Identification of Metabolic Changes and Comparison of Antioxidant Activities in Two <i>Pimpinella</i> Species

Pimpinella species are commonly consumed as favored edible herbs and accumulate diverse metabolites. To date, the identification and comparison of metabolites have not been studied well in Pimpinella brachycarpa and Pimpinella koreana. This study aimed to analyze the primary and secondary metabolites present in these two Pimpinella species. Using gas chromatography-time-of-flight mass spectrometry and high-performance liquid chromatography, 64 and 65 metabolites were identified in P. brachycarpa and P. koreana, respectively. Heatmap analysis showed that most of the primary and secondary metabolites were more abundant in P. koreana than in P. brachycarpa. Except for tryptophan, all 22 other amino acids were highly accumulated in P. koreana. Similarly, the total phenolic and flavonoid contents were also higher in P. koreana, which led to the highest antioxidant activities (ABTS, DPPH, and reducing power assay). In addition, ABTS and DPPH were also more efficient in P. koreana than in P. brachycarpa, as indicated by the IC₅₀ values. This study contributes to understanding the correlation between primary and secondary metabolites with synergistic antioxidant activities from each species.