Objective   Pharmaceutical property of the stems and leaves of Paeonia intersubgeneric hybrids (PIHs) was evaluated.

  Method   Secondary metabolites in 16 PIHs were extracted from the stems and leaves and analyzed by the high-performance liquid chromatography with a diode array detector (HPLC-DAD) and the high-performance liquid chromatography quadrupole time-of-fight mass spectrometry (HPLC-Q-TOF-MS). Total phenolic content and in vitro antioxidant activity of the extract were measured.

  Results   (1) Nineteen metabolites were identified from the extracts that included 5 monoterpene glycosides, 6 flavonoids, 4 tannins, and 4 phenols. (2) The compositions of all tested hybrids were essentially identical. (3) Except for phenols, the content of individual group or total amount of compounds in the 3 groups were significantly higher in the leaves than in the stems. (4) The in vitro antioxidant activity was tested significantly greater in the leaves than in the stems as well. (5) The contents of paeoniflorin in the leaves of 5 varieties were above the minimum 18 mg·g⁻¹ as stipulated by the pharmacopoeia. (6) A cluster analysis grouped the 16 cultivars into 3 categories with one that contained two varieties, which scored the highest on all indicators except being moderate on monoterpene glycosides.

  Conclusion   The stems and leaves of “Unique” and “Lollipop” in the 16 tested PIHs appeared to have pharmaceutical values.