceptual correlation between the molecular architecture and their photophysical characteristics, supramolecular assembly, and cellular internalization process, offering key insights on the development of rapid and effective drug delivery techniques.

A Facile Way to Enhance the Therapeutic Efficacy of Hydrophobic Drugs via Amorphous Solid Dispersions

Approximately 40% of marketed drugs and 75% of invested drugs in the pharmaceutical field are poorly soluble hydrophobic drugs with minimal solubility in water which make them difficult to be absorbed by the body and significantly limiting their applications. Among chemotherapeutic agents, numerous antitumor drugs such as platinum compounds, camptothecin, paclitaxel and others are also restricted in processing and preparation due to solubility issues. Therefore, improving the solubility and enhancing the therapeutic efficacy of drugs have always been significant research topics in current pharmaceutics. Herein, we propose an amorphous solid dispersion system PRTA-DOX, involving the protein drug protamine sulphate and hydrophobic doxorubicin as the model hydrophobic drug. In previous studies, ASD (Amorphous Solid Dispersion) has been demonstrated to enhance the solubility of hydrophobic drugs and result in a storage-stable system. Protamine sulphate as a marketed drug is reliable in safety and conveniently obtained. Doxorubicin, an antitumor drug with a broad antitumor spectrum, is commonly used in the treatment of breast cancer. Typically, doxorubicin is prepared in the form of a hydrochloride salt to increase its solubility. However, the utilization of doxorubicin hydrochloride is reduced due to drug resistance issues in biological cells and it exhibits higher toxicity to the body. In this system, protamine sulphate which is rich in arginine guanidino hydrophobic planes physically mixes with doxorubicin which is a hydrophobic molecule with aromatic rings and they are connected through weak interactions: π-π conjugation. They constitute an amorphous solid dispersion system which increases the solubility of hydrophobic doxorubicin, enhances cellular uptake, mitigate some cellular drug resistance and thereby achieves the purpose of improving therapeutic efficacy.

Regioregular Poly(p-phenylene iminoborane): A Strictly Alternating BN-Isostere of Poly(p-phenylene vinylene) with Stimuli-Responsive Behavior

Incorporation of BN units into π-conjugated organic compounds, as substitutes for specific CC couples, often leads to new hybrid materials with modified physical and chemical properties. Poly(p-phenylene iminoborane)s are derived from well-known poly(p-phenylene vinylene) (PPV) by replacement of the vinylene groups by B=N linking units. Herein, an unprecedented poly(p-phenylene iminoborane) is presented that features a strictly alternating sequence of BN units along the main chain. The synthesis thereof was achieved by AB-type polymerization of a monomer featuring an N and a B terminus. Monodisperse oligomers with up to three BN units in the chain were additionally prepared and structurally characterized. Associated with the introduction of a dipole in the regioregular backbone structure, they display notable fluorescence already in solution and large Stokes shifts, distinct from their previously reported BBNN-sequenced congeners. All compounds show aggregation-induced emission enhancement (AIEE) properties. Computational studies provided evidence for emission from either locally excited (LE) or twisted intramolecular charge transfer (TICT) states. These processes can be optionally addressed by various stimuli, giving rise to dual emission, solvatochromic, thermochromic, and reversible mechanochromic behavior.

Ratiometric Fluorescence and Chromogenic Probe for Trace Detection of Selected Transition Metals

The design and development of a fluorescence sensor aimed at detecting and quantifying trace amounts of toxic transition metal ions within environmental, biological, and aquatic samples has garnered significant attention from diagnostic and testing laboratories, driven by the imperative to mitigate the health risks associated with these contaminants. In this context, we present the utilization of a heterocyclic symmetrical Schiff Base derivative for the purpose of fluorogenic and chromogenic detection of Co2+, Cu2+ and Hg2+ ions. The characterization of the ligand involved a comprehensive array of techniques, including physical assessments, optical analyses, NMR, FT-IR, and mass spectrometric examinations. The mechanism of ligand-metal complexation was elucidated through the utilization of photophysical parameters and FT-IR spectroscopic analysis, both before and after the interaction between the ligand and the metal salt solution. The pronounced alterations observed in absorption and fluorescence spectra, along with the distinctive chromogenic changes, following treatment with Co2+, Cu2+ and Hg2+, affirm the successful formation of complexes between the ligands and the treated metal ions. Notably, the receptor's complexation response exhibited selectivity towards Co(II), Cu(II), and Hg(II), with no observed chromogenic changes, spectral variations, or band shifts for the various tested metal ions, including Na+, Ag+, Ni2+, Mn2+, Pd2+, Pb2+, Cd2+, Zn2+, Sn2+, Fe2+, Fe3+, Cr3+ and Al3+. This absence of interaction between these metal ions and the ligand could be attributed to their compact or inadequately conducive conduction bands for complexation with the ligand's structural composition. To quantify the sensor's efficacy, fluorescence titration spectra were employed to determine the detection limits for Co2+, Cu2+ and Hg2+, yielding values of 2.92 × 10-8, 8.91 × 10-8, and 4.39 × 10-3 M, respectively. The Benesi-Hildebrand plots provided association constant values for the ligand-cobalt, ligand-copper, and ligand-mercury complexes as 0.74, 2.52, and 13.89 M-1, respectively.

