By means the in situ halogenation of the vinyl C-H bond in o-hydroxyphenyl enaminones,the step efficient synthesis of 3-diphenylphosphinyl chromones has been realized through the challenging construction of C-P(Ⅲ) bo...By means the in situ halogenation of the vinyl C-H bond in o-hydroxyphenyl enaminones,the step efficient synthesis of 3-diphenylphosphinyl chromones has been realized through the challenging construction of C-P(Ⅲ) bond by using diphenyl phosphine as reaction partner.In addition,the tunable synthesis of 2-phosphoryl chromanones has been achieved via hydrophosphorylation by simply modifying reaction conditions without using metal reagent.展开更多
We herein present an efficient denitrative iodination method of(hetero)nitroarenes mediated by commercially available and cost-effective hydroiodic acid(HI).During the reaction process,HI plays its dual roles as both ...We herein present an efficient denitrative iodination method of(hetero)nitroarenes mediated by commercially available and cost-effective hydroiodic acid(HI).During the reaction process,HI plays its dual roles as both the sustainable reductant of nitro group and iodine source in the iodination step,which successfully integrates three steps into a one-pot procedure and significantly simplifies the reaction system.This approach enables a smooth metal-free conversion of nitroarenes to corresponding aryl iodides via one-pot process,exhibits a broad substrate scope and good reaction efficiency,and was conveniently applied in the concise synthesis of pharmaceuticals.展开更多
5-Iodouracil derivatives have interesting biological activities and can serve as important substrates for the metal-catalyzed cross-coupling reactions to introduce alkyl, alkenyl, and alkynyl groups to the C-5 positio...5-Iodouracil derivatives have interesting biological activities and can serve as important substrates for the metal-catalyzed cross-coupling reactions to introduce alkyl, alkenyl, and alkynyl groups to the C-5 position of uracil derivatives. In order to find a good method to iodinate directly the C-5 of uracil derivatives, we investigated three methods, which included iodine/lead （IV） dioxide, iodine/ammonium hexanitratocerate （CAN） and iodine chloride, and examined their reactivity to different types of uracil and thiouracil derivatives.展开更多
Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides sever...Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure.展开更多
Freeze-induced acceleration of I–oxidation and the consequent iodination of dissolved organic matter(DOM)contribute to the formation of organoiodine compounds(OICs)in cold regions.The formed OICs may be a potentially...Freeze-induced acceleration of I–oxidation and the consequent iodination of dissolved organic matter(DOM)contribute to the formation of organoiodine compounds(OICs)in cold regions.The formed OICs may be a potentially important source of risk and are very closely with the environment and human health.Herein,we investigated the acceleration effects of the freeze process on I–oxidation and the formation of OICs.In comparison to reactive iodine species(RIS)formed in aqueous solutions,I–oxidation and RIS formation were greatly enhanced in frozen solution and were affected by pH,and the content of I–and O_(2).Freeze-thaw process further promoted I–oxidation and the concentration of RIS reached 45.7μmol/L after 6 freeze-thaw cycles.The consequent products of DOM iodination were greatly promoted in terms of both concentration and number.The total content of OICs ranged from 0.02 to 2.83μmol/L under various conditions.About 183–1197 OICs were detected by Fourier transform ion cyclotron resonance mass spectrometry,and more than 96.2%contained one or two iodine atoms.Most OICs had aromatic structures and were formed via substitution and addition reactions.Our findings reveal an important formation pathway for OICs and shed light on the biogeochemical cycling of iodine in the natural aquatic environment.展开更多
Palladium-catalyzed highly meta-selective C—H iodination of phenylacetic acid,benzylphosphonate and benzylsulfonate scaffolds with molecular I2 is developed using a pyridine-type template.The practical ester linkages...Palladium-catalyzed highly meta-selective C—H iodination of phenylacetic acid,benzylphosphonate and benzylsulfonate scaffolds with molecular I2 is developed using a pyridine-type template.The practical ester linkages enable the directing template easily installed and readily removed.The substrate scope is broad,and alkyl,methoxyl,trifluomethyl,and halo substituents are compatible with this reaction.Further transformations of ibuprofen iodide intermediates by Pd-catalyzed C—C and C-heteroatom bond formation illustrate the broad utility of this method.展开更多
