Target isolation of diverse sesquiterpenoid from the stems of Daphne genkwa based on molecular networking

Guiding by LC-MS/MS analysis and the Global Natural Products Social (GNPS) Molecular Networking, three undescribed sesquiterpenoids, stedapgens A-C, and two known analogues were discovered in the barks of Daphne genkwa Sieb. et Zucc. The structures were determined by analysis of their spectroscopic data and quantum-chemical calculations. All the isolated novel compounds were tested for their acetylcholinesterase inhibitory activities with IC50 = 0.754 +/- 0.059, 0.696 +/- 0.026, and 0.337 +/- 0.023 mu g/ml. Among them, stedapgen A displayed promising inhibitory activities against AChE, and the binding sites were predicted by molecular docking. [GRAPHICS]