Stereoselective Synthesis of
(25<i>R</i>)-Dafachronic Acids and (25<i>R</i>)-Cholestenoic Acid as Potential Ligands
for the DAF-12 Receptor in <i>Caenorhabditis
elegans</i>
Commercially available diosgenin has been used as starting material for a highly efficient synthesis of (25R)-dafachronic acids and (25R)-cholestenoic acid, potential ligands for the receptor DAF-12 in the nematode Caenorhabditis elegans.
Synthesis and biological activity of the (25R)-cholesten-26-oic acids—ligands for the hormonal receptor DAF-12 in Caenorhabditis elegans
作者:René Martin、Arndt W. Schmidt、Gabriele Theumer、Tilo Krause、Eugeni V. Entchev、Teymuras V. Kurzchalia、Hans-Joachim Knölker
DOI:10.1039/b817358c
日期:——
We describe the stereoselective transformation of diosgenin (4a) to (25R)-Î4-dafachronic acid (1a), (25R)-Î7-dafachronic acid (2a), and (25R)-cholestenoic acid (3a), which represent potential ligands for the hormonal receptor DAF-12 in Caenorhabditis elegans. Key-steps of our synthetic approach are a modified Clemmensen reduction of diosgenin (4a) and a double bond shift from the 5,6- to the 7,8-position. In the 25R-series, the Î7-dafachronic acid 2a exhibits the highest hormonal activity.
new synthesis of both epimeric forms of 26-cholestanoic acids and 26-alcohols containing a 3beta-hydroxy-Delta(5)- or a Delta(4)-3-keto-functionality in ring A is described starting from stigmasterol or (20S)-3beta-acetoxy-pregn-5-en-20-carboxylic acid. The obtained compounds are useful as standards for studies of cholic acids. Construction of the side chain was achieved by linkage of steroidal 23-iodides
从豆甾醇或 (20S) 开始,描述了在环 A 中含有 3β-羟基-Delta(5)-或 Delta(4)-3-酮基官能团的 26-胆甾烷酸和 26-醇的差向异构形式的新合成)-3β-乙酰氧基-pregn-5-en-20-羧酸。所得化合物可用作研究胆酸的标准品。侧链的构建是通过将甾体 23-碘化物连接到由 (2R)- 和 (2S)-3-羟基-2-甲基丙酸酯制备的砜来实现的。使用由 TEMPO 和漂白剂催化的亚氯酸钠,将中间体 26-醇氧化成相应的羧酸,确保保留 C-25 的立体化学和环状部分的官能团。
Formation of the steroidal C-25 chiral center via the asymmetric alkylation methodology
作者:Yu. V. Ermolovich、V. N. Zhabinskii、V. A. Khripach
DOI:10.1039/c4ob02123a
日期:——
A novel approach for the preparation of steroids containing a chiral center at C-25 is reported. The key stereochemistry inducing step was asymmetric alkylation of pseudoephenamine amides of steroidal C-26 acids. The reaction proceeded with high diastereoselectivity (dr > 99 : 1). The developed methodology was successfully applied to the synthesis of (25R)- and (25S)-cholestenoic acids as well as (25R)-
COMPOUND AND METHOD FOR THE TREATMENT AND DIAGNOSIS OF NEURODEGENERATIVE CONDITIONS
申请人:ARENAS Ernest
公开号:US20160000807A1
公开(公告)日:2016-01-07
A reagent selected from cholestenoic acid or an inhibitor of an enzyme in the cholestenoic acid biosynthetic or metabolic pathway for use in the treatment of neurodegenerative conditions. In particular, the reagent is a cholestenoic acid of a particular form, such as 3β,7α-dihydroxycholest-5-en-26-oic (3β,7α-diHCA), not previously associated with neural tissue or CSF. Pharmaceutical compositions, methods of treatment or prevention of neurodegenerative conditions as well as diagnostic methods and novel biomarkers form further aspects of the invention.