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排序方式: 共有285条查询结果,搜索用时 15 毫秒
1.
Huadong Tang Maciej Radosz Youqing Shen 《Journal of polymer science. Part A, Polymer chemistry》2006,44(22):6607-6615
Uracil‐derivatized monomer 6‐undecyl‐1‐(4‐vinylbenzyl)uracil and diaminopyrimidine‐derivatized monomer 2,6‐dioctanoylamido‐4‐methacryloyloxypyrimidine (DMP) were synthesized and polymerized by atom transfer radical polymerization (ATRP). A well‐defined, highly soluble, uracil‐containing polymer, poly[6‐undecyl‐1‐(4‐vinylbenzyl)uracil] (PUVU), was prepared in dioxane at 90 °C with CuBr/1,1,4,7,10,10‐hexamethyltriethylenetetramine as the catalyst and methyl α‐bromophenylacetate as the initiator. PUVU was further used as a template for the ATRP of DMP. The enhanced apparent rate constant of the DMP polymerization in the presence of PUVU indicated that the ATRP of DMP occurred along the PUVU template. The template polymerization produced a stable and insoluble macromolecular complex, PUVU/poly(2,6‐dioctanoylamido‐4‐methacryloyloxypyrimidine). An X‐ray diffraction study confirmed that the complex had strandlike domains. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6607–6615, 2006 相似文献
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Qi SUN Qiang XIAO Yong JU* Yu Fen ZHAO The Key Laboratory of Bioorganic Phosphorus Chemistry of Education Ministry Department of Chemistry School of Life Sciences Engineering Tsinghua University Beijing 《中国化学快报》2003,14(7):685-688
It is known that saccharides linked to proteins via a phosphoester hinge can function as immunological determinants. Under regular physiological conditions, it has been suggested that the role of phosphonate group is to direct the protease towards basic substrates1. Phosphoramidon a, which was isolated from a culture filtrate, is a potent inhibitor of the thermolysin, a metallo-endopeptidase. It is a glycosylated dipeptide, which has a L-rhamnose attached to the N-terminal of Leu-Trp dipep… 相似文献
4.
~~Pulse radiolysis of one-electron oxidation of rare tricyclic nucleoside derivative@赵红卫$Shanghai Institute of Nuclear Research, Chinese Academy of Sciences! Shanghai 201800,China
@江致勤$Department of Chemistry, Tongji Unviersity!Shanghai 200092,China
@窦大营$Shanghai Institute of Nuclear Research, Chinese Academy of Sciences! Shanghai 201800,China
@吴铁一$Shanghai Institute of Nuclear Research, Chinese Academy of Sciences! Shanghai 201800,China
@王文锋$Shanghai… 相似文献
5.
Maria De Fenza Anna Esposito Daniele DAlonzo Annalisa Guaragna 《Molecules (Basel, Switzerland)》2021,26(6)
The de novo synthesis of piperidine nucleosides from our homologating agent 5,6-dihydro-1,4-dithiin is herein reported. The structure and conformation of nucleosides were conceived to faithfully resemble the well-known nucleoside drugs Immucillins H and A in their bioactive conformation. NMR analysis of the synthesized compounds confirmed that they adopt an iminosugar conformation bearing the nucleobases and the hydroxyl groups in the appropriate orientation. 相似文献
6.
Novel oligomeric intumescent flame retardants, poly(amino phosphonate ester)s (PAPEs), containing both phosphorous and nitrogen, were synthesized by reacting diethyl phosphite with two different polyschiff bases obtained from the reaction of diamines with dialdehyde. The target PAPEs (designated as PAPE‐d and PAPE‐e, respectively) were characterized by 1H NMR, 31P NMR, Fourier Transform infrared spectroscopy, elemental analysis, gel permeation chromatography and thermogravimetric analysis (TGA) techniques. Thermal stability and flammability of ethylene‐vinyl acetate copolymer (EVA)/PAPE blends with various PAPE content were investigated by TGA, limited oxygen index (LOI), vertical burning test (UL‐94) and microscale combustion colorimeter (MCC). The results indicate that PAPEs effectively improve the flame retardancy of EVA. The EVA/30%PAPE‐e blend has a LOI value of 28, and its peak heat release rate (PHRR) value in MCC measurement is reduced by 36%. At the same time, the EVA/PAPE blends also have high yield of residual char, indicating that PAPEs are effective charring agents. Scanning electron microscopy observations of the residues of the EVA/PAPE blends show the existence of compact char layer on the surface of the residues, which is responsible for the improvement of the flame retardancy of EVA. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
7.
Sophie Danappe Fabien Boeda Christian Alexandre Anne‐Marie Aubertin Nathalie Bourgougnon 《合成通讯》2013,43(21):3225-3239
Synthesis of eight nucleoside analogues 4–11 with a methylenecyclobutane unit is described. Wittig reaction with 2‐hydroxymethylcyclobutanone 12 gave a mixture of Z (13) and E (14) derivatives, which was separated before functional modifications. The heterocyclic moieties were introduced via a Mitsunobu reaction either on the saturated chain or on the unsaturated chain. When adenine was used in this reaction, only the N‐9 substitution products were obtained. Removal of the protecting groups provided the target products. 相似文献
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The primary structure of 3'-imino[60]fulleryl-3'-deoxythymidine ions is studied using mass spectrometry both in the positive and negative modes. Interaction between the subunits is discussed using collision-induced dissociation (CID) spectra. Collisional activation with argon of the sodiated cations leads to the cleavage of the glycosidic bond and the transfer of a radical hydrogen from the deoxyribose to the thymine. The sodiated thymine is the only fragment observed for low collision energies in the positive mode. In the negative mode, two different ionization mechanisms take place, reduction and deprotonation in the presence of triethylamine. The 2.7 eV electron affinity of C60 and its huge cross section compared to the small cross section and predicted 0.44 eV electron affinity of the thymidine subunit most likely localize the radical electron on the fullerene. On the other hand, deprotonation of the 3'-azido-3'-deoxythymidine (AZT) is known to occur in N-3, the most acidic site of the nucleobase. Consequently, deprotonation causes the negative charge to be initially localized on the thymine. Both types of parent anions give the radical anion C60*- as fragment. The other fragments detected are the dehydrogenated 3'-imino[60]fulleryl-3'-deoxyribose anion, C60NH2-, C60N- and C60H-. Since in negative ion mass spectrometry all fragments include the [60]fullerene unit, this suggests that the fragmentation is driven by the electron affinity of the [60]fullerene, likely responsible for a charge transfer between the deprotonated thymine and the C60. 相似文献
10.
Nicole AmannHans-Achim Wagenknecht 《Tetrahedron letters》2003,44(8):1685-1690
The protected ethidium nucleosides 8-(3′,5′-di-O-benzoyl-2′-deoxy-d-ribofuranosyl)-3-acetamido-5-ethyl-6-phenyl-phenanthridinium (5), 8-(3′,5′-di-O-acetyl-2′-deoxy-d-ribofuranosyl)-3-acetamido-5-ethyl-6-phenyl-phenanthridinium (6), and the acyclic analog 8-[(3R)-1,3-dihydroxy-4-yl]-acetamido-3-amino-5-ethyl-6-phenyl-phenanthridinium (3) were prepared. Based on to their different stability, only the acyclic derivative 3 seems to be suitable for oligonucleotide synthesis. Furthermore, the acyclic ethidium nucleoside analog 3 exhibits comparable absorption and emission properties of the underivatized ethidium (1). 相似文献