检索结果-南通市图书馆

Chinese Journal of Chemistry 2015年第9期33卷 1041-1048页

作者： Qian Li Junfeng Xiang yalin tang Beijing National Laboratory for Molecular Sciences (BNLMS) Center for Molecular SciencesState Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Aeademy of Sciences Beijing 100190 China

Compounds selectively binding and stabilizing G-quadruplex structures could inhibit the telomerase or down- regulate the oncogenes and may act as anti-cancer drugs. An alkaloid with non-flat structure, fangchinoline, showed to strongly stabilize the intermolecular and intramolecular parallel stranded G-quadruplex structure, increasing melting temperature by 20 and 23℃, respectively. The binding mode was investigated by using NMR and molec- ular modelling methods. Four human cell lines （HL-60, BGC-823, Be1-7402 and KB） were taken to test the an- ti-proliferation effects of fangchinoline and the IC50 values were ranged from 16 to 32 μmol/L. These results showed that the fangchinoline or related moiety derivatives may represent a class of telomere-targeted agents as po- tential anti-cancer drugs.

关键词： G-quadruplex alkaloid non-flat anti-cancer drug

A comparative study of assembly and disassembly process of dimeric and monomeric cyanine dyes with DNA templates

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2019年第3期30卷 694-697页

作者： Lijia Yu Qianfan Yang yalin tang National Center of Occupational Safety and Health State Administration of Work Safety College of Chemistry Sichuan University Beijing National Laboratory for Molecular Science Center for Molecular Science State Key Laboratory for Structural Chemistry for Unstable and State Species Institute of Chemistry Chinese Academy of Sciences

Cyanine dyes have attracted more and more interest due to their controllable assembly and disassembly process with biomolecular templates. The self-assembly of cyanine dye not only depend on the environment, but also on their structures. Here, we report assembly and disassembly of two cyanine dyes,a dimeric cyaine dye(TC-P4) and its corresponding monomer(TC). In PBS, these dyes could form aggregates. The parallel c-myc G-quadruplex as a template causes the transformation of TC-P4 from Haggregates to dimer and monomer; while duplex and single-stranded DNAs could not. The interaction between these DNAs motifs and TC could all induce the appearance of monomer band. Parallel c-myc Gquadruplex could enhance the fluorescence intensity of TC-P4 and TC. The self-assembly and disassembly of TC and TC-P4 could be regulated and used as probes for G-quadruplex recognition from duplex and single-stranded DNAs in solution.

关键词： Cyanine dye Supramolecular assembly DNA templates G-quadruplex c-myc

Nutrition impacts of non-solid cooking fuel adoption on under-five children in developing countries

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第2期23卷 397-413页

作者： yalin tang Yuhe Guo Gang Xie Chengfang Liu China Center for Agricultural Policy School of Advanced Agricultural SciencesPeking UniversityBeijing 100871China Agricultural Information Institute Chinese Academy of Agricultural SciencesBeijing 100081China

This paper examines the nutrition impacts of using non-solid cooking fuel on under-five children in developing *** draw on data from more than 1.12 million children in 62 developing countries from the Demographic and Health Surveys(DHS).Results from both fixed effects(FE)and instrumental variable(IV)estimates show that using non-solid cooking fuel significantly improves the nutrition outcomes of under-five *** with their peers from households mainly using solid fuel,children from households mainly using non-solid fuel exhibit a lower probability of experiencing stunting(by 5.9 percentage points)and being underweight(by 1.2 percentage points).Our further investigation provides evidence for several underlying mechanisms,such as improved indoor air quality,induced reduction in children’s respiratory symptoms,benefits on maternal health,and reduction in maternal time spent on fuel collection or *** analyses suggest that the nutrition benefits of using non-solid cooking fuel are more prominent among boys,children above three years old,and those from households of lower socioeconomic status,rural areas,and Southeast Asia.