Aminothiophenol and 7-diethylamino-4-hydroxycoumarin derived probe for reversible turn off-on-off detection of Cu2+ ions and cysteine

Here, we present a simple disulfide linked probe HTP for rapid detection of Cu2+ ions, which was prepared by a condensation reaction between 7-diethylamino-4-hydroxycoumarin aldehyde and 2-aminothiophenol. The disulfide linked probe HTP was characterized using 1H NMR, 13C NMR, and HRMS spectroscopic analysis and confirmed by single crystal X-ray diffraction analysis. The photophysical behavior of HTP in various solvents (non-polar to polar) was studied and HTP displayed aggregation induced emission (AIE) characteristics in CH3CN-water mixtures (0-99 %). Upon binding with Cu2+ ions, emission enhancement occurs along with color changes from weak green to intense yellow emission in CH3CN/Tris-HCl buffer (20 μM, 9:1, 10 mM Tris HCl Buffer, pH = 7.4). Detection limit for Cu2+ ions was found to be 0.97 nM which is lower than the recommended tolerance limit by the WHO and the association constant 0.42 × 108 M-1 was obtained using B-H plot. Furthermore, the stoichiometric ratio 1:1 was confirmed by Job's plot, 1H NMR, mass spectral analysis and DFT calculations were supported the formation of HTP-Cu2+ complex. The reversibility of HTP with Cu2+ ions was achieved by cysteine with detection limit and association constant value of 1.64 µM and 0.15 × 107 M-1 respectively. The reversible sensing nature of HTP with Cu2+/cysteine was further applied for constructing a molecular logic gate (INHIBIT) and practical applications such as paper strips, cotton swabs and real water analysis.

Therapeutic Innovations in Nanomedicine: Exploring the Potential of Magnetotactic Bacteria and Bacterial Magnetosomes

Nanotechnology has emerged as a revolutionary domain with diverse applications in medicine, and one of the noteworthy developments is the exploration of bacterial magnetosomes acquired from magnetotactic bacteria (MTB) for therapeutic purposes. The demand for natural nanomaterials in the biomedical field is continuously increasing due to their biocompatibility and eco-friendly nature. MTB produces uniform, well-ordered magnetic nanoparticles inside the magnetosomes, drawing attention due to their unique and remarkable features. MTB and magnetosomes have gained popularity in cancer treatment and diagnosis, especially in magnetic resonance imaging. Distinctive features highlighted include advancements in extraction, characterization, and functionalization techniques, alongside breakthroughs in utilizing MTB-based magnetosomes as contrast agents in imaging, biocompatible drug carriers, and tools for minimally invasive therapies. The biocompatible nature, functionalizing of the surface of bacterial magnetosomes, and response to the external magnetic field make them a potential candidate for the theragnostic purpose of MTB and magnetosomes. In the present review, emphasis has been given to the foundation of magnetosomes at a genetic level, mass production of magnetosomes, etc. Further authors have reviewed the various functionalization methods of the magnetosomes for cancer treatment. Finally, the authors have reviewed the recent advancements in MTB and magnetosome-based cancer detection, diagnosis, and treatment. Challenges such as scalability, long-term safety, and clinical translation are also discussed, presenting a roadmap for future research exploiting MTBs and magnetosomes' unique properties.

Clinical diagnostic value of PIMREG on liver cancer cell phenotype and tumorigenic ability in nude mice

OBJECTIVES

In vitro experiments were manipulated to investigate the effect of the PIMREG (PICALM-interacting mitotic regulator gene) expression level on the malignant phenotype of liver cancer cells and their tumorigenesis ability in nude mice, and bioinformatics were used to analyze the clinical diagnostic and prognostic value in liver cancer.

METHODS

After liver cancer-related data were obtained from the TCGA database and GTEx database, the differences in PIMREG expression in liver cancer and normal liver tissue were compared using bioinformatics, and their correlation with the clinical pathological characteristics of liver cancer and the prognosis value were analyzed. A knockdown and overexpression model of PIMREG was constructed using Huh7 cells. The effect of the PIMREG expression level on the malignant phenotype of Huh7 cells was tested through CCK-8 and Transwell experiments. At the same time, animal knockdown and overexpression models were constructed to study the effect of the PIMREG expression level on the tumorigenesis ability in nude mice.

RESULTS

Bioinformatics analysis showed that PIMREG mRNA was significantly overexpressed in liver cancer tissue (P<0.001). There were differences in T-staging (P<0.001), pathological staging (P=0.002), vascular infiltration (P<0.001), histological grading (P<0.001), and AFP levels (P<0.001) between the high- and low-expression groups. A high expression of PIMREG is associated with a poor prognosis, manifested as a significant decrease in the overall survival, disease-specific survival, and progression-free survival rates of patients (P values of 0.006, 0.014, and 0.002, respectively). In the PIMREG overexpression model, the proliferation rate and invasion ability of Huh7 cells were significantly increased, and the tumorigenesis ability of nude mice was significantly enhanced. In the knockdown model, the opposite results were observed.

