The NP-complete problems have been shown to be hard problems in the theory of computational complexity. They include many problems of great significance both in theory and in practice. If there is a fast (in the sense...The NP-complete problems have been shown to be hard problems in the theory of computational complexity. They include many problems of great significance both in theory and in practice. If there is a fast (in the sense of polynomial time) algorithm for the dual problem of an NP-complete problem, then there are fast algorithms for all. But so far,展开更多
文摘目的在正相色谱条件下建立了托吡卡胺、氢溴酸后马托品、硫酸阿托品和山莨菪碱共4种阿托品类药物的对映体分离方法。方法使用Chiralpak IC[纤维素-三(3,5-二氯苯基氨基甲酸酯)共价键合硅胶]手性色谱柱,考察了不同流动相体系、烷醇体积比、酸碱添加剂、柱温以及流速对对映体分离的影响。结果 4种药物均可达到良好的分离度,通过不断优化色谱分离条件最终确定分离4种药物的最佳流动相条件:柱温为25℃,流速为1.0 m L·min-1,分离托吡卡胺对映体的流动相为正己烷-乙醇-二乙胺(体积比70∶30∶0.05),分离氢溴酸后马托品和硫酸阿托品对映体的流动相为正己烷-乙醇-二乙胺(体积比80∶20∶0.05),在最佳条件下3种药物对映体之间的分离度分别为7.73、2.36和2.67。分离山莨菪碱4个对映体的最佳流动相为正己烷-异丙醇-乙酸-二乙胺(体积比70∶30∶0.05∶0.025)。结论纤维素键合手性固定相对除山莨菪碱以外的3种抗胆碱能药物均能达到完全分离。
基金Project supported by the National Natural Science Foundation of China
文摘The NP-complete problems have been shown to be hard problems in the theory of computational complexity. They include many problems of great significance both in theory and in practice. If there is a fast (in the sense of polynomial time) algorithm for the dual problem of an NP-complete problem, then there are fast algorithms for all. But so far,
