查看更多>>摘要：Drug loading capacity is very important in the construction of targeted drug delivery systems(TDDSs)for the improvement of drug delivery efficiency.However,the drug-loading capacity of most nanoma-terials is non-idealistic,and developing the high drug-loading TDDSs is still a critical challenge.In this work,an ultrahigh loading system(denoted as HMPB2)was prepared via J-aggregation of an aza-boron dipyrromethene derivative(Bod)by using hollow MnO2 modified with glucosamine pillar[5]arene as a carrier,which was demonstrated to have typical J-aggregate absorption of Bod,specific cancer cells tar-geting ability,negligible dark cytotoxicity,and potent phototoxicity.This work provides a successful ex-ample to construct an ultrahigh drug-loading system via J-aggregation for targeted delivery.
查看更多>>摘要：Early diagnosis and treatment of cancer requires the development of tools that are both sensitive and selective in detecting spermine.In this study,we presented a"supramolecular cyclization-induced emis-sion enhancement"strategy for the sensitive and selective detection of spermine.A new pillar[5]arene probe(P1)demonstrated excellent solution/solid dual-state emission properties,and the addition of cer-tain spermine(Spm)resulted in fluorescence enhancement due to the synergy of multiple weak inter-actions that restricted the free motion of P1 in the P1⊃Spm complex.This mechanism was further con-firmed by time-resolved spectroscopy,DFT calculations,and IGM analysis.With its low limit of detection and high selectivity,P1 is a promising tool for measuring spermine in artificial urine samples.
查看更多>>摘要：Four pillar[5]arene-based bicyclic compounds,so-called molecular universal joint(MUJ),were synthe-sized by incorporating a bisamide ring containing N,O,or S-heteroatom groups,which served as stimuli-responsive chiroptical molecular devices.The structure of MUJ was confirmed by 1H NMR spectra and single-crystal X-ray diffraction analysis,and their planar-chiral enantiomers were successfully separated.Chiroptical inversion behaviors from in to out configurations triggered by temperature,solvent,and guest complexation were investigated by circular dichroism spectra.Chiroptical inversion could be realized in the presence of adiponitrile in certain solvents due to the solvation effects on the side ring and the threading of the guest into the pillar[5]arene cavity.However,the stronger self-included interactions be-tween the cavity and the inside ring of certain MUJs led to inhibition of the switching.
查看更多>>摘要：N-formylation of amines,a class of synthetically important reactions,is typically conducted using metal catalysts that are relatively expensive or not readily available and usually needs harsh conditions to in-crease the reaction efficiency.Here,an efficient continuous microflow strategy was developed for the gas-liquid visible-light photocatalytic N-formylation of piperidine,which achieved a reaction yield of 82.97％and a selectivity of＞99％at 12 min using cheap organic dye photocatalyst under mild reaction con-ditions.The influence of essential parameters,including light intensity,temperature and equivalents of the gas,additive and photocatalyst,on the reaction yield was systematically studied.Furthermore,ki-netic investigations were conducted,exhibiting the dependence of reaction rate and equilibrium yield of N-formylpiperidine on light intensity,temperature and photocatalyst equivalent.The microflow photo-catalytic approach established in this work,which realized a markedly higher space-time yield than the conventional batch method(37.9 vs.0.212 mmol h-1 L-1),paves the way for the continuous,green and efficient synthesis of N-formamides.
查看更多>>摘要：A sustainable and practical process is presented for the direct synthesis of sodium tanshinone ⅡA sul-fonate(STS).Our approach was inspired by the well-established and industrially applied batch synthetic route for STS production.We constructed a telescoped two-step continuous flow platform.This involved a continuous tanshinone ⅡA sulfonation and in-line salt formation.For the setup,we constructed a 3D circular cyclone-type microreactor using femtosecond laser micromachining.Compared to the 68％yield for 2 h in batch,the two-step continuous flow had an STS yield of 90％,achieved for a total residence time of＜3.0 min under optimal conditions.The proposed continuous flow method vastly simplified the operation and improved procedural safety,while significantly reducing the required acid content and wastewater production.
查看更多>>摘要：The A2A adenosine receptor(A2AAR)has attracted attention as an emerging immunotherapeutic tar-get with several antagonists being evaluated in clinical trials.However,A2AAR antagonists show lim-ited efficacy as monotherapies.Herein,we communicate our design and synthesis of a novel series of A2AAR/histone deacetylase(HDAC)bifunctional inhibitors,based on the core structure of the A2AAR antag-onist PBF-509 The new compounds were designed using a pharmacophore-merging strategy and features a tri-substituted pyrimidine core.The binding affinity for A2AAR and inhibitory activity against HDACs of all the new compounds were tested.A number of compounds exhibited nanomolar or subnanomo-lar activity against both targets and some showed equally potent antiproliferative activity against MC38,CT26 and HCT116 colon cancer lines compared to HDAC inhibitors SAHA and MGCD-0103 in vitro.The binding poses of compound 5a in both A2AAR and HDAC1 were predicted by molecular docking stud-ies.Collectively,these results suggest these tri-substituted pyrimidine derivatives are promising leads for developing A2AAR/HDAC dual-acting compounds as novel antitumor agents.
