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异斯特维醇(Isosteviol)是一种贝叶烷二萜类化合物,具有广泛的生理活性,可由甜叶菊苷(Stevioside)经酸性水解得到.从异斯特维醇出发,利用其合适的二萜骨架,可以衍生出各种具有生物活性和光学活性的多羟基衍生物和具有抗肿瘤活性的其它衍生物.我国甜叶菊苷资源非常丰富,开发异斯特维醇衍生物的化学或生物合成,研究其生物生理活性、探讨其在新药开发和在不对称合成中的应用,具有重要的理论意义和应用前景.本文以甜叶菊苷(Ⅰ)为起始物,经水解制得异斯特维醇(Ⅱ),再经羟甲基化和氢化反应,可方便制得未见于文献报导的15-β-羟甲基16-α-羟基异斯特维醇衍生物(Ⅲ).经EA,IR,1H NMR,13C NMR和晶体结构测定,确定了化合物Ⅲ的结构.预期这类化合物具有某种生理活性,可用于手性药物的开发研究. 相似文献
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This article develops a model to examine the equilibrium behavior of the time inconsistency problem in a continuous time economy with stochastic and endogenized distortion. First, the authors introduce the notion of sequentially rational equilibrium, and show that the time inconsistency problem may be solved with trigger reputation strategies for stochastic setting. The conditions for the existence of sequentially rational equilibrium are provided. Then, the concept of sequentially rational stochastically stable equilibrium is introduced. The authors compare the relative stability between the cooperative behavior and uncooperative behavior, and show that the cooperative equilibrium in this monetary policy game is a sequentially rational stochastically stable equilibrium and the uncooperative equilibrium is sequentially rational stochastically unstable equilibrium. In the long run, the zero inflation monetary policies are inherently more stable than the discretion rules, and once established, they tend to persist for longer periods of the time. 相似文献
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