Here,we present a novel bioorthogonal platform that enables precise positioning of attached moieties in close proximity,thereby facilitating the discovery and optimization of biocompatible reactions.Using this platfor...Here,we present a novel bioorthogonal platform that enables precise positioning of attached moieties in close proximity,thereby facilitating the discovery and optimization of biocompatible reactions.Using this platform,we achieve a Horner-Wadsworth-Emmons(HWE)reaction under physiological conditions,generating a fluorophore in situ with a yield of up to 93%.This proximity platform should facilitate the discovery of various types of biocompatible reactions,making it a versatile tool for biomedical applica-tions.展开更多
The new title compound, 1-benzoyl-3,6-diphenyl-1,4-dihydro-1,2,4,5-tetrazine （C21H16N4O, Mr = 340.38）, has been prepared and its crystal structure can not be confirmed by the results of MS, elemental analysis, IR sp...The new title compound, 1-benzoyl-3,6-diphenyl-1,4-dihydro-1,2,4,5-tetrazine （C21H16N4O, Mr = 340.38）, has been prepared and its crystal structure can not be confirmed by the results of MS, elemental analysis, IR spectrum and 1H NMR spectrum, but determined by X-ray diffraction. The title compound crystallizes in an orthorhombic space group P212121 with a = 7.1100（19）, b = 12.115（3）, c = 19.884（6）, V = 1712.7（8）3, Z = 4, Dc = 1.320 g/cm3, F（000） = 712, μ = 0.085 mm-1, MoKa radiation （λ = 0.71073）, R = 0.0334 and wR = 0.0845 for 2254 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that the central tetrazine adopts an unsymmetrical boat conformation. According to the bond lengths of tetrazine ring, the molecule should be 1,4-dihydro-1,2,4,5-tetrazine, rather than 1,2-dihydro-1,2,4,5-tetrazine. The crystal structure is stabilized mainly by intermolecular N-H···O hydrogen bonds.展开更多
Visible-light heterogeneous photocatalyst with high activity and selectivity is crucial for the development of organic transformations, but remains a formidable challenge. Herein, a simple and effective strategy was d...Visible-light heterogeneous photocatalyst with high activity and selectivity is crucial for the development of organic transformations, but remains a formidable challenge. Herein, a simple and effective strategy was developed to integrate tetrazine moiety, a visible light active unit, into robust metal-organic frameworks(2D MOF-1(M), M = Co, Mn, Zn, and 3D MOF-2(Co)). MOF-1 series are isomorphous 2D porous frameworks, and MOF-2(Co) displays 3D porous framework. Interestingly, benefiting from the oxidative active species of O_(2)·-, these MOFs all exhibit obviously highly enhanced photocatalytic activities toward the straightforward condensation of o-aminothiophenol and aromatic aldehydes at room temperature in Et OH under visible-white-light irradiation. Notably, compared to 3D MOF, the 2D layered MOF-1(Co) exhibited more excellent catalytic activity with a wide range of substrates possessing preeminent tolerance of steric hindrance. Most impressively, MOF-1(Co) can be recycled at least five times without significant loss of catalytic activity or crystallinity, exhibiting excellent stability and reusability. This study sheds light on the wide-ranging prospects of visible light active 2D MOFs as green photocatalysts for the preparation of fine chemicals.展开更多
A dimesitylboryl-ended oligothiophene with tetrazine as core(BTz)was synthesized and its reactivity and spectral changes toward trans-cyclooctene((4E)-TCO-OH),cis-cyclooctene and bicyclo[6.1.0]non-4-yn-9-ylmethanol we...A dimesitylboryl-ended oligothiophene with tetrazine as core(BTz)was synthesized and its reactivity and spectral changes toward trans-cyclooctene((4E)-TCO-OH),cis-cyclooctene and bicyclo[6.1.0]non-4-yn-9-ylmethanol were comprehensively studied.The fluorescence intensity of BTz was enhanced up to more than 100 times upon bioorthogonal reaction with(4E)-TCO-OH.In addition,the first crystal structure of isolated product of tetrazine derivative with cyclooctene was determined,which clearly confirmed a dehydrogenation occurred after Diels-Alder reaction under ambient conditions.展开更多
