Fructooligosaccharides (FOS) and raffinose family oligosaccharides (RFOs) are two highly abundant water-soluble carbohydrates in plants. The typical procedures for the FOS and RFO structural determination using mass spectrometry involve permethylation, followed by the hydrolysis of the permethylated oligosaccharides into monosaccharides, and then the identification of linkage positions using GC mass spectrometry. However, the determination of linkage position sequence is not straightforward, thus this method is limited to small oligosaccharides or oligosaccharides with simple linkages. In this study, we employed a new mass spectrometry method, logically derived sequence tandem mass spectrometry, to determine the structures of FOS and RFOs. We first showed that the monosaccharide and disaccharide CID spectra of aldohexose and ketohexose can be rationalized using dissociation mechanisms. Then we demonstrated that the linkage positions of FOS and RFOs can be identified, the sequence of the linkages can be determined, and the ketohexose and aldohexose in FOS and RFOs can be differentiated, suggesting this new method is useful for structural determination of FOS and RFOs.

中文翻译：

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使用逻辑推导的序列串联质谱法对低聚果糖和棉子糖家族低聚糖进行结构测定


低聚果糖 （FOS） 和棉子糖家族低聚糖 （RFO） 是植物中两种含量丰富的水溶性碳水化合物。使用质谱法进行 FOS 和 RFO 结构测定的典型程序包括过甲基化，然后将过甲基化寡糖水解成单糖，然后使用 GC 质谱法鉴定键位。然而，键位序列的测定并不简单，因此该方法仅限于小寡糖或具有简单键的寡糖。在这项研究中，我们采用了一种新的质谱方法，即逻辑衍生的序列串联质谱法，来确定 FOS 和 RFO 的结构。我们首先表明醛糖和酮糖的单糖和二糖 CID 光谱可以使用解离机制合理化。然后我们证明了可以识别 FOS 和 RFOs 的键位，可以确定键的顺序，并且可以区分 FOS 和 RFOs 中的酮糖和醛糖，表明这种新方法可用于 FOS 和 RFO 的结构测定。