The diffusion coefficients of aqueous solutions ofglycine, L-alanine, L-valine and L-isoleucine at 298.15 K were determined by holographic interferometry with accuracy and promptness while without disturbance. The den...The diffusion coefficients of aqueous solutions ofglycine, L-alanine, L-valine and L-isoleucine at 298.15 K were determined by holographic interferometry with accuracy and promptness while without disturbance. The density and viscosity of these solutions were also determined. According to original Gordon model, a model for correlating the diffusion coefficients of amino acids in aqueous solutions was developed and applied. The results showed that this model provided significant convenience in correlation of diffusion coefficients for amino acids system.展开更多
The protected tetrapeptide, N-o-Ns-N （ Me ） -Val-N （ Me ） -Val-N （ Me ） -Val- N （ Me ） -Phe- OtBu, was prepared from L-valine and L-phenylalanine. Ted-butyl acetate and HClO4 were used to protect carbonyl grou...The protected tetrapeptide, N-o-Ns-N （ Me ） -Val-N （ Me ） -Val-N （ Me ） -Val- N （ Me ） -Phe- OtBu, was prepared from L-valine and L-phenylalanine. Ted-butyl acetate and HClO4 were used to protect carbonyl group, o-nitrobenzenesulfonyl chloride and triethyl amine were used to protect amino group, and N-alkylation was finished with iodomethane. Then the protected amino acid was turned into acid chloride which was taken as coupling reagent. After 14 steps, such as protection, alkylation, deprotection and coupling, the protected tetrapeptide was obtained with a yield of 26.9%. The structures of intermediates and target compound were identified with NMR spectra and high resolution mass spectra.展开更多
An improved synthesis of rupintrivir (AG7088) was accomplished using three amino acids (L-glutamic acid, D-4-fluorophenylalanine, and L-valine) as the building blocks. The key fragment ketomethylene dipeptide isostere...An improved synthesis of rupintrivir (AG7088) was accomplished using three amino acids (L-glutamic acid, D-4-fluorophenylalanine, and L-valine) as the building blocks. The key fragment ketomethylene dipeptide isostere was constructed with the valine derivative and phenylpropionic acid derivative, followed by coupling with a lactam derivative and an isoxazole acid chloride to provide AG7088 totally in eight steps.展开更多
基金Supported by the National 973 Program of China (No. 2003CB615701)the National 863 Project of China (No. 2003AA328020)the National Natural Science Foundation of China (No. 200276034)the Educational Ministry Doctor Foundation of China (No 2000005608).
文摘The diffusion coefficients of aqueous solutions ofglycine, L-alanine, L-valine and L-isoleucine at 298.15 K were determined by holographic interferometry with accuracy and promptness while without disturbance. The density and viscosity of these solutions were also determined. According to original Gordon model, a model for correlating the diffusion coefficients of amino acids in aqueous solutions was developed and applied. The results showed that this model provided significant convenience in correlation of diffusion coefficients for amino acids system.
文摘The protected tetrapeptide, N-o-Ns-N （ Me ） -Val-N （ Me ） -Val-N （ Me ） -Val- N （ Me ） -Phe- OtBu, was prepared from L-valine and L-phenylalanine. Ted-butyl acetate and HClO4 were used to protect carbonyl group, o-nitrobenzenesulfonyl chloride and triethyl amine were used to protect amino group, and N-alkylation was finished with iodomethane. Then the protected amino acid was turned into acid chloride which was taken as coupling reagent. After 14 steps, such as protection, alkylation, deprotection and coupling, the protected tetrapeptide was obtained with a yield of 26.9%. The structures of intermediates and target compound were identified with NMR spectra and high resolution mass spectra.
基金financial support from the National Natural Science Foundation of China (20872153, 21021063, 20720102040 and81025017)the National Basic Research Program of China grant(2009CB918502)+2 种基金the Chinese Academy of Sciences (XDA01040305)the SILVER project of the European Commission (contract HEALTH-F3-2010-260644)supported by a Chinese Academy of Sciences Visiting Professorship for Senior International Scientists (2010T1S6)
文摘An improved synthesis of rupintrivir (AG7088) was accomplished using three amino acids (L-glutamic acid, D-4-fluorophenylalanine, and L-valine) as the building blocks. The key fragment ketomethylene dipeptide isostere was constructed with the valine derivative and phenylpropionic acid derivative, followed by coupling with a lactam derivative and an isoxazole acid chloride to provide AG7088 totally in eight steps.
