Simultaneous Determination of the Absolute Configuration of Twelve Monosaccharide Enantiomers from Natural Products in a Single Injection by a UPLC-UV/MS Method
Simultaneous Determination of the Absolute Configuration of Twelve Monosaccharide Enantiomers from Natural Products in a Single Injection by a UPLC-UV/MS Method
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DOI：
10.1055/s-0031-1298432
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发表时间：
2012-05-01
期刊：
影响因子：
2.7
通讯作者：
Khan, Ikhlas A.
中科院分区：
文献类型：
--
作者：
Wang, Yan-Hong;Avula, Bharathi;Khan, Ikhlas A.
在天然产物化学中，测定糖的组成以及糖苷中各单糖的绝对构型往往是至关重要的。建立了一种同时使用光电二极管阵列(PDA)和质谱仪(UPLC-UV/MS)对单糖对映体绝对构型进行定性分析的超高效液相色谱方法。在一次注射中，在不到25分钟的时间内，确定了16个单糖衍生物，包括6对醛糖对映体(D/L-葡萄糖、D/L-半乳糖、D/L-异构体、D/L-阿拉伯糖、D/L-木糖和D/L-岩藻糖)和4种单糖(L-鼠李糖、2-脱氧-D-葡萄糖、6-脱氧-D-葡萄糖和2-脱氧-D-半乳糖)。研究发现，糖类对映体的结构与保留时间有关。在本研究的糖对映体衍生物中，C-3‘位R构型的立体异构体比相应的S构型的立体异构体保留的时间更长。与以前报道的方法相比，UPLC-MS方法可以将糖的检测灵敏度提高10倍以上。单糖与L-半胱氨酸甲酯和异硫氰酸苯酯的一锅反应在有螺丝盖的反应瓶中容易重现、清洁和相对简单。所建立的方法成功地应用于自然界中普遍存在的不同类型的糖苷，即三萜、甾体和黄酮苷的分析。从测试样品中可以清楚地确定组成单糖的绝对构型。
In natural product chemistry, it is often crucial to determine sugar composition as well as the absolute configuration of each monosaccharide in glycosides. An ultra-performance liquid chromatography method using both photodiode array (PDA) and mass spectrometry detectors (UPLC-UV/MS) was developed for qualitative analysis of the absolute configuration of monosaccharide enantiomers. Within a single injection, 16 monosaccharide derivatives including 6 pairs of aldose enantiomers (D/L-glucose, D/L-galactose, D/L-allose, D/L-arabinose, D/L-xylose, and D/L-fucose) and 4 other monosaccharides (L-rhamnose, 2-deoxy-D-glucose, 6-deoxy-D-glucose, and 2-deoxy-D-glalactose) were identified in less than 25 minutes. It was found that the structures of derivatives of sugar enantiomers correlated with retention time. Among derivatives of sugar enantiomers in the current study, the stereoisomer of R-configuration at C-3' retained longer than the corresponding S-configuration isomer. The UPLC-MS method can increase sensitivity of detection of the saccharides by more than 10 times compared to previously reported methods. The one-pot reaction of monosaccharide with L-cysteine methyl ester and phenyl isothiocyanate is easily reproduced, clean, and relatively simple in a screw-capped reaction vial. The developed method was successfully applied for the analysis of different types of glycosides, viz., glycosides of triterpenes, steroids, and flavonoids, that commonly exist in nature. The absolute configurations of composed monosaccharides are clearly characterized from tested samples.