关键词： non-solid cooking fuel nutrition benefits under-five children developing countries

Kinetic characterization of a slow chemical exchange between two sites in N,N-dimethylacetylamide by CEST NMR spectroscopy

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第9期33卷 4335-4338页

作者： Lixia Wang Jikun Li Junfeng Xiang Jie Cui yalin tang Beijing National Laboratory for Molecular Sciences(BNLMS) Center for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Nuclear magnetic resonance(NMR)spectroscopy has provided many powerful tools for the study of dynamic *** the reported methods,chemical exchange saturation transfer(CEST)is more suitable for systems with slow exchange rates,and there will be promising in the detection and dynamic mechanism of metastable *** has been widely used in magnetic resonance imaging(MRI),however whether it is applicable in the field of chemical kinetics needs more *** we studied,as a proof of concept,the kinetics of the slow chemical exchange between the two N-methyl protons of N,N-dimethylacetylamide(DMA),exploiting QUantifying Exchange using Z-spectrum(QUEZS)and QUantifying Exchange using Saturation Time(QUEST)*** turned out that both of QUEZS and QUEST could give the corresponding exchange rates,showcasing the capability of this method to provide accurate kinetic data under a range of *** results clearly demonstrated the reliability of CEST-based techniques as a tool for dynamic kinetics by NMR.

关键词： Chemical exchange saturation transfer(CEST) Chemical exchange N,N-Dimethylacetylamid Bloch-Mc Connell equation Dynamic kinetics

Novel sintering behavior of polystyrene nano-latex particles in filming process

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第12期46卷 991-995页

作者： Xiaozhong Qu yalin tang Liusheng Chen Xigao Jin Chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Polymer Phys & Chem Beijing 100080 Peoples R China

Filming process of polystyrene nano-latex (NPS) particles was studied by a combination of various methods. For a constant annealing time of 1 h, the AFM images showed that the deformation and sintering temperatures for NFS particles were ca. 90 ℃ and 100 ℃ respectively. In spin-lattice relaxation measurements of solid state NMR, it is found that TIL, T1S and /1L/I0 increased significantly after annealing at 90℃ and above. DSC results showed that there was an exothermic peak near Tg after annealing for 1 h at the selected temperatures below 95℃; otherwise, the exothermic peak disappeared after annealing at 100℃ or above. The apparent density of NPS increased suddenly in the temperature range. The results implied that the macromolecules in NPS particles are in a confined state with higher confor-mational energy and less cohensional interactions which are the drive force for the sintering at a lower temperature compared with the multichain PS particles and the bulk polymer.

关键词： polystyrene nano-latex filming process.

New insights into the effect of molecular crowding environment induced by dimethyl sulfoxide on the conformation and stability of G-quadruplex

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第3期34卷 326-331页

作者： Yumeng Yang Junfeng Xiang Hongxia Sun Hengwen Chen Hong Zhang yalin tang Beijing National Laboratory for Molecular Sciences State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Center for Physiochemical Analysis&Measurement Institute of ChemistryChinese Academy of SciencesBeijing 100190China Department of Cardiology Guang’anmen HospitalChina Academy of Chinese Medical SciencesBeijing 100053China

Various structures of G-quadruplex in biosystems play an important role in different diseases and are often regulated by a variety of molecular crowding environments induced by internal and even external factors(e.g.,a solvent).Dimethyl sulfoxide(DMSO),a universal solvent,has been widely used in biological studies and for drug therapy,but little is known regarding its effect on G-quadruplex structure and ***,we report the influence of molecular crowding environment induced by DMSO on the conformation and stability of G-quadruplex *** show that the G-quadruplex-forming sequences such as human telomeric sequence,which may have diverse conformations in different environments,tend to convert their topologies to parallel structures under the molecular crowding stimulated by ***,DMSO can increase the stability of the parallel and antiparallel topologies,especially the parallel G-quadruplex sequence c-kit,but not the hybrid *** analysis of c-kit using the CD and NMR technique,combined with the unique structural characteristics of c-kit,reveals that the crowding,dehydration and interaction of DMSO are conductive to the formation and stability of the parallel *** present study suggests that,DMSO,a common solvent used in DNA experiments,may have a nonnegligible influence on the structure and stability of G-quadruplex.

关键词： Dimethyl sulfoxide G-quadruplex c-kit Molecular crowding

Spectroscopic studies of the interaction between methyleneblue and G-quadruplex

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第14期51卷 1687-1692页

作者： SUN Hongxia XIANG Junfeng ZHANG Yazhou XU Guangzhi XU Lianghua tang yalin College of Material Science and Engineering Beijing University ofChemical Technology Beijing 100029 China Institute of Chemistry Chinese Academy of Sciences Beijing 100080China

G-rich single-stranded DNA (5′-TTAG-GG-3′) adopted a G-quadruplex structure in buffercontaining potassium ions. The spectroscopic featureand the interaction between methylene blue andG-quadruplex have been investigated by circular di-chroism, and nuclear magnetic resonance spectros-copy. The UV-Vis absorption and fluorescence spec-tral results show that the fluorescence behavior ofMB by single-stranded DNA fits Stern-Volmer staticquenching equation very well and they formed 1︰1complexes; dimeric G-quadruplexes were bound toMB with 1︰1 or 2︰1, and their equilibrium constantswere 1.047×105 and 8.79×104 L/mol, *** on the above results and 1H-NMR spectraldata, one may conclude that MB stacked either theterminal tetrads to form 1︰1 complexes or betweentwo terminal tetrads of G-quadruplexes to form 1︰2sandwich complexes with G-qudruplexes.

