查看更多>>摘要：Actin filaments play important physiological functions,which have become potential targets of antitumor drugs.Using chemicals to intervene their polymerization-depolymerization dynamics would generate new strategies for designing antitumor drugs.In this re-port,an artificial water channel appending acetazolamide moiety,a ligand that can selectively bind to carbonic anhydrase Ⅸ,has been prepared.We demonstrated that this conjugate can target colorectal cancer cells overexpressing carbonic anhydrase Ⅸ and trigger the depolymerization of actin filaments of the cancer cells by selectively mediating water transmembrane transport.Moreo-ver,the conjugate-promoted actin depolymerization led to tumor cell apoptosis and its high antitumor activity in vitro and in vivo against colorectal cancer.The method described herein represents a new and general strategy for designing antitumor drugs by us-ing artificial channel-mediated selective water transport to promote actin depolymerization.
查看更多>>摘要：The divergent synthesis of versatile 3,3'-disubstituted oxetane amino acids by utilizing visible-light-induced photocatalytic decarbox-ylative Giese-type reaction has been demonstrated.3-Methyleneoxetane-derived substrates are readily available in a single-step and highly reactive as radical acceptors,allowing the production of versatile oxetane γ-and α-amino acids in high yields.A distinct ring strain release-driven radical addition mechanism was preliminarily revealed.The preparative power was further highlighted by the application in the synthesis of oxetane-containing dipeptides and azetidine amino acids,as well as the transformation of the product into novel oxetane-containing spiro-heterocycle pharmacophore.
查看更多>>摘要：Cathode interlayers(CILs)play an essential role in achieving efficient organic solar cells(OSCs).However,the electronic structure at the electrode/CIL/active layer interfaces and the underlying mechanisms for electron collection remain unclear,which becomes a ma-jor obstacle to develop high-performance CILs.Herein,we investigate the relationship of the electron collection abilities of four cross-linked and n-doped CILs(c-NDI:P0,c-NDI:P1,c-NDI:P2,c-NDI:P3)with their electronic structure of space charge region at hetero-junction interface.By accurately calculating the depletion region width according to the barrier height,doping density and permittivi-ty,we put forward that the optimal thickness of CIL should be consistent with the depletion region width to realize the minimum en-ergy loss.As a result,the depletion region width is largely reduced from 13 nm to 0.8 nm at the indium tin oxide(ITO)/c-NDI:P0 inter-face,resulting in a decent PCE of 17.7％for the corresponding inverted OSCs.
查看更多>>摘要：An asymmetric synthesis of dihydrospirotryprostatin B was achieved in 15 steps(8 purifications)from L-tryptophan.The main feature of our synthetic strategy is the efficient construction of spirocyclic oxindole intermediate containing a chiral quaternary carbon center,involving the silica gel-mediated cyclization of tryptamine-ynamide and oxidation under neat conditions.
查看更多>>摘要：The conversion of CF3-alkenes to gem-difluoroalkenes using reductive cross-coupling strategy has received much attention in recent years,however,the use of green and readily available reducing salt to mediate these reactions remains to be explored.In this work,a concise construction of gem-difluoroalkenes,which requires neither a catalyst nor a metal reducing agent,was established.Ronga-lite,a safe and inexpensive industrial product,was employed as both a radical initiator and reductant.This procedure was compati-ble with both linear and cyclic diaryliodonium salts,enabling a wide variety of substrates(＞70 examples).The utility of this approach was demonstrated through gram-scale synthesis and efficient late-stage functionalizations of anti-inflammatory drugs.
查看更多>>摘要：The selective oxidative sulfonylation of alkenes with selenium sulfonate depended on the reaction conditions.The electrochemical C-H sulfonylation proceeded smoothly to afford(E)-vinyl sulfones with good selectivity in an undivided cell without external oxidant.While aerobic trifunctionalization of alkenes occurred in the presence of KI in the air,which provides B-keto selenosulfones via the formation of C-O,C-S,and C-Se bonds in one-pot.Following control experiments,a plausible mechanism is proposed to rationalize the experimental results.
查看更多>>摘要：The detection of critical endogenous species,such as bacteria in microenvironments in the body,requires better imaging tools for visualization and monitoring of biological events.Bioluminescence imaging is the most popular strategy for obtaining real-time in living cells and organisms.Herein,we introduced a nitroaryl group on the C-3 position and a hydroxy group at the C-6 phenyl ring on furimazine to report the first bioluminescent probe(7)based on NanoLuc-furimazine bioluminescent pair for the detection of ni-troreductase in bacteria.The probe,which possessed up to 560-fold intensity increase with a low detection limit of 16 ng/mL of ni-troreductase,has the most efficient uncage efficiency in comparison with other bioluminescent congeners,thus enabling highly se-lective and sensitive visualization of NTR activity in a panel of clinical priority pathogens.Additionally,imaging of the recombinant strain as well as the NTR from mouse feces indicated the potential of this probe in the application of different mouse disease mod-els.
查看更多>>摘要：A Pd-catalyzed regioselective hydroesterification of alkyl terminal olefins with aryl formates is described.A wide variety of linear car-boxylic esters bearing various functional groups can be obtained in good yields with high regioselectivities under mild reaction condi-tions by using 1,2-DTBPMB or(p-F-Ph)3P as ligand.The reaction process is operationally simple and requires no handling of toxic CO or strong acid.The resulting aryl esters can be readily converted to other carboxylic acid derivatives.
查看更多>>摘要：Currently,CRISPR/Cas9 technology has found widespread applications across various domains.However,the utility of CRISPR/Cas9 is encumbered by issues pertaining to its reliability and safety,primarily stemming from the uncontrolled activity of the system.There-fore,the design and development of CRISPR/Cas9 systems with controllable activity is of paramount importance.Biotin,characterized by its small molecular weight,and streptavidin,distinguished by its substantial spatial steric hindrance,can be harnessed as an ideal OFF switch(termed a"bioactivity brake")due to their interaction characteristics.In this work,we present a strategy that employs the streptavidin-biotin interaction as a"brake system"for CRISPR/Cas9,effectively allowing for the shutdown of the enzymatic activity of CRISPR/Cas9.
查看更多>>摘要：The development of switchable solvent-free multicomponent reactions to build high-value-added products is an important demand for organic synthesis.Herein,we detailed the successful implementation of a switchable strategy for the construction of diverse 4-fluoroalkyl-1,4-dihydropyrimidines and 4-fluoroalkyl-pyrimidines via a solvent/additive-free[3+2+1]annulation,starting from readily available enamines,trifluoroacetaldehyde hydrate or 1-ethoxy-2,2-difluoroethanol and amidines hydrochloride.This reaction conforms to the concept of green synthesis,and provides a new avenue to access valuable fluorinated heterocycles.
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