The synthesis of aryl iodides from commercially available raw chemicals by simple,cheap and green strategies is of fundamental signifi cance.Aryl iodides can undergo a series of homo-/cross-coupling reactions for the ...The synthesis of aryl iodides from commercially available raw chemicals by simple,cheap and green strategies is of fundamental signifi cance.Aryl iodides can undergo a series of homo-/cross-coupling reactions for the synthesis of important industrial chemicals and materials.Traditional methods require the electrophilic substitution on aromatic compounds by iodine or hypervalent iodine compounds,which suff ers from the use of erosive halogens or hazardous oxidants.With the development of green chemistry in the fi eld of electrochemical synthesis,anodic oxidation-derived I^(+)cations have been used for substitution reactions.However,the selectivity of the iodination by these electrochemical methods remains unsatisfactory.We believed that the anolyte is contaminated by trace platinum species from the working electrode.Herein,we report the generation of active I^(+)species from the anodic oxidation of I_(2) in acetonitrile using a glassy carbon electrode.With the presence of H^(+),electrolyte prepared with a glassy carbon anode can react with anisole to selectively form 4-iodoanisole with a yield as high as 97%.On contrast,the electrolytes prepared from Pt and graphite anodes fi nished the reaction with yields of 16%and 60%for 4-iodoanisole,respectively.This electrochemical method also applies to the iodination of toluene,benzonitrile and bromobenzene,delivering the target para-iodination products with 92%,84%,and 73%yields,respectively.Thus,an atom-effi cient and highly selective aryl iodination method was developed without the use of excessive oxidants.展开更多
Potassium ferrate impregnated on montmorillonite is a mild,cheap,and non-toxic reagent for the iodination of phenols, including naphthol,aromatic amines,and heterocyclic substrates in fair to excellent yields by a sim...Potassium ferrate impregnated on montmorillonite is a mild,cheap,and non-toxic reagent for the iodination of phenols, including naphthol,aromatic amines,and heterocyclic substrates in fair to excellent yields by a simple isolation procedure.展开更多
A simple and efficient method for the iodination of aromatic compounds has been achieved in the presence of iodine and 1,4- bis（triphenylphosphonium）-2-butene peroxodisulfate.
Arsenic(As)contamination in vegetables poses significant ecological and health risks,raising substantial public concern.While arsenic accumulation and transformation have been studied,the in-situ iodination effects an...Arsenic(As)contamination in vegetables poses significant ecological and health risks,raising substantial public concern.While arsenic accumulation and transformation have been studied,the in-situ iodination effects and mechanisms under co-contamination with arsenic and phenolic pollutants(e.g.,bisphenol F)remain unclear.This study addresses this gap by exposing Brassica chinensis L.to hydroponic solutions containing sodium hydrogen arsenate heptahydrate(As(V))at concentrations of 0-100μmol/L,BPF at 3 mg/L,and iodide ions at 40μmol/L under environmentally relevant conditions.Results demonstrate that As(V)enhances the iodination of BPF by increasing levels of reactive oxygen species(H_(2)O_(2)and•OH)and elevating peroxidase(POD)activity,as confirmed by transcriptomic analysis.As the concentration of As(V)increased from 0 to 100μmol/L,the diversity and concentration of iodinated BPF products in the roots exhibited a dose-dependent increase,while the variety of iodinated products in the leaves also showed a corresponding rise.Gaussian calculations and mass spectrometry identified the specific substitution sites and the number of iodide atoms incorporated into BPF molecules.By combining toxicity predictions of iodinated BPF using the Toxicity Estimation Software Tool(T·E·S·T)and the Ecological Structure-Activity Relationships(ECOSAR)model with measurements of HepG2 cell viability and lactate dehydrogenase(LDH)activity in the cell culture medium,it was found that the toxicity of iodinated BPF products in plants increased following the addition of As(V).This study highlights the combined risks of arsenic and bisphenol contamination,revealing arsenic’s role in enhancing bisphenol iodination and toxicity in plants.展开更多
Hydrogen peroxide was supported on polyvinylpyrrolidone to afford a stable and mild oxidizing reagent. Activated aromatic compounds were reacted with PVP-H2O2 in the presence of KI or I2 and a catalytic amount of H3PW...Hydrogen peroxide was supported on polyvinylpyrrolidone to afford a stable and mild oxidizing reagent. Activated aromatic compounds were reacted with PVP-H2O2 in the presence of KI or I2 and a catalytic amount of H3PW12O40 in refluxing CH2Cl2 to afford the corresponding iodinated arenes.展开更多