查看更多>>摘要：Talaroclauxins A and B(1 and 2),two novel duclauxin hybrids,were obtained from Talaromyces stipitatus,along with three new(3-5)and one known analogue(6).Their structures were determined by NMR spectroscopy,HRESIMS,single-crystal X-ray diffraction,and quantum chemical calculations.Compound 1 is the first example of duclauxin-ergosterol hybrid featuring an unprecedented dodecacyclic ring system formed via a[4+2]cycloaddition,while compound 2,bearing an unusual 6/6/6/5/6/6/6/6 ring system,is a new member of the rare duclauxin-polyketide hybrid class of natural products.Plausible biosynthetic pathways for 1-6 are proposed.Compound 5 displayed moderate neuroprotective effects in glutamate sodium-induced SH-SY5Y cells.
查看更多>>摘要：Photodynamic therapy(PDT)is a clinically approved cancer treatment that uses energy of light to gen-erate active substances that cause damage to the cancer.Photosensitizers are employed to absorb light and generate toxic reactive oxygen species(ROS)to damage biomolecules like DNA.At the same time,some chemotherapy drugs like nucleotide analogues can provide mechanism-guided promotion in the treatment efficacy of PDT.However,the photosensitizer and chemotherapy drugs used in PDT is usu-ally organic molecules,which suffers from bad solubility,fast clearance,and acute toxicity.To achieve targeted treatment,a reasonable delivery system is necessary.Therefore,we reported a metal-phenolic network where IR780 and gemcitabine were coupled chemically to overcome these shortcomings.The enhanced PDT effects can be realized by the promoted cell death both in vitro and in vivo.Moreover,the synergistic therapy also induced T-cell mediated anti-tumor immune response,which was significant for the inhibition of distant tumor growth.This work expanded the biomedical application of metal-phenolic materials and contribute to the wider application of photodynamic cancer therapy.
查看更多>>摘要：Metastable molybdenum carbide(α-MoC),as a catalyst and an excellent support for metal catalysts,has been widely used in thermo/electro-catalytic reactions.However,the selective synthesis of α-MoC remains a great challenge.Herein,a simple one-pot synthetic strategy for the selective preparation of metastable α-MoC is proposed by electrochemical co-reduction of CO2 and MoO3 in a low-temperature eutectic molten carbonate.The synthesized α-MoC shows a reed flower-like morphology.By controlling the electrolysis time and monitoring the phase and morphology of the obtained products,the growth pro-cess of α-MoC is revealed,where the carbon matrix is deposited first followed by the growth of α-MoC from the carbon matrix.Moreover,by analyzing the composition of the electrolytic products,the for-mation mechanism for α-MoC is proposed.In addition,through this one-pot synthetic strategy,S-dopedα-MoC is successfully synthesized.Density functional theory(DFT)calculations reveal that S doping en-hanced the HER performance of α-MoC by facilitating water absorption and dissociation and weakening the bond energy of Mo-H to accelerate H desorption.The present work not only highlights the valuable utilization of CO2 but also offers a new perspective on the design and controllable synthesis of metal carbides and their derivatives.
查看更多>>摘要：High monomer concentration is a requisite for engendering the aggregation-induced emssion(AIE)phe-nomenon as well as the formation of supramolecular polymers.Therefore,this is supposed to ensure the generation of AIE supramolecular polymers,wherein the monomer soluability takes effect.Neverthe-less,parts of supramolecular monomers are considered as poessessing different soluability towards the same sovlent,through which the polymerzation process is thus hard to proceed.Interfacial polymerza-tion gets over the soluabilty restriction,providing a facile method for propelling the reaction of the-semonomers.Herein,we had prepared M1 containing tetraphenylethene(TPE)functionalized with two terpyridine derivatives,then making M1 dissolving in CHCl3 to give solutions.Cu2+solutions were fabri-cated through dissolving CuCl2 into H2O.Towards mixing those solutions,AIE interfacial supramolecular polymers(AIEISPs)displaying green fluorescence were generated at the interface of two phases on the basis of metal-coordination between terpyridine and Cu2+.These AIEISPs were certificated to possess the stimuli-responsiveness,for which the excessive addition of tetrabutylammonium hydroxide would cause the structure destruction owing to the stronger bonding ability with Cu2+than that of terpyridine.These fabricated AIEISPs had provided a new avenue to prepare AIE supramolecular polymers.
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