Background Antibody-based positron emission tomography(PET)imaging holds great promise for visualizing disease-related proteins in the brain.However,its clinical utility is limited by poor antibody penetration across ...Background Antibody-based positron emission tomography(PET)imaging holds great promise for visualizing disease-related proteins in the brain.However,its clinical utility is limited by poor antibody penetration across the blood–brain barrier(BBB)and the requirement for long-lived radionuclides due to slow antibody pharmacokinetics.Pretargeted imaging strategies,in which antibody administration and radioligand injection are separated in time,enable the use of short-lived,high-resolution PET-compatible radionuclides such as fluorine-18.Methods A bispecific antibody,Bapi-Fab8D3,which targets both amyloid beta(Aβ)and the transferrin receptor(TfR)for TfR-mediated transport across the BBB,was conjugated with trans-cyclooctene(TCO)to enable in vivo click chemistry.Following antibody administration to Alzheimer’s disease(AD)model mice and sufficient time for accumulation at intrabrain Aβdeposits,a fluorine-18-labeled tetrazine was injected to react in vivo with the TCO handles on the antibody.PET imaging,autoradiography,ex vivo quantification,and histological analyses were performed to evaluate the specificity and distribution of the imaging signal.Results Bapi-Fab8D3 retained its binding affinity for both Aβand TfR after TCO-conjugation.In brain sections,reactive TCOs were detected up to three days after antibody injection,indicating successful transcytosis across the BBB and stable target engagement.Pretargeted PET imaging after fluorine-18-labeled tetrazine injection revealed significantly higher signals in AD mice that received TCO-Bapi-Fab8D3 compared to wild-type controls or AD mice that received the unmodified antibody.The uptake pattern corresponded to Aβplaque distribution,and quantitative analysis showed increased signal in AD-relevant brain regions including the hippocampus and thalamus.Conclusions This study demonstrates successful pretargeted PET imaging of brain Aβpathology using a systemically administered bispecific antibody capable of BBB penetration and a fluorine-18-labeled tetrazine.These findings establish a generalizable strategy for high-contrast in vivo imaging of brain protein targets using pretargeted PET,with the potential to expand molecular imaging to protein targets in the brain that are currently inaccessible.展开更多
The first example of unique coordination induced intramolecular pancake bonding was achieved through the reduction of two bis(pyrazolyl)-tetrazine ligands,affording[M_(2)^(Ⅲ)(μ-(bpytz)_(2))(THMD)4](M=Dy,Y;bpytz=3,6-...The first example of unique coordination induced intramolecular pancake bonding was achieved through the reduction of two bis(pyrazolyl)-tetrazine ligands,affording[M_(2)^(Ⅲ)(μ-(bpytz)_(2))(THMD)4](M=Dy,Y;bpytz=3,6-bis(3,5-dimethyl-pyrazolyl)-1,2,4,5-tetrazine;TMHD=2,2,6,6-tetramethyl-3,5-heptanedionate).To provide a cohesive magneto-structural correlation,the mono bis(pyrazolyl)-tetrazine bridged congener[Dy_(2)^(Ⅲ)(μ-bpytz)(THMD)6]·4(C6H6)was also isolated.Both metal complexes exhibit single-molecule magnet behaviour under an applied dc field.展开更多
