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(S)-3-羟基-γ-丁内酯(1)是重要的手性源化合物,也是制备降血脂药物阿托伐他汀[1]、神经介质L肉碱[2]、HIV蛋白酶抑制剂氨普那韦(amprenavir)[3]、饱感剂(2S,4S)-2-羟基-4-羟甲基-4-丁内酯[4]、治疗皮肤病药羟基二十碳四烯酸(12-HETE)[5]和抗癌药aplysistatin[6]等的关键中间体.近年来,国外关于1合成的报道较多,国内主要靠进口产品供应.因此,研究工业化合成1的方法具有重要意义. 相似文献
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西洋参多糖PPQI-1~4理化性质的研究 总被引:1,自引:0,他引:1
AIM: To study the characteristics of the four bioactive pure polysaccharides of Panax quiquefolium L. (PPQI 1~4). METHODS: The polysaccharides were extracted with hot water and grade precipitated with ethanol. They were further purified with Sephadex DEAE A50 and Sephadex G200 chromatography. The molecular weights of the polysaccharides were determined with matrix assisted laser desorption/ionization mass spectrometry (MALDI MS). The sugar compositions were analyzed with GC. The linkage positions of the component sugars were determined by methylation and GC MS. RESULTS: The four polysaccharides are all uronic acid containing heteropolysaccharides with the component sugars of arabinose, galactose and glucose in different molar ratios. The uronic acid contents are within 30%~60%. Their molecular weights are in the range of 2×104~7×104u. CONCLUSION: The four new bioactive polysaccharides are all uronic acid containing heteropolysaccharides. 相似文献
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手性双膦配体2,2’-双(二苯基膦基)-1,1’联萘与钌、铑离子形成的配合物可作为高效均相催化剂,用于烯烃和羰基的高对映造反性氢化,或烯烃的对映造反性异构化。本文对此领域的研究状况进行简介。 相似文献
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西洋参多糖PPQI-1~4理化性质的研究 总被引:2,自引:0,他引:2
西洋参(PanaxquinquefoliumL.)系五加科人参属多年生草本植物,药用历史悠久。作者用多糖皂甙联合提取法[1],从西洋参根中提取出西洋参多糖(PPQ)。小鼠体内活性实验结果显示,西洋参根粗多糖有较好的抑制S180肉瘤生长活性;对抗癌化疗药环磷酰胺所致小鼠免疫功能低下有拮抗作用[2]。以体外细胞因子刺激活性为指标进行活性跟踪实验,通过乙醇分级分离、Sephadex凝胶过滤多次分离,得到4个西洋参活性多糖(PPQI1~4)。它们有较好的刺激小鼠脾淋巴细胞转化、诱导白介素2(IL2… 相似文献
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