Chemical constituents of bird cherry ( <i>Prunus padus</i> L.) stemwood and knotwood bioactive-rich extracts and their antioxidant activity

This study compares the polyphenolic composition and antioxidant activity of <i>Prunus padus</i> stemwood and knotwood extracts. Results show that the knotwood extract contains significantly higher levels of phenolic compounds (485 ± 59 mg GAE g^-1) and superior antioxidant activity (385 ± 38 mg AAE g^-1) than the stemwood. Both wood tissues are rich in catechin (34 g kg^-1 in knotwood and 8 g kg^-1 in stemwood), a flavonoid recognised for its antioxidant, antimicrobial, anti-inflammatory, and anticancer properties. Additionally, bioactive lignan glucosides - lyoniside and ssioriside - were identified (up to 3.5 g kg^-1). These findings suggest that <i>P. padus</i> wood is a promising feedstock for the recovery of high-value polyphenols for potential future use in pharmaceuticals and dietary supplements with strong antioxidant activity.