Online extraction-LC-MS/MS is an alternative imaging tool for spatial-resolved metabolomics: Mint leaf as a pilot...

Area of Science:

• Analytical Chemistry
• Plant Metabolomics
• Mass Spectrometry Imaging

Background:

• Classical Mass Spectrometry Imaging (MSI) methods have limitations in detailed metabolite analysis.
• Understanding the spatial distribution of metabolites within plant tissues is crucial for biological insights.

Purpose of the Study:

• To develop and validate Open-Liquid Extraction-Liquid Chromatography-Tandem Mass Spectrometry (OLE-LC-MS/MS) as a novel analytical tool for spatial metabolome imaging.
• To demonstrate the capability of OLE-LC-MS/MS in resolving isomeric compounds and providing quantitative data.

Main Methods:

• Utilized OLE-LC-MS/MS for spatial metabolome analysis of a mint leaf.
• Employed OLE-LC-Qtof-MS for initial chemical composition characterization.
• Performed OLE-LC-SRM measurements on packed leaf tissue pieces.
• Optimized quantitative settings using an online ER-MS program.
• Focused on isomeric identification using fragment ion intensity ranking.

Main Results:

• Successfully mapped the spatial-resolved metabolome of the mint leaf.
• Identified 52 compounds, with 23 abundant ones selected for quantitative analysis.
• Achieved isomer-specific distribution observations, notably for luteolin-7-O-glucuronide and luteolin-3'-O-glucuronide.
• Demonstrated regioselective distributions for most analyzed metabolites.

Conclusions:

• OLE-LC-MS/MS is a viable alternative for spatial metabolome imaging.
• The method excels in isomeric separation, identification confidence, and quantitative accuracy.
• This approach enhances the analytical toolkit for plant metabolomics research.