Spatial Distribution and Comparative Analysis of Differential Metabolites in Curcuma longa L. Roots and Rhizomes Using UHPLC-Q-Orbitrap HRMS Combined With DESI-MSI.

Introduction: The roots and rhizomes of Curcuma longa L. serve as distinct traditional Chinese medicines with varying therapeutic effects, likely attributed to differences in the accumulation and distribution of metabolites in these parts.

Objective: The study aims to investigate the differences and spatial distribution patterns of metabolites in C. longa L. roots and rhizomes.

Methods: Metabolite analysis of roots and rhizomes was conducted using ultra-high-performance liquid chromatography-quadruple orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) combined with desorption electrospray ionization mass spectrometry imaging (DESI-MSI). Using principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) to screen for differential metabolites. The relative contents of differential metabolites were visualized using heat maps. Additionally, the spatial distribution of differential metabolites was analyzed based on DESI-MSI.

Results: A total of 49 main chemical components were identified in roots and rhizomes using UHPLC-Q-Orbitrap HRMS. Through nontargeted metabolomics analysis combining UHPLC-Q-Orbitrap HRMS with PCA and OPLS-DA, 24 differential markers were identified; Additionally, using DESI-MSI alongside PCA and OPLS-DA, 18 differential markers were selected. Based on the DESI-MSI results, curcuminoids and sesquiterpenoids, including bisdemethoxycurcumin, demethoxycurcumin, furanodienone, furanogermenone, furanodiene, β-elemene, and curzerene, were more abundant in the rhizomes compared to the roots. And these differential compounds exhibited spatial distribution differences in the epidermis, phloem, and xylem between the roots and rhizomes.

Conclusion: The metabolomics analysis using UHPLC-Q-Orbitrap HRMS combined with DESI-MSI suggest differences in the accumulation and spatial distribution of metabolites in C. longa L. roots and rhizomes, possibly related to the biosynthesis of secondary metabolites.