Metabolite differences between stems and leaves of Sarcandrae herba: A basis for rational medicinal part selection

The 2025 edition of the Chinese Pharmacopoeia designates the dried whole plant of Sarcandrae herba as the medicinal part; however, the frequent phenomenon of leaf detachment in practice raises concerns about its impact on the quality of the medicinal material. To address this, the present study systematically characterized the chemical basis of Sarcandrae herba using UPLC-Q-TOF-MS/MS technology. Combined with metabolomic approaches, we conducted chemical analyses on the stems and leaves of 30 batches of samples to identify and analyze differential metabolites and their distribution patterns. Additionally, the contents of two key marker components with significant differences in the whole plant, pure stems, and pure leaves were determined. The results demonstrated that a total of 103 chemical constituents were identified in the stems and leaves of Sarcandrae herba, encompassing organic acids, flavonoids, sesquiterpenoids, and coumarins, among which 24 were identified as significantly differential metabolites. Notably, isofraxidin exhibited specific enrichment in the stems, with its content in 15 batches of stems being five times higher than that in the leaves. Conversely, phenolic acids such as rosmarinic acid, chlorogenic acid, and neochlorogenic acid were predominantly distributed in the leaves, with the leaf content of rosmarinic acid being twice that of the stems. These findings reveal the characteristic distribution patterns of constituents in the stems and leaves of Sarcandrae herba, clarifying that leaf detachment may lead to the loss of bioactive phenolic acids and a relative increase in the proportion of isofraxidin, posing a quality risk for the medicinal material. This study provides a chemical foundation for understanding the scientific connotation of " whole plant for medicinal use" and offers important evidence for optimizing the quality control strategy of Sarcandrae herba medicinal materials.