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A new and efficient strategy for the stereoselective synthesis of tetrahydropyridino- and deazepanopyrrolo[1,2- c ]imidazolidines has been developed. Annulation of acylethynylpyrroles with six- and seven-membered cyclic imines (MeCN/THF, 20–25 °C, 24–72 h) leads to tetrahydropyrrolo[1′,2′:3,4]imidazo[1,2- a ]pyridines and hexahydropyrrolo[1′,2′:3,4]imidazo[1,2- a ]azepines with (E)-acylethenyl moiety in 28–96% yields. [ABSTRACT FROM AUTHOR]

Nitrogen-containing organofluorine derivatives, which are prepared using fluorinated building blocks, are among the most important active fragments in various pharmaceutical and agrochemical products. This review focuses on the reactivity, synthesis, and applications of fluoromethylated hydrazones and acylhydrazones. It summarizes recent methodologies that have been used for the synthesis of various nitrogen-containing organofluorine compounds.

This document is an editorial from the journal Frontiers in Chemistry titled "Recent advances in synthesizing and utilizing nitrogen-containing heterocycles." It explores the importance of nitrogen-containing heterocycles in various fields such as natural products, pharmaceuticals, agrochemicals, and functional materials. The editorial highlights ten original research articles and one perspective piece that discuss innovative synthetic methods, strategies for selectivity and reactivity control, and diverse applications of nitrogen-containing heterocycles. The research topic showcases the dynamic nature of this field and lays the groundwork for future investigations. The authors express their appreciation to the contributors and acknowledge financial support for the research. [Extracted from the article]

The discovery of new catalytic applications for metals remains an important goal in organic synthesis. If a catalyst has multiple functions, such as inducing bond cleavage and formation, it can streamline multi‐step transformations. Herein, the Cu‐catalyzed synthesis of imidazolidine through heterocyclic recombination between aziridine and diazetidine is reported. Mechanistically, Cu catalyzes the conversion of diazetidine into the corresponding imine, which then reacts with aziridine to form imidazolidine. The scope is sufficiently wide to form various imidazolidines, as many functional groups are compatible with the reaction conditions. [ABSTRACT FROM AUTHOR]

In fact, two outcome were possible as oxazolidine of type B 2 b can be viewed as bifunctional reagents possessing both O and N atoms susceptible to compete for electrophilic carbene intermediates. With these precedents in mind, we wondered what would happen with mixed oxazolidines and whether it would be possible to control the reactivity of -imino carbene intermediates toward either Lewis basic (LB) oxygen or nitrogen atoms. [54] From complex B A b , C-N bond formation occurs between the carbene complex and oxazolidines B 2 b carrying aryl substituents, achieving the nitrogen ylide intermediate B B b (blue cycle). Keywords: carbenes; diazaoxa heterocycles; 8-membered rings; regiodivergency; Rh(II) catalysis; triazoles; ylides EN carbenes diazaoxa heterocycles 8-membered rings regiodivergency Rh(II) catalysis triazoles ylides 1472 1476 5 07/11/23 20230725 NES 230725 Graph I N i -Sulfonyl-1,2,3-triazoles B 1 b , made readily through Cu(I)-catalyzed azide alkyne cycloadditions (CuAACs), [1] are prime building blocks in biological, medicinal, and synthetic chemistry. [Extracted from the article]

A highly efficient and straightforward synthetic methodology has been established for the preparation of imidazolidine derivatives through the [3 + 2]‐annulation of cyclic N‐sulfimines. This reaction involves the reaction of cyclic N‐sulfimines and γ‐sulfonamido‐α,β‐unsaturated carbonyl compounds, with Cs2CO3 serving as the catalyst. The outcome is a diverse range of imidazolidine derivatives with remarkable yields and stereoselectivities. In addition, the [4 + 2]‐annulation between cyclic N‐sulfimines and δ‐sulfonamido‐α,β‐unsaturated carbonyl compounds, catalyzed by Et3N, has been successfully applied for the synthesis of stereoselective hexahydropyrimidines. Furthermore, the base‐catalyzed annulation of cyclic N‐sulfimines with γ‐ and δ‐hydroxy‐α,β‐unsaturated carbonyl compounds has proven to be a reliable method for the synthesis of oxazolines and 1,3‐oxazinanes. [ABSTRACT FROM AUTHOR]

A series of inhibitors of the soluble epoxide hydrolase (sEH) containing imidazolidine-2,4,5-trione or pirimidine-2,4,6-trione has been synthesized. Inhibition potency of the described compounds ranges from 8.4 μM to 0.4 nM. The tested compounds possess higher water solubility than their preceding ureas. Molecular docking indicates new bond between the triones and the active site of sEH that in part explain the observed potency of the new pharmacophores. While less potent than the corresponding ureas, the modifications of urea group reported herein yield compounds with higher water solubility, thus permitting easier formulation.

