An Environmentally Sustainable Mechanochemical Route to Hydroxamic Acid Derivatives
作者:Rita Mocci、Lidia De Luca、Francesco Delogu、Andrea Porcheddu
DOI:10.1002/adsc.201600350
日期:2016.10.6
An operationally simple, and cost efficient conversion of carboxylic acids into hydroxamicacid derivatives via a high‐energy mechanochemical activation is presented. This ball milling methodology was applied to a wide variety of carboxylic acids dramatically improving purification issues associated with this class of molecules, which still remain one of the main bottlenecks of classical methodologies
-one). Here, four new results are reported concerning the synthesis of substituted bacteriochlorins. First, a new, scalable route to 1,1-dimethoxy-4-methylpent-3-en-2-one removes a significant previous impediment to the overall route. Second, the new route was employed to gain access to new α,β-unsaturatedketones and corresponding dihydrodipyrrins bearing alternative substituents in place of the dimethoxy
developed as a potential DNA-selective oligonucleotide analog. The synthesis of 2′-arabino-ethynyl-modified nucleosides was achieved starting from properly protected 2′-ketonucleosides by addition of lithium (trimethylsilyl)acetylide followed by reduction of the tertiary alcohol. After a series of protecting-group manipulations, phosphoramidite building blocks suitable for solid-phase synthesis were obtained
2-Ethynyl-DNA 被开发为潜在的 DNA 选择性寡核苷酸类似物。2'-阿拉伯-乙炔基修饰核苷的合成是从适当保护的 2'-酮核苷开始,通过添加锂(三甲基甲硅烷基)乙炔化物,然后还原叔醇来实现的。经过一系列保护基团操作,获得了适用于固相合成的亚磷酰胺结构单元。当使用快速脱保护方案时,从这些构件合成寡核苷酸是成功的。2'-阿拉伯-乙炔基修饰的寡核苷酸的配对特性可总结如下:1)嘧啶核苷的2'-阿拉伯-乙炔基修饰导致双链体与DNA以及RNA的强烈不稳定。可能的原因是乙炔基在空间上影响糖苷键周围的扭转偏好,导致不适合形成双链体的构象。2) 如果在嘌呤核苷中引入修饰,则观察不到这种影响。配对特性没有或仅轻微改变,并且在某些情况下(脱氧腺苷均聚物),观察到与 DNA 互补链的配对稳定化和与 RNA 互补链的去稳定化。3)在交替的脱氧胞苷-脱氧鸟苷序列的寡核苷酸中,2'-阿拉伯-乙炔基脱氧鸟苷的掺
Chlorogenic Acid and Synthetic Chlorogenic Acid Derivatives: Novel Inhibitors of Hepatic Glucose-6-phosphate Translocase
作者:Horst Hemmerle、Hans-Joerg Burger、Peter Below、Gerrit Schubert、Robert Rippel、Peter W. Schindler、Erich Paulus、Andreas W. Herling
DOI:10.1021/jm9607360
日期:1997.1.1
The enzyme system glucose-6-phosphatase (EC 3.1.3.9) plays a major role in the homeostatic regulation of blood glucose. It is responsible for the formation of endogenous glucose originating from gluconeogenesis and glycogenolysis. Recently, chlorogenic acid was identified as a specific inhibitor of the glucose-6-phosphate translocase component (G1-6-P translocase) of this enzyme system in microsomes of rat liver. Glucose B-phosphate hydrolysis was determined in the presence of chlorogenic acid or of new synthesized derivatives in intact rat liver microsomes in order to assess the inhibitory potency of the compounds on the translocase component. Variation in the 3-position of chlorogenic acid had only poor effects on inhibitory potency. Introduction of lipohilic side chain in the 1-position led to 100-fold more potent inhibitors. Functional assays on isolated perfused rat liver with compound 29i, a representative of the more potent derivatives, showed a dose-dependent inhibition of gluconeogenesis and glycogenolyosis, suggesting glucose-6-phosphatase as the locus of interference of the compound for inhibition of hepatic glucose production also in the isolated organ model. G1-6-P translocase inhibitors may be useful for the reduction of inappropriately high rates of hepatic glucose output often found in non-insulin-dependent diabetes.
A simple method for N-acylation of adenosine and cytidine nucleosides using carboxylic acids activated In-Situ with carbonyldiimidazole
作者:Nanda D. Sinha、Peter Davis、Lisa M. Schultze、Krishna Upadhya
DOI:10.1016/0040-4039(95)02011-d
日期:1995.12
Carboxylic acids are activated with 1,1'-carbonyldiimidazole in acetonitrile to form N-acylimidazoles which are then treated with per-trimethylsilyl ethers of nucleosides adenosine or cytidine at ambient temperature to generate exclusively N-acylated-Adenosine or N-acylated-Cytidine derivatives.