Mononucleoside phosphorodithiolates as mononucleotide prodrugs

Area of Science:

• Medicinal Chemistry
• Virology
• Drug Discovery

Background:

• HIV replication remains a significant global health challenge.
• Developing effective antiretroviral therapies is crucial.
• Nucleoside analogs are a cornerstone of HIV treatment.

Purpose of the Study:

• To synthesize and evaluate a novel series of pronucleotides as potential anti-HIV agents.
• To investigate the in vitro anti-HIV activity and intracellular release mechanisms of these prodrugs.
• To compare the efficacy and selectivity of the pronucleotides against the parent nucleoside.

Main Methods:

• Synthesis of pronucleotides utilizing a one-pot, three-step procedure.
• Characterization of prodrugs featuring a phosphorodithiolate core with biolabile phosphate protections.
• In vitro anti-HIV activity assays in various cell lines, including primary monocytes/macrophages.
• Determination of 50% effective concentration (EC50) and selectivity index.

Main Results:

• A novel series of pronucleotides with phosphorodithiolate structures were successfully synthesized.
• Prodrugs demonstrated efficient intracellular release of the active 5'-mononucleotide.
• The pronucleotide of 2',3'-dideoxyadenosine (ddA) 3 showed potent antiretroviral activity (nanomolar EC50).
• In monocytes/macrophages, ddA 3 was 500 times more potent than ddA, with a 50-fold higher selectivity index.

Conclusions:

• The novel pronucleotides represent a promising strategy for developing improved anti-HIV therapeutics.
• The phosphorodithiolate structure facilitates efficient prodrug activation and enhanced antiviral potency.
• ddA 3 exhibits superior efficacy and safety profile compared to the parent nucleoside, warranting further investigation.