In-silico-library-based method enables rapid and comprehensive annotation of cardiolipins and cardiolipin oxidation products using high resolution tandem mass spectrometer

Self Cite

Research on novel bioactive lipids has garnered increasing interest. Although lipids can be identified by searching mass spectral libraries, the discovery of novel lipids remains challenging as the query spectra of such lipids are not included in libraries. In this study, we propose a strategy to discover novel carboxylic acid-containing acyl lipids by integrating molecular networking with an extended in silico spectral library. Derivatization was performed to improve the response of this method. The tandem mass spectrometry spectra enriched by derivatization facilitated the formation of molecular networking and 244 nodes were annotated. We constructed consensus spectra for these annotations based on molecular networking and developed an extended in silico spectral library based on these consensus spectra. The spectral library included 6879 in silico molecules covering 12,179 spectra. Using this integration strategy, 653 acyl lipids were discovered. Among these, O-acyl lactic acids and N-lactoyl amino acid-conjugated lipids were annotated as novel acyl lipids. Compared with conventional methods, our proposed method allows for the discovery of novel acyl lipids, and extended in silico libraries significantly increase the size of the spectral library.

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Discovery of N-Acyl Amino Acids and Novel Related N-, O-Acyl Lipids by Integrating Molecular Networking and an Extended In Silico Spectral Library

Yuan

et al. 2023

Self Cite

“…Owing to the proposal of an in silico tandem mass spectrometry database for lipid identification by Tobias Kind, lipid annotation has been greatly advanced in recent years. − However, automatic and high-throughput annotation of oxidized lipids remains challenging due to the complexity of the reactions involved, the huge number of candidate structures far exceeding unoxidized lipids, and the lack of standard validation. Significant efforts have been made in the in silico -predicted MS/MS spectra for oxidized lipids with high chemical diversity, such as CEU mass mediator, LipidMatch, LPPtiger, and some combinations of manual and automated small-scale MS/MS spectra predicting methods, but they are mainly for the prediction of oxidized phospholipids, and lipid species, class of fatty acyl chains, and the oxidation cleavage reaction sites involved in oxidized lipid prediction are greatly restricted.…”

Section: Introductionmentioning

confidence: 99%

In Silico-Predicted Dynamic Oxlipidomics MS/MS Library: High-Throughput Discovery and Characterization of Unknown Oxidized Lipids

Zhou,

Huang,

Zhang

et al. 2024

Nontargeted lipidomics using liquid chromatography-tandem mass spectrometry can detect thousands of molecules in biological samples. However, the annotation of unknown oxidized lipids is limited to the structures present in libraries, restricting the analysis and interpretation of experimental data. Here, we describe Doxlipid, a computational tool for oxidized lipid annotation that predicts a dynamic MS/MS library for every experiment. Doxlipid integrates three key simulation algorithms to predict libraries and covers 32 subclasses of oxidized lipids from the three main classes. In the evaluation, Doxlipid achieves very high prediction and characterization performance and outperforms the current oxidized lipid annotation methods. Doxlipid, combined with a molecular network, further annotates unknown chemical analogs in the same reaction or pathway. We demonstrate the broad utility of Doxlipid by analyzing oxidized lipids in ferroptosis hepatocellular carcinoma, tissue samples, and other biological samples, substantially advancing the discovery of biological pathways at the trace oxidized lipid level.

“…Oxidized PS80 samples were prepared using three methods: an iron(II)-induced reaction, 25 the Fenton reaction, 31 and the t-BuOOH reaction. 32 Detailed experimental methods are described in the SI (1.3 Sample preparation).…”

Section: ■ Introductionmentioning

confidence: 99%

Novel Strategy to Rapidly Profile and Identify Oxidized Species of Polysorbate 80 Using Ultra-High-Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry

Wang

Zheng

et al. 2023

Polysorbate 80 (PS80) is widely used as an excipient in vaccines and biopharmaceuticals. The oxidized species of PS80 have raised concern because of their potential to compromise product stability and pose a clinical risk. Analytical methods to profile and identify the oxidized species are hard to develop owing to their complexity and low abundance. Herein, a novel strategy was demonstrated to comprehensively profile and identify the oxidized species of PS80 using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The characteristic fragmentation patterns of the oxidized species were obtained under the “all ions” scan mode. Then, 10 types of distinct fragments from oxidized oleates were identified and confirmed using two purified oxidized species (polyoxyethylene (POE) sorbitan mono-hydroxy oleate and POE mono-keto oleate) whose structures were elucidated via nuclear magnetic resonance. A total of 348 (32 types) oxidized species were profiled and identified in the oxidized PS80 samples, including 119 (10 types) species found for the first time to our knowledge. Mathematical models were established and validated based on the good logarithmic relation between the POE degree of polymerization and the relative retention time and used to rapidly discover and identify the oxidized species. A novel strategy was established to profile and identify the PS80 oxidized species based on their retention time, HRMS, and HRMS2 data of the detected peaks using an in-house dataset. Using this strategy, 104 (14 types) and 97 (13 types) oxidized species were identified for the first time in PS80 and its preparations, respectively.