Table 1.

Structures of Eg5 inhibitors discussed in the text and their biochemical and cellular inhibitory activities

Compound Class	Compound Identifier	Structure	Eg5 Biochemical IC50 (nM)a	Eg5 Cellular EC50 (nM)b	References
Dihydropyrimidine-thione	(S)-Monastrol 1		30000	14000c	[42–44]
	rac-Mon-97 2		2(R) 150 2(S) 650	2(R) 1700 2(S) 6500	[44,45]
	(S)-Enastron 3		2000	ND	[42,44]
	(S)-Dimethyl enastron 4		200	ND	[42,44]
(R)-Fluorastrol 5		ND	330	[44]
Tetrahydro-β-carboline	6		2500	ND	[46]
	7		200	ND	[46]
	8		20	83	[46]
	9		100	ND	[46]
Tritylcysteine	STLC 10		140	700d	[47]
	11		29	ND	[48]
	12		10e	28	[49]
	13		14	28	[50]
Thiophene-containing	14		23000	>30000f	[51]
	15		1700	2000f	[51]
	16		480	1000f	[51]

^aValues are IC₅₀s in a microtubule-stimulated biochemical assay unless otherwise indicated;

^bEffective concentration for 50% growth inhibition in colon cancer HCT116 cells unless otherwise indicated;

^cConcentration for 50% inhibition of microtubule motility in mammalian epithelial kidney BS-C-1 cells;

^dConcentration for 50% induction of mitotic arrest in HeLa cells;

^eMT-stimulated ATPase activity expressed as Ki_app;

^fEffective concentration for 50% growth inhibition due to prolonged mitotic arrest in A-549 hNSCLC cells.