A combination of high-performing lanthanide metallocenes and tetrazine-based radical ligands leads to a new series of radical-bridged dinuclear lanthanide metallocenes;[(Cp^(*)_(2)Ln^(Ⅲ))_(2)(bpytz^(•−))][BPh_(4)](wh...A combination of high-performing lanthanide metallocenes and tetrazine-based radical ligands leads to a new series of radical-bridged dinuclear lanthanide metallocenes;[(Cp^(*)_(2)Ln^(Ⅲ))_(2)(bpytz^(•−))][BPh_(4)](where Ln=Gd(1),Tb(2),Dy(3)and Y(4);Cp_(*)=pentamethylcyclopentadienyl;bpytz=3,6-bis(3,5-dimethyl-pyrazolyl)-1,2,4,5-tetrazine).The formation of the radical species is achieved via a controlled,stepwise synthesis and verified in all complexes by X-ray crystallography and SQUID magnetometry,as well as EPR spectroscopy of 4.Through the judicious choice of the Cp_(*)ancillary ligands and by taking advantage of the steric effects imposed by their bulkiness,we were able to promote the trans coordination mode of the bpytz^(•−)radical anion that enables stronger magnetic exchange coupling compared to the cis fashion.This yields a J_(Gd–rad)=−14.0 cm^(−1) in 1,which is the strongest exchange coupling observed in organic monoanionic radical-bridged lanthanide metallocene systems.The strong Ln-rad exchange coupling was further confirmed by high-frequency EPR(HF-EPR)spectroscopy and broken-symmetry(BS)density functional theory(DFT)calculations.This combined with the highly anisotropic nature of Tb^(Ⅲ) and Dy^(Ⅲ) ions in 2 and 3,respectively,leads to strong SMM behavior and slow relaxation of the magnetization at zero fields.展开更多
A variety of bioorthogonal chemical tools have been developed and widely used in the study of biological phenomena in situ.Tetrazine bioorthogonal chemistry exhibits ultrafast reaction kinetics,excellent biocompatibil...A variety of bioorthogonal chemical tools have been developed and widely used in the study of biological phenomena in situ.Tetrazine bioorthogonal chemistry exhibits ultrafast reaction kinetics,excellent biocompatibility,and precise optical regulatory capabilities.Fluorogenic tetrazine bioorthogonal probes have achieved particularly diverse applications in bioimaging and disease diagnosis and treatment.This Viewpoint briefly introduces the characteristics and advantages of tetrazine bioorthogonal chemistry,some design strategies of fluorogenic tetrazine probes,and the status of applications of these tools to in vivo imaging,as well as disease diagnosis and treatment.Finally,we discuss challenges and propose future trends in the field of fluorogenic tetrazine probes.This Viewpoint offers insights into the development of new bioorthogonal tools for chemical biology research and for the design of new drugs.展开更多
Fluorescence imaging,a key technique in biological research,frequently utilizes fluorogenic probes for precise imaging in living systems.Tetrazine is an effective emission quencher in fluorogenic probe designs,which c...Fluorescence imaging,a key technique in biological research,frequently utilizes fluorogenic probes for precise imaging in living systems.Tetrazine is an effective emission quencher in fluorogenic probe designs,which can be selectively damaged upon bioorthogonal click reactions,leading to considerable emission enhancement.Despite significant efforts to increase the emission enhancement ratio(I_(AC)/I_(BC))of tetrazine-functionalized fluorogenic probes,the influence of molecular aggregation on the emission properties has been largely overlooked in these probe designs.In this study,we reveal that an ultrahigh I_(AC)/I_(BC)can be realized in the aggregate system when tetrazine is paired with aggregation-induced emission(AIE)luminogens.Tetrazine amplifies its quenching efficiency upon aggregation and drastically reduce background emissions.Subsequent click reactions damage tetrazine and trigger significant AIE,leading to considerably enhanced I_(AC)/I_(BC).We further showcase the capability of these ultra-fluorogenic systems in selective imaging of multiple organelles in living cells.We term this unique fluorogenicity of AIE luminogen-quencher complexes with amplified dark-bright states as“Matthew effect”in aggregate emission,potentially providing a universal approach to attain ultrahigh I_(AC)/I_(BC)in diverse fluorogenic systems.展开更多
