Two New Picoline-Derived Meroterpenoids with Anti-Acetylcholinesterase Activity from Ascidian-Derived Fungus Amphichorda felina

Amphichoterpenoids D (1) and E (2), two new picoline-derived meroterpenoids with a rare 6/6/6 tricyclic pyrano[3,2-c]pyridinyl-gamma-pyranone scaffold, were isolated from the ascidian-derived fungus Amphichorda felina SYSU-MS7908. Their structures, including the absolute configurations, were established by extensive spectroscopic methods (1D and 2D NMR and high-resolution mass spectrometry) and ECD calculations. Compounds 1 and 2 showed anti-acetylcholinesterase (anti-AChE) activities with IC50 values of 12.5 mu M and 11.6 mu M, respectively. The binding interactions between 1, 2, and AChE were investigated using molecular docking analyses.