(±)-Yanhusuomide A, a pair of ornithine-fused benzylisoquinoline enantiomers from Corydalis yanhusuo.

ABSTRACT

(±)-Yanhusuomide A (1), a novel enantiomeric pair of ornithine-fused benzylisoquinoline, were characterized from the dried tubers of Corydalis yanhusuo, along with a biogenetically related intermediate oblongine (2). Yanhusuomide A features an unprecedented skeleton based on a benzylisoquinoline coupled with an ornithine derivative to form a rare 5,6-dihydro-4H-pyrido[3,4,5-de]quinazoline motif. Plausible biosynthetic pathway of 1 was proposed, and (±)-yanhusuomide A (1) presented potential inhibitory bioactivity against acetylcholinesterase (AChE) with IC50 = 14.07 ± 2.38 µM. The simulation of molecular docking displayed that 1 generated strong interaction with Asp-74 and Trp-86 residues of AChE through attractive charge of the quaternary nitrogen.