Tree age influences plant secondary metabolism, but its effect on antioxidant components in Chinese bayberry leaves remains unclear. Combining chemical assays and widely targeted metabolomics, we analyzed bayberry leaves of different ages, including young (<100 years) and mature (∼300, ∼400, and ∼500 years old) groups. We found that the contents of polyphenols and flavonoids significantly increased with tree age, which in turn enhanced their antioxidant activity. The 500-year-old leaves exhibited the highest activity. Metabolomic analysis identified a total of 3152 metabolites, with terpenoids, flavonoids, and phenolic acids being the predominant classes, collectively representing 50.44% of the total identified metabolites (20.43%, 20.11%, and 9.90%, respectively). Subsequent multivariate analysis revealed that the “Subclass 1” metabolites-comprising phenolic acids, flavonoids, and terpenoids-were positively correlated with antioxidant activity. Furthermore, two compounds, picfeltarraenin X and isothankunic acid, were identified in Chinese bayberry leaves for the first time. These results demonstrate that tree age enhances antioxidant capacity by regulating the accumulation of key secondary metabolites, predominantly terpenoids, flavonoids, and phenolic acids, thereby providing a scientific basis for the high-value utilization of bayberry leaves. • Chinese bayberry leaves were abundant bioactive secondary metabolites. • Picfeltarraenin X and isothankunic acid were first identified in bayberry leaves. • Antioxidant activity in bayberry leaves increased with tree age. • Polyphenol and flavonoid contents significantly increased with tree age.
Zhang et al. (Sun,) studied this question.