Diagnostic fragmentation-assisted mass spectral networking coupled with in silico dereplication for deep annotation of steroidal alkaloids in medicinal Fritillariae Bulbus

Feng Jie Liu, Yan Jiang, Ping Li, Yang Dan Liu, Gui Zhong Xin, Zhong Ping Yao (Corresponding Author), Hui Jun Li

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

Fully understanding the chemicals in an herbal medicine remains a challenging task. Molecular networking (MN) allows to organize tandem mass spectrometry (MS/MS) data in complex samples by mass spectral similarity, which yet suffers from low coverage and accuracy of compound annotation due to the size limitation of available databases and differentiation obstacle of similar chemical scaffolds. In this work, an enhanced MN-based strategy named diagnostic fragmentation-assisted molecular networking coupled with in silico dereplication (DFMN-ISD) was introduced to overcome these obstacles: the rule-based fragmentation patterns provide insights into similar chemical scaffolds, the generated in silico candidates based on metabolic reactions expand the available natural product databases, and the in silico annotation method facilitates the further dereplication of candidates by computing their fragmentation trees. As a case, this approach was applied to globally profile the steroidal alkaloids in Fritillariae bulbus, a commonly used antitussive and expectorant herbal medicine. Consequently, a total of 325 steroidal alkaloids were discovered, including 106 cis-D/E-cevanines, 142 trans-D/E-cevanines, 29 jervines, 23 veratramines, and 25 verazines. And 10 of them were confirmed by available reference standards. Approximately 70% of the putative steroidal alkaloids have never been reported in previous publications, demonstrating the benefit of DFMN-ISD approach for the comprehensive characterization of chemicals in a complex plant organism.

Original languageEnglish
Pages (from-to)e4528
JournalJournal of mass spectrometry : JMS
Volume55
Issue number9
DOIs
Publication statusPublished - 1 Sep 2020

Keywords

  • fragmentation pattern
  • in silico
  • mass spectrometry
  • molecular networking
  • steroidal alkaloids

ASJC Scopus subject areas

  • Spectroscopy

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