21世纪中国新药研究开发策略探讨

分别从仿制药物、me-too药物及创新药物三方面入手,分析目前的现状及存在的问题,从知识产权、工作思路、制度规范、企业重组等角度探讨我国制药工业在加入WTO后应采取的新药研究开发策略。     

A 21st century technique for food control: Electronic noses

This work examines the main features of modern electronic noses (e-noses) and their most important applications in food control in this new century. The three components of an electronic nose (sample handling system, detection system, and data processing system) are described. Special attention is devoted to the promising mass spectrometry based e-noses, due to their advantages over the more classical gas sensors. Applications described include process monitoring, shelf-life investigation, freshness evaluation, authenticity assessment, as well as other general aspects of the utilization of electronic noses in food control. Finally, some interesting remarks concerning the strengths and weaknesses of electronic noses in food control are also mentioned.     

Three new C21 steroidal glycosides from the roots of Cynanchum inamoenum

Three new C_(21) steroidal glycosides named inamoside E (1),inamoside F (2) and inamoside G (3) were isolated from the roots of Cynanchum inamoenum (Maxim.) Loes.Their structures were determined by spectroscopic analysis,especially by 1D and 2D NMR experiments.     

Simultaneous Determination of 21 Sulfonamides in Poultry Eggs Using Ionic Liquid-Modified Molecularly Imprinted Polymer SPE and UPLC–MS/MS

An ionic liquid-modified molecularly imprinted polymer (IL-MIP) composite with sulfamethazine as a template molecule and methyl acrylic acid and 1-aminopropyl-3-methylimidazolium bromide as functional monomers was successfully synthesized. The achieved IL-MIP was characterized and evaluated in detail and utilized in the extraction and cleanup of sulfonamides (SAs) in poultry egg samples. The results demonstrated that the IL-MIP possessed a broad reorganization toward SAs and could selectively adsorb 21 kinds of SA compounds. Furthermore, the solid-phase extraction column based on the IL-MIP was used in the extraction and cleanup of 21 SAs in eggs, and the confirmatory detection of SAs was performed using ultraperformance liquid chromatography–tandem mass spectrometry. Under optimum conditions, the limits of detection (LODs) for all SAs ranged from 0.1 ng·g⁻¹ to 1.5 ng·g⁻¹, and the LOD of this method was better than those of the existing methods. The recoveries of SA compounds spiked in egg samples ranged from 84.3% to 105.8%, with low relative standard deviations (<15%). The developed method based on the IL-MIP extraction and cleanup was successfully used in the detection of 21 SAs in more than 100 real poultry egg samples. The results indicated that the proposed method was suitable for detecting 21 SAs in poultry eggs.     

化学选择性还原21-叠氮基皮质激素法制备21-伯胺基皮质激素

以锌/氯化铵为还原剂,在含水四氢呋喃中将21-叠氮基皮质激素化学选择性地还原为21-伯氨基皮质激素.11β-羟基-21-叠氮基皮质激素比相应的11-酮基和11-去氧皮质激素容易还原,含水四氢呋喃是该反应的最适合溶剂,水的含量在还原体系中起着极其重要的作用.     

Synthesis of 21-Thioureido or 21-Ureidocorticosteroids as NOS Inhibitors

Aryl or alkyl thioureas are known as NOS inhibitors, [1～ 4] in this paper we reported the synthesis of 21-thioureido or 21-ureidocorticosteroids as potential NOS inhibitors. The title compounds were prepared from primary 21aminocorticosteroids and in vivo generated aryl isothiocynates. For comparison, 21-ureidocorticoids were synthesized in a similar way. Scheme 1 shows the preparation of 21-thioureido and 21-ureidoprednisolone. Other corticosteroids' 2 1-thioureido or ureido derivatives, such as hydrocortisone' s, methylprednisolne' s, dexamethasone' s, betamethasone' s, RS' s, cortisone' s and prednisone' s, were also prepared. Preliminary pharmacology evaluation showed that they possessed NOS inhibiting activities.     

Fermi and Coulomb correlations in the 21 S state of the helium isoelectronic sequence

The Fermi and Coulomb holes of the 2¹ S state of the helium isoelectronic sequence are investigated. Several interesting differences between the results obtained and those which might be expected on the basis of the corresponding 2³ S state are pointed out and discussed.     

Gas-phase 21Ne NMR studies and the nuclear magnetic dipole moment of neon-21

Gas-phase ²¹Ne nuclear magnetic resonance spectra were measured at the natural abundance of ²¹Ne isotope for samples consisting of pressurized neon up to 60 bar at room temperature and applying the magnetic field of the strength B₀ = 11.7574 T. It showed that the nuclear magnetic resonance frequency is linearly dependent on the density of gaseous neon. The resonance frequency was extrapolated to the zero-density point, and it permitted the determination of the ²¹Ne nuclear magnetic moment, μ(²¹Ne) = 0.6617774(10) μ_N. The present value of μ(²¹Ne) is not influenced by the bulk magnetic susceptibility of neon and interactions between neon atoms; therefore, it is more precise and reliable than the previous result obtained for μ(²¹Ne).