Flavin-dependent halogenases (FDHs) are well known to introduce carbon halide bonds (mainly C–Cl and C–Br) into natural products with the assistance of a partner protein flavin reductase to generate reduced flavin (...Flavin-dependent halogenases (FDHs) are well known to introduce carbon halide bonds (mainly C–Cl and C–Br) into natural products with the assistance of a partner protein flavin reductase to generate reduced flavin (FADH_(2)or FMNH_(2)).Compared with the common chloride-and bromide-containing natural products (approximately 5,000 compounds),iodinated natural products(approximately 100 compounds) are very limited.Specific iodinases have also rarely been identified in nature to date.This study discovered a novel relationship between iodination and flavin reductases for the first time.Through mechanistic studies,it was identified that peroxide (H_(2)O_(2)) was released from the uncoupling reaction of flavin reductases and then reacted with iodide ions(I^(-)) to produce hypoiodous acid (IOH) for the final iodination.Furthermore,this study also unintentionally verified that the recently reported flavin-dependent iodinase Vir X1 from the marine virus and its two homologs (MBG and NCV) did not catalyze iodination in the in vitro biochemical system but likely belonged to a new phylogenetic clade in the tryptophan halogenase superfamily.As a consequence,actual flavin-dependent iodinases in nature remain to be discovered by the scientific community in the future.展开更多
Tiacumicin B(also known as fidaxomicin or difimicin)is a marketed 18-membered macrolide antibiotic for the treatment of Clostridium difficile infections.Tiacumicin B is structurally characterized with two chlorine ato...Tiacumicin B(also known as fidaxomicin or difimicin)is a marketed 18-membered macrolide antibiotic for the treatment of Clostridium difficile infections.Tiacumicin B is structurally characterized with two chlorine atoms substituted on the aromatic ring,which is installed by the halogenase Tia M.During the study on halide compatibility of Tia M,a facile and nonenzymatic iodination method of didechlorotiacumicin B was discovered,requiring Na I,acid and air for iodination at room temperature.This method was also amenable to other 9 aromatic substrates with electron-rich sites for iodination.展开更多
Metathesis reactions represent powerful synthetic tools that have been used in a number of fields from the synthesis of natural product to functional material preparation.However,the C-H metathesis reaction is extreme...Metathesis reactions represent powerful synthetic tools that have been used in a number of fields from the synthesis of natural product to functional material preparation.However,the C-H metathesis reaction is extremely rare.Herein,we report the first Pd(Ⅱ)-catalyzed C-H iodination of arenes using 2-nitrophenyl iodides as the mild iodinating reagents via a formal metathesis reaction.Unusual C-I bond formation occurred with aryl iodides in preference to competing C-C coupling in this reaction.Assisted by aliphatic carboxyl directing groups,a range of hydrocinnamic acids and related arenes could be selectively iodinated at either meta-or orthopositions of the phenyl ring.Remote diastereoselective C-H activation was also promising.This method might unfold a novel approach to iodinate challenging substrates.展开更多
Neoadjuvant therapy(NAT)has become the standard treatment for patients with locally advanced breast cancer and stage II-III HER2-positive(HER2+)or triple-negative breast cancer(TNBC)1,2.It is essential to accurately m...Neoadjuvant therapy(NAT)has become the standard treatment for patients with locally advanced breast cancer and stage II-III HER2-positive(HER2+)or triple-negative breast cancer(TNBC)1,2.It is essential to accurately mark the primary breast tumor and positive axillary lymph nodes(ALNs)prior to NAT to ensure precise surgical excision,guide axillary downstaging,and guarantee reliable lesion retrieval for pathologic evaluation3.The false-negative rate of sentinel lymph node biopsy(SLNB)after NAT can be reduced to<10%by applying modalities,such as the identification of≥3 sentinel lymph nodes(SLNs)with dual-mapping techniques or removal of the marked lymph node with target axillary dissection(TAD)according to the ASCO,NCCN,and CBCS guidelines3-5.However,there is a lack of consensus regarding the optimal methods and materials for accurate marking6,7.Conventional techniques include clip placement,guidewire localization,and carbon or ink