Chemical profiling and antioxidant activity of Japanese apricot flowers with green sepals: Insights into medicinal potential and harvest optimization

The Japanese apricot (Prunus mume Sieb. et Zucc.), a deciduous tree within the Rosaceae family, is esteemed for its medicinal and ornamental attributes. In Chinese tradition, the ‘Lve’ group of the Japanese apricot, including varieties like ‘Lve’ and ‘Xiaolve’, is commonly employed for medicinal purposes and tea production. This study endeavors to delineate the chemical distinctions among four Japanese apricot varieties. Quantitative analysis, utilizing ultra-performance liquid chromatography (UPLC), was conducted on ‘Lve’, ‘Xiaolve’, ‘Qingfeng’, and ‘Touguhong’. The research explores the chemical components of different floral organs and stages within the ‘Xiaolve’ cultivar, correlating them with hydroxyl radical (·OH) and 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging rates. Results indicate significant variation in flower composition among the varieties. Notably, chlorogenic acid varies markedly, ranking highest in ‘Xiaolve’, followed by ‘Touguhong’, ‘Lve’ and ‘Qingfeng’, ‘Qingfeng’ exhibits elevated levels of hyperoside and quercetin. In the ‘Xiaolve’, stamens show heightened chlorogenic acid levels, while petals display increased flavonoids and catechins. Additionally, chemical components decrease with flowering stages. Correlations between chemical components in ‘Xiaolve’ and scavenging rates of OH and ABTS free radicals were observed. Molecular docking analysis reveals that chlorogenic acid binds to multiple antioxidant proteins, suggesting its dual role in scavenging free radicals and internal antioxidant activity. These findings form a theoretical foundation for exploring the medicinal potential of the ‘Xiaolve’, determining optimal harvest times, and unraveling underlying mechanisms.