Metabolomic Differentiation of Malpighiaceae From Dry and Humid Tropics via UHPLC-MS/MS and Chemometrics

Various factors can trigger water stress in plants, particularly in those growing in dry tropical regions. To survive under such conditions, plants produce metabolites with adaptive functions. However, metabolomic data on the leaves of Malpighiaceae species cultivated in both dry and humid tropical areas of Brazil remain scarce. This study aimed to evaluate seasonal water stress in 10 species (from 7 genera) of Malpighiaceae inhabiting contrasting Brazilian biomes: Cerrado and Caatinga (dry areas), and Atlantic and Amazon Forests (humid areas). Metabolic profiles obtained by liquid chromatography coupled to mass spectrometry were compared using Variable Importance in Projection Scores from Partial Least Squares Discriminant Analysis. The results revealed a clear distinction between the leaf metabolites from dry versus humid environments. Cyanidin-3-O-sambubioside (positive ionization mode) and 3,4-di-O-galloylquinic acid (negative ionization mode) were identified as key discriminant compounds. Additionally, 15 previously unreported metabolites were annotated in the chromatographic profiles of Malpighiaceae leaves. This is the first study to demonstrate the influence of water availability on metabolomic synthesis across multiple species of Malpighiaceae. By integrating chromatographic and chemometric approaches, this study proposes a novel analytical strategy capable of revealing how environmental conditions shape metabolomic synthesis, thereby reinforcing its methodological relevance within analytical science.