Recognition of bioactive saponins from Polygonatum based on UPLC-QTOF/MS and molecular docking

Saponins are one of the main active ingredients in Polygonatum. This study aimed to identify Polygonatum saponins with superior biological properties from four species and screen for saponin compounds with high bioactivities. The results indicated that saponins content and bioactivity varied by species, especially PK, which demonstrated superior performance in both yield (extraction yield = 2.43 %, purification yield = 9.86 %) and bioactivities. Specifically, the IC₅₀ values for α-amylase and α-glucosidase were 0.877 mg/mL and 0.747 mg/mL, respectively. UPLC-QTOF/MS analysis further identified three saponins in PK, namely Sibiricoside B, Kingianoside C, and Kingianoside H, which demonstrated remarkable antioxidant activity in vitro. Molecular docking analyses revealed that Sibiricoside B (-8.051 kcal/mol) and Kingianoside H (-7.757 kcal/mol) exhibited significantly lower binding energies and shorter hydrogen bond distances compared to acarbose (-7.641 kcal/mol). These findings suggest that Sibiricoside B and Kingianoside H may serve as promising candidates for the development of natural inhibitors targeting type 2 diabetes mellitus, as well as potential active components in functional foods. Furthermore, all these findings also provide a basis for the valorization of Polygonatum species as natural resources, highlighting their potential to develop novel natural antioxidants and functional food ingredients.