关键词：甲基蓝吸收荧光分光检查钾离子

Metabonomics analysis of the urine of rats with Qi deficiency and blood stasis syndrome based on NMR techniques

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2007年第22期52卷 3068-3073页

作者： LI Lin WANG JianNong REN JianXun XIANG JunFeng tang yalin LIU JianXun HANDing State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China Xi Yuan Hospital China Academy of Chinese Medical Sciences Beijing 100091 China

Metabonomics analysis of the urine of rats with Qi deficiency and blood stasis syndrome has been performed by comparison with those of normal rats based on NMR techniques. The relative contents of formate,creatinine,2-oxoglutarate(2-OG) ,citrate,taurine,trimethylamine-N-oxide(TMAO) ,succinate and hippurate in the urine of the rats with Qi deficiency and blood stasis syndrome have been changed. These results have provided evidence for understanding the mechanism and the therapy of Qi defi-ciency and blood stasis syndrome.

关键词：代谢组学尿大鼠血液核磁共振技术

An important functional group, benzo[1,3]dioxole, of alkaloids induces the formation of the human telomeric DNA G-quadruplex

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2011年第7期56卷 613-617页

作者： YANG Shu XIANG JunFeng YANG QianFan ZHOU QiuJu ZHANG XiuFeng Li Qian tang yalin XU GuangZhi Beijing National Laboratory for Molecular Sciences Centre for Molecular SciencesState Key Laboratory for Structural Chemistry for Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China Graduate University of Chinese Academy of Sciences Beijing 100049China

Over the past few decades, numerous molecules have been discovered or designed to interact efficiently and selectively with a peculiar DNA structure named G-quadruplex. Some of these molecules have been developed as anticancer agents. To aid the design of anticancer agents, the ability of alkaloids possessing Protoberberine and Benzophenanthridine groups to induce the formation of G-quadruplexes were studied using CD spectroscopy. By careful examination of their structures, we found that a benzo[1,3]dioxole group plays an important role in influencing their inductive properties. The more functional groups the alkaloids have, the stronger their G-quadruplex inductive ability.

关键词：端粒DNA 生物碱诱导职能人类四链苯抗癌药物

Roles of flanking sequences in the binding between unimolecular parallel-stranded G-quadruplexes and ligands

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2013年第7期58卷 731-744页

作者： GAI Wei YANG QianFan XIANG JunFeng SUN HongXia SHANG Qian LI Qian JIANG Wei GUAN AiJiao ZHANG Hong tang yalin XU GuangZhi Beijing National Laboratory for Molecular Sciences Center for Molecular SciencesState Key Laboratory for Structural Chemistry for Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of Sciences Graduate University of Chinese Academy of Sciences

G-quadruplexes attract more and more attention in recent *** small molecules which can induce or stabilize the formation of G-quadruplexes have been investigated on the purpose of anticancer drug *** a motif existed in physiological condition,flanking sequences are an important part of G-quadruplexes but the study on the impact of flanking sequences on (G-quadruplex)-ligand binding is rarely *** this paper,the effects of flanking sequences on binding affinity between a series of unimolecular parallel-stranded G-quadruplex sequences derived from c-myc oncogene promoter (termed as c-myc G-quadruplexes) and their ligands are discussed in *** results showed that the flanking sequences on c-myc G-quadruplexes play key roles in (G-quadruplex)-ligand *** a c-myc G-quadruplex is bound to its ligands,the flanking sequences might form a binding cavity above the terminal G-quartet,which could provide a suitable site for ligands to dock ***,the bases on flanking sequences could interact with ligand through π-π stacking,and finally form a sandwich-stacking mode (terminal G-quartet,ligand and bases on the flanking sequence).This mode could stabilize the (G-quadruplex)-ligand complex effectively and enhance the binding affinity ***,flanking sequences are also found to exhibit steric hindrance effect which could impede the (G-quadruplex)-ligand binding.

关键词： G-quadruplex flanking sequences interaction mechanism c-myc cyanine dye