A redox-active tetrazine moiety is immobilized within a metal-organic framework(MOF)aiming at targeted construction of a cathode with improved performance for lithium–oxygen batteries.A 1,2,4,5-tetrazine(Tz)functiona...A redox-active tetrazine moiety is immobilized within a metal-organic framework(MOF)aiming at targeted construction of a cathode with improved performance for lithium–oxygen batteries.A 1,2,4,5-tetrazine(Tz)functionalized ligand is used to construct a nanoporous MOF,Tz-Mg-MOF-74,in which the redox activity of the Tz moiety is retained.Combining the redox activity of Tz with the porous nature of a MOF produced a Tz-Mg-MOF-74-based cathode with significantly improved electrochemical performance.Specifically,the material has improved sustainable capacity with a lower overpotential compared with otherwise similar batteries without Tz and other reported MOF-based catalysts.The present approach productively integrates electrochemical activity derived from redox-active moieties and MOFs,and this combination opens a new avenue for the design of effective materials for energy storage and conversion.展开更多
6-（3,5-Dimethylpyrazol-1-yl）-3-（2,4,6-trinitroanilino）-1,2,4,5-tetrazin （1） has been synthesized and characterized by ^1H NMR, MS, elemental analysis, infrared spectra and thermal analyses. The crystal structure...6-（3,5-Dimethylpyrazol-1-yl）-3-（2,4,6-trinitroanilino）-1,2,4,5-tetrazin （1） has been synthesized and characterized by ^1H NMR, MS, elemental analysis, infrared spectra and thermal analyses. The crystal structure was determined by X-ray diffraction method. 1 is crystallized in P21/c space group of monoclinic crystal system, and exhibits good physical properties, such as high densities （〉 1.55 g·cm^-3） and good thermal stabilities （Td〉220 ℃）. The intrermolecular hydrogen bonds construct the P- and M-helices from organic molecules and may contribute to the high melting points.展开更多
While self-assembly is relatively well-known and widely used to form hierarchical structures and thin film coatings,controlled assembly is less known and utilized.Our prior work has demonstrated the concept of control...While self-assembly is relatively well-known and widely used to form hierarchical structures and thin film coatings,controlled assembly is less known and utilized.Our prior work has demonstrated the concept of controlled assembly of macromolecules such as star polymers[molecular weight(M_(w))∼383 kDa,hydrodynamic radius R∼13.8 nm]in droplets.This work extends this concept to smaller molecules,in this case,poly(ethylene glycol)bis-tetrazine(PEGbisTz,M_(w) 8.1 kDa,R∼1.5 nm).The key to controlled molecular assembly is to first deliver ultrasmall volumes(sub-fL)of solution containing PEG-bisTz to a substrate.The solvent evaporates rapidly due to the minute volume,thus forcing the assembly of solute,whose overall size and dimension are dictated by the initial liquid geometry and size.Using prepatterned surfaces,this work revealed that the initial liquid shape can be further tuned,and we could control the final assembly of solute such as PEGbisTz molecules.The degree of control was demonstrated by varying the micropatterns and delivery conditions.This work demonstrated the validity of controlled assembly for PEG-bisTz and enables three-dimensional(3D)nanoprinting of functional materials.The technology has promising applications in nanophotonics,nanoelectronics,nanocomposite materials,and tissue engineering.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21977075,22271200)the National Key R&D Program of China(Nos.2022YFC2009902,2022YFC2009900)+1 种基金the Science and Technology Plan Project of Sichuan Province(No.2023YFS0121)the 1·3·5 Project for Disciplines of Excellence at West China Hospital(No.ZYYC23003),Sichuan University。
文摘Here,we present a novel bioorthogonal platform that enables precise positioning of attached moieties in close proximity,thereby facilitating the discovery and optimization of biocompatible reactions.Using this platform,we achieve a Horner-Wadsworth-Emmons(HWE)reaction under physiological conditions,generating a fluorophore in situ with a yield of up to 93%.This proximity platform should facilitate the discovery of various types of biocompatible reactions,making it a versatile tool for biomedical applica-tions.