New trifluoromethyl-substituted imidazo[4,5-b][1,4]oxazines were synthesized by the condensation of 4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-one with 2-aminoethanol and 2-aminophenol. An un-usual pathway was observed in the reactions of 1-methyl- and 1-phenyl-4,5-dihydroxy-4,5-bis(trifluoromethyl)-imidazolidin-2-ones with 2-aminoethanol, which led to the formation of 5-[(2-hydroxyethyl)amino]-3-methyl(phenyl)hydantoins. 1-Methyl- and 1-phenyl-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-ones reacted with 2-aminophenol under similar conditions to give rearrangement products, 5,5-bis(trifluoromethyl)-hydantoins. The molecular structure of 5-[(2-hydroxyethyl)amino]-3-methyl-5-(trifluoromethyl)imidazolidine-2,4-dione was determined by X-ray analysis. [ABSTRACT FROM AUTHOR]

Allyl halides with triflamide under oxidative conditions form halogen-substituted amidines. Allyl cyanide reacts with triflamide in acetonitrile or THF solutions in the presence of NBS to give the products of bromotriflamidation with a solvent interception, whereas in CH2Cl2 two regioisomers of the bromotriflamidation product without a solvent interception were obtained. The formed products undergo base-induced dehydrobromination to give linear isomers with the new C=C bond conjugated either with the nitrile group or the amidine moiety or alkoxy group. Under the same conditions, the reaction of allyl alcohol with triflamide gives rise to amidine, which was prepared earlier by the reaction of diallyl formal with triflamide. Unlike their iodo-substituted analogs, bromo-substituted amidines successfully transform into imidazolidines under the action of potassium carbonate. [ABSTRACT FROM AUTHOR]

Purpose: Based on nanomedicine strategies, this study employed cucurbit[7]uril (Q[7]) as the macromolecular carrier to synthesize nanocomplex drug delivery system for chlorogenic acid (CGA). The nanocomplex drug delivery system is intended to overcome the unsatisfactory biocompatibility and bioavailability of CGA and realizing its potential role in long-term osteoporosis (OP) medication., Methods: The nanocomplex was synthesized by the reflux stirring method. The chemical structure of the nanocomplex was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction analysis (XRD), UV-visible spectrophotometry (UV-vis), zeta potential analysis and transmission electronic microscope (TEM). The Cell Counting Kit-8 (CCK-8) assay, Live/Dead staining assay, and cytoskeleton staining were conducted to testify the biocompatibility of the nanocomplex. The release assay, Ferric Reducing Ability of Plasma (Frap) assay and Reactive oxygen species (ROS) staining were implemented to evaluate the release profile of CGA as well as its remaining antioxidative levels., Results: CGA and Q[7] formed hydrogen bonding through an exclusion interaction, with the binding ratio more than 1:1. The nanocomplex had a crystalline and spherical-like structure and improved thermal stability. The nanocomplex demonstrated better biocompatibility than free CGA. The release profile of CGA from the nanocomplex was much steadier, and 70% of CGA was released in 5 days. The CGA released from the nanocomplex maintained its antioxidative properties at high levels and effectively eliminated the accumulated ROS in MC3T3-E1 cells under oxidative stress., Conclusion: Q[7] has been demonstrated to be an ideal nanocarrier for CGA and the nanocomplex delivery system holds the potential for the long-term medication strategy of OP., Competing Interests: The authors report no conflicts of interest in this work., (© 2024 Jiang et al.)

The antibiotic resistance of bacterial membranes poses a significant threat to global public health, highlighting the urgent need for novel therapeutic agents and strategies to combat bacterial membranes. In response, we have developed a novel macrocyclic host molecule (GCPCB) based on guanidiniocarbonyl-pyrrole (GCP) functionalized cucurbit[7]uril with an aggregation-induced luminescence effect. GCPCB exhibits high antimicrobial potency against bacterial membranes, particularly demonstrating strong antibacterial activity against Gram-positive strains of S. aureus and Gram-negative strains of E. coli . Significantly, due to the strong binding between GCP and the bacterial membrane, GCPCB can effectively eradicate the bacteria encapsulated within. Furthermore, the formation of a host-guest complex between GCPCB and berberine hydrochloride (BH) not only enhances synergistic destructive activity against both species of bacteria but also provides a potential supramolecular platform for effective bacterial membrane destruction.

The supramolecular drug delivery systems (SDDSs) based on host-guest recognition through noncovalent interactions, capable of responsive behavior and dynamic switching to external stimuli, have attracted considerable attention in cancer therapy. In this study, a targeted dual-functional drug delivery system was designed and synthesized. A hydrophilic macrocyclic host molecule (acyclic cucurbit[ n ]uril ACB) was modified with folic acid (FA) as a targeting ligand. The guest molecule consists of a disulfide bond attached to adamantane (DA) and cannabidiol (CBD) at both ends of the response element of glutathione. Recognition and self-assembly of host and guest molecules successfully functionalize supramolecular nanomicelles (SNMs), targeting cancer cells and releasing drugs in a high glutathione environment. The interactions between host and guest molecules were investigated by using nuclear magnetic resonance (NMR), fluorescence titration, Fourier-transform infrared spectroscopy (FT-IR), and thermal analysis (TGA). Transmission electron microscopy (TEM) and dynamic light scattering (DLS) confirmed the nanostructure of the SNMs. Experimentation with 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) demonstrated the responsiveness of SNMs to glutathione (GSH). In vitro cytotoxicity assays demonstrated that SNMs had a greater targeting efficacy for four types of cancer cells (HeLa, HCT-116, A549, and HepG2) compared to normal 293T cells. Cellular uptake studies revealed that HeLa cells more readily absorbed SNMs, leading to their accumulation in the tumor cell cytoplasm. Fluorescence colocalization assays verified that SNMs efficiently accumulated in organelles related to energy metabolism and signaling, including mitochondria and the endoplasmic reticulum, affecting cellular metabolic death. Both flow cytometry and confocal nuclear staining assays confirmed that SNMs effectively induced apoptosis over time, ultimately resulting in the death of cancer cells. These findings demonstrate that SNMs exhibit excellent targeting ability, responsiveness, high bioavailability, and stability, suggesting significant potential in drug delivery applications.

