AZT 5′-Cholinephosphate as an Anti-HIV Agent: The Study of Biochemical Properties and Metabolic Transformations Using Its ³²P-Labelled Counterpart

Abstract

Biochemical and metabolic transformations of 3′-azido-3′-deoxythymidine 5′-choline phosphate (1) were studied using its ³²P-labelled counterpart for the evaluation of possible reasons for its enhanced anti-HIV activity. An effective synthesis of ³²P-labelled 1 with a specific activity >1,000 Ci/mmol was developed by esterification of ³²P-phosphoric acid with choline in the presence of BrCN followed by the coupling of the resulting choline phosphate with 3′-azido-3′-deoxythymidine (AZT). Chemical and enzymatic stabilities of 1 as well as the dynamics of penetration through HL-60 cell membranes were studied at the concentrations comparable to its antiviral concentrations. The products of intracellular transformations of the studied nucleotide were identified.

Keywords:

• 3′-Azido-3′-deoxythymidine 5′-[³²P]-choline phosphate
• [³²P]orthophos-phoric acid
• Phosphorylation
• Synthesis of [³²P]-labeled nucleotides

The work was supported by the Russian Foundation for Basic Research, projects 04-03-32481, 05-04-49500 and 04-04-49617; and the program of Presidium of Russian Academy of Sciences “Molecular and Cellular Biology.”