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3-β，7-β-二羟基-5-氯代-24-酸、N-乙酰氨基葡萄糖(C-7)和甘氨酸(或牛磺酸)的化学合成。合成了类似的3-β-羟基-7-氧代-5-氯代-24-酸双偶联物。主要反应包括：1)在沸腾的甲苯中，2-acetamido-1α-chloro-1，2-dideoxy-3，4，6-tri-O-acetyl-D-glucopyranose与3-β-3-叔丁基二甲基硅氧基-7-β-羟基-5-氯代-24-甲酸甲酯在C-7位上的β-D-N-乙酰氨基化反应，2)生成的3-β-TBDMSi-7β-GlcNAc与三氧化硫-三甲胺在吡啶中的络合物在C-3上的硫酸化，3)以4-(4，6-dimethoxy-1，3，5-triazin-2-yl)-4-methylmorpholinium氯化物为偶联剂，在二甲基甲酰胺中，3-β-磺酸-7-β-GlcNAc与甘氨酸甲酯盐酸盐(或牛磺酸)的C-24位直接氨基酰化反应。采用电喷雾电离探针液相色谱质谱联用技术，在正负电离模式下对多共轭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.