Stemoninine is a lycoris alkaloid that can be used as an antitussive. Stemoninine has significant inhibitory activity against human acetylcholinesterase (AChE) (IC50=5.52 μM).
References:
[1].Peixi Bi, et al. Method of making antitussive medicine and relieving cough. CN1931171A. 2006-09-12
[2].Ramli, et al. "Alkaloids from the roots and leaves of Stichoneuron halabalensis and their acetylcholinesterase inhibitory activities." Natural Product Communications 8.6 (2013): 1934578X1300800603.