Taxonomy-Guided Discovery of Antiviral Resources in Korean Peucedanum L. (Apiaceae).

The genus Peucedanum (Apiaceae) contains diverse coumarins and related secondary metabolites with a wide range of pharmacological activities; however, the antiviral potential of Korean taxa remains largely unexplored. In this study, we evaluated the cytotoxicity and anti-influenza activity of aerial-part extracts from Korean Peucedanum taxa and the allied species Sillaphyton podagraria. Twenty-six ethanol extracts, comprising 24 accessions representing eight identified taxa and two unidentified Peucedanum samples, were screened against influenza A/Puerto Rico/8/34 (H1N1) virus in MDCK cells. Cytotoxicity and antiviral activity were assessed using MTT-based assays, and the half-maximal inhibitory concentration (IC50), half-maximal cytotoxic concentration (CC50), and selectivity index (SI) were determined. Most extracts showed low cytotoxicity, with CC50 values > 100 μg/mL. P. terebinthaceum var. deltoideum showed the strongest and most consistent activity across all three accessions, with IC50 values of 6.42 to 12.18 μg/mL and SI values ranging from >8.21 to >15.57. One P. japonicum extract (Pj2) was also active (IC50 = 15.52 μg/mL; SI > 6.44). Comparative chromatographic profiling further revealed taxon-specific chemical patterns. Collectively, these findings identify P. terebinthaceum var. deltoideum as a promising source of antiviral compounds and highlight the utility of a taxonomy-guided approach for bioprospecting and natural-product-based antiviral discovery.