title: AZT and AZT-monophosphate prodrugs incorporating HIV-protease substrate fragment: synthesis and evaluation as specific drug delivery systems.
abstract: With the view to deliver anti-HIV nucleoside and nucleoside-monophosphate (MP) analogues specifically into HIV-infected cells, we synthesized a series of ester and phosphoramidate peptide conjugates of zidovudine (AZT) and of AZT-MP, respectively, wherein the peptide sequences derive from a HIV-protease (PR) hydrolysable substrate. Their in vitro stability with respect to hydrolysis, anti-HIV activity and cytotoxicity, and ability to inhibit the HIV-PR activity were investigated. Concerning the ester AZT-peptide conjugates, their antiviral activity level in thymidine kinase-expressing (TK+) CEM-SS and MT-4 cells was in most cases closely correlated to their hydrolysis rate: the faster the hydrolysis, the closer the anti-HIV activity to that of AZT. None of them was a HIV-PR substrate, indicating that their antiviral activity was not related to their intracellular hydrolysis by this enzyme. None of them inhibited HIV in TK-deficient (TK-) CEM cells, demonstrating that they probably act as prodrugs of AZT. Most of the phosphoramidate peptide conjugates of AZT-MP were rapidly degraded in a physiological buffer into several metabolites including AZT. Their anti-HIV activity in TK+ CEM-SS and MT-4 cells was much lower than that of AZT, indicating that only low amounts of AZT or AZT-MP were released into cells during incubation. Antiviral activities measured on TK- CEM cells for some phosphoramidates suggest that low amounts of AZT-MP could be released intracellularly. However, this AZT-MP release was not initiated by a HIV-PR hydrolysis, as no evidence for peptide cleavage was obtained by HPLC analysis of one representative compound after incubation with HIV-PR.
authors.affiliation: Laboratoire de Chimie des Molecules Bioactives et des Arômes, UMR-CNRS 6001, Institut de Chimie de Nice, Université de Nice-Sophia Antipolis, France
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Liotard
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mehiri
authors.forename: Audrey
authors.initials: A
authors.lastname: Di Giorgio
authors.forename: Nicole
authors.initials: N
authors.lastname: Boggetto
authors.forename: Michèle
authors.initials: M
authors.lastname: Reboud-Ravaux
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Aubertin
authors.forename: Roger
authors.initials: R
authors.lastname: Condom
authors.forename: Nadia
authors.initials: N
authors.lastname: Patino
mesh_terms: D000577:Amides / Q000138:chemical synthesis; D019380:Anti-HIV Agents / Q000138:chemical synthesis / Q000627:therapeutic use; D002478:Cells, Cultured; D054306:Dideoxynucleotides; D016503:Drug Delivery Systems; D004341:Drug Evaluation; D004355:Drug Stability; D004952:Esters / Q000138:chemical synthesis; D015658:HIV Infections / Q000188:drug therapy*; D016333:HIV Protease / Q000737:chemistry* / Q000187:drug effects; D015497:HIV-1 / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D008954:Models, Biological; D010756:Phosphoric Acids / Q000138:chemical synthesis; D011355:Prodrugs / Q000138:chemical synthesis / Q000627:therapeutic use; D011480:Protease Inhibitors / Q000494:pharmacology; D013937:Thymidine Kinase / Q000235:genetics; D013942:Thymine Nucleotides / Q000138:chemical synthesis* / Q000627:therapeutic use*; D015215:Zidovudine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000627:therapeutic use*
chemical_list: D000577:Amides; D019380:Anti-HIV Agents; D054306:Dideoxynucleotides; D004952:Esters; D010756:Phosphoric Acids; D011355:Prodrugs; D011480:Protease Inhibitors; D013942:Thymine Nucleotides; C057287:3'-azido-3'-deoxythymidine 5'phosphate; D015215:Zidovudine; C011067:phosphoramidic acid; D013937:Thymidine Kinase; D016333:HIV Protease