Cueille G, Man N K, Sausse A, Farges J P, Funck-Brentano J L
Artif Organs. 1981;4 Suppl:28-32.
The Middle Molecules (MM) within the molecular weight (MW) range of vitamin B12 (1355 daltons) are assumed to be partly responsible for uremic toxicity. We have isolated a solute, b4.2, the purity of which is controlled by thin layer chromatography on silica gel. It correlates with active clinical polyneuropathy. The Stockholm group is dealing with a MM they call peak 7c. After exchange of purified solutes between the Stockholm group and us, comparative analyses demonstrate that 7c and b4.2 are different. The b4.2 solute is a glucuronide but it is impossible to obtain the aglycon moiety after enzymatic or acidic hydrolysis. Desorption chemical ionization and electron-impact ionization mass spectrometry results of b4.2 after transformation in methyl ester trimethylsilyl derivative are compatible with a b4.2 MW of 568 daltons (or 526 in native form) corresponding to a glucuronoconjugate of an aglycon with a MW 392 daltons (or 350 in native form). Moreover mass spectrometry confirms that b4.2 isolated from normal human urine and from uremic RP6 hemofiltrate fluid are identical.
分子量（MW）在维生素B12（1355道尔顿）范围内的中分子（MM）被认为是尿毒症毒性的部分原因。我们分离出了一种溶质b4.2，其纯度通过硅胶薄层层析法控制。它与活动性临床多发性神经病变相关。斯德哥尔摩小组正在研究一种他们称为峰7c的中分子。在斯德哥尔摩小组和我们之间交换纯化溶质后，对比分析表明7c和b4.2是不同的。b4.2溶质是一种葡糖醛酸苷，但在酶解或酸解后无法获得苷元部分。b4.2转化为甲酯三甲基硅烷基衍生物后的解吸化学电离和电子轰击电离质谱结果与b4.2分子量568道尔顿（天然形式为526道尔顿）相符，对应于一个分子量392道尔顿（天然形式为350道尔顿）的苷元的葡糖醛酸共轭物。此外，质谱证实从正常人尿液和尿毒症RP6血液滤过液中分离出的b4.2是相同的。
