Binding free energy and ligand efficiency of indole-2-carboxylic acid derivatives.

Compd	ΔGa (kcal mol−1)	N b	Ligand efficiency
1	−9.49	12	0.79
4a	−8.39	23	0.36
4b	−9.25	23	0.40
10a	−10.37	28	0.37
13b	−8.09	24	0.34
16a	−6.82	22	0.31
17a	−17.46	20	0.87
17g	−16.3	21	0.78

^aΔG is the binding free energy.

^b N is the number of heavy atoms.