Table 2.

Antiproliferative activity of the neocryptolepine derivatives 3a–3d, 4a, and 4b against the human leukemia MV4-11 cell line.

Compound	n	R1	R2	R3	Yield, %	IC50 (μM)
3a	1	H	Me	Me	91 a	0.549 ± 0.108
3b	1	Me	Me	Me	83 a	0.427± 0.092
3c	1	Cl	Me	Me	84 a	0.790 ± 0.302
3d	0	H	Me	Me	89 a	0.464 ± 0.141
4a	1	H	Me	Me	90 b	0.680 ± 0.215
4b	0	Cl	Me	Me	84 b	2.330 ± 1.015

^a Yield of ureidation of the precursor amine 2; ^b Yield of thioureidation of the precursor amine 2. The IC₅₀ value is defined as the concentration of a compound that corresponds to a 50% growth inhibition. Data are expressed as the mean ± SD.