Summary of the binding interactions and energies of AChE and BuChE complexed with alkaloids from the tubers of Stephania pierrei.

Compound	Residue	Interaction	Distance (Å)	ΔGdocking (Kcal mol−1)	IC50 (μM)
AChE-inhibitor interaction
38	F295	Hydrogen bond	2.82	−9.57	1.21
	W286	Pi–Pi	4.02, 4.92, 5.36
	S293	Pi–Pi	3.63
	F297	Pi–Pi	5.16
	Y341	Pi–Pi	4.93
42	R296	Hydrogen bond	1.70	−8.95	1.09
	W286	Pi–Pi	4.15, 3.71, 5.46, 4.13, 5.59, 5.56
	Y124	Pi–Pi	5.78
	S293	Pi–Pi	4.30
Galanthamine	G121	Pi–σ	3.76	−7.91	1.21
	F338	Pi–Pi	5.94
BuChE-inhibitor interaction
22	W82	Pi–Pi	4.68, 5.40, 5.32, 5.35	−8.07	2.85
		Pi–σ	3.89
	T120	Pi–Pi	3.36
23	W82	Pi–Pi	4.95, 5.72, 4.38, 5.26	−8.28	2.80
			3.86, 5.26
		Pi–σ	3.42, 3.87
38	W82	Pi–Pi	4.64, 5.52, 5.21, 5.42	−8.01	3.34
	T120	Pi–σ	3.37
39	W82	Pi–Pi	5.88, 4.56, 5.31, 5.20	−7.89	3.26
			5.04
Galanthamine	W82	Pi–σ	3.83	−7.41	3.59