tattooing,whereas wireless technologies,such as MagseedR,radiofrequency identification tags,SAVI SCOUTR,and radioactive iodine-125(125I)seeds,have also been adopted.Traditional marking techniques have a localization failure rate of approximately 10%.In contrast,the use of 125I seeds(with a radiation dose of 0.1-0.3 mCi)has significantly improved localization accuracy8,9.Nevertheless,owing to radioactive properties,concerns have been raised regarding the potential impact of 125I seed marking on assessing the pathologic complete response(pCR)after NAT10.Moreover,whether the influence of 125I seed marking on pCR could lead to suboptimal adjuvant treatment decisions and potentially compromise long-term oncologic outcomes has not been established.To investigate the potential impact of 125I seed placement on the pCR rate and long-term outcomes in breast cancer patients receiving NAT,we conducted a retrospective cohort study utilizing propensity score matching(PSM).展开更多
Imbibitional chilling injury occurs under a sharp gradient of water potential between seeds and soil associated with low temperature (【10℃), which causes the physical change in membrane structure and a resulting met...Imbibitional chilling injury occurs under a sharp gradient of water potential between seeds and soil associated with low temperature (【10℃), which causes the physical change in membrane structure and a resulting metabolic dysfunction in it. The cracking lesions perhaps is the most severe manifestation. In general, vigor decreases and ultimately viability completely loses in seeds. Imbibitional chilling injury, which is a common phenomenon in a展开更多
A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cy...A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cyclic protected amines were readily synthesized without requiring exogenous transition-metal or photoredox catalysts.Moreover,this ap-proach facilitates late-stage functionalization of complex molecules and is amenable to continuous-flow process on gram scale.展开更多
A synthetic method for heteroatom-bridged cyclic diaryliodonium salts by using ortho-substituted functionalized diaryliodonium salts is presented.Coumarin skeleton was also incorporated into cyclic diaryliodonium salt...A synthetic method for heteroatom-bridged cyclic diaryliodonium salts by using ortho-substituted functionalized diaryliodonium salts is presented.Coumarin skeleton was also incorporated into cyclic diaryliodonium salts.UV-Visible absorption of these cyclic diaryliodonium salts was performed to demonstrate their potential applications in photo-chemistry.展开更多
Iodine is an essential element for the synthesis of thyroid hormones.Iodine deficiency increases the burden on thyroid function and causes harm to health.The identification of convenient and reliable biomarkers for as...Iodine is an essential element for the synthesis of thyroid hormones.Iodine deficiency increases the burden on thyroid function and causes harm to health.The identification of convenient and reliable biomarkers for assessing iodine nutritional status is essential for evaluating iodine intake.Urinary iodine concentration(UIC)is commonly used for population level iodine status assessment but is less reliable for individuals.A 24-h urine sample is more accurate but difficult to collect[1].Thyroid volume(Tvol)and goiter rate are suitable for evaluating the long-term iodine nutritional status in populations[2].Blood indicator collection is an invasive procedure.展开更多
A recent paper published in Journal of the American Chemical Society by W.Zhang and co-workers reported a ground-breaking advance by establishing 209 Bi and 127 I ultra-wideline solid-state NMR(UW SSNMR)as powerful to...A recent paper published in Journal of the American Chemical Society by W.Zhang and co-workers reported a ground-breaking advance by establishing 209 Bi and 127 I ultra-wideline solid-state NMR(UW SSNMR)as powerful tools for probing bismuth and iodine ions in metal-organic frameworks(MOFs),despite the severe challenges associated with their exceptionally large quadrupolar interactions,and enabled the elucidation of key structural features that are otherwise difficult to access[1].展开更多
基金financially supported by the National Natural Science Foundation of China (No.22261026)。
文摘By means the in situ halogenation of the vinyl C-H bond in o-hydroxyphenyl enaminones,the step efficient synthesis of 3-diphenylphosphinyl chromones has been realized through the challenging construction of C-P(Ⅲ) bond by using diphenyl phosphine as reaction partner.In addition,the tunable synthesis of 2-phosphoryl chromanones has been achieved via hydrophosphorylation by simply modifying reaction conditions without using metal reagent.
