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排序方式: 共有252条查询结果,搜索用时 34 毫秒
71.
Jeroen van Westrenen A. Dean Sherry Won Dae Kim Anne E. Vivian Duane C. Hrncir 《Journal of chemical crystallography》1993,23(11):885-890
C5H10N2O3S,1, monoclinicC2/c,a=17.545(5),b=6.822(8),c=13.928(2),=108.36(7),Z=8, MoK, =0.7107 Å,=3.56cm–1,R=0.061,R
w
=0.099. C8H16N3O6S2Na·2H2O,2, orthorhombicPna21,a=17.964(8),b=10.157(1),c=8.263(4),Z=4, MoK, =0.7107 Å,=4.07 cm–1,R=0.040,R
w
=0.043. C10H20N4O6S2·2H2O,3, monoclinicP21/n,a=9.142(9),b=13.576(7),c=14.028(8),=94.096(8),Z=4, MoK, =0.7107 Å,=3.37 cm–1,R=0.063,R
w
=0.074. Compounds1, 2, and3 were prepared from the pH-dependent sulfomethylation of the di- and polyazamacrocycles. 相似文献
72.
R. T. Pardasani P. Pardasani R. Ghosh D. Sherry T. Mukherjee 《Heteroatom Chemistry》1999,10(5):381-384
The present article reports our approach toward the synthesis of spiro compounds via indol‐2,3‐diones. Thus, reaction of indol‐2,3‐dione derivatives with a secondary cyclic amino acid, namely, (R)‐(−)‐thiazolidine‐4‐carboxylic acid, affords a thiazolo‐oxazolidinone as the main product. When the reaction is carried out in the presence of a dipolarophile, 1,3‐dipolar cycloaddition to the intermediate azomethine ylide leads to a novel spiro compound. The products have been characterized on the basis of spectral studies, and the geometry of the intermediate iminium compound has been optimized by use of the semiempirical molecular orbital method. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 381–384, 1999 相似文献
73.
Andre Rosowsky Clara E. Mota Sherry E. Queener 《Journal of heterocyclic chemistry》1996,33(6):1959-1966
Five previously undescribed trimetrexate analogues with bulky 2′-bromo substitution on the phenyl ring were synthesized in order to assess the effect of this structure modification on dihydrofolate reductase inhibition. Condensation of 2-[2-(2-bromo-3,4,5-trimethoxyphenyl)ethyl]-1,l-dicyanopropene with sulfur in the presence of N,N-diethylamine afforded 2-amino-5-(2′-bromo-3′,4′,5′-trimethoxybenzyl)-4-methyl-thiophene-3-carbonitrile ( 15 ) and 2-amino-4-[2-(2′-bromo-3′,4′,5′-trimethoxyphenyl)ethyl]thiophene-3-car-bonitrile ( 16 ). Further reaction with chloroformamidine hydrochloride converted 15 and 16 into 2,4-diamino-5-(2′-bromo-3′,4′,5′-trimethoxybenzyl)-4-methylthieno[2,3-d]pyrimidine ( 8a ) and 2,4-diamino-4-[2-(2′-bromo-3′,4′,5′-trimethoxyphenyl)ethylthieno[2,3-d]pyrimidine ( 12 ) respectively. Other analogues, obtained by reductive coupling of the appropriate 2,4-diaminoquinazoline-6(or 5)-carbonitriles with 2-bromo-3,4,5-trimethoxyaniline, were 2,4-diamino-6-(2′-bromo-3′,4′,5′-trimethoxyanilinomethyl)-5-chloro-quinazoline ( 9a ), 2,4-diamino-5-(2′-bromo-3′,4′,5′-trimethoxyanilinomethyl)quinazoline ( 10 ), and 2,4-diamino-6-(2′-bromo-3′,4′,5′-trimethoxyanilinomethyl)quinazoline ( 11 ). Enzyme inhibition assays revealed that space-filling 2′-bromo substitution in this limited series of dicyclic 2,4-diaminopyrimidines with a 3′,4′,5′-trimethoxyphenyl side chain and a CH2, CH2CH2, or CH2NH bridge failed to improve species selectivity against either P. carinii or T. gondii dihydrofolate reductase relative to rat liver dihydrofolate reductase. 相似文献
74.
75.
Imines can be generated in situ from -aminonitriles and efficiently trapped by a variety of lithiated heterocycles. This variation of the Bruylants reaction has proven to be a general method for the synthesis of -heteroaryl secondary amines. 相似文献
76.
77.
G. C. Sherry 《Foundations of Physics Letters》1990,3(3):255-265
A Poisson bracket structure is defined on associative algebras which allows for a generalized Hamiltonian dynamics. Both classical and quantum mechanics are shown to be special cases of the general formalism. 相似文献
78.
A new theory of four-dimensional symmetry introduced by Hsu has been criticized as logically inconsistent. We answer the criticisms that have been raised and show that in fact this theory is not logically inconsistent.Supported in part by the U.S. ERDA, NASA and NRC. 相似文献
79.
Tully SE Mabon R Gama CI Tsai SM Liu X Hsieh-Wilson LC 《Journal of the American Chemical Society》2004,126(25):7736-7737
Chondroitin sulfate glycosaminoglycans are sulfated polysaccharides involved in cell division, neuronal development, and spinal cord injury. Here, we report the synthesis and identification of a chondroitin sulfate tetrasaccharide that stimulates the growth and differentiation of neurons. These studies represent the first, direct investigations into the structure-activity relationships of chondroitin sulfate using homogeneous synthetic molecules and define a tetrasaccharide as a minimal motif required for activity. 相似文献
80.
Sherry Sin-Hang Yeung Yuen-Shan Ho Raymond Chuen-Chung Chang 《Experimental & molecular medicine》2021,53(9):1251
Recent research into meningeal lymphatics has revealed a never-before appreciated role of type II innate lymphoid cells (ILC2s) in modulating neuroinflammation in the central nervous system (CNS). To date, the role of ILC2-mediated inflammation in the periphery has been well studied. However, the exact distribution of ILC2s in the CNS and therefore their putative role in modulating neuroinflammation in neurodegenerative diseases such as Alzheimer’s disease (AD), multiple sclerosis (MS), Parkinson’s disease (PD), and major depressive disorder (MDD) remain highly elusive. Here, we review the current evidence of ILC2-mediated modulation of neuroinflammatory cues (i.e., IL-33, IL-25, IL-5, IL-13, IL-10, TNFα, and CXCL16-CXCR6) within the CNS, highlight the distribution of ILC2s in both the periphery and CNS, and discuss some challenges associated with cell type-specific targeting that are important for therapeutics. A comprehensive understanding of the roles of ILC2s in mediating and responding to inflammatory cues may provide valuable insight into potential therapeutic strategies for many dementia-related disorders.Subject terms: Neuroimmunology, Neuroimmunology 相似文献