CONCLUSIONS

The PIMREG gene is highly expressed in hepatocellular carcinoma, and increasing its expression level can significantly promote the malignant phenotype of liver cancer cells and their tumorigenesis ability in nude mice. Knocking down its expression level has the opposite effect. The expression level of PIMREG is related to the pathological stages of liver cancer patients, and its elevated expression is a risk factor for poor prognosis. PIMREG may become a new target for the clinical diagnosis, treatment, and prognosis evaluation of liver cancer.

Protein-driven interaction enhanced electrochemiluminescence biosensor of hydrogen-bonded biohybrid organic frameworks for sensitive immunoassay of disease markers

The oriented design of reticular materials as emitters can significantly enhance the sensitivity of electrochemiluminescence (ECL) sensing analysis for disease markers. However, due to the structural fragility of hydrogen bonds, relational research on hydrogen-bonded organic frameworks (HOFs) has not been thoroughly conducted. Additionally, the modulation of luminescence behavior through HOFs has been rarely reported. In view of this, hydrogen-bonded biohybrid organic frameworks (HBOFs) were synthesized and recruited for ECL immunoassay applications. HBOFs was easily prepared using 6,6',6″,6‴-(pyrene-1,3,6,8-tetrayl)tetrakis(2-naphthoic acid) as linkers via bovine serum albumin (BSA) activated hydrogen-bonded cross-linking. The material exhibited good fluorescence emission characteristics. And the highly ordered topological structure and molecular motion limitation mediated by BSA overcome aggregation-caused quenching and generate strong aggregation induced emission, expressing hydrogen-bond interaction enhanced ECL (HIE-ECL) activity with the participation of tri-n-propylamine. Furthermore, a sandwich immunosensor was constructed employing cobalt-based metal-phenolic network (CMPN) coated ferrocene nanoparticles (FNPs) as quenchers (CMPN@FNPs). Signal closure can be achieved by annihilating the excited state through electron transfer from both CMPN and FNPs. Using a universal disease marker, carcinoembryonic antigen, as the analysis model, the signal-off sensor obtained a detection limit of 0.47 pg/mL within the detection range of 1 pg/mL - 50 ng/mL. The synthesis and application of highly stable HBOFs triggered by proteins provide a reference for the development of new reticular ECL signal labels, and electron transfer model provides flexible solutions for more sensitive sensing analysis.

A novel BN aromatic module modified near-infrared fluorescent probe for monitoring carbon monoxide-releasing molecule CORM-3 in living cells and animals

Carbon monoxide (CO), a significant gas transmitter, plays a vital role in the intricate functioning of living systems and is intimately linked to a variety of physiological and pathological processes. To comprehensively investigate CO within biological system, researchers have widely adopted CORM-3, a compound capable of releasing CO, which serves as a surrogate for CO. It aids in elucidating the physiological and pathological effects of CO within living organisms and can be employed as a therapeutic drug molecule. Therefore, the pivotal role of CORM-3 necessitates the development of effective probes that can facilitate the visualization and tracking of CORM-3 in living systems. However, creating fluorescent probes for real-time imaging of CORM-3 in living species has proven to be a persisting challenge that arises from factors such as background interference, light scattering and photoactivation. Herein, the BNDN fluorescent probe, a brand-new near-infrared is proposed. Remarkably, the BNDN probe offers several noteworthy advantages, including a substantial Stokes shift (201 nm), heightened sensitivity, exceptional selectivity, and an exceedingly low CORM-3 detection limit (0.7 ppb). Furthermore, the underlying sensing mechanism has been meticulously examined, revealing a process that revives the fluorophore by reducing the complex Cu2+ to Cu+. This distinctive NIR fluorescence "turn-on" character, coupled with its larger Stokes shift, holds great promise for achieving high resolution imaging. Most impressively, this innovative probe has demonstrated its efficacy in detecting exogenous CORM-3 in living animal. It is important to underscore that these endeavors mark a rare instance of a near-infrared probes successfully detecting exogenous CORM-3 in vivo. These exceptional outcomes highlighted the potential of BNDN as a highly promising new tool for in vivo detection of CORM-3. Considering the impressive imaging capabilities demonstrated by BNDN presented in this study, we anticipate that this tool may offer a compelling avenue for shedding light on the roles of CO in future research endeavors.

Janus plasmonic-aggregation induced emission nanobeads as high-performance colorimetric-fluorescent probe of immunochromatographic assay for the ultrasensitive detection of staphylococcal enterotoxin B in milk

Herein, a colorimetric-fluorescent hybrid bifunctional nanobead with Janus structure (J-cf-HBN) was synthesized via one-pot microemulsification. Oleylamine-coated AuNPs and aggregation-induced emission luminogens (AIEgens) were suggested as building blocks to obtain high-performance colorimetric-fluorescent signals. The as-prepared J-cf-HBNs were used as a signal amplification probe to construct an immunochromatographic assay (J-cf-HBNs-ICA) platform for the ultrasensitive detection of staphylococcal enterotoxin B (SEB) in milk samples. Owing to the rational spatial distribution of AuNPs and AIEgens, the J-cf-HBNs present a highly retained photoluminescence and enhanced colorimetric signals. Combined with a pair of highly affinitive anti-SEB antibodies, the J-cf-HBN-ICA platform enabled the fast naked-eye visualization and fluorescent quantitative detection of SEB in various milk matrices. Given the advantages of the dual-mode high-performance J-cf-HBNs, the proposed strip achieved a high sensitivity for SEB qualitative determination with a visual limit of detection (LOD) of 1.56 ng mL-1 and exhibited ultrasensitivity for SEB quantitative detection with a LOD of 0.09 ng mL-1, which is 139-fold lower than that of ELISA using same antibodies. In conclusion, this work provides new insights into the construction of multimode immunochromatographic methods for food safety detection in the field.

