Linked Life Data

17346178

Source:http://linkedlifedata.com/resource/pubmed/id/17346178

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2007-3-9
pubmed:abstractText
Opportunistic infections are known to cause morbidity and mortality in immunocompromised individuals. In addition, serious infections due to several parasites are also known to affect the quality and duration of life in normal individuals. The importance of dihydrofolate reductase (DHFR) in parasitic chemotherapy arises from its function in DNA biosynthesis and cell replication. DHFR catalyzes the reduction of dihydrofolate (DHF) to tetrahydrofolate (THF), an essential cofactor in the biosynthesis of thymidylate monophosphate (dTMP). Inhibition of DHFR leads to a deficiency of dTMP since DHF cannot be recycled, and thus causes inhibition of cell growth. Methotrexate (MTX) and aminopterin (AMT) were among the first known classical inhibitors of DHFR. Trimethoprim (TMP) and pyrimethamine (PYR) are among the first known non classical inhibitors of DHFR. TMP and PYR are selective but weak inhibitors of DHFR from several parasitic organisms and coadministration of sulfonamides is required to provide synergistic effects for clinical utility. Unfortunately, the side effects associated with sulfa drugs in this combination often result in cessation of therapy. Trimetrexate (TMQ) and piritrexim (PTX) are two potent non classical inhibitors, neither of which exhibit selectivity for pathogen DHFR and must be used with host rescue. However, the current combination therapy suffers from high cost, in addition, several mutations have been reported in the active site of parasitic DHFR rendering the infections refractive to known DHFR inhibitors. The selectivity of TMP is a hallmark in the development of DHFR inhibitors and several efforts have been made to combine the potency of PTX and TMQ with the selectivity of TMP. Thus the structural requirements for DHFR inhibition are of critical importance in the design of antifolates for parasitic chemotherapy. Structural requirements for inhibition have been studied extensively and novel agents that exploit the differences in the active site of human and parasitic DHFR have been proposed. This review discusses the synthesis and structural requirements for selective DHFR inhibition and their relevance to parasitic chemotherapy, since 1995.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1873-4286
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
13
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
609-39
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Dihydrofolate reductase as a target for chemotherapy in parasites.
pubmed:affiliation
Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282, USA. gangjee@duq.edu
pubmed:publicationType
Journal Article, Review