Comprehensive identification of chemical constituents in <i>Cortex Mori Radicis</i> based on precursor ion features localization and targeted MS2 analysis

Cortex Mori Radicis, which is the dried root bark of Morus alba L. from the Moraceae family, is a commonly used traditional Chinese medicine in clinical practice with multiple pharmacological activities. However, its chemical constituents are unclear. Traditional methods for chemical composition analysis, have only been able to identify a small fraction of the chemical constituents present in wood material. To comprehensively identify the chemical constituents in Cortex Mori Radicis, this study localized them based on their precursor ion features, and then performed targeted MS2 analysis for structure identification. Firstly, the chemical components isolated from Cortex Mori Radicis were analyzed to derive their precursor ion features. And then, ions extracted from the MS scan data of Cortex Mori Radicis, which match the precursor ion features, were located. After constructing the precursor ion lists, targeted MS2 analysis was performed for structure identification. This approach allowed for the identification of not only high-abundance but also low-abundance compounds. As a result, a total of 402 chemical constituents were successfully identified from Cortex Mori Radicis, and a large number of isomers of known compounds were also discovered, which provides a reference for the isolation and research of new compounds in Cortex Mori Radicis.