基金supported by the National Natural Science Foundation of China (20802069/B020601)Science Foundation for the Excellent Youth Scholars of Department of Education of Zhejiang Province
文摘The new title compound, 1-benzoyl-3,6-diphenyl-1,4-dihydro-1,2,4,5-tetrazine （C21H16N4O, Mr = 340.38）, has been prepared and its crystal structure can not be confirmed by the results of MS, elemental analysis, IR spectrum and 1H NMR spectrum, but determined by X-ray diffraction. The title compound crystallizes in an orthorhombic space group P212121 with a = 7.1100（19）, b = 12.115（3）, c = 19.884（6）, V = 1712.7（8）3, Z = 4, Dc = 1.320 g/cm3, F（000） = 712, μ = 0.085 mm-1, MoKa radiation （λ = 0.71073）, R = 0.0334 and wR = 0.0845 for 2254 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that the central tetrazine adopts an unsymmetrical boat conformation. According to the bond lengths of tetrazine ring, the molecule should be 1,4-dihydro-1,2,4,5-tetrazine, rather than 1,2-dihydro-1,2,4,5-tetrazine. The crystal structure is stabilized mainly by intermolecular N-H···O hydrogen bonds.
基金financially supported by the National Natural Science Foundation of China (Nos. 22171223, 22077099 and 21531007)the Innovation Capability Support Program of Shaanxi (Nos. 2023-CX-TD-75 and 2022KJXX-32)+2 种基金the Natural Science Foundation of Shaanxi Province of China (Nos. 2020TG-031, 2022JQ125, 2023-JC-YB-141, 2022JQ-151 and 2021JQ-440)the special fund of Shaanxi Key Laboratory of Special Fuel Chemistry and Material (No. SPCF-SKL-2021-0011)Young Talent Fund of Association for Science and Technology in Shaanxi, China (No. SWYY202206)。
文摘Visible-light heterogeneous photocatalyst with high activity and selectivity is crucial for the development of organic transformations, but remains a formidable challenge. Herein, a simple and effective strategy was developed to integrate tetrazine moiety, a visible light active unit, into robust metal-organic frameworks(2D MOF-1(M), M = Co, Mn, Zn, and 3D MOF-2(Co)). MOF-1 series are isomorphous 2D porous frameworks, and MOF-2(Co) displays 3D porous framework. Interestingly, benefiting from the oxidative active species of O_(2)·-, these MOFs all exhibit obviously highly enhanced photocatalytic activities toward the straightforward condensation of o-aminothiophenol and aromatic aldehydes at room temperature in Et OH under visible-white-light irradiation. Notably, compared to 3D MOF, the 2D layered MOF-1(Co) exhibited more excellent catalytic activity with a wide range of substrates possessing preeminent tolerance of steric hindrance. Most impressively, MOF-1(Co) can be recycled at least five times without significant loss of catalytic activity or crystallinity, exhibiting excellent stability and reusability. This study sheds light on the wide-ranging prospects of visible light active 2D MOFs as green photocatalysts for the preparation of fine chemicals.
基金National Natural Science Foundation of China(Nos.52150222,21672130 and 52073163)the Shenzhen Science and Technology Research and Development Funds(No.JCYJ20190806155409104)the State Key Laboratory of Crystal Materials.We acknowledge Prof.Dr.Cuihua Zhao of Shandong University for her valuable suggestions.
文摘A dimesitylboryl-ended oligothiophene with tetrazine as core(BTz)was synthesized and its reactivity and spectral changes toward trans-cyclooctene((4E)-TCO-OH),cis-cyclooctene and bicyclo[6.1.0]non-4-yn-9-ylmethanol were comprehensively studied.The fluorescence intensity of BTz was enhanced up to more than 100 times upon bioorthogonal reaction with(4E)-TCO-OH.In addition,the first crystal structure of isolated product of tetrazine derivative with cyclooctene was determined,which clearly confirmed a dehydrogenation occurred after Diels-Alder reaction under ambient conditions.
