Synthesis of 2,4-diamino-6-[2'-O-(omega-carboxyalkyl)oxydibenz[b,f]azepin-5-yl]methylpteridine s as potent and selective inhibitors of Pneumocystis carinii, Toxoplasma gondii, and Mycobacterium avium dihydrofolate reductase.
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Rosowsky A, Fu H, Chan DC, Queener SF
Synthesis of 2,4-diamino-6-[2'-O-(omega-carboxyalkyl)oxydibenz[b,f]azepin-5-yl]methylpteridine s as potent and selective inhibitors of Pneumocystis carinii, Toxoplasma gondii, and Mycobacterium avium dihydrofolate reductase.
J Med Chem. 2004 May 6;47(10):2475-85.
- PubMed ID
- 15115391 [ View in PubMed]
- Abstract
Six previously undescribed N-(2,4-diaminopteridin-6-yl)methyldibenz[b,f]azepines with water-solubilizing O-carboxyalkyloxy or O-carboxybenzyloxy side chains at the 2'-position were synthesized and compared with trimethoprim (TMP) and piritrexim (PTX) as inhibitors of dihydrofolate reductase (DHFR) from Pneumocystis carinii (Pc), Toxoplasma gondii (Tg), and Mycobacterium avium (Ma), three of the opportunistic organisms known to cause significant morbidity and mortality in patients with AIDS and other disorders of the immune system. The ability of the new analogues to inhibit reduction of dihydrofolate to tetrahydrofolate by Pc, Tg, Ma, and rat DHFR was determined, and the selectivity index (SI) was calculated from the ratio IC(50)(rat DHFR)/IC(50)(Pc, Tg, or Ma DHFR). The IC(50) values of the 2'-O-carboxypropyl analogue (10), with SI values in parentheses, were 1.1 nM (1300) against Pc DHFR, 9.9 nM (120) against Tg DHFR, and 2.0 nM (600) against Ma DHFR. The corresponding values for the 2'-O-(4-carboxybenzyloxy) analogue (12) were 1.0 nM (560), 22 nM (21), and 0.75 nM (630). By comparison, the IC(50) and SI values for TMP were Pc, 13 000 nM (14); Tg, 2800 nM (65); and Ma, 300 nM (610). For the prototypical potent but nonselective inhibitors PTX and TMX, respectively, these values were Pc, 13 nM (0.26) and 47 nM (0.17); Tg, 4.3 nM (0.76) and 16 nM (0.50); Ma, 0.61 nM (5.4) and 1.5 nM (5.3). Thus 10 and 12 met the criterion for DHFR inhibitors that combine the high selectivity of TMP with the high potency of PTX and TMX.
DrugBank Data that Cites this Article
- Drug Targets
Drug Target Kind Organism Pharmacological Action Actions Trimethoprim Dihydrofolate reductase Protein Escherichia coli (strain K12) YesInhibitorDetails - Binding Properties