Chloramphenicol (CAP) poses a threat to human health due to its toxicity and bioaccumulation, and it is very important to measure it accurately and sensitively. This work explored a host-guest recognition strategy to mediate dual aggregation-induced electrochemiluminescence (AIECL) of 1,1,2,2-tetrakis(4-(pyridin-4-yl) phenyl)-ethene (TPPE) for ratio detection of CAP, in which, cucurbit[8]uril (CB[8]) served as host to assemble guest TPPE. The resulting supramolecular complex CB[8]-TPPE exhibited excellent dual-AIECL-emission with signal strength approximately four times that of TPPE aggregates and black hole quencher-1 (BHQ1) could efficiently quench dual-AIECL signal. CB[8]-TPPE coupled dual-function quencher BHQ1 and high-efficiency DNA reactor to achieve ultra-sensitive detection of CAP, exhibiting a linearity range of 10 fmol·L -1 -100 nmol·L -1 and limit of detection of 1.81 fmol·L -1 . CB[8]-TPPE provides a novel way to improve the dual-emission of TPE derivatives and sets up a promising platform for CAP detection, demonstrating a good practical application potential., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

The N -methyl-4-thiophenylpyridinium cation (ThioPy) is a high affinity ( K d ca. 5 nM), fast-exchanging fluorescent probe for cucurbit[7]uril (CB7). The CB7/ThioPy complex shows a unique fluorescence turn-ON response upon displacement by an analyte in sensing application. This enabled the development of a real-time fluorescence assay with the MRFA peptide for the protease thermolysin, which is also suitable for the cancer biomarker cathepsin B. Moreover, liposome encapsulation of CB7/ThioPy in large unilamellar vesicles (LUVs) provided mechanistic insight into intravesicular dye displacement reactions.

Bacterial infection is one of the major concerns of the growing society, and over the years, different permutations and combinations of various drugs and adjuvants have been attempted, which led to considerable improvements in the efficacy of the antibacterial drugs. In this regard, macrocyclic receptors such as cyclodextrin, cucurbiturils, calixarene, etc., have played a major role by modulating the drug properties that supplement the antibacterial efficacy. In this study, we have developed cucurbit[7]uril (CB7)-functionalized Au nanoparticles (CB7AuNPs) to modulate the activity of an antibiotic, levofloxacin (LOFL). From the spectroscopic and thermodynamic changes in the LOFL, it has been established that two of the prototropic forms, LOFLH and LOFLH 2 + , form strong 1:1 host/guest complexes with CB7/CB7AuNP. Both these interactions led to significant upward shifts in the p K a values as well as photostability of LOFL, thereby enhancing the availability of the active form for the antibacterial activity, at the physiological pH. Further, the LOFL uptake has also been established on CB7AuNP, which retained the CB7-LOFL activity at very low concentration of the CB7 host, functionalized on AuNP. Detailed antibacterial studies of LOFL, both as complexed with CB7 and CB7AuNP, were carried out using four food-borne pathogens ( Escherichia coli , S. Typhimurium , Bacillus cereus, and Staphylococcus aureus ), which revealed a creditable enhancement in the antibacterial property, irrespective of the bacterium strain. These results are quite promising at this stage for the development of drugs customized for multidrug-resistant bacteria.

The regulation of the cell membrane potential plays a crucial role in governing the transmembrane transport of various ions and cellular life processes. However, in situ and on-demand modulation of cell membrane potential for ion channel regulation is challenging. Herein, we have constructed a supramolecular assembly system based on water-soluble cationic oligo(phenylenevinylene) (OPV) and cucurbit[7]uril (CB[7]). The controllable disassembly of OPV/4CB[7] combined with the subsequent click reaction provides a step-by-step adjustable surface positive potential. These processes can be employed in situ on the plasma membrane to modulate the membrane potential on-demand for precisely controlling the activation of the transient receptor potential vanilloid 1 (TRPV1) ion channel and up-regulating exogenous calcium-responsive gene expression. Compared with typical optogenetics, electrogenetics, and mechanogenetics, our strategy provides a perspective supramolecular genetics toolbox for the regulation of membrane potential and downstream intracellular gene regulation events.

Bacterial infections have emerged as a significant contributor to global mortality and morbidity rates. Herein, we introduce a dual fluorescence "turn-on" supramolecular sensor array composed of three assembled complexes ( C1 - C3 ), formed from three positively charged fluorophores ( A1 - A3 ) and one cucurbit[7]uril (CB[7]). The ability of this three-element array to simultaneously recognize 10 bacterial species within just 30 s was remarkable, boasting an impressive 100% accuracy. Additionally, the array excelled at distinguishing among various bacterial mixtures and enabled the quantitative detection of common bacterial strains. Notably, it has been skillfully applied to differentiate 10 bacterial samples in urine, achieving excellent differentiation and showcasing promising potential for medical diagnostic applications.

New photostable and bright supramolecular complexes based on cucurbit[7]uril (CB7) host and diketopyrrolopyrole (DPP) guest dyes having two positively charged 4-(trimethylammonio)phenyl groups were prepared and characterized. The dye core displays large Stokes shift (in H 2 O, abs./emission max. 480/550 nm; ϵ~19 000, τ fl >4 ns), strong binding with the host (~560 nM K d ) and a linker affording fluorescence detection of bioconjugates with antibody and nanobody. Combination of protein-functionalized DPP dye with CB7 improves photostability and affords up to 12-fold emission gain. Two-color confocal and stimulated emission depletion (STED) microscopy with 595 nm or 655 nm STED depletion lasers shows that the presence of CB7 not only leads to improved brightness and image quality, but also results in DPP becoming cell-permeable., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Host-guest complex has attracted much attention because of their fantastic capability. Accurate prediction of their binding affinity and enthalpy is essential to the rational design of guest molecules. The attach-pull-release (APR) method proposed by Henriksen et al. (J. Chem. Theory Comput., 2015, 11:4377.) shows good prediction capability of binding affinity especially for host-guest system. In order to further evaluate the performance of APR method in practice, we have conducted the calculations on the macrocycle cucurbit [7]urils (CB7) encapsulated with four structurally similar alkaloids (berberine, coptisine, epiberberine and palmatine) with two force fields (GAFF and GAFF2) and three water models (TIP3P, SPC/E and OPC). Compared to the experimental data, the calculation by the combination of GAFF2 and SPC/E force field presents the best performance, of which the Pearson correlation coefficients (R 2 ) is 0.95, and the root-mean-square-deviation is 3.04 kcal/mol. While the predictions from GAFF force field all overestimated the binding affinity, suggesting a systematic error may be involved. Comparison of calculation also indicates that the accuracy of prediction was susceptible to the combination of force field. Therefore, it would be necessary to repeat the simulation with different combination of force fields in practice., Competing Interests: Declaration of competing interest All authors disclosed no relevant relationships., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The review summarizes for the first time methods of synthesis, properties, and applications of five- and six-membered N,O- and N,N-heterocycles containing (η6-arene)tricarbonylchromium fragments. Major attention has been given to highly selective processes guided by the presence of a tricarbonylchromium moiety in the reactions molecules, which have found application in fine organic synthesis and biomedicinal chemistry. Supplementary materials include tabulated characteristics of the examined compounds. [ABSTRACT FROM AUTHOR]

Dynamic self-assembly has significant implications in the regulation of the enzyme activities. In this study, we present a histidine-based enzyme-mimicking catalyst, formed by the self-assembly of carefully-engineered FH-based short peptides with hemin, showcasing switchable catalytic activity of hemin due to externally induced reversible inclusion of a cucurbit[7]uril-peptide hybrid. 1H NMR, ITC and theoretical simulation are employed to examine the binding affinity between the guest and host components, and UV-vis spectra are used to investigate changes in the hemin coordination environment. The histidine segment of the short peptide can be partially shielded by the cucurbituril and released following addition of the azo compound, leading to a decrease and subsequent restoration of the histidine-hemin coordination affinity and hemin activity. The photoisomeriziable nature of the azo compound enabled the activation of FHH/hemin activity to be switched on and off by exposure to different wavelengths of light. During the operation, the Phe residue remained within the cucurbituril, allowing reversible inclusion and exposure of the histidine residues. The hemin stayed connected to FHH/cucurbit[7]uril hybrid, preventing the severe aggregation of hemin and irreversible deactivation. This work may provide insights into engineering the dynamic behaviors of the cofactor-dependent catalytic assemblies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

A novel CB[6]-based supramolecular assembly [K(ANS)(CB[6]) 2 (DMF) 2 (H 2 O) 0.5 ] (1) (CB[6] = cucurbit[6]uril, ANS - = 8-amino-1-naphthalene sulfonic acid ion) was successfully synthesized under solvothermal condition. Performance studies have shown that 1 exhibited excellent chemical stability and recycling performance. Meanwhile, 1 exhibited remarkable potential as a fluorescence sensor for the detection of 2,4,6-trinitrophenol (TNP), 4-nitrophenol (4-NP), and rifampicin (RFP) in both aqueous environments and practical samples. This sensing capability is achieved through fluorescence quenching, which offers fast response times and exceptional sensitivity, with detection limits of 0.19 μM for both TNP and 4-NP, and 0.21 μM for RFP. Even more remarkably, an anti-counterfeiting ink based on 1 and a portable test hydrogel were devised for encrypting information and visually detecting using a smartphone application. This work has the potential to expand the utilization of CB[6]-based materials in optical applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Reaction of imidazolidineiminothiones with some amino acids methyl ester afforded imidazopyrazine and imidazolidine derivatives. Some of obtained products were synthesized by nano technology; where this method reduces the reaction time significantly. The evaluation of biological activity of some selected compounds was carried out and some of synthesized compounds displayed anticancer activity.

Piroxicam (PX) is a nonsteroidal anti-inflammatory drug (NSAID) commonly associated with gastrointestinal (GI) injuries, including dyspepsia, heartburn, inflammation, bleeding, ulceration, and life-threatening perforation. The β-cyclodextrin (β-CD)-based PX formulation (PX@CD) has been shown to reduce gastric side effects by improving PX's solubility and dissolution rates. However, the solubility of PX can only be increased to a limited extent by β-CD, due to the low binding constant between PX and β-CD (∼100 M -1 ). As a result, adverse reactions such as epigastric pain and pyrosis are still commonly reported. Cucurbit[7]uril (CB[7]) is a synthetic macrocyclic host compound that binds strongly to various drugs. In this study, we demonstrated that CB[7] forms complexes with PX in the gastric acid environment with a binding constant approximately 70 times higher than that between β-CD and PX. The PX@CB[7] inclusion complexes exhibited rapid dissolution rates in the gastric environment. In addition, PX@CB[7] showed significantly higher oral bioavailability and maximum concentration (C max ) compared to PX and PX@CD (1:2.5), resulting in improved anti-inflammatory effects in both mouse and rat models. Moreover, PX@CB[7] (1:2.5) had the least adhesion to the gastric mucosa and caused the mildest gastric side effects in rat models when compared to PX, PX@CD (1:2.5), and PX@CB[7] (1:1). Lastly, CB[7] demonstrated good oral biocompatibility in a subacute toxicity evaluation study. These findings indicate that CB[7] could be used as an excipient to improve treatment effectiveness and decrease adverse reactions in orally administered formulations with a favorable safety profile., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Xiangjun Zhang reports financial support was provided by Natural Science Foundation Project of Chongqing. Xiangjun Zhang reports financial support was provided by Chongqing Municipal Education Commission Foundation. Yan Wang, Chao Yu and Xiangjun Zhang has patent pending to National Intellectual Property Administration，PRC. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Gene expression technology has become an indispensable tool for elucidating biological processes and developing biotechnology. Cell-free gene expression (CFE) systems offer a fundamental platform for gene expression-based technology, in which the reversible and programmable control of transcription can expand its use in synthetic biology and medicine. This study shows that CFE can be controlled via the host-guest interaction of cucurbit[7]uril (CB[7]) with N 6 -guest-modified adenosines. These adenosine derivatives were conveniently incorporated into the DNA strand using a post-synthetic approach and formed a selective and stable base pair with complementary thymidine in DNA. Meanwhile, alternate addition of CB[7] and the exchanging guest molecule induced the reversible formation of a duplex structure through the formation and dissociation of a bulky complex on DNA. The kinetics of the reversibility was fine-tuned by changing the size of the modified guest moieties. When incorporated into a specific region of the T7 promoter sequence, the guest-modified adenosines enabled tight and reversible control of in vitro transcription and protein expression in the CFE system. This study marks the first utility of the host-guest interaction for gene expression control in the CFE system, opening new avenues for developing DNA-based technology, particularly for precise gene therapy and DNA nanotechnology.

DNA hydrogels have been demonstrated with the advantages of good stability, easy modification, and extraordinary biocompatibility, which enables their great application prospects in biosensing, tissue engineering, and biomedicine. Based on the host-guest recognition properties of cucurbit[8]uril (CB[8]), we proposed a general method for constructing functional supramolecular DNA nanogels. Guest molecules have been conjugated into the DNA building units, which could be further crosslinked with CB[8] to construct supramolecular DNA nanogels. At the same time, the aptamer has also been modified into the hydrogel network to achieve cell targeting. These supramolecular DNA nanogels have been demonstrated with a controllable size and multiple stimuli responses, in addition to the excellent biocompatibility, stability and good targeting drug transport ability. Such a host-guest based strategy will provide a molecular library as a "toolbox" for the functionalization of DNA nanogels.

Pure organic phosphorescence resonance energy transfer is a research hotspot. Herein, a single-molecule phosphorescence resonance energy transfer system with a large Stokes shift of 367 nm and near-infrared emission is constructed by guest molecule alkyl-bridged methoxy-tetraphenylethylene-phenylpyridines derivative, cucurbit[n]uril (n = 7, 8) and β-cyclodextrin modified hyaluronic acid. The high binding affinity of cucurbituril to guest molecules in various stoichiometric ratios not only regulates the topological morphology of supramolecular assembly but also induces different phosphorescence emissions. Varying from the spherical nanoparticles and nanorods for binary assemblies, three-dimensional nanoplate is obtained by the ternary co-assembly of guest with cucurbit[7]uril/cucurbit[8]uril, accompanying enhanced phosphorescence at 540 nm. Uncommonly, the secondary assembly of β-cyclodextrin modified hyaluronic acid and ternary assembly activates a single intramolecular phosphorescence resonance energy transfer process derived from phenyl pyridines unit to methoxy-tetraphenylethylene function group, enabling a near-infrared delayed fluorescence at 700 nm, which ultimately applied to mitochondrial targeted imaging for cancer cells., (© 2024. The Author(s).)

The reactions of pyridoxal imidazolidines with diphenylchlorophosphine oxide, depending on the substituents nature in the imidazolidine ring, resulted in the formation of new salt-like tricyclic structures or a bisalt structure based on N,N′-dibenzylethylenediamine and diphenylphosphinic acid. The benzoylation of pyridoxal imidazolidines also led to decomposition of the imidazolidine fragment with the formation of dibenzoylated N,N′-dimethylethylenediamine. [ABSTRACT FROM AUTHOR]

[Display omitted] New pathways of reaction between 1-methylthiourea or 1-methylurea and benzil bring about new derivatives of (2 S *,3a R *,6a S *)-perhydro-3a H -[1,3]dioxolo[4,5- d ]imidazole and racemic (4 S *,5 R *)-4-alkoxy-5-hydroxy-1-methyl-4,5-diphenylimidazolidine-2-thiones. Some of the obtained urea-and thiourea derivatives were characterized by X-ray diffraction, which showed their supramolecular organization governed by the directionality of hydrogen bonds at the acceptor side C=O or C=S groups. [ABSTRACT FROM AUTHOR]

A method for the synthesis of imidazolinium salts through a catalytic dehydrogenation was developed using Pd/C as a catalyst with ammonium salt as an additive. Optimization of the reaction conditions revealed the existence of a proton source that was necessary to accomplish the reaction. Under the optimal conditions, oxidation‐sensitive components, such as an allyl, a furan, and a thiophene can be introduced into the corresponding imidazolinium salts. In addition to the varied N‐substituents, the presented method can be used to synthesize a series of 2‐substituted imidazolinium salts. [ABSTRACT FROM AUTHOR]

A Y(OTf)3‐catalyzed [3+2] cycloaddition of 1,3,5‐triazinanes with donor‐acceptor aziridines has been developed, accessing diversely substituted imidazolidines high efficiency. Mechanistic investigations support the formation of imidazolidines through an SN1‐like pathway. Furthermore, these imidazolidines exhibit promising anti‐tumor activity against a series of human cancer cell lines. [ABSTRACT FROM AUTHOR]

Different from most of the conventional platforms with dissatisfactory theranostic capabilities, supramolecular nanotheranostic systems have unparalleled advantages via the artful combination of supramolecular chemistry and nanotechnology. Benefiting from the tunable stimuli-responsiveness and compatible hierarchical organization, host-guest interactions have developed into the most popular mainstay for constructing supramolecular nanoplatforms. Characterized by the strong and diverse complexation property, cucurbit[8]uril (CB[8]) shows great potential as important building blocks for supramolecular theranostic systems. In this review, we summarize the recent progress of CB[8]-based supramolecular theranostics regarding the design, manufacture and theranostic mechanism. Meanwhile, the current limitations and corresponding reasonable solutions as well as the potential future development are also discussed., (© 2024. The Author(s).)

The non-canonical amino acid adamantylglycine (Ada) is introduced into peptides to allow high-affinity binding to cucurbit[7]uril (CB7). Introduction of Ada into a cell-penetrating peptide (CPP) sequence had minimal influence on the membrane transport, yet enabled up- and down-regulation of the membrane transport activity.

Room temperature phosphorescence (RTP) nanoprobes play crucial roles in hypoxia imaging due to their high signal-to-background ratio (SBR) in the time domain. However, synthesizing RTP probes in aqueous media with a small size and high quantum yield remains challenging for intracellular hypoxic imaging up to present. Herein, aqueous RTP nanoprobes consisting of naphthalene anhydride derivatives, cucurbit[7]uril (CB[7]), and organosilicon are reported via supermolecular confined methods. Benefiting from the noncovalent confinement of CB[7] and hydrolysis reactions of organosilicon, such small-sized RTP nanoprobes (5-10 nm) exhibit inherent tunable phosphorescence (from 400 to 680 nm) with microsecond second lifetimes (up to ∼158.7 μs) and high quantum yield (up to ∼30%). The as-prepared RTP nanoprobes illustrate excellent intracellular hypoxia responsibility in a broad range from ∼0.1 to 21% oxygen concentrations. Compared to traditional fluorescence mode, the SBR value (∼108.69) of microsecond-range time-resolved in vitro imaging is up to 2.26 times greater in severe hypoxia (<0.1% O 2 ), offering opportunities for precision imaging analysis in a hypoxic environment.

Guadinomines are a recently discovered family of anti-infective compounds produced by Streptomyces sp. K01-0509 with a novel mode of action. With an IC(50) of 14 nM, guadinomine B is the most potent known inhibitor of the type III secretion system (TTSS) of Gram-negative bacteria. TTSS activity is required for the virulence of many pathogenic Gram-negative bacteria including Escherichia coli , Salmonella spp., Yersinia spp., Chlamydia spp., Vibrio spp., and Pseudomonas spp. The guadinomine (gdn) biosynthetic gene cluster has been cloned and sequenced and includes 26 open reading frames spanning 51.2 kb. It encodes a chimeric multimodular polyketide synthase, a nonribosomal peptide synthetase, along with enzymes responsible for the biosynthesis of the unusual aminomalonyl-acyl carrier protein extender unit and the signature carbamoylated cyclic guanidine. Its identity was established by targeted disruption of the gene cluster as well as by heterologous expression and analysis of key enzymes in the biosynthetic pathway. Identifying the guadinomine gene cluster provides critical insight into the biosynthesis of these scarce but potentially important natural products.

Two derivatives of Iimidazolidin 4-one (IMID4) and Oxazolidin 5-one (OXAZ5), were investigated as corrosion inhibitors of corrosion carbon steel in sea water by employing the theoretical and experimental methods. The results revealed that they inhibit the corrosion process and their %IE followed the order: IMID4 (89.093%)  OXAZ5 (80.179%). The %IE obtained via theoretical and experimental methods were in a good agreement with each other. The thermodynamic parameters obtained by potentiometric polarization measurements have supported a physical adsorption mechanism which followed Langmuir adsorption isotherm. Quantum mechanical method of Density Functional Theory (DFT) of B3LYP with a level of 6-311++G (2d, 2p) were used to calculate the geometrical structure, physical properties and inhibition efficiency parameters, in vacuum and two solvents (DMSO and H2O), all calculated at the equilibrium geometry, and correlated with the experimental %IE. The local reactivity has been studied through Mulliken charges population analysis. The morphology of the surface changes of carbon steel were studied using SEM and AFM techniques. [ABSTRACT FROM AUTHOR]

Trifluoromethylated N‐acylhydrazones are used as dipolarophiles to perform 1,3‐dipolar cycloadditions with azomethine ylides to afford trifluoromethylated 1,2,4,5‐tetrasubstituted imidazolidines in good yields under mild conditions. The role switch of the trifluoromethylated N‐acylhydrazones demonstrates that they are versatile trifluoromethyl building blocks for CF3‐containing heterocycles. [ABSTRACT FROM AUTHOR]

The research includes the preparation of new heterocyclic imidazolodine-4-one derivative,starting from 2- hydroxy-5-((4-nitrophenyl)diazenyl)benzaldehyde (F1). This work involved the synthesis and identification of imidazolodine-2- one derivative (F2) from the Schiff base derivative(F1). These compounds were characterized by Fourier-transform infrared spectroscopy (FTIR) and the Proton nuclear magnetic resonance (1H-NMR) spectrum. The biological activity of the Imidazolidine derivative was also investigated by the thiazolyl blue tetrazolium bromide (MTT) cytotoxicity test on the LS -174T colorectal adenocarcinoma cells,the African green monkey kidney (VERO) cells and the assessment of the concentration that inhibits the growth of 50% of cell viability (IC50). Doxorubicin (DOX) and 5-Fluorouracil (5-FU) were also used for comparative goals. The results showed that Imidazolidine derivative was effectively and significantly inhibited the cell proliferation (p<0.00001) by decreasing the viability of LS -174T cells at different concentrations, which involved 1, 10, 50, 100, 250, 500 and 1000 μg/ml, with a half maximal inhibitory concentration (IC50) of 54.406μg/ml. The DOX and 5-FU IC50 values were 63.140 μg/ml and 55.006 μg/ml, respectively. We concluded that the Imidazolidine derivative has an anticancer effect against the LS -174T colorectal carcinoma cell line. [ABSTRACT FROM AUTHOR]

Reaction of imidazolidineiminothiones with some amino acids methyl ester afforded imidazopyrazine and imidazolidine derivatives. Some of obtained products were synthesized by nano technology; where this method reduces the reaction time significantly. The evaluation of biological activity of some selected compounds was carried out and some of synthesized compounds displayed anticancer activity. [ABSTRACT FROM AUTHOR]

AKR1B10 is an aldose reductase (AR) homologue overexpressed in liver cancer and various forms of that enzyme in carcinomas catalyze the reduction of anticancer drugs, potential cytostatic drug, and dl-glyceraldehyde but do not catalyze the reduction of glucose. Kinetic parameters for wild-type and C299S mutant AKR1B10 indicate that substitution of serine for cysteine at position 299 reduces the affinity of this protein for dl-glyceraldehyde and enhances its catalytic activity. Fibrates suppress peroxisome proliferation and the development of liver cancer in human. Here we report the potency of fibrate-mediated inhibition of the carbonyl reduction catalyzed by wild-type and C299S mutant AKR1B10 and compare it with known AR inhibitors. Wild-type AKR1B10-catalyzed carbonyl reduction follows pure non-competitive inhibition kinetics using zopolrestat, EBPC or sorbinil, whereas fenofibrate, Wy 14,643, ciprofibrate and fenofibric acid follow mixed non-competitive inhibition kinetics. In contrast, catalysis of reaction by the C299S AKR1B10 mutant is not inhibited by sorbinil and EBPC. Despite these differences, the C299S AKR1B10 mutant still manifests kinetics similar to the wild-type protein with other fibrates including zopolrestat, fenofibrate, Wy 14,346, gemfibrozil and ciprofibrate that show mixed non-competitive inhibition kinetics. The reaction of the mutant AKR1B10 is inhibited by fenofibric acid, but manifests pure non-competitive inhibition kinetics that are different from those demonstrated for the wild-type enzyme.

[Display omitted] An efficient synthesis of new (Z , E)-2-(alkylthio)alk-2-en-4-ynals by aldol condensation reaction of ynals with (alkylthio)-acetaldehydes using NaOH/DMF system has been developed.The reaction of these products with N , N -diphenylethylene-diamine and p -tosylmethyl isocyanide proceeds at the carbonyl group to form the corresponding imidazolidine and oxazole derivatives. [ABSTRACT FROM AUTHOR]

Neonicotinoid insecticides (NNIs), which have been detected across diverse aquatic environments, have sparked substantial concerns regarding their potential adverse ecological and health risks. In this study, the removal of NNIs by unactivated peroxymonosulfate (PMS) and peroxydisulfate (PDS) was systematically investigated. Results showed that PMS/PDS direct oxidation is mainly responsible for the degradation of imidacloprid (IMD), and the degradation kinetics can be well described by a second-order kinetics model, first-order in both IMD and PMS/PDS concentration. The species-specific reaction rate constants of HSO 5 - and SO 5 2- with IMD were calculated to be 429.36 ± 15.41 M -1 h -1 and 9.72 ± 35.48 M -1 h -1 , while the corresponding rate constant between S 2 O 8 2- and IMD is 25.04 ± 3.04 M -1 h -1 . Over 100 transformation products in the degradation of IMD by PMS/PDS were identified by HPLC/Q-Orbitrap HRMS, and five major reaction pathways were proposed thereafter: hydroxylation on imidazolidine ring, olefin reaction on imidazolidine ring, desnitro reaction on nitroguanidine moiety, and two chain-breaking reactions between imidazolidine ring and chloro-pyridyl moiety. Toxicity evaluation on the transformation products found that their ecotoxicity is various at a wide range with an overall indeterminacy, while their bioconcentration factors show a definite decrease. The reactivity of six NNIs with PMS/PDS was found varied by structures but generally low, indicating that in-situ oxidation with unactivated PMS/PDS is safe but inefficiency for the mitigation of NNIs. It is thus suggested that further investigations into activated PMS/PDS systems involving radicals promise enhanced remediation of NNIs, and fundamental data in this study has laid the groundwork., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Arynes have been found to undergo formal σ‐bond insertion into a C(sp3)–N bond for the first time. This transformation is utilized in the ring expansion of 1,3‐diaza‐heterocycles to afford benzofused medium‐ring N‐heterocycles in a single step. This represents a novel route to biologically relevant 2,3,4,5‐tetrahydro‐1H‐benzo[e][1,4]diazepines, prepared directly from easily accessible imidazolidines. An example of the ring expansion of a 1,3‐diazetidine is also reported, which affords the corresponding 1,2,3,4‐tetrahydroquinazoline. [ABSTRACT FROM AUTHOR]

Heterocyclization of furan-2-carbonyl isothiocyanate 1 with a variety of aliphatic and aromatic nitrogen nucleophiles resulted in the formation of a new series of heterocycles including triazines, pyrimidines, oxadiazines, imidazolidines, thiadiazoles and their condensed candidates. The antibacterial screening for a group of the newly synthesized compounds showed that they possess moderate antibacterial activities against examples of Gram-positive and Gram-negative bacteria. [ABSTRACT FROM AUTHOR]

In order to extend knowledge about pharmacophoric features responsible for ABCB1 inhibitory properties of imidazolidin‐2,4‐dione derivatives, 1′‐[4‐(4‐(o‐methoxyphenyl)‐piperazin‐1‐yl)butyl]‐3′‐methyl‐spiro(fluoren‐9,5′‐imidazolidine)‐2′,4′‐dione (3) and its salt (4) with rhodanine‐3‐acetic acid (RA) were prepared and investigated by X‐ray diffraction method, as well as their efflux modulating effects in cancer cells (mouse T‐lymphoma), cytotoxic and antiproliferative activities were evaluated in vitro. The molecular geometry, intermolecular interactions, and crystal packing of base and acid forms of 3 were analyzed to see, if conformational changes influence the biological activities. The geometry of 2‐methoxyphenylpiperazine and 5‐spirofluorenehydantoin moieties was compared with other crystal structures containing these fragments. Our results indicated a very potent inhibitory action on ABCB1 pump, and significant cytotoxic and antiproliferative properties of 3 in T‐lymphoma, even more potent in the case of multidrug resistance cells. Furthermore, the compound 3 converted into the salt 4 of inactive acid (RA) has maintained both, the efflux pump inhibitory and antiproliferative activities, showing strong synergism with doxorubicin. A comparison of geometry of 3 in both crystal structures (3 and 4) shows a significant difference in the arrangement of piperazine ring with respect to the aliphatic linker. [ABSTRACT FROM AUTHOR]

Abstract A novel Schiff base chemosensor HMID, ((E)‑1‑((2‑hydroxy‑3‑methoxybenzylidene)amino)imidazolidine‑2,4‑dione), have been designed and synthesized. Sensor HMID showed a selectivity to Zn2+ through fluorescence enhancement in aqueous solution. Its detection limit was analyzed as 11.9 μM. Importantly, compound HMID could be applied to image Zn2+ in live cells. Detection mechanism of Zn2+ by HMID was suggested to be an effect of chelation-enhanced fluorescence (CHEF) by DFT calculations. Moreover, HMID could detect Cu2+ with a change of color from colorless to pink. The selective detection mechanism of Cu2+ by HMID was demonstrated to be the promotion of intramolecular charge transfer band by DFT calculations. Additionally, HMID could be employed as a naked-eye colorimetric kit for Cu2+. Therefore, HMID has the ability as a 'single sensor for dual targets'. Graphical Abstract Unlabelled Image Highlights • New Schiff-base chemosensor HMID was developed for detection of Zn2+ and Cu2+. • HMID can detect Zn2+ through "turn on" fluorescence in living cells. • HMID was used to detect Cu2+ from colorless to pink though ICT mechanism. • Chemosensor HMID could be used as a practical visible colorimetric test kit for Cu2+. • Sensing mechanisms for Zn2+ and Cu2+ by HMID were explained by DFT calculations. [ABSTRACT FROM AUTHOR]

Graphical abstract H ighlights • Aroyl azides for the synthesis of 3-arylimidazolidin-4-ones. • Nonstabilized azomethine ylides react readily with aryl isocyanates. • An unique example of the conversion of oxazolidine ring to imidazolidine core. Abstract Aryl isocyanates generated in situ from aroyl azides react with N -methylazomethine ylide generated in situ from N -methylspiroanthraceneoxazolidine at 210 °C in a microwave reactor to form 3-arylimidazolidin-4-ones in 30–81% yield. [ABSTRACT FROM AUTHOR]