A simple, convenient and direct method for assessing the purity of cobalamins
A simple, convenient and direct method for assessing the purity of cobalamins
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DOI：
10.1016/s0162-0134(99)00018-5
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发表时间：
1999-04-15
影响因子：
3.9
通讯作者：
Finke, RG
中科院分区：
文献类型：
--
作者：
Brasch, NE;Finke, RG
提出了一种直接、简单但强大且直接的方法，用于检测和定量商业钴胺素或亚稳态钴胺素 (Cbls)（例如 RSCbls）中的钴胺素杂质。该方法非常简单，是利用钴胺素的 LH NMR 的芳香区；它是我们在制备亚稳态硫醇钴胺素 (RSCbls) 的过程中开发出来的一种方法，并且是一种被证明对于表征那些（并通过推断其他）对 HPLC 分离条件不稳定的钴胺素（即，因此，在钴胺素化学中常用的通常强大的 HPLC 方法失败的情况）所必需的方法。尽管有大量关于钴胺素的现代多维 NMR 文献，但目前的方法尚未明确指出，也没有人报道过证明该方法有效所需的 NMR 数据（即，一系列钴胺素及其常见杂质的数据证明，当在相同的 NMR 溶剂、pH 和其他条件下检查时，它们在 H-1 NMR 的芳香区具有不同的化学位移）。直接 NMR 方法易于执行、易于定量，适用于对分离钴胺素杂质所需的 HPLC 条件不稳定的物质。结果允许对例如商业 HOCbl.HX 中的 5-11% 杂质进行定量，结果证明一些市售钴胺素并不像制造商声称的那么纯。 (C) 1999 Elsevier Science Inc. 保留所有权利。
A straightforward and simple, but powerful and direct, method is presented for both the detection and quantitation of cobalamin impurities in either commercial cobalamins or in metastable cobalamins (Cbls), such as RSCbls. The method is, quite simply, the use of the aromatic region of the LH NMR Of cobalamins; it is a method developed as an outgrowth of our work preparing metastable thiolatocobalamins (RSCbls) and is a method that proved necessary for characterizing those (and by inference other) cobalamins unstable to HPLC separation conditions (i.e., and, therefore, where the normally powerful HPLC method so commonly used in cobalamin chemistry fails). Despite considerable, prior, modern multidimensional NMR literature on cobalamins, the present method has not yet been indicated explicitly, nor has anyone reported previously the NMR data required to prove-that the method works (i.e., the data for a series of cobalamins and their common impurities proving that they have different chemical shifts in the aromatic region of their H-1 NMR when examined under identical NMR solvent, pH and other conditions). The direct NMR method is easy to perform, readily quantitated and applicable to species unstable to the HPLC conditions required to separate cobalamin impurities. The results have allowed quantitation of the 5-11% impurities in, for example, commercial HOCbl.HX, results which document that some commercially available cobalamins are not as pure as the manufacturers' claims. (C) 1999 Elsevier Science Inc. All rights reserved.