Linked Life Data

15832506

Source:http://linkedlifedata.com/resource/pubmed/id/15832506

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-4-18
pubmed:abstractText
Amino acid phosphoramidates of nucleosides have been shown to be potent antiviral and anticancer agents with the potential to act as nucleoside monophosphate prodrugs. To access their ability to deliver 3'-azido-3'-deoxythymidine (AZT) 5'-monophosphate to cells, the decomposition pathway of an 18O-labeled AZT amino acid phosphoramidate was investigated by capillary reverse-phase high-performance liquid chromatography interfaced with negative ion electrospray ionization mass spectrometry (LC-ESI(-)-MS/MS). 18O-labeled L-AZT tryptophan phosphoramidate methyl ester ([18O]2) was synthesized with an 18O/16O relative ratio of 1.22 +/- 0.18. For CEM cells, a human T-lymphoblast leukemia cell line, incubated with [18O]2, values of 1.55 +/- 0.37, 0.34, and 0.13 were found for the 18O/16O relative ratio of intracellular AZT-MP for time intervals of 0.5, 4, and 20 h, respectively. The decrease in the level of labeled AZT-MP in CEM cells corresponded to a rapid increase in the amount of intracellular AZT presumably by dephosphorylation of AZT-MP. In contrast, for peripheral blood mononuclear cells (PBMCs), the 18O/16O relative ratio values of intracellular AZT-MP were 1.43, 1.06, and 0.61 for time intervals of 0.5, 4, and 20 h, respectively. Intracellular AZT in PBMCs was nearly undetectable for each time interval. Taken together, these results are consistent with the detection of direct P-N bond cleavage by CEM cells and PBMCs. However, AZT phosphoramidates are able to more effectively deliver AZT-MP to PBMCs than to CEM cells. Differential expression of 5'-nucleotidase in CEM cells relative to PBMCs is likely the reason for this discrepancy. Although applied to a phosphoramidate pronucleotide, the judicious use of 18O labeling and LC-MS is a general approach that could be applied to the investigation of the intracellular fate of other pronucleotides.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1543-8384
pubmed:author
pubmed:issnType
Print
pubmed:volume
1
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
102-11
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:articleTitle
Direct measurement of nucleoside monophosphate delivery from a phosphoramidate pronucleotide by stable isotope labeling and LC-ESI(-)-MS/MS.
pubmed:affiliation
Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, N.I.H., Extramural