Determination and measurement of unusual metabolites of bile acid multi-conjugates excreted in a patient with Nimann-Pick disease type C1.

本文报道了3β，7 β-二羟基-5-胆烯-24-酸的化学合成方法，该化合物是C1型尼曼-匹克病患者尿液中不常见的主要代谢产物，其C-3位为硫酸，C-7位为N-乙酰氨基葡萄糖（GlcNAc），C-24位为甘氨酸（或牛磺酸）。还制备了3β-羟基-7-氧代-5-胆烯-24-酸的类似双缀合物。涉及的主要反应为：1）3β-叔丁基二甲基硅氧基（TBDMSi）-7β-羟基-5-胆烯-24-酸甲酯与2-乙酰氨基-1 α-氯-1，2-二脱氧-3，4，6-三-O-乙酰基-D-吡喃葡萄糖在CdCO_3存在下于沸腾甲苯中的C-7位β-D-N-乙酰基葡萄糖胺化反应，2）在吡啶中用三氧化硫-三甲基胺络合物在所得3β-TBDMSi-7β-GlcNAc的C-3处硫酸化，和3）在3β-磺基-7 β-GlcNAc缀合物的C-24处与甘氨酸甲酯盐酸盐直接氨酰酰胺化在DMF中使用4-（4，6-二甲氧基-1，3，5-三嗪-2-基）-4-甲基吗啉鎓氯化物作为偶联剂，通过将所述化合物（或牛磺酸）与所述化合物（或牛磺酸）反应来制备。采用液相色谱-质谱联用技术，以电喷雾离子化探针在正负离子模式下对多结合胆汁酸的结构进行了表征。

The chemical synthesis of 3β,7β-dihydroxy-5-cholen-24-oic acid triply conjugated by sulfuric acid at C-3,N-acetylglucosamine (GlcNAc) at C-7 and glycine (or taurine) at C-24, which are unusual, major metabolites excreted in urine of a patient with Niemann-Pick diseases type C1,is described. Analogous double-conjugates of 3β-hydroxy-7-oxo-5-cholen-24-oic acid were also prepared. The principal reactions involved were : 1)β-D-N-acetylglueosaminidation at C-7 of methyl 3β-tert-butyldimethylsilyloxy (TBDMSi)-7β-hydroxy-5-cholen-24-oate with 2-acetamido-1α-chloro-1,2-dideoxy-3,4,6-tri-O-acetyl-D-glucopyranose in the presence of CdCO_3 in boiling toluene, 2)sulfation at C-3 of the resulting 3β-TBDMSi-7β-GlcNAc with sulfur trioxide-trimethylamine complex in pyridine, and 3)direct aminoacyl amidation at C-24 of the 3β-sulfo-7β-GlcNAc conjugate with glycine methyl ester hydrochloride (or taurine) using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride as a coupling agent in DMF. The structures of the multi-conjugated bile acids were characterized by liquid chromatography-mass spectrometry with electrospray ionization probe under the positive and the negative ionization modes.