Structural studies on bioactive compounds. 28. Selective activity of triazenyl-substituted pyrimethamine derivatives against Pneumocystis carinii dihydrofolate reductase.

Article Details

Citation

Stevens MF, Phillip KS, Rathbone DL, O'Shea DM, Queener SF, Schwalbe CH, Lambert PA

Structural studies on bioactive compounds. 28. Selective activity of triazenyl-substituted pyrimethamine derivatives against Pneumocystis carinii dihydrofolate reductase.

J Med Chem. 1997 Jun 6;40(12):1886-93.

PubMed ID
9191966 [ View in PubMed
]
Abstract

Triazenyl-substituted pyrimethamine derivatives 10a-s have been prepared by coupling diazotized 2,4-diamino-5-(3-amino-4-chlorophenyl)-6-ethyl pyrimidine (1c) with a series of secondary amines in aqueous sodium carbonate solution. The triazenes which are stable and poorly soluble as free bases form more soluble, but unstable, salts with alkanesulfonic acids. The lead dimethyltriazene 2,4-diamino-5[4-chloro-3-(3,3-dimethyltriazen-1-yl)phenyl]-6-et hylpyrimidine (4a) forms a crystalline ethanesulfonic acid salt (solvated with 2-propanol), which is protonated at the pyrimidine N-1 position, as determined by X-ray crystallography. The ability of these new triazenes to inhibit Pneumocystis carinii dihydrofolate reductase in vitro has been compared to that of triazene 4a. The most potent and selective compound, 2,4-diamino-5-[3-[3-[2-(acetyloxy)ethyl]-3-benzyltriazen-1-y l]-4- chlorophenyl]-6-ethylpyrimidine (14a), has an IC50 value of 0.17 microM against the microbial enzyme and potentially useful selectivity (rat liver IC50/P. carinii IC50 = 114).

DrugBank Data that Cites this Article

Binding Properties
DrugTargetPropertyMeasurementpHTemperature (°C)
PyrimethamineDihydrofolate reductaseIC 50 (nM)3650N/AN/ADetails
TrimetrexateDihydrofolate reductaseIC 50 (nM)42N/AN/ADetails