Table 3.

The antiproliferative activities (% Growth inhibition (GI) at 10 µM and GI₅₀ (µM)) of compounds I, 4a, 4b, and 5 against a panel of six human leukaemia cell lines.^a,b.

Leukaemia	I		4a		4b		5
cell lines	GI %	GI50	GI %	GI50	GI %	GI50	GI %	GI50
CCRF-CEM	9.49	1.36	L	1.22	96.4	1.60	L	0.436
HL-60(TB)	99.01	1.40	NT	0.278	NT	0.593	L	0.0979
K-562	97.96	< 0.01	NT	< 0.01	NT	< 1.00	L	< 0.01
MOLT-4	92.33	1.31	NT	0.494	NT	1.42	L	0.227
RPMI-8226	L	1.98	L	1.22	L	1.59	L	0.488
SR	87.42	2.40	NT	1.10	NT	1.78	L	0.238

^aL: lethal effect (% GI > 100), NT: not tested, NI: no inhibition. ^bBold figures refer to GI₅₀ less than 10 nM.