Table 1.

Inhibitory Activity of Triazoloquinazolinones Modified in Zones 5 and 6 at the Plk1 PBD^a,b

Cmpd	Triazole	R1=	IC50 (μM, ELISA)	t1/2 (min, RLM)	PAMPA (1e-6 cm/s)	Solub. (μg/ml)
PLHSpT 6a	--	--	14.74 ± 0.48 (12)	ND	ND	ND
7		H	4.38 ± 0.41 (6)	ND	ND	ND
15		H	>50	ND	ND	<1
16		F	>50	29.4	885	2.2
17		F	>50	10.7	1084	11.0
18		F	>50	11.8	924	14.8
19		H	>50	ND	ND	ND

^a(IC₅₀ values are n = 3 unless noted in parentheses) and microsomal half-life, PAMPA assays, and aqueous solubility.

^bND, not determined.