Comparative analysis of metabolic profile of various organs (root, stem, and leaf part) in Sida acuta Burm. f. and exploration of antioxidant and antifungal properties associated characteristic metabolic compounds

Sida acuta Burm. f. (SA) is a traditionally important herb used to treat asthma, headaches, diabetes, and leucorrhoea. However, limited phytochemical and biological studies are available for the various organs of SA. Metabolomics, a fast-evolving technology, enables in-depth exploration of plant metabolic diversity and function. Therefore, the present study aimed to investigate the total polyphenol and flavonoid content, as well as specialized metabolite profiling of different organs of SA, and to discuss their relationships with biological activities (antioxidant and antifungal). The stem of SA exhibited the highest contents of total phenols (70.46 mg GAE/g DW) and total flavonoids (135.87 mg RE/g DW) among the analyzed plant organs. All extracts of SA demonstrated noteworthy antioxidant and antifungal potential. A total of 2117 metabolites were identified by UPLC-MS/MS. The stem was a source of phenolic acids, alkaloids, terpenoids, and tannins, with superior antioxidant capacities. Multivariate analyses unveiled a specific accumulation of metabolites in various organs of SA, with 446, 597, and 281 differentially accumulated metabolites, of which 42 metabolites were shared among the pairwise comparisons. KEGG enrichment analysis showed that flavone and flavonol biosynthesis, phenylpropanoid biosynthesis, flavonoid biosynthesis, galactose metabolism, and tryptophan metabolism were the most differentially regulated pathways. Furthermore, the Pearson correlation between antioxidant/antifungal activity and metabolites was found to be both positive and negative. A total of 107 potential metabolic biomarkers were positively associated with these bioactivities. This comprehensive investigation enhances our understanding of the metabolome and biological activity, supporting the health benefits of SA.