基金Open access funding provided by Uppsala University.Vetenskapsradet(2021-01083,Stina Syvanen,2021–03524,Dag Sehlin)Parkinsonfonden,Alzheimerfonden,Hjarnfonden,Ahlen-stiftelsen,Gun och Bertil Stohnes Stiftelse,Stiftelsen for Gamla Tjanarinnor,Tore Nilsons stiftelse,Konung Gustaf V:s och Drottning Victorias Frimurarestiftelse。
文摘Background Antibody-based positron emission tomography(PET)imaging holds great promise for visualizing disease-related proteins in the brain.However,its clinical utility is limited by poor antibody penetration across the blood–brain barrier(BBB)and the requirement for long-lived radionuclides due to slow antibody pharmacokinetics.Pretargeted imaging strategies,in which antibody administration and radioligand injection are separated in time,enable the use of short-lived,high-resolution PET-compatible radionuclides such as fluorine-18.Methods A bispecific antibody,Bapi-Fab8D3,which targets both amyloid beta(Aβ)and the transferrin receptor(TfR)for TfR-mediated transport across the BBB,was conjugated with trans-cyclooctene(TCO)to enable in vivo click chemistry.Following antibody administration to Alzheimer’s disease(AD)model mice and sufficient time for accumulation at intrabrain Aβdeposits,a fluorine-18-labeled tetrazine was injected to react in vivo with the TCO handles on the antibody.PET imaging,autoradiography,ex vivo quantification,and histological analyses were performed to evaluate the specificity and distribution of the imaging signal.Results Bapi-Fab8D3 retained its binding affinity for both Aβand TfR after TCO-conjugation.In brain sections,reactive TCOs were detected up to three days after antibody injection,indicating successful transcytosis across the BBB and stable target engagement.Pretargeted PET imaging after fluorine-18-labeled tetrazine injection revealed significantly higher signals in AD mice that received TCO-Bapi-Fab8D3 compared to wild-type controls or AD mice that received the unmodified antibody.The uptake pattern corresponded to Aβplaque distribution,and quantitative analysis showed increased signal in AD-relevant brain regions including the hippocampus and thalamus.Conclusions This study demonstrates successful pretargeted PET imaging of brain Aβpathology using a systemically administered bispecific antibody capable of BBB penetration and a fluorine-18-labeled tetrazine.These findings establish a generalizable strategy for high-contrast in vivo imaging of brain protein targets using pretargeted PET,with the potential to expand molecular imaging to protein targets in the brain that are currently inaccessible.
基金the University of Ottawa,the CFI,the NSERC and the Academy of Finland(projects 315829,320015)for their financial supportConselho Nacional de Desenvolvimento Científico e Tecnológico(CNPQ,201395/2014-6)for a PhD scholarship.
文摘The first example of unique coordination induced intramolecular pancake bonding was achieved through the reduction of two bis(pyrazolyl)-tetrazine ligands,affording[M_(2)^(Ⅲ)(μ-(bpytz)_(2))(THMD)4](M=Dy,Y;bpytz=3,6-bis(3,5-dimethyl-pyrazolyl)-1,2,4,5-tetrazine;TMHD=2,2,6,6-tetramethyl-3,5-heptanedionate).To provide a cohesive magneto-structural correlation,the mono bis(pyrazolyl)-tetrazine bridged congener[Dy_(2)^(Ⅲ)(μ-bpytz)(THMD)6]·4(C6H6)was also isolated.Both metal complexes exhibit single-molecule magnet behaviour under an applied dc field.
基金support from the US Department of Energy,Basic Energy Sciences(DE-SC0020260)the National High Magnetic Field Laboratory is supported by the US National Science Foundation(DMR-1644779)+4 种基金the State of Florida.A.M.acknowledges funding provided by the Academy of Finland(grant no.332294)the University of Oulu(Kvantum Institute)the Academy of Finland(projects 315829 and 345484)for the financial supportthe CSC-IT Centre for Science in Finland,the Finnish Grid and Cloud Infrastructure(persistent identifier urn:nbn:fi:research-infras-2016072533)Prof.H.M.Tuononen(University of Jyväskylä)for providing computational resources for the project.
