. Author manuscript; available in PMC: 2013 Dec 4.

Published in final edited form as: Bioorg Med Chem. 2006 Sep 28;14(24):10.1016/j.bmc.2006.09.008. doi: 10.1016/j.bmc.2006.09.008

Table 1. Inhibitory concentration (IC₅₀ μM) and selectivity ratios against rlDHFR, pcDHFR, tgDHFR and maDHFR versus rlDHFR by compounds 18–23^a.

Compound	pc	rl	rl/pc	tg	rl/tg	ma	rl/ma
17^b	0.77	0.20	0.26	0.037	5.4	0.077	2.6
18	17.1	0.696	0.04	0.138	5	5.34	0.13
19	0.859	0.0399	0.05	0.0148	2.7	0.109	0.37
20	2.09	0.0567	0.03	0.0483	1.2	0.246	0.23
21	1.99	0.142	0.07	0.0717	2	0.0747	1.9
22	8.06	0.516	0.06	0.16	3.2	1.86	0.28
23	2.22	0.396	0.2	0.0414	9.6	0.321	1.23
TMP	12	180.0	14	2.8	65	0.30	600
PTX	0.013	0.0033	0.26	0.0043	0.76	0.00061	5.3
TMQ	0.042	0.003	0.07	0.01	0.3	0.0015	2.0

All enzymes were assayed spectroscopically in a solution containing 90 micromolar dihydrofolate, 119 μM NADPH, 41 mM Na phosphate buffer, and 8.9 mM 2-mercaptoethanol at pH 7.4 and 37 C. Rat liver and Toxoplasma DHFR are assayed in the presence of 150 mM KCl. Reactions are initiated with an amount of enzyme yielding a change in OD at 340 nM of 0.035/min.

The data for 17 was taken from Ref. 13.

Table 1. Inhibitory concentration (IC50 μM) and selectivity ratios against rlDHFR, pcDHFR, tgDHFR and maDHFR versus rlDHFR by compounds 18–23a.

Table 1. Inhibitory concentration (IC₅₀ μM) and selectivity ratios against rlDHFR, pcDHFR, tgDHFR and maDHFR versus rlDHFR by compounds 18–23^a.