Chemometrics-driven LC-MS analysis reveals key metabolites and chemical diversity in Abrus cantoniensis Hance stems and leaves.

Abrus cantoniensis Hance (A. cantoniensis) is a common medicinal and edible plant. Its stems and leaves are widely used in food, pharmaceutical, and daily chemical products. However, the leaves of A. cantoniensis often detach during processing, leading to substantial quality variations. This study aimed to develop an identification method by analyzing the differences in characteristic components between stems and leaves, thereby improving the quality control standards of A. cantoniensis. A total of 130 chemical components of A. cantoniensis were identified using UPLC-Q-TOF-MS/MS, comprising 44 flavonoids, 25 triterpenoids, 15 organic acids, and 46 compounds from other categories. PCA revealed distinct clustering of stems and leaves, indicating considerable compositional divergence. OPLS-DA further identified 34 differential metabolites, with stems predominantly enriched in organic acids (e.g., chlorogenic acid and neochlorogenic acid), whereas leaves exhibited higher levels of C-glycosyl flavonoids, notably vicenin II and schaftoside. Quantitative analysis revealed that the contents of vicenin II and schaftoside in leaves were ∼100- and ∼40-fold higher, respectively, than those in stems. The contents of the three components were as follows: chlorogenic acid (0.027, 0.052, and 0.002 mg/g), vicenin II (0.295, 0.008, and 0.081 mg/g), and schaftoside (0.362, 0.023, and 0.928 mg/g). These findings indicate the substantial chemical heterogeneity between the stems and leaves of A. cantoniensis, with vicenin II and schaftoside serving as key biomarkers for leaves. The results provide a scientific basis for refining the quality control protocols of A. cantoniensis-derived herbal materials by enabling tissue-specific authentication and standardization.