A new ureido-substituted amino acid,conopsamide A（1）,has been isolated from an ethanolic extract of the tubers of Gymnadenia conopsea.Its structure was elucidated by extensive spectroscopic analysis,and the absolute...A new ureido-substituted amino acid,conopsamide A（1）,has been isolated from an ethanolic extract of the tubers of Gymnadenia conopsea.Its structure was elucidated by extensive spectroscopic analysis,and the absolute configuration was assigned by Marfey＇s method.The new compound was evaluated for in vitro assay for HDACl（Histone Deacetylase 1） inhibitory activity.展开更多
2-Ureido-4[1H]-pyrimidinone quadruple hydrogen-bonded assembly 1,1 containing N,N-dimethylaminophenyl moiety exhibits a sensitive response to fluoride anion and lead cation. Spectroscopic studies reveal that the prese...2-Ureido-4[1H]-pyrimidinone quadruple hydrogen-bonded assembly 1,1 containing N,N-dimethylaminophenyl moiety exhibits a sensitive response to fluoride anion and lead cation. Spectroscopic studies reveal that the presence of small amount of fluoride anions and lead cations can easily disassemble and intercalate 2-ureido- 4[ 1H]-pyri mi di none hydrogen-bonded supramolecular architectures.展开更多
With high association constants in nonpolar solvents, the quadruple hydrogen bonding arrays of 2-ureido-4[1H]-pyrimidinones are recently considered to be one of the ideal building blocks to construct the complicated a...With high association constants in nonpolar solvents, the quadruple hydrogen bonding arrays of 2-ureido-4[1H]-pyrimidinones are recently considered to be one of the ideal building blocks to construct the complicated and functional supramole- cular systems. In this paper, we review the latest achievements of the supramolecular assemblies based on 2-ureido-4[1H]-pyrimidinone AADD quad- ruple hydrogen bonding building blocks.展开更多
Due to high temperature and acid substance in exhaust, gasoline usually produces deposits on the chamber and gasoline jet of intake air system in engines of a car, carbonating on the jet, even blocking the jet, make e...Due to high temperature and acid substance in exhaust, gasoline usually produces deposits on the chamber and gasoline jet of intake air system in engines of a car, carbonating on the jet, even blocking the jet, make engine fail to start and run. The methods of selecting optimum engine design have less effect on reducing deposits and carbonating than does that of adding detergent-dispersant additive into gasoline. A new compound──ureido-urethane is synthesized by reacting di-iso-cyanate with alcohols and amines. After experiments of selecting optimum reaction condition, testing solubility and percentage of relative oxidation,and evaluating in the PFI imitating device. The results show that the detergent-dispersant property of that compound is superior to the new product of USA(paradyne 748) and compound produced in Shanghai.展开更多
基金Financial support from the National Natural Science Foundation of China (No. 81522050)Beijing outstanding talents cultivation fund (No. 2013D009008000002)the Natural Science Foundation of Qinghai Province (No. 2014-ZJ-923)
文摘A new ureido-substituted amino acid,conopsamide A（1）,has been isolated from an ethanolic extract of the tubers of Gymnadenia conopsea.Its structure was elucidated by extensive spectroscopic analysis,and the absolute configuration was assigned by Marfey＇s method.The new compound was evaluated for in vitro assay for HDACl（Histone Deacetylase 1） inhibitory activity.
基金Project supported by the National Natural Science Foundation of China （Nos. 20732007, 21002108 and 91024041）, the Ministry of Science and Technology of China （Nos. 2007CB808004, 2007CB936001）. and the Bureau for Basic Research of the Chinese Academy of Sciences.
文摘2-Ureido-4[1H]-pyrimidinone quadruple hydrogen-bonded assembly 1,1 containing N,N-dimethylaminophenyl moiety exhibits a sensitive response to fluoride anion and lead cation. Spectroscopic studies reveal that the presence of small amount of fluoride anions and lead cations can easily disassemble and intercalate 2-ureido- 4[ 1H]-pyri mi di none hydrogen-bonded supramolecular architectures.
基金Project supported by the Ministry of Science and Technology of China (No. G2000078104 G2000077502) and the National Natural Science Foun-dation of China.
文摘The first intramolecular charge transfer transition based on 2-ureido- 4[1H]-pyrimidinone binding module was reported.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.20125207,20272066,20333080)the Ministry of Science and Technology of China(Grant No.2003CB716802).
文摘With high association constants in nonpolar solvents, the quadruple hydrogen bonding arrays of 2-ureido-4[1H]-pyrimidinones are recently considered to be one of the ideal building blocks to construct the complicated and functional supramole- cular systems. In this paper, we review the latest achievements of the supramolecular assemblies based on 2-ureido-4[1H]-pyrimidinone AADD quad- ruple hydrogen bonding building blocks.
文摘Due to high temperature and acid substance in exhaust, gasoline usually produces deposits on the chamber and gasoline jet of intake air system in engines of a car, carbonating on the jet, even blocking the jet, make engine fail to start and run. The methods of selecting optimum engine design have less effect on reducing deposits and carbonating than does that of adding detergent-dispersant additive into gasoline. A new compound──ureido-urethane is synthesized by reacting di-iso-cyanate with alcohols and amines. After experiments of selecting optimum reaction condition, testing solubility and percentage of relative oxidation,and evaluating in the PFI imitating device. The results show that the detergent-dispersant property of that compound is superior to the new product of USA(paradyne 748) and compound produced in Shanghai.