Synthesis, Fluorescence, and Bioactivity of Novel Isatin Derivatives

The isatin group is widespread in nature and is considered to be a privileged building block for drug discovery. In order to develop novel SHP1 inhibitors with fluorescent properties as tools for SHP1 biology research, this work designed and synthesized a series of isatin derivatives. The presentive compound 5a showed good inhibitory activity against SHP1PTP with IC50 of 11 ± 3 μM, displayed about 92% inhibitory rate against MV-4-11 cell proliferation at the concentration of 20 μM, exhibited suitable fluorescent properties with a long emission wavelength and a large Stokes shift, and presented blue fluorescent imaging in HeLa cells with low cytotoxicity. This study could offer chemical tool to further understand SHP1 biology and develop novel SHP1 inhibitors in therapy.

Study of cell and drug interactions based on dual-mode detection using SPR and fluorescence imaging

The investigation of the interactions between cells and drugs forms a crucial aspect of biological and clinical medical studies. Generally, single-cell or local-cellular studies require a microscopic imaging system with high magnifications, which suffers from low detection throughputs and poor time responses. The study presented in this paper combined SPR and fluorescence to achieve cell localization, real-time monitoring of cell images and quantitative analysis of drugs. In order to obtain more comprehensive, accurate and real-time data, a dual-mode system based on surface plasmon resonance (SPR) and fluorescence was constructed based on a 4× magnification lens. This enables simultaneous studies of an entire cell and a specific region of the cell membrane. An adaptive adjustment algorithm was established for distorted SPR images, achieving temporal and spatial matching of the dual-mode detection. The combination of SPR and fluorescence not only achieved micro-detection but also complemented the qualitative or quantitative limitations of SPR or fluorescence method alone. In system characterization, the response signal of SPR was noticed to increase with the increasing concentration of EGF in stimulated cells. It indicated that this platform could be employed for quantitative detection of the cell membrane region. Upon addition of EGF, a peak in the SPR curve was observed, and the cells in the corresponding SPR image turned whiter. This indicated that the platform can simultaneously monitor the SPR response signal and image changes. The response time of fluorescence in EGF testing was several seconds earlier than SPR, revealing that signal transduction first occurred in the whole cell and then propagated to the cell membrane region. The inhibitory ability of Gefitinib on cells was verified in a fast and real-time manner within 20 min. The results indicated that the detection limit of this method was 20 IU/mL for EGF and 10 µg/mL for Gefitinib. In conclusion, this study demonstrates the advantages of SPR and fluorescence dual-mode techniques in the analysis of cell-drug interactions, as well as their strong potential in drug screening.

Engineering Nanoplatforms for Theranostics of Atherosclerotic Plaques

Atherosclerotic plaque formation is considered the primary pathological mechanism underlying atherosclerotic cardiovascular diseases, leading to severe cardiovascular events such as stroke, acute coronary syndromes, and even sudden cardiac death. Early detection and timely intervention of plaques are challenging due to the lack of typical symptoms in the initial stages. Therefore, precise early detection and intervention play a crucial role in risk stratification of atherosclerotic plaques and achieving favorable post-interventional outcomes. The continuously advancing nanoplatforms have demonstrated numerous advantages including high signal-to-noise ratio, enhanced bioavailability, and specific targeting capabilities for imaging agents and therapeutic drugs, enabling effective visualization and management of atherosclerotic plaques. Motivated by these superior properties, various noninvasive imaging modalities for early recognition of plaques in the preliminary stage of atherosclerosis are comprehensively summarized. Additionally, several therapeutic strategies are proposed to enhance the efficacy of treating atherosclerotic plaques. Finally, existing challenges and promising prospects for accelerating clinical translation of nanoplatform-based molecular imaging and therapy for atherosclerotic plaques are discussed. In conclusion, this review provides an insightful perspective on the diagnosis and therapy of atherosclerotic plaques.

GC-MS based antioxidants characterization in Saussurea heteromalla (D. Don) Hand-Mazz by inhibition of nitric oxide generation in macrophages

For centuries, medicinal plants have served as the cornerstone for traditional health care systems and same practice is still prevalent today. In the Himalayan region, Saussurea heteromalla holds a significant place in traditional medicine and is used to address various health issues. Despite its historical use, little exploration has focused on its potential for scavenging free radicals and reducing inflammation. Hence, our current study aims to investigate the free radical scavenging capabilities of S. heteromalla extracts. The n-hexane extract of entire plant revealed promising activity. This extract underwent extensive extraction on a larger scale. Subsequent purification, employing column chromatography, HPLC-DAD techniques, led to the identification of active compounds, confirmed via GC-MS and the NIST database as 1-O-butyl 2-O-octyl benzene-1,2-dicarboxylate and 2,4-ditert-butylphenol. Assessing the free radical scavenging properties involved utilizing RAW-264.7 macrophages activated by lipopolysaccharides. Notably, the compound 2,4-di-tert-butylphenol exhibited remarkable scavenging abilities, demonstrating over 80% inhibition of Nitric oxide. This study stands as the inaugural report on the isolation of these compounds from S. heteromalla.

