Niwa T, Koshiyama T, Goto J, Nambara T
Pharmaceutical Institute, Tohoku University, Sendai, Japan.
Steroids. 1992 Nov;57(11):522-9. doi: 10.1016/0039-128x(92)90021-z.
3-N-Acetylglucosaminides of unconjugated, glycine- and taurine-conjugated bile acids have been synthesized. Bile acids appropriately protected were condensed with acetochloroglucosamine through the 3 alpha-hydroxyl group by means of the Koenigs-Knorr reaction using cadmium carbonate as a catalyst. Subsequent borohydride reduction and/or alkaline hydrolysis provided desired 3-N-acetylglucosaminides of unconjugated bile acids. Glycine-conjugates were obtained from N-acetylglucosaminides of unconjugated bile acids and ethyl glycinate by the carbodiimide method. The preparation of N-acetylglucosaminides of taurine-conjugates was attained by the Koenigs-Knorr reaction of bile acid p-nitrophenyl esters followed by condensation with taurine. 7-N-Acetylglucosaminides of ursodeoxycholates were prepared in a similar fashion. The convenient synthesis of 3-N-acetylglucosaminides of unconjugated bile acids is also described.
未结合的、甘氨酸结合型和牛磺酸结合型胆汁酸的3 - N - 乙酰氨基葡萄糖苷已被合成。将适当保护的胆汁酸通过3α - 羟基与乙酰氯葡萄糖胺，借助柯尼希斯 - 克诺尔反应，以碳酸镉作为催化剂进行缩合。随后的硼氢化物还原和/或碱性水解得到所需的未结合胆汁酸的3 - N - 乙酰氨基葡萄糖苷。甘氨酸结合物是通过未结合胆汁酸的N - 乙酰氨基葡萄糖苷与甘氨酸乙酯，采用碳二亚胺法得到的。牛磺酸结合物的N - 乙酰氨基葡萄糖苷的制备是通过胆汁酸对硝基苯酯的柯尼希斯 - 克诺尔反应，随后与牛磺酸缩合实现的。熊去氧胆酸盐的7 - N - 乙酰氨基葡萄糖苷以类似的方式制备。还描述了未结合胆汁酸的3 - N - 乙酰氨基葡萄糖苷的简便合成方法。
