Alternative Identification of Glycosides Using MS/MS Matching with an In Silico-Modified Aglycone Mass Spectra Library.
Alternative Identification of Glycosides Using MS/MS Matching with an In Silico-Modified Aglycone Mass Spectra Library.
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DOI：
10.1021/acs.analchem.3c00957
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发表时间：
2023-06
影响因子：
7.4
通讯作者：
E. Rodriguez;Yuanyue Li;Arpana Vaniya;P. Shih;O. Fiehn
中科院分区：
文献类型：
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作者：
E. Rodriguez;Yuanyue Li;Arpana Vaniya;P. Shih;O. Fiehn
代谢物的糖基化有多种用途。添加糖使代谢物更具水溶性，并改善其生物分布，稳定性和解毒。在植物中，熔点的增加使得能够储存在需要时通过水解释放的挥发性化合物。传统上，通过质谱法（MS/MS）使用[M-糖]中性损失鉴别糖基化代谢物。在此，我们研究了71对糖苷及其各自的糖苷配基，包括己糖，戊糖，和葡糖苷酸部分。使用液相色谱（LC）耦合电喷雾电离高分辨率质谱，我们检测到经典的[M-糖]产品离子只有68%的糖苷。相反，我们发现，大多数糖苷配基MS/MS产物离子在其相应糖苷的MS/MS光谱中是保守的，即使没有观察到[M-糖]中性损失。我们将戊糖和己糖单元添加到3057个糖苷配基的MS/MS库的前体质量中，以使得能够用标准MS/MS搜索算法快速鉴定糖基化天然产物。在巧克力和茶的非靶向LC-MS/MS代谢组学数据中寻找未知化合物时，我们在标准MS-DIAL数据处理中对108个新糖苷进行了结构注释。我们将这个新的硅糖基化产物MS/MS库上传到GitHub，使用户能够在没有真实化学标准的情况下检测天然产物糖苷。
Glycosylation of metabolites serves multiple purposes. Adding sugars makes metabolites more water soluble and improves their biodistribution, stability, and detoxification. In plants, the increase in melting points enables storing otherwise volatile compounds that are released by hydrolysis when needed. Classically, glycosylated metabolites were identified by mass spectrometry (MS/MS) using [M-sugar] neutral losses. Herein, we studied 71 pairs of glycosides with their respective aglycones, including hexose, pentose, and glucuronide moieties. Using liquid chromatography (LC) coupled to electrospray ionization high-resolution mass spectrometry, we detected the classic [M-sugar] product ions for only 68% of glycosides. Instead, we found that most aglycone MS/MS product ions were conserved in the MS/MS spectra of their corresponding glycosides, even when no [M-sugar] neutral losses were observed. We added pentose and hexose units to the precursor masses of an MS/MS library of 3057 aglycones to enable rapid identification of glycosylated natural products with standard MS/MS search algorithms. When searching unknown compounds in untargeted LC-MS/MS metabolomics data of chocolate and tea, we structurally annotated 108 novel glycosides in standard MS-DIAL data processing. We uploaded this new in silico-glycosylated product MS/MS library to GitHub to enable users to detect natural product glycosides without authentic chemical standards.