Synthesis, antimicrobial, and in silico studies of C5'-O-substituted cytidine derivatives: cinnamoylation leads to improvement of antimicrobial activity

Nucleoside derivatives are important therapeutic drugs that have drawn significant attention recently. In this study, cytidine (1) was first exposed to react with cinnamoyl chloride in N,N-dimethylformamide, and trimethylamine to obtain 5'-O-(cinnamoyl)cytidine, which was further treated with several acylating agents to obtain a series of 2',3'-di-O-acyl derivatives. The chemical structures of the synthesized compounds were established through spectral, analytical, and physicochemical techniques. In vitro antimicrobial efficacy was evaluated, and the antimicrobial effect was greater than that of the precursor compound; in particular, compound 3 exhibited the most promising activity. Cytotoxicity measurements revealed that the compounds demonstrated a decreased degree of toxicity. A structure-activity relationship (SAR) study showed that the ribose moiety combined with the acyl chains (C-12/C13) and (C6H5CH = CHCO) had enhanced effects on bacteria and fungi. Molecular docking was applied for the potential inhibitors (3, 4, and 6) to predict their mode of action and confirm their efficacy against isozymes, tubulin-like protein TubZ, Bacillus cereus [PDB: 4ei9], and dihydrofolate reductase of Aspergillus flavus [PDB: 6dtc]. A molecular dynamics simulation study was performed to evaluate the deformability, flexibility, and stiffness of the target enzyme residues. Density functional theory (DFT) indicates the high polarizability and chemical reactivity of the synthesized compounds. The ADMET (absorption, distribution, mechanism, excretion, and toxicity) study suggested that all the designed molecules have moderate human intestinal absorption and good distribution values in addition to the absence of CNS side effects and structural toxicity. Above all else, these cytidine derivatives possess potential antimicrobial behavior, thereby rendering them suitable drug candidate(s) for additional exploration.

Design and synthesis of novel dihydropyridine- and benzylideneimine-based tyrosinase inhibitors

Tyrosinase (TYR) inhibitors are very significant as they inhibit enzyme tyrosinase activity, and its inhibition is vital for skin care, anticancer medication, and antibrowning of fruits and vegetables. This work presents a novel and economical route for the preparation of new synthetic tyrosinase inhibitors using amlodipine (4). The novel conjugates 6 (a-o) were designed, synthesized, and characterized by spectroscopic analyses, including Fourier transform infrared and low- and high-resolution mass spectroscopy. The purified compound 4 was refluxed with various aldehydes and ketones 5 (a-o) for 5-8 h in methanol at 60°C-90°C. This research modified the drug in a step-by-step manner to develop therapeutic properties as a tyrosinase inhibitor. The structures of synthesized ligands 6 (a-o) were established based on spectral and analytical data. The synthesized compounds 6 (a-o) were screened against tyrosinase enzyme. Kojic acid was taken as standard. All the prepared compounds 6 (a-o) have good inhibition potential against the enzyme tyrosinase. Compounds 6o, 6b, 6f, and 6k depicted excellent antityrosinase activity. Compound 6k, with an IC50 value of 5.34 ± 0.58 µM, is as potent as the standard kojic acid (IC50 6.04 ± 0.11 µM), standing out among all synthesized compounds 6 (a-o). The in silico studies of the conjugates 6 (a-o) were evaluated via PatchDock. Compound 6k showed a binding affinity score of 8,999 and an atomic contact energy (ACE) value of -219.66 kcal/mol. The structure-activity relationship illustrated that the presence of dihydropyridine nuclei and some activating groups at the ortho and para positions of the benzylideneimine moiety is the main factor for good tyrosinase activity. The compound 6k could be used as a lead compound for drug modification as a tyrosinase inhibitor for skin care, anticancer medication, and antibrowning for fruits and vegetables.

Synthesis, biochemical and computational evaluations of novel bis-acylhydrazones of 2,2'-(1,1'-biphenyl)-4,4'-diylbis(oxy))di(acetohydrazide) as dual cholinesterase inhibitors

