This study aims to establish a time-resolved harvesting standard for Penthorum chinense. To achieve this, we systematically integrated growth phenology, phytochemical accumulation dynamics, and antioxidant activity across six key developmental stages. The contents of total phenolics, flavonoids, proanthocyanidins, and tannins exhibited a biphasic fluctuation pattern, which was closely correlated with variations in antioxidant capacity. Principal component analysis identified the optimal harvest windows: flowers achieved the highest integrated score at the full blooming stage, whereas leaves scored highest at the early fruiting stage. These periods also corresponded with greater fresh biomass, supporting favorable economic returns. Accordingly, we recommend the full blooming stage as the optimal harvest time for flowers and the early fruiting stage for leaves and stems. Future research should focus on elucidating how environmental factors regulate the accumulation of bioactive compounds, which will further refine cultivation and harvest strategies to enhance the quality of this medicinal herb.
Xiang et al. (Wed,) studied this question.