基金the National Key Research and Development Project(No.2023YFF1205103)the National Natural Science Foundation of China(No.22371007)the Peking University Medicine plus X Pilot Program-Key Technologies R&D Project(No.2024YXXLHGG001)for financial support。
文摘We herein present an efficient denitrative iodination method of(hetero)nitroarenes mediated by commercially available and cost-effective hydroiodic acid(HI).During the reaction process,HI plays its dual roles as both the sustainable reductant of nitro group and iodine source in the iodination step,which successfully integrates three steps into a one-pot procedure and significantly simplifies the reaction system.This approach enables a smooth metal-free conversion of nitroarenes to corresponding aryl iodides via one-pot process,exhibits a broad substrate scope and good reaction efficiency,and was conveniently applied in the concise synthesis of pharmaceuticals.
基金National Natural Science Foundation of China (Grant No.2017200720672008).
文摘5-Iodouracil derivatives have interesting biological activities and can serve as important substrates for the metal-catalyzed cross-coupling reactions to introduce alkyl, alkenyl, and alkynyl groups to the C-5 position of uracil derivatives. In order to find a good method to iodinate directly the C-5 of uracil derivatives, we investigated three methods, which included iodine/lead （IV） dioxide, iodine/ammonium hexanitratocerate （CAN） and iodine chloride, and examined their reactivity to different types of uracil and thiouracil derivatives.
文摘Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure.
基金This work was supported by the National Natural Science Foundation of China(Nos.22176199,21806173,and 42192571)the Jinan University and Institute Innovation Team Project(No.2021GXRC061).
文摘Freeze-induced acceleration of I–oxidation and the consequent iodination of dissolved organic matter(DOM)contribute to the formation of organoiodine compounds(OICs)in cold regions.The formed OICs may be a potentially important source of risk and are very closely with the environment and human health.Herein,we investigated the acceleration effects of the freeze process on I–oxidation and the formation of OICs.In comparison to reactive iodine species(RIS)formed in aqueous solutions,I–oxidation and RIS formation were greatly enhanced in frozen solution and were affected by pH,and the content of I–and O_(2).Freeze-thaw process further promoted I–oxidation and the concentration of RIS reached 45.7μmol/L after 6 freeze-thaw cycles.The consequent products of DOM iodination were greatly promoted in terms of both concentration and number.The total content of OICs ranged from 0.02 to 2.83μmol/L under various conditions.About 183–1197 OICs were detected by Fourier transform ion cyclotron resonance mass spectrometry,and more than 96.2%contained one or two iodine atoms.Most OICs had aromatic structures and were formed via substitution and addition reactions.Our findings reveal an important formation pathway for OICs and shed light on the biogeochemical cycling of iodine in the natural aquatic environment.
基金Shanghai Institute of Materia Medica,Chinese Academy of Sciences,National Natural Science Foundation of China(No.21772211)Youth Innovation Promotion Association CAS(Nos.2014229 and 2018293)+4 种基金Institutes for Drug Discovery and Development,Chinese Academy of Sciences(No.CASIMM0120163006)Science and Technology Commission of Shanghai Municipality(No.17JC1405000)Program of Shanghai Academic Research Leader(No.19XD1424600)National Science&Technology Major Project“Key New Drug Creation and Manufacturing Program”,China(No.2018ZX09711002-006)the State Key Laboratory of Natural and Biomimetic Drugs for financial support。
文摘Palladium-catalyzed highly meta-selective C—H iodination of phenylacetic acid,benzylphosphonate and benzylsulfonate scaffolds with molecular I2 is developed using a pyridine-type template.The practical ester linkages enable the directing template easily installed and readily removed.The substrate scope is broad,and alkyl,methoxyl,trifluomethyl,and halo substituents are compatible with this reaction.Further transformations of ibuprofen iodide intermediates by Pd-catalyzed C—C and C-heteroatom bond formation illustrate the broad utility of this method.