A series of twenty-seven bis(acylhydrazones) were successfully synthesized with high yields through a multistep process, which entailed the esterification of hydroxyl groups, hydrazination with an excess of hydrazine hydrate, and subsequent reactions with various carbonyl moieties (aldehydes). In the final stage of synthesis, different chemical species including aromatic, heterocyclic, and aliphatic compounds were integrated into the framework. The resulting compounds were characterized using several spectroscopic techniques (1H NMR, 13C NMR, and mass spectrometry). Their anticholinesterase activities were assessed in vitro by examining their interactions with two cholinesterase enzymes: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Among the synthesized hits, compounds 3, 5, 6, 9-12, and 14 exhibited good to moderate inhibition of AChE. Specifically, 10 (IC50 = 26.3 ± 0.4 μM) and 11 (IC50 = 28.4 ± 0.5 μM) showed good inhibitory activity against AChE, while 9, 12, 3, and 6 exhibited significant inhibition potential against AChE with IC50 values ranging from 35.2 ± 1.1 μM to 64.4 ± 0.3 μM. On the other hand, 5 (IC50 = 22.0 ± 1.1 μM) and 27 (IC50 = 31.3 ± 1.3 μM) displayed significant, and 19 (IC50 = 92.6 ± 0.4 μM) showed moderate inhibitory potential for BChE. Notably, 5 and 27 exhibited dual inhibition of AChE and BChE, with greater potency than the standard drug galantamine. The binding patterns of these molecules within the binding cavities of AChE and BChE were anticipated by molecular docking which showed good correlation with our in vitro findings. Further structural optimization of these molecules may yield more potent AChE and BChE inhibitors.

Investigating Novel Thiophene Carbaldehyde Based Thiazole Derivatives as Potential Hits for Diabetic Management: Synthesis, In Vitro and In Silico Approach

This research work is based on synthesis of eleven novel thiazole derivatives (3 a‐k) of thiophene carbaldehyde. All the synthesized compounds were successfully synthesized, characterized by 1H‐NMR and EI‐MS spectroscopic techniques and finally subjected for their in vitro α‐glucosidase inhibitory activity. Seven derivatives 3 i (IC50=10.21±1.84 μM), 3 b (IC50=11.14±0.99 μM), 3 f (IC50=13.21±2.76 μM), 3 h (IC50=14.21±0.31 μM), 3 k (IC50=15.21±1.02 μM), 3 e (IC50=16.21±1.32 μM), and 3 c (IC50=18.21±1.89 μM), in the series displayed excellent inhibitory potential better than the standard acarbose. However, two compounds 3 g (IC50=33.21±1.99 μM) and 3 d (IC50=42.31±2.12 μM) showed significant activity while two compounds 3 j and 3 a were found less active with IC50 values of 82.31±0.31 and 88.36±1.21 μM respectively. Additional research revealed that the compounds are not exhibiting any cytotoxic effects. The molecular docking study of these derivatives showed their good binding potential for α‐glucosidase active site with excellent interactions and docking scores.

A Review of Benzophenone-Based Derivatives for Organic Light-Emitting Diodes

Organic light-emitting diodes (OLEDs) have garnered considerable attention in academic and industrial circles due to their potential applications in flat-panel displays and solid-state lighting technologies, leveraging the advantages offered by organic electroactive derivatives over their inorganic counterparts. The thin and flexible design of OLEDs enables the development of innovative lighting solutions, facilitating the creation of customizable and contoured lighting panels. Among the diverse electroactive components employed in the molecular design of OLED materials, the benzophenone core has attracted much attention as a fragment for the synthesis of organic semiconductors. On the other hand, benzophenone also functions as a classical phosphor with high intersystem crossing efficiency. This characteristic makes it a compelling candidate for effective reverse intersystem crossing, with potential in leading to the development of thermally activated delayed fluorescent (TADF) emitters. These emitting materials witnessed a pronounced interest in recent years due to their incorporation in metal-free electroactive frameworks and the capability to convert triplet excitons into emissive singlet excitons through reverse intersystem crossing (RISC), consequently achieving exceptionally high external quantum efficiencies (EQEs). This review article comprehensively overviews the synthetic pathways, thermal characteristics, electrochemical behaviour, and photophysical properties of derivatives based on benzophenone. Furthermore, we explore their applications in OLED devices, both as host materials and emitters, shedding light on the promising opportunities that benzophenone-based compounds present in advancing OLED technology.

Juggling Optoelectronics and Catalysis: The Dual Talents of Bench Stable 1,4-Azaborinines

Boron- and nitrogen-doped polycyclic aromatic hydrocarbons (B-PAHs) have established a strong foothold in the realm of organic electronics. However, their catalytic potential remains largely untapped. In this study, we synthesise and characterise two bench stable B,N-doped PAH derivatives based on a 1,4-azaborinine motif. Most importantly, the anthracene derived structure is an efficient catalyst in the reduction of various carbonyls and imines. These results underscore the potential of B,N-PAHs in catalytic transformations, setting the stage for deeper exploration in this chemical space.

Study on the modulating effect of halogen atom substitution on the detection range of water content detection probes in organic solvents

Fluorescence probes based on the variations of aggregation state (Aggregation-Induced Emission (AIE) and Aggregation-Caused Quenching (ACQ)) have received widespread attention due to their simplicity, efficiency and intuitiveness. However, typical probes are highly sensitive to changes in polarity and slight variations in the external environment can cause a complete change in the aggregation state. With the aim of expanding the detection range of the molecular probe, this work adopts a different design strategy from adjusting the molecular backbone but regulates the fluorescence behavior of the Schiff base molecular backbone by introducing different halogen atoms. Systematic studies show that when chlorine serves as substitutional atoms (3,5-Cl Salen), the probe can achieve full-range detection of water content (0-100 vol%) in ethanol and DMF. To our knowledge, the 3,5-Cl Salen represents the best water content probe in organic molecules. Experimental and theoretical studies have shown that the adjustment of halogen atoms can linearly change the charge distribution on the benzene ring and precisely control the strength of intermolecular interactions. At the same time, we developed a fluorescent filter paper based on 3,5-Cl Salen and used smartphones for rapid, sensitive and precise on-site measurement of water content in organic solvents.

