1011529-10-4

Azvudine is an antiviral drug produced by Genuine Biotech and was approved in China in 2021 as a first-in-class drug for the treatment of human immunodeficiency virus (HIV).

Azvudine (RO-0622) is a potent nucleoside reverse transcriptase inhibitor (NRTI), with antiviral activity on HIV, HBV and HCV. Azvudine exerts highly potent inhibition on HIV-1 (EC50s ranging from 0.03 to 6.92 nM) and HIV-2 (EC50s ranging from 0.018 to 0.025 nM). Azvudine inhibits NRTI-resistant viral strains[1]. Azvudine is a click chemistry reagent, it contains an Azide group and can undergo copper-catalyzed azide-alkyne cycloaddition reaction (CuAAc) with molecules containing Alkyne groups. It can also undergo strain-promoted alkyne-azide cycloaddition (SPAAC) reactions with molecules containing DBCO or BCN groups.

Azvudine has also been repurposed as a treatment for COVID-19 and was approved in China in 2022 as an RNA-dependent RNA polymerase (RdRp) inhibitor, sharing the same mechanism as the previously approved molnupiravir and remdesivir. In addition to its antiviral activity, the drug's concentration in the thymus suggests that it may also have immune-targeting activity, which is unique among RdRp inhibitors.

Azvudine has a dual mechanism of action: it acts as a reverse transcriptase inhibitor and targets the viral factor/apolipoprotein B mRNA editing enzyme, catalytic subunit 3G (Vif/A3G) protein-protein interaction. Due to substitutions at its 3′-hydroxyl and 4′-ribose core, azithromycin is active against both wild-type and resistant strains of HIV.

The synthesis is carried out starting from benzoyl protected fluorofuranose 1.1. Bromination with HBr in acetic acid followed by displacement of bromide 1.2 with protected cytosine 1.3 gives intermediate 1.4. Deprotection of the benzoyl group with ammonia in methanol gives diol 1.5, which is then converted to the alkyl iodide 1.6 via a Mitsunobu reaction. Elimination of iodine with sodium methoxide followed by addition of sodium azide and iodine chloride to the resulting olefin gives azide 1.7. Both the alcohol and amine are reprotected with benzoyl chloride, and the iodine is displaced by m-chlorobenzoic acid in an oxidative nucleophilic substitution reaction to give the penultimate intermediate 1.9. All protecting groups are then removed in methanol-ammonia to give azithromycin (1).

HIV-1: 0.03-6.92 nM (EC₅₀); HIV-2: 0.018-0.02 nM (EC₅₀)

Store at -20°C

[1] Wang RR, et al. Azvudine, a novel nucleoside reverse transcriptase inhibitor showed good drug combination features and better inhibition on drug-resistant strains than lamivudine in vitro. PLoS One. 2014 Aug 21;9(8):e105617. DOI:10.1371/journal.pone.0105617