Phytoconstituents of Selaginella effusa Alston and Their α‐Glucosidase as well as Urease Inhibitory Activities

Abstract

Three new compounds (1–2, 14), as well as 22 known compounds (3–13, 15–25), were extracted for the first time from the Selaginella effusa Alston (S. effusa). For the unknown compounds, the planar configurations were determined via NMR and by high‐resolution mass spectrometry, while their absolute configurations were determined by calculated electronic circular dichroism (ECD), and the configuration of the stereogenic center of biflavones 4–5 were established for the first time. The pure compounds (1–25) were tested in vitro to determine the inhibitory activity of the enzyme‐catalyzed reactions. Compounds 1–9 inhibited α‐glucosidase with IC50 values ranging from 0.30±0.02 to 4.65±0.04 μM and kinetic analysis of enzyme inhibition indicated that biflavones 1–3 were mixed‐type α‐glucosidase inhibitors. Compounds 12–13 showed excellent inhibitory activity against urease, with compound 12 (IC50=4.38±0.31 μM) showing better inhibitory activity than the positive control drug AHA (IC5013.52±0.61 μM). In addition, molecular docking techniques were used to simulate inhibitor‐enzyme binding and to estimate the binding posture of the α‐glucosidase and urease catalytic sites.