Cellular metabolism in lymphocytes of a novel thioether–phospholipid–AZT conjugate with anti-HIV-1 activity
We previously synthesized a thioetherphospholipid–AZT conjugate (3′-azido-3′-deoxy-5′-(1-hexadecylthio-2-methoxypropyl)-phosphothymidine, CP-102) with potent anti-HIV-1 activity and significant reduction in cell cytotoxicity compared to AZT alone. To study the cellular metabolism of the conjugate co...
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Published in | Antiviral research Vol. 50; no. 2; pp. 129 - 137 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Amsterdam
Elsevier B.V
01.05.2001
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | We previously synthesized a thioetherphospholipid–AZT conjugate (3′-azido-3′-deoxy-5′-(1-hexadecylthio-2-methoxypropyl)-phosphothymidine, CP-102) with potent anti-HIV-1 activity and significant reduction in cell cytotoxicity compared to AZT alone. To study the cellular metabolism of the conjugate compound we synthesized a double-tritium-labeled thioetherphospholipid-AZT conjugate (3′-azido-3′-deoxy-5′-(1-[9, 10-
3H]-
S-octadecylthio-2-
O-methoxypropyl)-phosphothymidine-[methyl-
3H], [
3H]CP-102). The intracellular radioactive metabolic products of [
3H]CP-102 treated human lymphoblastoid CEM-SS cells were analyzed by HPLC and thin-layer chromatography. Results of this investigation provide evidence that a putative intracellular lipid cleavage enzyme metabolizes [
3H]CP-102 to form a thioetherdiglyceride compound that migrates with an authentic 1-
S-octadecyl-2-
O-methyl-thioglycerol standard on TLC. The thioetherdiglyceride metabolite did not react with the ninhydrin reagent indicating it did not contain a primary amine such as that found on serine or ethanolamine containing phospholipids. Also, the product did not contain a phosphatidic acid group based on migration characteristics in the TLC plate. The other major hydrophilic metabolite was 3′-azido-3′-deoxythymidine-[methyl-
3H]-monophosphate (AZT–MP) with lesser amounts of AZT, AZT–DP and AZT–TP. In summary, the best interpretation of these data is that the thioetherphospholipid–AZT conjugate, [
3H]CP-102, is cleaved by a putative intracellular lipid cleavage enzyme to release a thioetherdiglyceride compound and AZT–MP. The resulting AZT–MP was either dephosphorylated to AZT or sequentially phosphorylated to AZT–DP and, ultimately, to AZT–TP, the known inhibitory metabolite against HIV-1 reverse transcriptase. Phospholipid–nucleoside conjugates may provide a unique approach for developing anti-HIV-1 prodrugs that do not have a strict requirement for a nucleoside kinase for initial activation of the prodrug to an antiviral form. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0166-3542 1872-9096 |
DOI: | 10.1016/S0166-3542(01)00137-1 |