Table 1.

Kinase inhibitory activities of roscovitine and its derivatives

	1	2	3	4	5	6	7
CDK1/cyclin B	0.48	0.82	5.2	0.24	45	100	63
CDK2/cyclin A	0.20	0.22	3.3	0.13	23	120	60
CDK5/p25	0.32	0.65	5.2	0.28	48	200	110
CDK9/cyclin T	0.85	0.94	1.2	0.18	51	>1000	150
CK1	5.1	6.8	83	1.4	80	80	180
CLK3	34	14	−(100)	27	81	−(1000)	>1000
DYRK1A	2.3	0.79	74	0.84	18	47	120
ERK2	20	8.2	33	6, 7	>100	>1000	−(1000)
GSK-3	81	>100	98	>100	−(100)	−(1000)	>1000

Compounds were tested on nine purified kinases. IC₅₀ values, calculated from the dose-response curves, are reported in μM. Key: 1, (R)-roscovitine; 2, (S)-roscovitine; 3, olomoucine; 4, (S)-CR8; 5, metabolite M3; 6, O-benzyl-(R)roscovitine; 7, N6-Methyl-(R)-roscovitine. −, no inhibition at highest dose tested (in parentheses).