Comparative Phytochemical Profiling and In Vitro Antibiofilm Activity of the Aerial and Underground Parts of Primula veris subsp. columnae (Ten.) Lȕdi

The comparative UHPLC-MS/MS analysis of the underground and aerial parts of Primula veris subsp. columnae (Ten.) Lȕdi revealed a diverse range of secondary metabolites, including flavonoids and phenolic compounds and their glycosides, bisbibenzyl compounds and triterpene saponins. Phytochemical study of the aerial parts led to the isolation of 13 surface flavonoids and 6 flavonoid glycosides, of which 8,2′-dimethoxy-5-hydroxyflavone and 8,3′-dimethoxy-5-hydroxyflavone are new natural compounds. From the underground parts, a new triterpene saponin, primulasaponin VI, was isolated together with the known primulasaponins I, III and V; priverosaponin B 22-acetate; primulaverin; primverin; gaultherin; and 3-methoxy-4-primeverosylacetophenone. The structures of the new compounds were elucidated by NMR and HR-ESI-MS. The acetone extract obtained from the aerial parts and methanol extracts obtained from both aerial and underground parts were evaluated for their antibiofilm activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The methanol extract obtained from underground parts possessed the strongest overall antibiofilm activity, particularly against E. coli and S. aureus. While the acetone extract inhibited the biofilm formation by E. coli and S. aureus, it promoted biofilm formation by P. aeruginosa. All tested extracts exhibited low cytotoxicity toward human keratinocytes and melanoma cells.