Biosensor-Based Multimodal Deep Human Locomotion Decoding via Internet of Healthcare Things

Multiple Internet of Healthcare Things (IoHT)-based devices have been utilized as sensing methodologies for human locomotion decoding to aid in applications related to e-healthcare. Different measurement conditions affect the daily routine monitoring, including the sensor type, wearing style, data retrieval method, and processing model. Currently, several models are present in this domain that include a variety of techniques for pre-processing, descriptor extraction, and reduction, along with the classification of data captured from multiple sensors. However, such models consisting of multiple subject-based data using different techniques may degrade the accuracy rate of locomotion decoding. Therefore, this study proposes a deep neural network model that not only applies the state-of-the-art Quaternion-based filtration technique for motion and ambient data along with background subtraction and skeleton modeling for video-based data, but also learns important descriptors from novel graph-based representations and Gaussian Markov random-field mechanisms. Due to the non-linear nature of data, these descriptors are further utilized to extract the codebook via the Gaussian mixture regression model. Furthermore, the codebook is provided to the recurrent neural network to classify the activities for the locomotion-decoding system. We show the validity of the proposed model across two publicly available data sampling strategies, namely, the HWU-USP and LARa datasets. The proposed model is significantly improved over previous systems, as it achieved 82.22% and 82.50% for the HWU-USP and LARa datasets, respectively. The proposed IoHT-based locomotion-decoding model is useful for unobtrusive human activity recognition over extended periods in e-healthcare facilities.

Highly Efficient Stable Luminescent Radical-Based X-ray Scintillator

Stable luminescent radicals are open-shell emitters with unique doublet emission characteristics. This feature makes stable luminescent radicals exhibit widespread application prospects in constructing optical, electrical, and magnetic materials. In this work, a stable luminescent radical-based X-ray scintillator of AuPP-1.0 was prepared, which exhibited a high X-ray excited luminescence (XEL) efficiency as well as excellent stability. A mechanism study showed that the heavy atom of Au in AuPP-1.0 endowed it with effective absorption of X-rays, and the doublet emission characteristics of AuPP-1.0 significantly increased its exciton utilization rate in the radioluminescence process. Moreover, AuPP-1.0 has good processability to fabricate a flexible screen for high-quality X-ray imaging, whose resolution can reach 20 LP mm-1. This work demonstrates that the doublet emission is beneficial for improving the exciton utilization rate of radioluminescence, providing a brand-new strategy for the construction of high-performance X-ray scintillators.

Solvatochromic and Aggregation-Induced Emission Active Nitrophenyl-Substituted Pyrrolidinone-Fused-1,2-Azaborine with a Pre-Twisted Molecular Geometry

Boron-nitrogen-containing heterocycles with extended conjugated π-systems such as polycyclic aromatic 1,2-azaborines, hold the fascination of organic chemists due to their unique optoelectronic properties. However, the majority of polycyclic aromatic 1,2-azaborines aggregate at high concentrations or in the solid-state, resulting in aggregation-caused quenching (ACQ) of emission. This practical limitation poses significant challenges for polycyclic aromatic 1,2-azaborines' use in many applications. Additionally, only a few solvatochromic polycyclic aromatic 1,2-azaborines have been reported and they all display minimal solvatochromism. Therefore, the scope of available polycyclic 1,2-azaborines needs to be expanded to include those displaying fluorescence at high concentration and in the solid-state as well as those that exhibit significant changes in emission intensity in various solvents due to different polarities. To address the ACQ issue, we evaluate the effect of a pre-twisted molecular geometry on the optoelectronic properties of polycyclic aromatic 1,2-azaborines. Specifically, three phenyl-substituted pyrrolidinone-fused 1,2-azaborines (PFAs) with similar structures and functionalized with diverse electronic moieties (-H, -NO2, -CN, referred to as PFA 1, 2, and 3, respectively) were experimentally and computationally studied. Interestingly, PFA 2 displays two distinct emission properties: 1) solvatochromism, in which its emission and quantum yields are tunable with respect to solvent polarity, and 2) fluorescence that can be completely "turned off" and "turned on" via aggregation-induced emission (AIE). This report provides the first example of a polycyclic aromatic 1,2-azaborine that displays both AIE and solvatochromism properties in a single BN-substituted backbone. According to time-dependent density function theory (TD-DFT) calculations, the fluorescence properties of PFA 2 can be explained by the presence of a low-lying n-π* charge transfer state inaccessible to PFA 1 or PFA 3. These findings will help in the design of future polycyclic aromatic 1,2-azaborines that are solvatochromic and AIE-active as well as in understanding how molecular geometry affects these compounds' optoelectronic properties.

