Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2004-3-4
pubmed:abstractText
In a continuing effort to design small-molecule inhibitors of dihydrofolate reductase (DHFR) that combine the enzyme-binding selectivity of 2,4-diamino-5-(3',4',5'-trimethoxybenzyl)pyrimidine (trimethoprim, TMP) with the potency of 2,4-diamino-5-methyl-6-(2',5'-dimethoxybenzyl)pyrido[2,3-d]pyrimidine (piritrexim, PTX), seven previously undescribed 2,4-diamino-5-[2'-methoxy-5'-(substituted benzyl)]pyrimidines were synthesized in which the substituent at the 5'-position was a carboxyphenyl group linked to the benzyl moiety by a bridge of two or four atoms in length. The new analogues were all obtained from 2,4-diamino-5-(5'-iodo-2'-methoxybenzyl)pyrimidine via a Sonogashira reaction, followed, where appropriate, by catalytic hydrogenation. The new analogues were tested as inhibitors of DHFR from Pneumocystis carinii (Pc), Toxoplasma gondii (Tg), and Mycobacterium avium (Ma), three life-threatening pathogens often found in AIDS patients and individuals whose immune system is impaired as a result of treatment with immunosuppressive chemotherapy or radiation. The selectivity index (SI) of each compound was obtained by dividing its 50% inhibitory concentration (IC(50)) against Pc, Tg, or Ma DHFR by its IC(50) against rat DHFR. 2,4-Diamino-[2'-methoxy-5'-(3-carboxyphenyl)ethynylbenzyl]pyrimidine (28), with an IC(50) of 23 nM and an SI of 28 in the Pc DHFR assay, had about the same potency as PTX and was 520 times more potent than TMP. As an inhibitor of Tg DHFR, 28 had an IC(50) of 5.5 nM (510-fold lower than that of TMP and similar to that of PTX) and an SI value of 120 (2-fold better than TMP and vastly superior to PTX). Against Ma DHFR, 28 had IC(50) and SI values of 1.5 nM and 430, respectively, compared with 300 nM and 610 for TMP. Although it had 2.5-fold lower potency than 28 against Ma DHFR (IC(50) = 3.7 nM) and was substantially weaker against Pc and Tg DHFR, 2,4-diamino-[2'-methoxy-5'-(4-carboxyphenyl)ethynylbenzyl]pyrimidine (29), with the carboxy group at the para rather than the meta position, displayed 2200-fold selectivity against the Ma enzyme and was the most selective 2,4-diamino-5-(5'-substituted benzyl)pyrimidine inhibitor of this enzyme we have encountered to date. Additional bioassay data for these compounds are also reported.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1475-86
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:14998335-AIDS-Related Opportunistic Infections, pubmed-meshheading:14998335-Animals, pubmed-meshheading:14998335-Folic Acid Antagonists, pubmed-meshheading:14998335-Humans, pubmed-meshheading:14998335-Inhibitory Concentration 50, pubmed-meshheading:14998335-Liver, pubmed-meshheading:14998335-Microbial Sensitivity Tests, pubmed-meshheading:14998335-Mycobacterium avium, pubmed-meshheading:14998335-Opportunistic Infections, pubmed-meshheading:14998335-Pneumocystis carinii, pubmed-meshheading:14998335-Pyrimidines, pubmed-meshheading:14998335-Rats, pubmed-meshheading:14998335-Recombinant Proteins, pubmed-meshheading:14998335-Species Specificity, pubmed-meshheading:14998335-Structure-Activity Relationship, pubmed-meshheading:14998335-Tetrahydrofolate Dehydrogenase, pubmed-meshheading:14998335-Toxoplasma
pubmed:year
2004
pubmed:articleTitle
New 2,4-diamino-5-(2',5'-substituted benzyl)pyrimidines as potential drugs against opportunistic infections of AIDS and other immune disorders. Synthesis and species-dependent antifolate activity.
pubmed:affiliation
Dana-Farber Cancer Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA. andre_rosowsky@dfci.harvard.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.