文摘A combination of high-performing lanthanide metallocenes and tetrazine-based radical ligands leads to a new series of radical-bridged dinuclear lanthanide metallocenes;[(Cp^(*)_(2)Ln^(Ⅲ))_(2)(bpytz^(•−))][BPh_(4)](where Ln=Gd(1),Tb(2),Dy(3)and Y(4);Cp_(*)=pentamethylcyclopentadienyl;bpytz=3,6-bis(3,5-dimethyl-pyrazolyl)-1,2,4,5-tetrazine).The formation of the radical species is achieved via a controlled,stepwise synthesis and verified in all complexes by X-ray crystallography and SQUID magnetometry,as well as EPR spectroscopy of 4.Through the judicious choice of the Cp_(*)ancillary ligands and by taking advantage of the steric effects imposed by their bulkiness,we were able to promote the trans coordination mode of the bpytz^(•−)radical anion that enables stronger magnetic exchange coupling compared to the cis fashion.This yields a J_(Gd–rad)=−14.0 cm^(−1) in 1,which is the strongest exchange coupling observed in organic monoanionic radical-bridged lanthanide metallocene systems.The strong Ln-rad exchange coupling was further confirmed by high-frequency EPR(HF-EPR)spectroscopy and broken-symmetry(BS)density functional theory(DFT)calculations.This combined with the highly anisotropic nature of Tb^(Ⅲ) and Dy^(Ⅲ) ions in 2 and 3,respectively,leads to strong SMM behavior and slow relaxation of the magnetization at zero fields.
基金support from the National Natural Science Foundation of China(No.22277083)Natural Science Foundation of Sichuan Province(Grant Nos.2023NSFSC53332024NSFTD0023).
文摘A variety of bioorthogonal chemical tools have been developed and widely used in the study of biological phenomena in situ.Tetrazine bioorthogonal chemistry exhibits ultrafast reaction kinetics,excellent biocompatibility,and precise optical regulatory capabilities.Fluorogenic tetrazine bioorthogonal probes have achieved particularly diverse applications in bioimaging and disease diagnosis and treatment.This Viewpoint briefly introduces the characteristics and advantages of tetrazine bioorthogonal chemistry,some design strategies of fluorogenic tetrazine probes,and the status of applications of these tools to in vivo imaging,as well as disease diagnosis and treatment.Finally,we discuss challenges and propose future trends in the field of fluorogenic tetrazine probes.This Viewpoint offers insights into the development of new bioorthogonal tools for chemical biology research and for the design of new drugs.
基金Hong Kong PhD Fellowship Scheme,Grant/Award Number:PF18-15484National Natural Science Foundation of China,Grant/Award Numbers:21788102,22274106+4 种基金Research Grants Council of Hong Kong,Grant/Award Numbers:16306620,16303221,N_HKUST609/19,C6014-20WInnovation and Technology Commission,Grant/Award Number:ITC-CNERC14SC01Shenzhen Science and Technology Innovation CommitteeJSPS KAKENHI,Grant/Award Numbers:JP23H01977,JP23H04631JST the establishment of university fellowships towards the creation of science technology innovation,Grant/Award Number:JPMJFS2132。
文摘Fluorescence imaging,a key technique in biological research,frequently utilizes fluorogenic probes for precise imaging in living systems.Tetrazine is an effective emission quencher in fluorogenic probe designs,which can be selectively damaged upon bioorthogonal click reactions,leading to considerable emission enhancement.Despite significant efforts to increase the emission enhancement ratio(I_(AC)/I_(BC))of tetrazine-functionalized fluorogenic probes,the influence of molecular aggregation on the emission properties has been largely overlooked in these probe designs.In this study,we reveal that an ultrahigh I_(AC)/I_(BC)can be realized in the aggregate system when tetrazine is paired with aggregation-induced emission(AIE)luminogens.Tetrazine amplifies its quenching efficiency upon aggregation and drastically reduce background emissions.Subsequent click reactions damage tetrazine and trigger significant AIE,leading to considerably enhanced I_(AC)/I_(BC).We further showcase the capability of these ultra-fluorogenic systems in selective imaging of multiple organelles in living cells.We term this unique fluorogenicity of AIE luminogen-quencher complexes with amplified dark-bright states as“Matthew effect”in aggregate emission,potentially providing a universal approach to attain ultrahigh I_(AC)/I_(BC)in diverse fluorogenic systems.
