Developmental stage-dependent changes in kaempferol derivatives and associated antioxidant, antibacterial, and quorum sensing inhibitory activities in Hylotelephium verticillatum leaves.

This study investigated the phytochemical profiles and bioactivities of ethanolic extracts from the first and second true leaves (FLH and SLH) of Hylotelephium verticillatum during early development. Total phenolic content (TPC), total flavonoid content (TFC), antioxidant, antibacterial, and quorum sensing (QS) inhibitory activities were evaluated, and major flavonoids were characterized using UPLC-Q-orbitrap-ESI-MS/MS and HPLC. SLH exhibited significantly higher TPC than FLH, whereas TFC showed no significant difference. Despite lower TPC, FLH demonstrated stronger ABTS radical scavenging, antibacterial, and QS inhibitory activities (based on diffusion assays). Phytochemical analysis revealed that kaempferol derivatives were the predominant constituents and displayed clear developmental stage-dependent variations. Correlation and hierarchical clustering analyses indicated that biological activities were more closely associated with specific flavonoid constituents than with overall phenolic accumulation. These findings demonstrate that early leaf development significantly influences flavonoid composition and bioactivities in H. verticillatum, highlighting the functional importance of kaempferol derivatives in this edible species.