Inhibitory properties of human DNA topoisomerase IIα for the tested piperidinecarboxamides, Methotrexate and Combretastatin.

Entry	Compound	IC50 (μM ± SD)a
1	27	33.64 ± 1.30
2	29	28.97 ± 1.39
3	30	41.79 ± 2.42
4	34	30.69 ± 1.32
5	35	26.39 ± 1.61
6	36	23.04 ± 1.37
7	37	27.23 ± 1.72
8	38	35.01 ± 2.08
9	39	41.30 ± 1.60
10	40	40.35 ± 1.56
11	41	50.17 ± 1.94
12	42	31.49 ± 1.22
13	43	28.30 ± 1.09
14	44	46.18 ± 1.79
15	45	39.31 ± 1.52
16	46	56.23 ± 2.18
17	47	33.01 ± 1.28
18	Methotrexate (Met)	23.25 ± 1.31
19	Combretastatin A-4 (CA-4)	22.02 ± 0.85

^aIC₅₀ is the concentration producing 50% inhibition of the tested enzyme, SD is the standard division.