Synthesis, characterization and preclinical formulation of a dual-action phenyl phosphate derivative of bromo-methoxy zidovudine (compound WHI-07) with potent anti-HIV and spermicidal activities

• Published in: Molecular human reproduction 1999-05, Vol.5 (5), p.421-432
• Main Authors: D'Cruz, Osmond J., Shih, