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Supramolecular recognition of nucleobases and short sequences is an emerging research field focusing on possible applications to treat many diseases. Controlling the affinity and selectivity of synthetic receptors to target desired nucleotides or short sequences is a highly challenging task. Herein, we elucidate the effect of substituents in the phenyl ring of the anthracene-benzene azacyclophane on the recognition of nucleoside triphosphates (NTPs) and double-stranded DNA. We show that introducing phenyl rings increases the affinity for NTPs 10-fold and implements groove and intercalation binding modes with double-stranded DNA. NMR studies and molecular modeling calculations support the ability of cyclophanes to encapsulate nucleobases as part of nucleotides., (© 2024 The Author(s). Chemistry - A European Journal published by Wiley-VCH GmbH.)

A new calix[4]triazacrown-5-derived fluorescence chemosensor (AntUr-AzClx) at cone conformation was synthesized to afford an effective fluorescent probe, which enables an enhancement in the fluorescence intensity specifically in the presence of Co 2+ metal ions as well as a turnoff response for hazardous dichromate anions. 1 H-NMR, 13 C-NMR, ESI-MS, and elemental analysis techniques were used to characterize the structure of the anthracene-appended calix[4]triazacrown-5 (AntUr-AzClx). The metal ion-binding ability of AntUr-AzClx was evaluated against Co 2+ , Ba 2+ , Ni 2+ , Pb 2+ , and Zn 2+ ions. On the basis of various metal ion recognition phenomena, AntUr-AzClx exhibited outstanding selectivity for only the Co 2+ ion among other metal ions. Also, the calix[4]triazacrown-5-derived fluorescence chemosensor showed high sensitivity towards the Co 2+ ion with a very low limit of detection (LOD) 0.142 μmol L -1 . In addition, anion binding abilities of AntUr-AzClx against various anions such Cr 2 O 7 2- , HCO 3 - , CO 3 2- , NO 3 - , SO 3 2- , SO 4 2- , N 3 - , F - , and I - demonstrated that AntUr-AzClx enables selective and highly sensitive detection of the Cr 2 O 7 2- anion with an excellent LOD of 4.182 nmol L -1 in DMF/PBS (1/1, v/v; pH: 7.05). Furthermore, the calix[4]triazacrown-5-derived fluorescence chemosensor displayed a significant sensing behavior to detect the presence of dichromate anions even in real samples., (© 2024 John Wiley & Sons Ltd.)

GroEL, a chaperone protein responsible for peptide and denatured protein folding, undergoes substantial conformational changes driven by ATP binding and hydrolysis during folding. Utilizing these conformational changes, we demonstrated the GroEL-mediated regioselective photocyclodimerization of 2-anthracenecarboxylic acid (AC) using ATP hydrolysis as an external stimulus. We designed and prepared an optimal GroEL mutant to employ in a docking simulation that has been actively used in recent years. Based on the large difference in the motif of hydrogen bonds between AC and GroEL mutant compared with the wild-type, we predicted that GroEL MEL , in which the 307‒309th amino acid residues were mutated to Ala, could alter the orientation of bound AC in GroEL. The GroEL MEL -mediated photocyclodimerization of AC can be used for regioselective inversion upon ATP addition to a moderate extent., (Copyright © 2024 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

Protection against the negative effects of solar radiation involves using cosmetics with a UV filter, but visible radiation can also have negative effects. We use dietary supplements and take medications; unfortunately, many of them contain substances that degrade under the influence of visible light, which transform into chemical compounds harmful to health. Manufacturers often include information on the prohibition of exposure to sunlight on the packaging, but consumers often do not read the product leaflet. The solution to this problem may be the addition of silver particles to preparations. In the presented article, we proposed the use of silver nanoparticles to reduce the photobleaching and photoreaction of fluorophore, while increasing the fluorescence intensity. For our research, we used a compound that is particularly sensitive to radiation: hypericin.

Various crossover phenomena are immanent to supercritical fluids due to multidirectional temperature effects in highly compressible supercritical fluid media. Solubility crossover, i.e. controversial effect of temperature on solubility at different pressures, is probably the most well-known among them. A curious discrepancy in upper crossover pressure values between solubility in supercritical carbon dioxide and retention in supercritical fluid chromatography with pure CO 2 as an eluent was unexpectedly observed for several non-polar compounds on different stationary phases. In some cases, retention crossover was found to happen at pressures almost twice as high as pressures for solubility crossover for the same compound. Retention data for three solutes with known solubility crossovers: anthracene, benzoic acid and vanillin, were collected at different pressures and temperatures for several stationary phases. The existence of upper retention crossovers, i.e. such pressure values beyond which temperature increase starts decreasing retention, were registered for all solute-sorbent combinations. Using known thermodynamic models of temperature effect on retention in supercritical fluid chromatography and on solubility in supercritical carbon dioxide, possible reasoning for the observed discrepancies is discussed. Major contribution of the balance between adsorption and partition retention mechanisms in defining retention crossover values is hypothesized., 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.)

In previous work, we reported on iridium(III) (Ir(III)) complex-peptide hybrids as amphiphilic conjugates (IPH-ACs) and triptycene-peptide hybrids as amphiphilic conjugates (TPH-ACs) and found that these hybrid compounds containing three cationic KK(K)GG peptide units through C 6 -C 8 alkyl linkers induce paraptosis II, which is one of the nonapoptotic programmed cell death (PCD) types in Jurkat cells and different from previously reported paraptosis. The details of that study revealed that the paraptosis II induced by IPH-ACs (and TPH-ACs) proceeds via a membrane fusion or tethering of the endoplasmic reticulum (ER) and mitochondria, and Ca 2+ transfer from the ER to mitochondria, which results in a loss of mitochondrial membrane potential ( ΔΨ m ) in Jurkat cells. However, the detailed mechanistic studies of paraptosis II have been conducted only in Jurkat cells. In the present work, we decided to conduct mechanistic studies of paraptosis II in HeLa-S3 and A549 cells as well as in Jurkat cells to study the general mechanism of paraptosis II. Simultaneously, we designed and synthesized new TPH-ACs functionalized with peptides that contain cyclohexylalanine, which had been reported to enhance the localization of peptides to mitochondria. We found that TPH-ACs containing cyclohexylalanine promote paraptosis II processes in Jurkat, HeLa-S3 and A549 cells. The results of the experiments using fluorescence Ca 2+ probes in mitochondria and cytosol, fluorescence staining agents of mitochondria and the ER, and inhibitors of paraptosis II suggest that TPH-ACs induce Ca 2+ increase in mitochondria and the membrane fusion between the ER and mitochondria almost simultaneously, suggesting that our previous hypothesis on the mechanism of paraptosis II should be revised.

Hepatocellular carcinoma (HCC) is a significant global health concern. However, there are limited effective treatments available for it. The use of natural products in the management and treatment of HCC is gaining more attention. Baicalein is a flavonoid compound that has been reported to have antitumor activities in HCC. However, the direct binding targets of baicalein are still unknown. Therefore, we used the DNA-programmed affinity labeling method to identify the target of baicalein and validated its function in HCC cells. We set blank and competitive DNA probes as negative controls. The results showed that baicalein had 136 binding targets, of which 13 targets were differently expressed in HCC tissues. The enriched cellular process of these targets was apoptosis, which involved MAPK9. We tested the binding affinity of baicalein with MAPK9 as 89.7 nM (Kd) by surface plasmon resonance and analyzed the binding sites by virtual docking. Notably, the binding of baicalein with MAPK9 increased the protein levels of MAPK9 itself and the related downstream apoptosis signaling, triggering the apoptosis of HCC cells. However, the inhibitor of MAPK9, SP600125, blocked the baicalein-induced apoptosis, and the amounts of MAPK9 and downstream molecules were also decreased, indicating that baicalein acted through MAPK9 to induce apoptosis of HCC cells. In conclusion, we used the DNA-programmed affinity labeling method to identify the direct-binding target MAPK9 of baicalein and validated its function in baicalein-induced apoptosis of HCC cells, which would be helpful to understand and use baicalein in HCC therapy., (© 2024 John Wiley & Sons Ltd.)

To solve the problems existing in the clinical application of hypericin (Hyp) and tirapazamine (TPZ), a nano-drug delivery system with synergistic anti-tumor functions was constructed using mesoporous silica nanoparticles (MSN) and sodium alginate (SA). The system exhibited excellent stability, physiological compatibility and targeted drug release performance in tumor tissues. In the in vitro and in vivo experiments, Hyp released from MSN killed tumor cells through photodynamic therapy (PDT). The degree of hypoxia in the tumor tissue site was exacerbated, enabling TPZ to fully exert its anti-tumor activity. Our studies suggested that the synergistic effects between the components of the nano-drug delivery system significantly improve the anti-tumor properties of Hyp and TPZ., 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.)

Stimuli-responsive supramolecular chemotherapy, particularly in response to cancer biomarkers, has emerged as a promising strategy to overcome the limitations associated with traditional chemotherapy. Spermine (SPM) is known to be overexpressed in certain cancers. In this study, we introduced a novel supramolecular chemotherapy system triggered by SPM. The system featured pyridine salts of a diphenylanthracene derivative (PyEn) and a complementary water-soluble pillar[5]arene (WP5C5) with long alkyl chains. The diphenylanthracene unit of PyEn is effectively encapsulated within the long alkyl chains of WP5C5, resulting in a substantial reduction in the cytotoxicity of PyEn towards normal cells. The therapeutic effect of PyEn is selectively triggered intracellularly through SPM, leading to the endosomal release of PyEn and concurrent in situ cytotoxicity. This supramolecular chemotherapy system exhibits notable tumor inhibition against SPM-overexpressed cancers with reduced side effects on normal tissues. The supramolecular strategy for intracellular activation provides a novel tool with potential applications in chemotherapeutic interventions, offering enhanced selectivity and reduced cytotoxicity to normal cells.

The lipopolyplex, a multicomponent nonviral gene carrier, generally demonstrates superior colloidal stability, reduced cytotoxicity, and high transfection efficiency. In this study, a new concept, photochemical reaction-induced transfection, using photosensitizer (PS)-loaded lipopolyplexes was applied, which led to enhanced transfection and cytotoxic effects by photoexcitation of the photosensitizer. Hypericin, a hydrophobic photosensitizer, was encapsulated in the lipid bilayer of liposomes. The preformed nanosized hypericin liposomes enclosed the linear polyethylenimine (lPEI)/pDNA polyplexes, resulting in the formation of hypericin lipopolyplexes (Hy-LPP). The diameters of Hy-LPP containing 50 nM hypericin and 0.25 μg of pDNA were 185.6 ± 7.74 nm and 230.2 ± 4.60 nm, respectively, measured by dynamic light scattering (DLS) and atomic force microscopy (AFM). Gel electrophoresis confirmed the encapsulation of hypericin and pDNA in lipopolyplexes. Furthermore, in vitro irradiation of intracellular Hy-LPP at radiant exposures of 200, 600, and 1000 mJ/cm 2 was evaluated. It demonstrated 60- to 75-fold higher in vitro luciferase expression than that in nonirradiated cells. The lactate dehydrogenase (LDH) assay supported that reduced transfection was a consequence of photocytotoxicity. The developed photosensitizer-loaded lipopolyplexes improved the transfection efficiency of an exogenous gene or induced photocytotoxicity; however, the frontier lies in the applied photochemical dose. The light-triggered photoexcitation of intracellular hypericin resulted in the generation of reactive oxygen species (ROS), leading to photoselective transfection in HepG2 cells. It was concluded that the two codelivered therapeutics resulted in enhanced transfection and a photodynamic effect by tuning the applied photochemical dose.

In biological systems, nucleosides play crucial roles in various physiological processes. In this study, we designed and synthesized four achiral anthracene-based tetracationic nanotubes (1-4) as artificial hosts and chiroptical sensors for nucleosides in aqueous media. Notably, different nanotubes exhibit varied chirality sensing on circular dichroism (CD)/circularly polarized luminescence (CPL) spectra through the host-guest complexation, which prompted us to explore the factors influencing their chiroptical responses. Through systematic host-guest experiments, the structure-chirality sensing relationship between achiral anthracene-based tetracationic nanotubes and nucleosides in the host-guest complexation was unraveled. Firstly, the CD response originates from the anthracene rings situated at the side-wall position, resulting from the right-handed (P)- or left-handed (M)-twisted conformation of the macrocyclic structure. Secondly, the CPL signal is influenced by the presence of anthracene rings at the linking-wall position, which results from intermolecular chiral twisted stacking between these anthracene rings. Therefore, these nanotubes can serve as chiroptical sensor arrays to enhance the accuracy of nucleotide recognition through principal component analysis (PCA) analysis based on the diversified CD spectra. This study provides insights for the construction of adaptive chirality from achiral nanotubes with dynamic conformational nature and might facilitate further design of chiral functional materials for several applications., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, a novel drug delivery system (MSN-PEG-Hypericin) was successfully fabricated using tetraethyl orthosilicate and 3-aminopropyltriethoxysilane as raw materials, and the PEGylation of the prepared aminated mesoporous silica and grafting of hypericin onto the carrier were further conducted to obtain MSN-PEG-Hypericin. The successful preparation of MSN-PEG-Hypericin was characterized by several physical-chemical techniques. Furthermore, the MSN-PEG-Hypericin system increased the ability of hypericin to generate reactive oxygen species (ROS) in vitro . The cytotoxicity assay and hemolysis analysis showed that MSN-PEG-Hypericin had good biocompatibility. For antibacterial studies, the irradiation time and incubation time of photodynamic therapy (PDT) for S. aureus and E. coli were respectively 8 min and 8 h, and the concentrations of hypericin were 2.5 and 5 μg/mL. The result of triphenyl tetrazolium chloride assay indicated that MSN-PEG-Hypericin had stronger photodynamic antibacterial activity than free hypericin, and S. aureus was more sensitive to PDT than E. coli , which was related to their cell structural differences. The antibacterial mechanism study indicated that the generated ROS could destroy the bacterial structures and cause bacterial death due to the leakage of the contents. The MSN-PEG-Hypericin system prepared in this study had potential application prospects in the antibacterial field.

Depression is a significant global health concern that remains inadequately treated due to the limited effectiveness of conventional drug therapies. One potential therapeutic agent, hypericin (HYP), is identified as an effective natural antidepressant. However, its poor water solubility, low bioavailability, and limited ability to penetrate the brain parenchyma have hindered its clinical application. To address these shortcomings and enhance the therapeutic efficacy of HYP, it is loaded onto black phosphorus nanosheets (BP) modified with the neural cell-targeting peptide RVG29 to synthesize a nanoplatform named BP-RVG29@HYP (BRH). This platform served as a nanocarrier for HYP and integrated the advantages of BP with advanced delivery methods and precise targeting strategies. Under the influence of 808 nm near-infrared irradiation (NIR), BRH effectively traversed an in vitro BBB model. In vivo experiments validated these findings, demonstrating that treatment with BRH significantly alleviated depressive-like behaviors and oxidative stress in mice. Importantly, BRH exhibited an excellent safety profile, causing minimal adverse effects, which highlighted its potential as a promising therapeutic agent. In brief, this novel nanocarrier holds great promise in the development of antidepressant drugs and can create new avenues for the treatment of depression., (© 2024 Wiley‐VCH GmbH.)

A fluorescent molecule, pyridine-coupled bis-anthracene (PBA), has been developed for the selective fluorescence turn-on detection of Cu 2+ . Interestingly, the ligand PBA also exhibited a red-shifted ratiometric fluorescence response in the presence of water. Thus, a ratiometric water sensor has been utilized as a selective fluorescence turn-on sensor for Cu 2+ , achieving a 10-fold enhancement in the fluorescence and quantum yield at 446 nm, with a lower detection limit of 0.358 μM and a binding constant of 1.3 × 10 6 M -1 . For practical applications, sensor PBA can be used to detect Cu 2+ in various types of soils like clay soil, field soil and sand. The interaction of the PBA-Cu(II) complex with transport proteins like bovine serum albumin (BSA) and ct-DNA has been investigated through fluorescence titration experiments. Additionally, the structural optimization of PBA and the PBA-Cu(II) complex has been demonstrated by DFT, and the interaction of the PBA-Cu(II) complex with BSA and ct-DNA has been analyzed using theoretical docking studies.

The effective measurement of temperature in living systems at the nano and microscopic scales continues to be a challenge to this day. Here, we study the use of 2-(anthracen-2-yl)-1,3-diisopropylguanidine, 1, as a nanothermometer based on fluorescence lifetime measurements and its bioimaging applications. In aqueous solution, 1 is shown in aggregated form and the equilibrium between the two main aggregate types (T-shaped and π-π) is highly sensitive to the temperature. The heating of the medium shifts the equilibrium toward the formation of highly emissive T-shaped aggregates. This species shows a high fluorescence emission and a long lifetime in comparison with the π-π aggregates and the freé monomer. A linear relationship between the fluorescence lifetime and the temperature both in aqueous solution and in a synthetic intracellular buffer was found. Fluorescence lifetime imaging microscopy (FLIM) also showed a linear relationship between lifetime and temperature with an excellent sensitivity in MCF7 breast cancer cells, which opens the door for its potential use as FLIM nanothermometer in the biomedical field., 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.)

Endogenous CO acts as an important messenger for signal transduction and therapeutic effect in the human body. Fluorescent imaging appears to be a promising method for endogenous CO recognition, but traditional luminescent probes based on Pd-complexes suffered from defects of high cost. In this work, four anthracene-derived dyes having an = N-N = group were synthesized for Cu 2+ -assisted CO sensing. Their molecular structure, photophysical performance and spectral response to Cu 2+ and CO were analyzed in detail. The optimal probe showed good selectivity and quenching effect to Cu 2+ , with PLQY (photoluminescence quantum yield) decreased from 0.33 to 0.04. The quenching mechanism was found as a static quenching mechanism by forming a non-fluorescent complex with Cu 2+ (stoichiometric ratio = 1:1), as revealed by single crystal, EPR (electron paramagnetic resonance), and XPS (X-ray photoelectron spectroscopy) analysis. Such quenching effect could be reversed by CO, showing recovered fluorescence, with PLQY recovered to 0.32 within 328 s. Discussion on cellular endogenous CO imaging was included as well., 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.)

Laccases (EC 1.10.3.2) are multicopper oxidases with the capability to oxidize diverse phenolic and non-phenolic substrates. While the molecular mechanism of their activity towards phenolic substrates is well-established, their reactivity towards non-phenolic substrates, such as polycyclic aromatic hydrocarbons (PAHs), remains unclear. To elucidate the oxidation mechanism of PAHs, particularly the activation mechanism of the sp 2 aromatic C-H bond, we conducted a density functional theory investigation on the oxidation of two PAHs (anthracene and benzo[ a ]pyrene) using an extensive model of the T1 copper catalytic site of the fungal laccase from Trametes versicolor .

Anthracene carboximides (ACIs) conjugated with gluco-, galacto- and mannopyranosides are synthesized, by glycosylation of N-hydroxyethylanthracene carboximide acceptor with glycosyl donors. Glycoconjugation of anthracene carboximide increases the aq. solubility by more than 3-fold. The glycoconjugates display red-shifted absorption and emission, as compared to anthracene. Large Stokes shift (λ abs /λ em =445/525 nm) and high fluorescence quantum yields (Φ) of 0.86 and 0.5 occur in THF and water, respectively. The ACI-glycosides undergo facile photodimerization in aqueous solutions, leading to the formation of the head-to-tail dimer, as a mixture of syn and anti-isomers. Solution phase and solid-state characterizations by dynamic light scattering (DLS), microscopic imaging by atomic force (AFM) and transmission electron (TEM) microscopies reveal self-assembled vesicle structures of ACI glycosides. These self-assembled structures act as multivalent glycoclusters for ligand-specific lectin binding, as evidenced by the binding of Man-ACI to Con A, by fluorescence and turbidity assays. The conjugates do not show cellular cytotoxicity (IC 50 ) till concentrations of 50 μM with HeLa and HepG2 cell lines and are cell-permeable, showing strong fluorescence inside the cells. These properties enable the glycoconjugates to be used in cell imaging. The non-selective cellular uptake of the glycoconjugates suggests a passive diffusion through the membrane., (© 2024 Wiley-VCH GmbH.)

The oncogenic and genetic properties of anthracene, a member of the polycyclic aromatic hydrocarbons (PAHs) family, pose a significant health threat to humans. This study aims to investigate the photocatalytic decomposition of anthracene under various conditions, such as different concentrations of PAHs, varying amounts of NiO (nickel oxide) nanoparticles, and different pH levels under ultraviolet light and sunlight. The synthesized NiO nanoparticles showed surface plasma resonance at 230 and 360 nm, while XRD and SEM analysis confirmed the nanoparticles were cubic crystalline in structure with sizes ranging between 37 and 126 nm. NiO nanoparticles exhibited 79% degradation of pyrene at 2 μg/mL of anthracene within 60 min of treatment. NiO at 10 μg/mL concentration showed significant adsorption of 57%, while the adsorption method worked efficiently (72%) at 5 pH. Photocatalytic degradation was confirmed by isotherm and kinetic studies through monolayer adsorption and pseudo-first-order kinetics. Further, the absorption process was confirmed by performing GC-MS analysis of the NiO nanoparticles. On the other hand, NiO nanoparticles showed antimicrobial activity against Gram negative and Gram-positive bacteria. Therefore, the present work is one of its kind proving the dual application of NiO nanoparticles, which makes them suitable candidates for bioremediation by treating PAHs and killing pathogenic bacteria., 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.)

The collapse or folding of an individual polymer chain into a nanoscale particle gives rise to single-chain nanoparticles (SCNPs), which share a soft nature with biological protein particles. The precise control of their properties, including morphology, internal structure, size, and deformability, are a long-standing and challenging pursuit. Herein, a new strategy based on amphiphilic alternating copolymers for producing SCNPs with ultrasmall size and uniform structure is presented. SCNPs are obtained by folding the designed alternating copolymer in N,N-dimethylformamide (DMF) and fixing it through a photocatalyzed cycloaddition reaction of anthracene units. Molecular dynamics simulation confirms the solvophilic outer corona and solvophobic inner core structure of SCNPs. Furthermore, by adjusting the length of PEG units, precise control over the mean size of SCNPs is achieved within the range of 2.8 to 3.9 nm. These findings highlight a new synthetic strategy that enables enhanced control over morphology and internal structure while achieving ultrasmall and uniform size for SCNPs., (© 2024 Wiley‐VCH GmbH.)

Anthracene, a polycyclic aromatic hydrocarbon (PAH), is a widespread environmental pollutant that poses potential risks to human health. Exposure to anthracene can result in various adverse health effects, including skin-related disorders. Photo exposure sufficiently removes the anthracene from the environment but also generates more degradation products which can be more toxic. The goal of this study was to assess the change in anthracene dermotoxicity caused by photodegradation and understand the mechanism of this change. In the present study, over 99.99% of anthracene was degraded within 24 h of sunlight exposure, while producing many intermediate products including 9,10-anthraquinone and phthalic acid. The anthracene products with different durations of photo exposure were applied to 2D and 3D human keratinocyte cultures. Although the non-degraded anthracene significantly delayed the cell migration, the cell viability and differentiation decreased dramatically in the presence of the photodegraded anthracene. Anthracene photodegradation products also altered the expression patterns of a number of inflammation-related genes in comparison to the control cells. Among these genes, il1a, il1b, il8, cxcl2, s100a9, and mmp1 were upregulated whereas the tlr4 and mmp3 were downregulated by the photodegraded anthracene. Topical deliveries of the photodegraded and non-degraded anthracene to the dorsal skin of hairless mice showed more toxic effects by the photodegraded anthracene. The 4-hour photodegradation products of anthracene thickened the epidermal layer, increased the dermal cellularity, and induced the upregulation of inflammatory markers, il1a, il1b, s100a9, and mmp1. In addition, it also prevented the production of a gap junction protein, Connexin-43. All the evidence suggested that photodegradation enhanced the toxicities of anthracene to the skin. The 4-hour photodegradation products of anthracene led to clinical signs similar to acute inflammatory skin diseases, such as atopic and contact dermatitis, eczema, and psoriasis. Therefore, the potential risk of skin irritation by anthracene should be also considered when an individual is exposed to PAHs, especially in environments with strong sunlight., 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.)

The problem of plastic waste in the environment calls for the development of new polymeric materials designed specifically for easy recycling at the end of their life cycle. Herein, a green polymer system comprising a series of necklace-shaped polydimethylsiloxanes bearing anthracene dimer units is developed. The polymers have low environmental impact and are easily recycled. Further, their flexibility and glass transition temperatures are easy to control. These necklace-shaped inorganic polymers are synthesized by photopolymerizing (dimerizing) anthracene-terminated oligo-dimethylsiloxane monomers. A key achievement of the present work is the successful chemical recovery of the monomers from the polymers through thermal depolymerization, enabling monomer-polymer recycling. By applying equilibrium polymerization with base catalysts, monomers with a controlled distributed chain length are synthesized from monomers with a constant chain length. The necklace-shaped polymers synthesized from these randomized monomers have amorphous structures and readily form transparent films. It is possible to modulate the thermal and mechanical properties of the polymers by controlling the average chain length of the polydimethylsiloxane between the anthracene dimers. This investigation presents a method for the synthesis and cyclic utilization of polymer materials with a wide range of applications, including plastics and elastomers., (© 2024 Wiley‐VCH GmbH.)

Phthalocyanine and hypericin have been previously identified as possible SARS-CoV-2 Spike glycoprotein fusion inhibitors through a virtual screening procedure. In this paper, atomistic simulations of metal-free phthalocyanines and atomistic and coarse-grained simulations of hypericins, placed around a complete model of the Spike embedded in a viral membrane, allowed to further explore their multi-target inhibitory potential, uncovering their binding to key protein functional regions and their propensity to insert in the membrane. Following computational results, pre-treatment of a pseudovirus expressing the SARS-CoV-2 Spike protein with low compounds concentrations resulted in a strong inhibition of its entry into cells, suggesting the activity of these molecules should involve the direct targeting of the viral envelope surface. The combination of computational and in vitro results hence supports the role of hypericin and phthalocyanine as promising SARS-CoV-2 entry inhibitors, further endorsed by literature reporting the efficacy of these compounds in inhibiting SARS-CoV-2 activity and in treating hospitalized COVID-19 patients.Communicated by Ramaswamy H. Sarma.

The aggregation of α-Syn is a pivotal mechanism in Parkinson's disease (PD). Effectively maintaining α-Syn proteostasis involves both inhibiting its aggregation and promoting disaggregation. In this study, we developed a series of aromatic amide derivatives based on Rhein. Two of these compounds, 4,5-dihydroxy-N-(3-hydroxyphenyl)-9,10-dioxo-9,10-dihydroanthracene-2-carboxamide (a5) and 4,5-dihydroxy-N-(2-hydroxy-4-chlorophenyl)-9,10-dioxo-9,10-dihydroanthracene-2-carboxamide (a8), exhibited good binding affinities to α-Syn residues, demonstrating promising inhibitory activity against α-Syn aggregation in vitro, with low IC 50 values (1.35 and 1.08 μM, respectivly). These inhibitors acted throughout the entire aggregation process by stabilizing α-Syn's conformation and preventing the formation of β-sheet aggregates. They also effectively disassembled preformed α-Syn oligomers and fibrils. Preliminary mechanistic insights indicated that they bound to the specific domain within fibrils, inducing fibril instability, collapse, and the formation of smaller aggregates and monomeric α-Syn units. This research underscores the therapeutic potential of Rhein's aromatic amides in targeting α-Syn aggregation for PD treatment and suggests broader applications in managing and preventing neurodegenerative diseases., 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.)

In this study, 9-aminoanthracene (9AA) was used as a new fluorescence reagent for the in vivo imaging of tumor hypoxia by taking advantage of the maintenance of its green fluorescence under hypoxic conditions. As 9AA is insoluble in water, polyethylene glycol (PEG)-400 was used to dissolve 9AA in saline. Each organ was successfully stained with 9AA, as observed by green fluorescence using in vivo imaging, following intragastric administration of a 9AA PEG-saline solution in mice. Therefore, the intragastric administration of 9AA can be used for in vivo imaging of normal mice. Tumor hypoxia staining using the 9AA fluorescence method was evaluated by in vivo imaging of mice subcutaneously transplanted with Ehrlich ascites carcinoma cells and compared with conventional pimonidazole (PIMO) staining under hypoxic conditions. The tumor sections were stained with green fluorescence derived from 9AA and the same sections corresponded to hypoxic areas upon immunohistochemical staining with PIMO., 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.)

Unraveling the causes underlying polycyclic aromatic hydrocarbon phototoxicity is an essential step in understanding the harmful effects of these compounds in nature. Toward this end, we have studied the DNA interactions and photochemistry of N 1 -(anthracen-9-ylmethyl)ethane-1,2-diaminium dichloride in the presence and absence of NaF, KF, NaCl, KCl, NaBr, KBr, NaI, and KI (350 nm hν, pH 7.0). Exposing pUC19 plasmid to UV light in solutions containing 400 mM KCl formed significantly more direct strand breaks in DNA compared to no-salt control reactions. In contrast, NaCl increased DNA damage moderately, while the sodium(I) and potassium(I) fluoride, bromide, and iodide salts generally inhibited cleavage (I - > Br - > F - ). A halide anion-induced heavy-atom effect was indicated by monitoring anthracene photodegradation and by employing the hydroxyl radical ( • OH) probe hydroxyphenyl fluorescein (HPF). These studies revealed that among no-salt controls and the eight halide salts, only NaCl and KCl enabled the anthracene to photosensitize the production of high levels of DNA-damaging reactive oxygen species (ROS). Pre-irradiation of N 1 -(anthracen-9-ylmethyl)ethane-1,2-diaminium dichloride at 350 nm increased the amounts of chloride salt-induced • OH detected by HPF in subsequent anthracene photoactivation experiments. Taking into consideration that • OH and other highly reactive ROS are extremely short-lived, this result suggests that the pre-irradiation step might lead to the formation of oxidized anthracene photoproducts that are exceedingly redox-active. The fluorometric probes HPF and Singlet Oxygen Sensor Green revealed that KCl concentrations ranging from 150 to 400 mM and from 100 to 400 mM, respectively, enhanced N 1 -(anthracen-9-ylmethyl)ethane-1,2-diaminium dichloride photosensitized • OH and singlet oxygen ( 1 O 2 ) production over no-salt controls. Considering the relatively high levels of Na + , K + , and Cl - ions that exist in the environment and in living organisms, our findings may be relevant to the phototoxic effects exhibited by anthracenes and other polycyclic hydrocarbons in vivo .

Two novel anthracene derivatives were synthesized, and detailed photo-physical and biological investigations were carried out using a variety of spectroscopy techniques. The effect of cyano (-CN) substitution was found to be effective to alter the charge population and frontier orbital energy levels via Density Functional Theory (DFT) calculations. Particularly, the introduction of styryl and triphenylamine groups attached to the anthracene core helped to increase the conjugation relative to the anthracene moiety. The results revealed that the molecules have intramolecular charge transfer (ICT) properties, occurring from the electron donating triphenylamine to the electron accepting anthracene moiety in solutions. In addition, the photo-physical properties are strongly cyano-dependent, where the cyano-substituted ( E / Z )-(2-anthracen-9-yl)-3-(4'-(diphenylamino)biphenyl-4yl)acrylonitrile molecule showed stronger electron affinity due to the enhanced internal steric hindrance compared to the ( E )-4'-(2-(anthracen-9-yl)vinyl)- N , N -diphenylbiphenyl-4-amine molecule, which resulted in a lower photoluminescence quantum yield (PLQY) value and a shorter lifetime in the molecule. Besides, the Molecular Docking approach was used to investigate possible cellular staining targets to confirm cellular imaging potential of the compounds. Moreover, cell viability analyses put forth that synthesized molecules do not exhibit significant cytotoxicity under 125 μg mL -1 concentration on the human dermal fibroblast cell line (HDFa). Moreover, both of the compounds showed great potential in cellular imaging of HDFa cells. Compared to Hoechst 33258, a common fluorescent dye used for nuclear staining, the compounds showed higher magnification of cellular structure imaging capacity by staining the whole cellular compartment. On the other hand, bacterial staining showed that ethidium bromide has higher resolution in monitoring Staphylococcus aureus ( S. aureus ) cell culture.

Barbaloin (10-glucopyranosyl-1,8-dihydroxy-3-(hydroxymethyl)-9(10H)-anthraquinone: aloin A), present in Aloe species, is widely used in food, cosmetic and pharmaceutical industries. Here we characterize its optical absorption and emission spectra in aqueous solution at different pH values. Through pH titration, using both absorption and fluorescence spectroscopy, two pK a values for Barbaloin were determined: pK a1 =9.6±0.6 and pK a2 =12.6±0.8. These acidity constants were found to be higher than those found for Emodin, a similar molecule which lacks the sugar moiety present in Barbaloin. Performing quantum mechanical calculations for non-ionized, singly, doubly, and triply deprotonated forms of Barbaloin in vacuum and in water, we assigned the positions of the site for the first and third deprotonation in the anthraquinone group, and the second deprotonation in the glucose group. The instability of Barbaloin in high pH solutions is discussed here, and the optical absorption and fluorescence spectra due to products resulted from Barbaloin degradation at high pH is well separated from the Barbaloin original spectra. Biological fluids have specific pH values to maintain homeostasis, hence determining the pK a of Barbaloin is important to evaluate the mechanism of action of this drug in different parts of an organism as well as to predict pharmacological relevant parameters, such as absorption, distribution, metabolism, and excretion., 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., (Published by Elsevier B.V.)

1,8-dihydroxy-9-anthrone are tricyclic compounds with a ketone group in the middle ring and two hydroxyl groups substituted in the side-aromatic rings what results in formation of two intramolecular hydrogen bonds in which the oxygen atom from the ketone group is the proton acceptor. 1,8-dihydroxy-9-anthrones in which intramolecular proton transfer between C10 and CO in the middle ring occurs, can exist in a tautomeric keto-enol equilibrium. For anthralin, the most important representative of this group, this equilibrium has been studied previously, but it has not been studied for its derivatives. Substituents in the middle ring change the geometry of 1,8-dihydroxy-9-anthrones so they are also expected to affect the keto-enol equilibrium. It is also important to study the effect of intramolecular hydrogen bonds on the structure of both tautomeric forms. It was found that the nature of the substituent in the middle ring could affect the antioxidant properties of the investigated compound.

Motion-induced change in emission (MICE) is a phenomenon that can be employed to develop various types of probes, including temperature and viscosity sensors. Although MICE, arising from the conformational motion in particular compounds, has been studied extensively, this phenomenon has not been investigated in depth in mechanically interlocked molecules (MIMs) undergoing coconformational changes. Herein, we report the investigation of a thermoresponsive dynamic homo[2]catenane incorporating pyrene units and displaying relative circumrotational motions of its cyclophanes as evidenced by variable-temperature 1 H NMR spectroscopy and supported by its visualization through molecular dynamics simulations and quantum mechanics calculations. The relative coconformational motions induce a significant change in the fluorescence emission of the homo[2]catenane upon changes in temperature compared with its component cyclophanes. This variation in the exciplex emission of the homo[2]catenane is reversible as demonstrated by four complete cooling and heating cycles. This research opens up possibilities of using the coconformational changes in MIMs-based chromophores for probing fluctuations in temperature which could lead to applications in biomedicine or materials science.

The photocyclodimerization of 2-anthracenecarboxylic acid has been extensively studied as a model reaction of asymmetric photochemistry. So far, numerous chiral environments have been employed to control this photoreaction, while the scope of photoreactants has been limited only to 2-anthracenecarboxylic acid and its simple esters and amides. Here, we developed a systematic series of photoreactants (2 a-d) by introducing various substituents to 2-anthracenecarboxylic acid, which showed different reactivities and selectivities depending on the substituents. By using the photoreactants 2 a-d, we evaluated the performance of a chiral environment composed of an amphiphilic amino alcohol (1), where the photocyclodimerization of 2 a-d generally proceeded in excellent regio- and enantioselectivities (71-98 % regio ratio, 76-86 % ee). Furthermore, by reacting 2 a and 2 b together in the chiral environment of 1, we succeeded in the first stereocontrolled cross-photocyclodimerization between two prochiral anthracenes (58 % chemo ratio, 83 % regio ratio, 90 % ee)., (© 2022 Wiley-VCH GmbH.)

Molecular oxygen (O 2 ) remains to be an ideal yet underutilized feedstock for the oxidative transformation of organic substrates and renewable energy systems such as fuel cells. Palladium (Pd) has shown particular promise in enabling these applications. The present study describes a Pd-mediated O 2 reduction to water via C-H activation of 9,10-dihydroanthracene (DHA) by a Pd(II) η 2 -peroxo complex 1O 2 . The reaction yields stoichiometric anthracene and Pd(0) product 1 and is notable in two respects. First, plots of concentrations of the reaction participants over time have distinctly sigmoidal shapes, indicating that conversion accelerates over time and implying autocatalysis. Second, the reaction proceeds via a genuine monometallic Pd(II) dihydroxide 1(OH) 2 directly observed to grow and decay as an intermediate. Confirming its role as an intermediate, the dihydroxide 1(OH) 2 was found to mediate C-H oxidation of DHA on par in activity with the peroxo compound 1O 2 . Mechanistic studies with density functional theory (DFT) calculations suggested that both 1O 2 and 1(OH) 2 react with DHA by hydrogen atom transfer (HAT) and that autocatalysis in the 1O 2 reaction results from oxidative addition of the initial Pd(II) complex 1O 2 to the Pd(0) product 1 . This reaction forms a transient bis(μ-oxo) Pd(II) dimer 1O 2 1 that is more active in the HAT oxidation of DHA than the initial 1O 2 .

Ethnopharmacological Relevance: Polygonum multiflorum Thunb. (PM) is a common traditional Chinese medicine with diverse biological activities of resolving toxins, nourishing livers and promoting hairs. Nevertheless, in recent years hepatotoxic adverse reactions caused by the administration of PM have raised worldwide concerns. In our previous study, we found that emodin dianthrones showed hepatotoxicity and may be potential toxicity markers. However, the metabolic transformation and pharmacokinetic behavior of emodin dianthrones in vivo have still not been elucidated., Aim of the Study: Taking trans-emodin dianthrones (TED) as an example, the present study was conducted to investigate the pharmacokinetics and bioavailability of TED in rats and characterized its metabolic transformation in the plasma, urine and feces of rats., Materials and Methods: A rapid and sensitive UPLC-qqq-MS/MS method was developed for accurate quantification of TED in plasma and successfully applied to the pharmacokinetic evaluation of TED in rats after intravenous and oral administration. A reliable UFLC-Q-TOF-MS high resolution mass spectrometry combined with a scientific metabolite identification strategy was used to comprehensively characterize the metabolic transformation of TED in plasma, urine and feces in rats., Results: The established UPLC-qqq-MS/MS method had a linear range of 1-500 ng/mL, and the method was accurate and reliable to meet the quantitative requirements. When 20 mg/kg TED was given by gavage rats, it was rapidly absorbed into the circulatory system and had a long half-life time of 6.44 h and wide tissue distribution in vivo. While intravenous injection of 0.4 mg/kg TED in rats, it was rapidly metabolized and eliminated with a half-life time of 1.82 h. The oral absorption bioavailability of TED was only 2.83%. Furthermore with a sensitive UFLC-Q-TOF-MS technique and metabolite identification strategy, 21 metabolites were successfully identified, including 11 in plasma, 12 in urine and 18 in feces. The main Ⅰ and Ⅱ phase metabolic processes involved glucuronidation, oxidation, carbonylation, (de)methylation, sulfation and hydrogenation., Conclusion: TED could be rapidly absorbed into the blood circulation and widely distributed and slowly metabolized in the body and underwent extensive cleavage and metabolic transformation in vivo. The study provided a basis for in-depth elucidation of the toxicology and mechanism research of TED, but also laid the foundation for further research on the material basis of hepatotoxicity of PM., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Anthracene crude oil is a common source of phenanthrene for its industrial use. The isolation of phenanthrene from this source is a challenging task due to very similar physical properties to its isomer anthracene. We report here a water-soluble Pd(II) molecular boat ( MB1 ) with unusual structural topology that was obtained by assembling a flexible tetrapyridyl donor ( L ) with a cis -Pd(II) acceptor. The flexible backbone of the boat enabled it to breathe in the presence of a guest optimizing the fit within the cavity. The boat binds phenanthrene more strongly than anthracene, which enabled separation of phenanthrene with an >98% purity from an equimolar mixture of the two isomers using MB1 as an extracting agent. MB1 represents a unique example of a coordination receptor suitable for selective aqueous extraction of phenanthrene from anthracene with reusability of several cycles.

We identified the anti-Mullerian hormone (also known as Müllerian inhibiting substance or MIS) as an inhibitory hormone that induces long-term contraception in mammals. The type II receptor to this hormone, AMHR2 (also known as MISR2), represents a promising druggable target for the modulation of female reproduction with a mechanism of action distinct from steroidal contraceptives. We designed an in vitro platform to screen and validate small molecules that can activate MISR2 signaling and suppress ovarian folliculogenesis. Using a bone morphogenesis protein (BMP)–response element luciferase reporter cell–based assay, we screened 5,440 compounds from a repurposed drug library. Positive hits in this screen were tested for specificity and potency in luciferase dose–response assays, and biological activity was tested in ex vivo Mullerian duct regression bioassays. Selected candidates were further evaluated in ex vivo follicle/ovary culture assays and in vivo in mice and rats. Here, we report that SP600125, CYC-116, gandotinib, and ruxolitinib can specifically inhibit primordial follicle activation and repress folliculogenesis by stimulating the MISR2 pathway.

Members of the aldo-keto reductase and short-chain dehydrogenase/reductase enzyme superfamilies catalyze the conversion of a wide range of substrates, including carbohydrates, lipids, and steroids. These enzymes also participate in the transformation of xenobiotics, inactivation of the cytostatics doxo- and daunorubicin, and play a role in the development of cancer. Therefore, inhibitors of such enzymes may improve therapeutic outcomes. Plant-derived compounds such as anthraquinones have been used for medicinal purposes for several centuries. In the current study, the inhibitory potential of selected anthrone and anthraquinone derivatives (from plants) was tested on six recombinant human carbonyl reducing enzymes (AKR1B1, AKR1B10, AKR1C3, AKR7A2, AKR7A3, CBR1) isolated from an Escherichia coli expression system. Overall, the least inhibition was observed with the anthrone derivative aloin, while IC 50 values obtained with the anthraquinone derivatives (frangula emodin, aloe emodin, frangulin A, and frangulin B) and the aldo-keto reductase AKR1B10 were in the low micromolar range (3.5-16.6 μM). AKR1B1 inhibition was significantly weaker in comparison with AKR1B10 inhibition (IC 50 values > 50 μM). The strongest inhibition was observed with the short-chain dehydrogenase/reductase CBR1. AKR7A2, AKR7A3, and AKR1C3 were not, or less inhibited by inhibitor concentrations of up to 50 μM. Analysis of the kinetic data suggests noncompetitive or uncompetitive inhibition mechanisms. The new inhibitors described here may serve as lead structures for the development of future drugs., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Medicinal phytochemicals, such as artemisinin and taxol, have impacted the world, and hypericin might do so if its availability issue could be addressed. Hypericin is the hallmark component of Saint John's wort (Hypericum perforatum L.), an approved depression alleviator documented in the US, European, and British pharmacopoeias with its additional effectiveness against diverse cancers and viruses. However, the academia-to-industry transition of hypericin remain hampered by its low in planta abundance, unfeasible bulk chemical synthesis, and unclear biosynthetic mechanism. Here, we present a strategy consisting of the hypericin-structure-centered modification and reorganization of microbial biosynthetic steps in the repurposed cells that have been tamed to enable the designed consecutive reactions to afford hypericin (43.1 mg L -1 ), without acquiring its biosynthetic knowledge in native plants. The study provides a synthetic biology route to hypericin and establishes a platform for biosustainable access to medicinal phytochemicals., (© 2021 Wiley-VCH GmbH.)

Supramolecular structures, such as micelles, liposomes, polymerosomes or dendrimerosomes, are widely studied and used as drug delivery systems. The behavior of amphiphilic building blocks strongly depends on their spatial distribution and shape of polar and nonpolar component. This report is focused on the development of new versatile synthetic protocols for amphiphilic carbosilane dendrons (amp-CS-DDNs) capable of self-assembly to regular micelles and other supramolecular objects. The presented strategy enables the fine modification of amphiphilic structure in several ways and also enables the facile connection of a desired functionality. DLS experiments demonstrated correlations between structural parameters of amp-CS-DDNs and the size of formed nanoparticles. For detailed information about the organization and spatial distribution of amp-CS-DDNs assemblies, computer simulation models were studied by using molecular dynamics in explicit water.

Ethnopharmacological Relevance: Hypericum perforatum L. is a traditional Chinese medicine used to sooth the liver, relieve depression, reduce body temperature, reduce sweating, and stimulate lactation. HP was extracted from Hypericum perforatum L., Aim of Study: The antifatigue effects of hypericin were assessed in a series of experiments., Materials and Methods: Six-to eight-week-old male ICR mice were raised in our lab. Mice were subjected to swimming training for 2 h, 6 days/week for 6 weeks. One hour prior to each swimming session, intraperitoneal injection of saline or HP (2 or 4 mg/kg) was performed., Results: Compared with the fatigue model control group, HP was found to significantly increase the swimming time in forced swimming tests. The molecular mechanisms underlying the antifatigue effects were further revealed by analysing energy metabolism, the oxidant-antioxidant system and the inflammatory response. HP normalized changes in BLA, LDH, BUN, and CK, LG in the liver. In addition, multiple assays have confirmed that HP improved the MDA, T-AOC, GSH-PX and SOD activity, and the relevant signalling pathways involved in the antifatigue effects were clarified. Furthermore, HP improves the expression of pro- and anti-inflammatory cytokines in skeletal muscle., Conclusion: These results suggested that the anti-chronic fatigue effects of HP are likely achieved by normalizing energy metabolism and attenuating oxidative and inflammatory responses. Consequently, this study supports HP use in the clinic to alleviate chronic fatigue., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Hypericin tautomerization that involves the migration of the labile protons is believed to be the primary photophysical process relevant to its light-activated antiviral activity. Despite the difficulty in isolating individual tautomers, it can be directly observed in single-molecule experiments. We show that the tautomerization of single hypericin molecules in free space is observed as an abrupt flipping of the image pattern accompanied with fluorescence intensity fluctuations, which are not correlated with lifetime changes. Moreover, the study can be extended to a λ/2 Fabry-Pérot microcavity. The modification of the local photonic environment by a microcavity is well simulated with a theoretical model that shows good agreement with the experimental data. Inside a microcavity, the excited state lifetime and fluorescence intensity of single hypericin molecules are correlated, and a distinct jump of the lifetime and fluorescence intensity reveals the temporal behavior of the tautomerization with high sensitivity and high temporal resolution. The observed changes are also consistent with time-dependent density functional theory calculations. Our approach paves the way to monitor and even control reactions for a wider range of molecules at the single molecule level.

In contrast to monotopic receptor 3 , the anthracene functionalized squaramide dual-host receptor 1 is capable of selectively extracting sulfate salts, as was evidenced unambiguously by DOSY, mass spectrometry, fluorescent and ion chromatography measurements. The receptors were investigated in terms of anion and ion pair binding using the UV-vis and 1 H NMR titrations method in acetonitrile. The reference anion receptor 3 , lacking a crown ether unit, was found to lose the enhancement in anion binding induced by the presence of cations. Besides the ability to bind anions in an enhanced manner exhibited by ion pair receptors 2 and 4 , changing the 1-aminoanthracene substituent resulted in their exhibiting a lower anion affinity than receptor 1 . By using receptor 1 and adjusting the water content in organic phase it was possible to selectively detect sulfates both by "turn-off" and "turn-on" fluorescence, and to do so homogenously and under interfacial conditions. Such properties of receptor 1 have allowed the development of a new type of sensor capable of recognizing and extracting potassium sulfate from the aqueous medium across a phase boundary, resulting in an appropriate fluorescent response in the organic solution.

Targeting and monitoring the dynamics of mitochondria are of great significance because mitochondria are involved in a variety of physiological and pathological processes. For achieving this purpose, highly sensitive, photostable, tolerance and specific fluorescent probe is necessary. To obtain a superior mitochondrial fluorescent probe, (4-distyreneanthracenoxybutyl) bis(triphenylphosphonium) bromide (DSA-TPP) with aggregation-induced emission (AIE) characteristic was designed and synthesized for mitochondrial targeting. DSA-TPP dots with high fluorescence quantum yield (Φ = 17.9) and small particle size (8 nm) can be easily prepared by self-assembly formation. DSA-TPP dots had the ability of lightning mitochondria in living cells with high brightness, superior photostability and strong tolerance to cell environment change., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Selective molecular recognition in water is the foundation of numerous biological functions but is a challenge for most synthetic hosts. We employ the concept of endo-functionalized cavity and the strategy of simultaneous construction to address this issue. The concept and the strategy were demonstrated in the construction of a biomimetic host for selectively recognizing quinones in water. The host was synthesized by joining two pieces of bent anthracene dimer through amide bond formation, affording a deep hydrophobic cavity and inward-directing hydrogen bonding sites. The host can recognize quinones over their close analogues in water, and its association affinity to p-benzoquinone is the highest among all the known hosts and is even comparable to that of the bioreceptor. The binding with an anthraquinone reaches nanomolar affinity. Shielded hydrogen bonding, C-H⋅⋅⋅π, and charge transfer interactions, and the hydrophobic effect are responsible for the high binding affinity and selectivity., (© 2021 Wiley-VCH GmbH.)

A chemical sensor that can induce near-infrared red-shifted response represents a promising strategy for the design and development of anion probes. In this work, novel CH-controlled colorimetric probe 3 based on anthracene carboximide was developed for near-infrared detection of cyanide. Probe 3 consisted of CHCN binding site to anthracene carboximide fluorophore, and showed a significant visual change from yellow-green (535 nm) to deep violet (825 nm) with a larger redshift (≈ 290 nm) and fluorescence quenching at 480 nm and 520 nm upon interacting with cyanide. Job curves determined 1:1 binding stoichiometry of probe 3 with cyanide. Additonally, probe 3 detected cyanide ion conveniently in aqueous solution and could be reused after trifluoroacetic acid treatment. Colorimetric test paper was used to detect cyanide in aqueous solutions. The C-H deprotonation sensing mechanism was confirmed by 1 H NMR titration. The near-infrared detection of cyanide by CH-controlled probes was founded for the first time., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Several sulfoxide- and sulfone-bridged β-cyclodextrin (CD) dimers were synthesized for mediating the enantiodifferentiating [4+4] photocyclodimerization of 2-anthracenecarboxylic acid (AC). The complexation behavior of these chiral hosts with AC was investigated by UV-vis, circular dichroism, fluorescence, and NMR spectroscopies and certified the formation of 1 : 1 and 1 : 2 host-guest complexes. The product distribution and enantioselectivity of the photoreaction turned out to be a critical function of the chemical structure of bridged CDs. Comparing to the sulfur-bridged 2A X -3G X β-CD dimer 7, the conversion of the photolyzes with sulfoxide-bridged was significantly improved, and the ee of cyclodimer 2 was remarkably increased from -82.8% with 7 to -96.7% with the sulfoxide-bridged 2A X -3G X β-CD dimer 8. The relative yields and ee values of the slipped cyclodimers 5 and 6 were greatly enhanced in the presence of 6 M CsCl. The reaction selectivity is susceptible to the pH variation of the aqueous buffer solution, demonstrating that the supramolecular photochirogenesis is controlled by multidimensional factors, including the chemical structure of the chiral host, solvent, and pH conditions., (© 2021 Wiley-VCH GmbH.)

Triplet-triplet annihilation (TTA) upconversion has shown promising potentials in the augmentation of solar energy conversion. However, challenging issues exist in improving TTA upconversion efficiencies in solid-states, one of which is the back energy transfer from upconverted singlet annihilators to sensitizers, resulting in decreasing upconversion emission. Here we present a light-harvesting molecular wire consisting of dendrons with 9,10-diphenylanthracene derivatives (DPAEH) at the periphery and p -phenylene ethynylene oligomers (PPE) as the wire core. The peripheral DPAEH antenna funnels singlet excitonic energy to the wire on a 12 ps time scale. Incorporating the molecular wire into the TTA upconversion solid consisting of the DPAEH annihilator and the porphyrin sensitizer evidently improves the upconversion quantum yield from 1.5% to 2.7% upon 532 nm excitation by suppressing the back energy transfer from the singlet annihilator to the sensitizer. This finding offers a potential route to use a singlet energy light-harvesting architecture for enhancing TTA upconversion.

Hypericin (Hy) is a hydrophobic photosensitizer used in photodynamic therapy for cancer therapeutic. In this study, Hy-loaded oil-in-water (O/W) nanoemulsions (NEs) were produced by the ultrasonication method combing different biocompatible oils and surfactants to enhance Hy aqueous solubility and bioavailability. Experimental parameters were optimized by the characterization of droplet size, zeta potential, and physicochemical properties. In vitro studies based on the release profile, cytotoxicity, cell morphology, and Hy intracellular accumulation were assayed. Hy at 100 mg L -1 was incorporated into the low viscosity (~0.005 Pa s) NEs with spherical droplets averaging 20-40 nm in size and polydispersity index <0.02. Hy release from the NE was significantly higher (4-fold) than its suspension (p < 0.001). The NEs demonstrated good physical stability during storage at 5 °C for at least six months. The Hy-loaded NEs exhibited an IC50 value 6-fold lower than Hy suspension during PDT against breast cancer cell lines (MCF-7). Cell microscopy imaging confirmed the increased cytotoxic effects of Hy-loaded NEs, showing damaged and apoptotic cells. Confocal laser scanning microscopy evidenced greater Hy delivery through NE into MCF-7 cells followed by improved intracellular ROS generation. Our results suggest that the Hy-loaded NEs can improve hypericin efficacy and assist Hy-PDT's preclinical development as a cancer treatment., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The Ultraviolet-visible (UV-Vis) spectra indicate that anthracenyl chalcones (ACs) have high maximum wavelengths and good transparency windows for optical applications and are suitable for optoelectronic applications owing to their HOMO-LUMO energy gaps (2.93 and 2.76 eV). Different donor substituents on the AC affect their dipole moments and nonlinear optical (NLO) responses. The positive, negative, and neutral electrostatic potential regions of the molecules were identified using molecular electrostatic potential (MEP). The stability of the molecule on account of hyperconjugative interactions and accompanying charge delocalization was analyzed using natural bond orbital (NBO) analysis. Open and closed aperture Z-scans were performed using a continuous-wave frequency-doubled diode-pumped solid-state (DPSS) laser to measure the nonlinear absorption and nonlinear refractive index coefficients, respectively. The valley-to-peak profile of AC indicated a negative nonlinear refractive index coefficient. The obtained single crystals possess reverse saturation absorption due to excited-state absorption. The structural and nonlinear optical properties of the molecules have been discussed, along with the role of anthracene substitution for enhancing the nonlinear optical properties. The calculated third-order susceptibility value was 1.10 x10-4 esu at an intensity of 4.1 kW/cm2, higher than the reported values for related chalcone derivatives. The NLO response for both ACs offers excellent potential in optical switching and limiting applications., Competing Interests: The authors have declared that no competing interests exist.

The use of a small molecule compound to reduce toxic repeat RNA transcripts or their translated aberrant proteins to target repeat-expanded RNA/DNA with a G4C2 motif is a promising strategy to treat C9orf72-linked disorders. In this study, the crystal structures of DNA and RNA-DNA hybrid duplexes with the -GGGCCG- region as a G4C2 repeat motif were solved. Unusual groove widening and sharper bending of the G4C2 DNA duplex A-DNA conformation with B-form characteristics inside was observed. The G4C2 RNA-DNA hybrid duplex adopts a more typical rigid A form structure. Detailed structural analysis revealed that the G4C2 repeat motif of the DNA duplex exhibits a hydration shell and greater flexibility and serves as a 'hot-spot' for binding of the anthracene-based nickel complex, NiII(Chro)2 (Chro = Chromomycin A3). In addition to the original GGCC recognition site, NiII(Chro)2 has extended specificity and binds the flanked G:C base pairs of the GGCC core, resulting in minor groove contraction and straightening of the DNA backbone. We have also shown that Chro-metal complexes inhibit neuronal toxicity and suppresses locomotor deficits in a Drosophila model of C9orf72-associated ALS. The approach represents a new direction for drug discovery against ALS and FTD diseases by targeting G4C2 repeat motif DNA., (© The Author(s) 2021. Published by Oxford University Press on behalf of Nucleic Acids Research.)

The unique structure of a natural nucleic acid, calf thymus DNA, which can provide an appropriate scaffold for an efficient cascaded energy transfer among organic chromophores, has been used for the generation of bright and pure white light on UV light excitation. Two most commonly used DNA stains, 4',6-diamidino-2-phenylindole (DAPI) and ethidium bromide (EB) have been used as a part of the donor-acceptor pairs. We have judiciously selected 10-anthracene-10-yl-3-methylbenzothiazol-3-ium chloride (AnMBTZ), an ultrafast molecular rotor, to act as a bridge between DNA bound DAPI and EB for the cascaded flow of energy. The unique molecular rotor properties of AnMBTZ and its exceptional binding ability with natural DNA help to form a distinct tri-chromophoric system in DNA template which can produce bright and pure white light on UV excitation. Detailed flow of energy from photoexcited DAPI to EB via AnMBTZ has been explored using steady state and time-resolved emission spectroscopy. Further, unique binding nature of AnMBTZ with DNA molecules has been used to modulate the colour of the emission from the present tri-chromophoric system by external stimuli, like salt and temperature. Such unique stimuli responsive multi-chromophoric system in a bio-template has great potential for different lightening applications., (Copyright © 2021 Elsevier B.V. All rights reserved.)