Brachyantheraoside A8, a new natural nor-oleanane triterpenoid as a kidney-type glutaminase inhibitor from Stauntonia brachyanthera†
With the aim of finding a better kidney-type glutaminase (KGA) inhibitor with potential anti-cancer properties, 18 nor-oleanane triterpenoids from Stauntonia brachyanthera, including 2 new ones, were screened against KGA. The structure-based virtual ligand screening identified 8 compounds, which might have more chance to become inhibitors of KGA with low binding energy. Glutaminase inhibition experiments and a series of cellular level assays, including cytotoxicity, wound healing, transwell invasion, western blot, and cell apoptosis, further confirmed the inhibitory effect of 5 (brachyantheraoside A8). These provided the possibility for 5 to become an inhibitor.