Table 2.

Leishmania CRK3–CYC6 and HsCDK2–CYCA activity (compounds 14–39) from initial SAR development at the R¹ position of triazolopyridine 19

Compd	R1	CRK3–CYC6 IC50 [μm][a]	HsCDK2–CYCA IC50 [μm][b]
14	4-hydroxy-3-methoxyphenyl	0.23	0.36
21	H	>100	>100
22	phenyl	0.27	>100
23	4-hydroxyphenyl	0.12	0.86
24	3-methoxyphenyl	0.36	>100
25	3-methylphenyl	0.06	>100
26	3-chlorophenyl	0.35	>100
27	1-napthyl	0.09	>100
28	4-indole	0.07	>100
29	4-N-methylindole	0.04	>100
30	3-morpholinophenyl	1.6	>100
31	2,6-dimethylphenyl	19.0	>100
32	2,5-dimethylphenyl	0.65	>100
33	3,5-dimethylphenyl	0.02	>100
34	4-methoxy-3-methylphenyl	0.03	>100

^[a]Concentration required to inhibit Leishmania CRK3–CYC6 activity by 50 %; data represent the mean of two or more experiments.

^[b]Concentration required to inhibit HsCDK2–CYCA activity by 50 %; data represent the mean of two or more experiments.