文摘The synthesis of aryl iodides from commercially available raw chemicals by simple,cheap and green strategies is of fundamental signifi cance.Aryl iodides can undergo a series of homo-/cross-coupling reactions for the synthesis of important industrial chemicals and materials.Traditional methods require the electrophilic substitution on aromatic compounds by iodine or hypervalent iodine compounds,which suff ers from the use of erosive halogens or hazardous oxidants.With the development of green chemistry in the fi eld of electrochemical synthesis,anodic oxidation-derived I^(+)cations have been used for substitution reactions.However,the selectivity of the iodination by these electrochemical methods remains unsatisfactory.We believed that the anolyte is contaminated by trace platinum species from the working electrode.Herein,we report the generation of active I^(+)species from the anodic oxidation of I_(2) in acetonitrile using a glassy carbon electrode.With the presence of H^(+),electrolyte prepared with a glassy carbon anode can react with anisole to selectively form 4-iodoanisole with a yield as high as 97%.On contrast,the electrolytes prepared from Pt and graphite anodes fi nished the reaction with yields of 16%and 60%for 4-iodoanisole,respectively.This electrochemical method also applies to the iodination of toluene,benzonitrile and bromobenzene,delivering the target para-iodination products with 92%,84%,and 73%yields,respectively.Thus,an atom-effi cient and highly selective aryl iodination method was developed without the use of excessive oxidants.
基金the Islamic Azad University of Qaemshahr for financial support
文摘Potassium ferrate impregnated on montmorillonite is a mild,cheap,and non-toxic reagent for the iodination of phenols, including naphthol,aromatic amines,and heterocyclic substrates in fair to excellent yields by a simple isolation procedure.
文摘A simple and efficient method for the iodination of aromatic compounds has been achieved in the presence of iodine and 1,4- bis（triphenylphosphonium）-2-butene peroxodisulfate.
基金supported by the National Key Research and Developmental Program of China(No.2022YFC3701301)the National Natural Science Foundation of China(Nos.42230706 and 42377428)+1 种基金the Shandong Provincial Natural Science Foundation,China(Nos.ZR2020ZD34 and ZR2023YQ031)the Instrument Improvement Funds of Shandong University Public Technology Platform(China)(No.ts20230108).
文摘Arsenic(As)contamination in vegetables poses significant ecological and health risks,raising substantial public concern.While arsenic accumulation and transformation have been studied,the in-situ iodination effects and mechanisms under co-contamination with arsenic and phenolic pollutants(e.g.,bisphenol F)remain unclear.This study addresses this gap by exposing Brassica chinensis L.to hydroponic solutions containing sodium hydrogen arsenate heptahydrate(As(V))at concentrations of 0-100μmol/L,BPF at 3 mg/L,and iodide ions at 40μmol/L under environmentally relevant conditions.Results demonstrate that As(V)enhances the iodination of BPF by increasing levels of reactive oxygen species(H_(2)O_(2)and•OH)and elevating peroxidase(POD)activity,as confirmed by transcriptomic analysis.As the concentration of As(V)increased from 0 to 100μmol/L,the diversity and concentration of iodinated BPF products in the roots exhibited a dose-dependent increase,while the variety of iodinated products in the leaves also showed a corresponding rise.Gaussian calculations and mass spectrometry identified the specific substitution sites and the number of iodide atoms incorporated into BPF molecules.By combining toxicity predictions of iodinated BPF using the Toxicity Estimation Software Tool(T·E·S·T)and the Ecological Structure-Activity Relationships(ECOSAR)model with measurements of HepG2 cell viability and lactate dehydrogenase(LDH)activity in the cell culture medium,it was found that the toxicity of iodinated BPF products in plants increased following the addition of As(V).This study highlights the combined risks of arsenic and bisphenol contamination,revealing arsenic’s role in enhancing bisphenol iodination and toxicity in plants.