One-Step Transformations from ACQ Luminogens to DSEgens via the Boc Protection Process

Dual-state emission luminogens (DSEgens), as a new type of luminescent materials that can effectively emit light in solution and solid state, have attracted tremendous attention due to their potential application in chemical sensing, biological imaging, organic electronic devices, etc. In this study, two new rofecoxib derivatives ROIN and ROIN-B have been synthesized, and their photophysical properties are fully investigated by experimental studies and theoretical calculations. The key intermediate ROIN, resulting from one-step conjugation of rofecoxib with an indole unit, shows the classical aggregation-caused quenching (ACQ) effect. Meanwhile, by introducing a tert-butoxycarbonyl (Boc) group on the basis of ROIN without enlarging the π conjugation system, ROIN-B was successfully developed with an obvious DSE property. In addition, both fluorescent behaviors and their transformation from ACQ to DSE were elucidated clearly by going through the analysis of their single X-ray data. Moreover, the target ROIN-B, as a new DSEgens, also displays reversible mechanofluorochromism and lipid droplet-specific imaging ability in HeLa cells. Taken together, this work proposes a precise molecular design strategy to afford a new DSEgens, which may provide guidance for the future exploration of new DSEgens.

Visible-light-induced selective defluoroalkylations of polyfluoroarenes with alcohols

To provide α-polyfluoroarylalcohols, a novel protocol for the selective defluoroalkylation of polyfluoroarenes with easily accessible alcohols was reported via the cooperation of photoredox and hydrogen atom transfer (HAT) strategies with the assistance of Lewis acids under visible light irradiation. The protocol featured broad scope, excellent regioselectivity for both C-H and C-F bond cleavages, and mild conditions. Mechanistic studies suggested that the reaction occurred through Lewis acid-promoted HAT to provide an alkyl radical and sequential addition to polyfluoroarenes. Impressively, the regioselectivity for C-F cleavage was verified with the Fukui function. The feasibility and application of this protocol on fluoroarene synthesis were well illustrated by gram-scale synthesis under both batch and flow conditions, late-stage decoration of bioactive compounds, and further transformations of the fluoroarylalcohols.

Expanding new chemistry of aza-boracyclophanes with unique dipolar structures, AIE and redox-active open-shell characteristics

π-Conjugated macrocycles involving electron-deficient boron species have received increasing attention due to their intriguing tunable optoelectronic properties. However, most of the reported B(sp²)-doped macrocycles are difficult to modify due to the synthetic challenge, which limits their further applications. Motivated by the research of non-strained hexameric bora- and aza-cyclophanes, we describe a new class of analogues MC-BN5 and MC-ABN5 that contain charge-reversed triarylborane (Ar₃B) units and oligomeric triarylamines (Ar₃N) in the cyclics. As predicted by DFT computations, the unique orientation of the donor-acceptor systems leads to an increased dipole moment compared with highly symmetric macrocycles (M1, M2 and M3), which was experimentally represented by a significant solvatochromic effect with large Stokes shifts up to 12 318 cm^-1. Such a ring-structured design also allows the easy peripheral modification of aza-boracyclophanes with tetraphenylethenyl (TPE) groups, giving rise to a change in the luminescence mechanism from aggregation-caused quenching (ACQ) in MC-BN5 to aggregation-induced emission (AIE) in MC-ABN5. The open-shell characteristics have been chemically enabled and were characterized by UV-Vis-NIR spectroscopy and electron paramagnetic resonance (EPR) for MC-BN5. The present study not only showed new electronic properties, but also could expand the research of B/N doped macrocycles into the future scope of supramolecular chemistry, as demonstrated in the accessible functionalization of ring systems.

Catalytic Atroposelective Electrophilic Amination of Indoles

Reported here is the first catalytic atroposelective electrophilic amination of indoles, which delivers functionalized atropochiral N-sulfonyl-3-arylaminoindoles with excellent optical purity. This reaction was furnished by 1,6-nucleophilic addition to p-quinone diimines. Control experiments suggest an ionic mechanism that differs from the radical addition pathway commonly proposed for 1,6-addition to quinones. The origin of 1,6-addition selectivity was investigated through computational studies. Preliminary studies show that the obtained 3-aminoindoles atropisomers exhibit anticancer activities. This method is valuable with respect to enlarging the toolbox for atropochiral amine derivatives.

Pyrene-Based AIE Active Materials for Bioimaging and Theranostics Applications

Aggregation-induced emission (AIE) is a unique research topic and property that can lead to a wide range of applications, including cellular imaging, theranostics, analyte quantitation and the specific detection of biologically important species. Towards the development of the AIE-active materials, many aromatic moieties composed of tetraphenylethylene, anthracene, pyrene, etc., have been developed. Among these aromatic moieties, pyrene is an aromatic hydrocarbon with a polycyclic flat structure containing four fused benzene rings to provide an unusual electron delocalization feature that is important in the AIE property. Numerous pyrene-based AIE-active materials have been reported with the AIE property towards sensing, imaging and theranostics applications. Most importantly, these AIE-active pyrene moieties exist as small molecules, Schiff bases, polymers, supramolecules, metal-organic frameworks, etc. This comprehensive review outlines utilizations of AIE-active pyrene-based materials on the imaging and theranostics studies. Moreover, the design and synthesis of these pyrene-based molecules are delivered with discussions on their future scopes.