基金supported by the NSFC(nos.21421001,21531005,21905142,and 21671112)the Program of Introducing Talents of Discipline to Universities(no.B18030)+1 种基金the Natural Science Fund of Tianjin(nos.19JCZDJC37200 and 19JCQNJC02600)China.The authors thank Professor Brian Space(University of South Florida,Tampa,FL)for discussion and help.
文摘A redox-active tetrazine moiety is immobilized within a metal-organic framework(MOF)aiming at targeted construction of a cathode with improved performance for lithium–oxygen batteries.A 1,2,4,5-tetrazine(Tz)functionalized ligand is used to construct a nanoporous MOF,Tz-Mg-MOF-74,in which the redox activity of the Tz moiety is retained.Combining the redox activity of Tz with the porous nature of a MOF produced a Tz-Mg-MOF-74-based cathode with significantly improved electrochemical performance.Specifically,the material has improved sustainable capacity with a lower overpotential compared with otherwise similar batteries without Tz and other reported MOF-based catalysts.The present approach productively integrates electrochemical activity derived from redox-active moieties and MOFs,and this combination opens a new avenue for the design of effective materials for energy storage and conversion.
文摘6-（3,5-Dimethylpyrazol-1-yl）-3-（2,4,6-trinitroanilino）-1,2,4,5-tetrazin （1） has been synthesized and characterized by ^1H NMR, MS, elemental analysis, infrared spectra and thermal analyses. The crystal structure was determined by X-ray diffraction method. 1 is crystallized in P21/c space group of monoclinic crystal system, and exhibits good physical properties, such as high densities （〉 1.55 g·cm^-3） and good thermal stabilities （Td〉220 ℃）. The intrermolecular hydrogen bonds construct the P- and M-helices from organic molecules and may contribute to the high melting points.
基金supported by the National Science Foundation(nos.CHE-1808829 and DMR 1809612)National Institutes of Health(no.R01DC014461)the United States,and the Gordon and Betty Moore Foundation.
文摘While self-assembly is relatively well-known and widely used to form hierarchical structures and thin film coatings,controlled assembly is less known and utilized.Our prior work has demonstrated the concept of controlled assembly of macromolecules such as star polymers[molecular weight(M_(w))∼383 kDa,hydrodynamic radius R∼13.8 nm]in droplets.This work extends this concept to smaller molecules,in this case,poly(ethylene glycol)bis-tetrazine(PEGbisTz,M_(w) 8.1 kDa,R∼1.5 nm).The key to controlled molecular assembly is to first deliver ultrasmall volumes(sub-fL)of solution containing PEG-bisTz to a substrate.The solvent evaporates rapidly due to the minute volume,thus forcing the assembly of solute,whose overall size and dimension are dictated by the initial liquid geometry and size.Using prepatterned surfaces,this work revealed that the initial liquid shape can be further tuned,and we could control the final assembly of solute such as PEGbisTz molecules.The degree of control was demonstrated by varying the micropatterns and delivery conditions.This work demonstrated the validity of controlled assembly for PEG-bisTz and enables three-dimensional(3D)nanoprinting of functional materials.The technology has promising applications in nanophotonics,nanoelectronics,nanocomposite materials,and tissue engineering.