文摘Hydrogen peroxide was supported on polyvinylpyrrolidone to afford a stable and mild oxidizing reagent. Activated aromatic compounds were reacted with PVP-H2O2 in the presence of KI or I2 and a catalytic amount of H3PW12O40 in refluxing CH2Cl2 to afford the corresponding iodinated arenes.
基金the National Natural Science Foundation of China(21632007,21661140002 for S.Lin81903525 for Y.Zhang)+1 种基金Research Fund for High-level Talents of Xinxiang Medical University(300-505272)Open Funding Project of State Key Laboratory of Microbial Metabolism,Shanghai Jiao Tong University(MMLKF2011)。
文摘Flavin-dependent halogenases (FDHs) are well known to introduce carbon halide bonds (mainly C–Cl and C–Br) into natural products with the assistance of a partner protein flavin reductase to generate reduced flavin (FADH_(2)or FMNH_(2)).Compared with the common chloride-and bromide-containing natural products (approximately 5,000 compounds),iodinated natural products(approximately 100 compounds) are very limited.Specific iodinases have also rarely been identified in nature to date.This study discovered a novel relationship between iodination and flavin reductases for the first time.Through mechanistic studies,it was identified that peroxide (H_(2)O_(2)) was released from the uncoupling reaction of flavin reductases and then reacted with iodide ions(I^(-)) to produce hypoiodous acid (IOH) for the final iodination.Furthermore,this study also unintentionally verified that the recently reported flavin-dependent iodinase Vir X1 from the marine virus and its two homologs (MBG and NCV) did not catalyze iodination in the in vitro biochemical system but likely belonged to a new phylogenetic clade in the tryptophan halogenase superfamily.As a consequence,actual flavin-dependent iodinases in nature remain to be discovered by the scientific community in the future.
基金the Key Science and Technology Project of Hainan Province(Key Science and Technology Project ZDKJ202018)the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou,2019ZD0406)+2 种基金the Chinese Academy of Sciences(QYZDJ-SSW-DQC004)the National Natural Science Foundation of China(81872778,31630004,41911530078)the Ministry of Science and Technology of China(2018YFC1406705)。
文摘Tiacumicin B(also known as fidaxomicin or difimicin)is a marketed 18-membered macrolide antibiotic for the treatment of Clostridium difficile infections.Tiacumicin B is structurally characterized with two chlorine atoms substituted on the aromatic ring,which is installed by the halogenase Tia M.During the study on halide compatibility of Tia M,a facile and nonenzymatic iodination method of didechlorotiacumicin B was discovered,requiring Na I,acid and air for iodination at room temperature.This method was also amenable to other 9 aromatic substrates with electron-rich sites for iodination.
基金NSFC(grant nos.22022111 and 22071248)the Natural Science Foundation of Fujian Province(grant nos.2020J02008 and 2020J01108)+1 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(grant no.2020306)the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB20000000).
文摘Metathesis reactions represent powerful synthetic tools that have been used in a number of fields from the synthesis of natural product to functional material preparation.However,the C-H metathesis reaction is extremely rare.Herein,we report the first Pd(Ⅱ)-catalyzed C-H iodination of arenes using 2-nitrophenyl iodides as the mild iodinating reagents via a formal metathesis reaction.Unusual C-I bond formation occurred with aryl iodides in preference to competing C-C coupling in this reaction.Assisted by aliphatic carboxyl directing groups,a range of hydrocinnamic acids and related arenes could be selectively iodinated at either meta-or orthopositions of the phenyl ring.Remote diastereoselective C-H activation was also promising.This method might unfold a novel approach to iodinate challenging substrates.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.82573747,82172873,W2421095,and 82503888)National Science and Technology Major Project(Grant No.2025ZD0543900)+2 种基金Natural Science Foundation of Shandong Province(Grant Nos.ZR2024LMB011 and ZR2024QH058)Taishan Scholars Program of Shandong Province(Grant No.tsqn202211337)Collaborative Academic Innovation Project of Shandong Cancer Hospital(Grant No.GF003).
文摘Neoadjuvant therapy(NAT)has become the standard treatment for patients with locally advanced breast cancer and stage II-III HER2-positive(HER2+)or triple-negative breast cancer(TNBC)1,2.It is essential to accurately mark the primary breast tumor and positive axillary lymph nodes(ALNs)prior to NAT to ensure precise surgical excision,guide axillary downstaging,and guarantee reliable lesion retrieval for pathologic evaluation3.The false-negative rate of sentinel lymph node biopsy(SLNB)after NAT can be reduced to<10%by applying modalities,such as the identification of≥3 sentinel lymph nodes(SLNs)with dual-mapping techniques or removal of the marked lymph node with target axillary dissection(TAD)according to the ASCO,NCCN,and CBCS guidelines3-5.However,there is a lack of consensus regarding the optimal methods and materials for accurate marking6,7.Conventional techniques include clip placement,guidewire localization,and carbon or ink tattooing,whereas wireless technologies,such as MagseedR,radiofrequency identification tags,SAVI SCOUTR,and radioactive iodine-125(125I)seeds,have also been adopted.Traditional marking techniques have a localization failure rate of approximately 10%.In contrast,the use of 125I seeds(with a radiation dose of 0.1-0.3 mCi)has significantly improved localization accuracy8,9.Nevertheless,owing to radioactive properties,concerns have been raised regarding the potential impact of 125I seed marking on assessing the pathologic complete response(pCR)after NAT10.Moreover,whether the influence of 125I seed marking on pCR could lead to suboptimal adjuvant treatment decisions and potentially compromise long-term oncologic outcomes has not been established.To investigate the potential impact of 125I seed placement on the pCR rate and long-term outcomes in breast cancer patients receiving NAT,we conducted a retrospective cohort study utilizing propensity score matching(PSM).
文摘Imbibitional chilling injury occurs under a sharp gradient of water potential between seeds and soil associated with low temperature (【10℃), which causes the physical change in membrane structure and a resulting metabolic dysfunction in it. The cracking lesions perhaps is the most severe manifestation. In general, vigor decreases and ultimately viability completely loses in seeds. Imbibitional chilling injury, which is a common phenomenon in a
文摘A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cyclic protected amines were readily synthesized without requiring exogenous transition-metal or photoredox catalysts.Moreover,this ap-proach facilitates late-stage functionalization of complex molecules and is amenable to continuous-flow process on gram scale.
基金Project supported by the National Natural Science Foundation of China(No.22478117)。
文摘A synthetic method for heteroatom-bridged cyclic diaryliodonium salts by using ortho-substituted functionalized diaryliodonium salts is presented.Coumarin skeleton was also incorporated into cyclic diaryliodonium salts.UV-Visible absorption of these cyclic diaryliodonium salts was performed to demonstrate their potential applications in photo-chemistry.
基金supported by the National Natural Science Foundation of China(Grant numbers 82204041)Gansu Provincial Science and Technology Program Funded Projects(Grant numbers 22JR11RA184).
文摘Iodine is an essential element for the synthesis of thyroid hormones.Iodine deficiency increases the burden on thyroid function and causes harm to health.The identification of convenient and reliable biomarkers for assessing iodine nutritional status is essential for evaluating iodine intake.Urinary iodine concentration(UIC)is commonly used for population level iodine status assessment but is less reliable for individuals.A 24-h urine sample is more accurate but difficult to collect[1].Thyroid volume(Tvol)and goiter rate are suitable for evaluating the long-term iodine nutritional status in populations[2].Blood indicator collection is an invasive procedure.
基金supported by the National Natural Science Foundation of China(Grants 22472075 and 22272075).
文摘A recent paper published in Journal of the American Chemical Society by W.Zhang and co-workers reported a ground-breaking advance by establishing 209 Bi and 127 I ultra-wideline solid-state NMR(UW SSNMR)as powerful tools for probing bismuth and iodine ions in metal-organic frameworks(MOFs),despite the severe challenges associated with their exceptionally large quadrupolar interactions,and enabled the elucidation of key structural features that are otherwise difficult to access[1].
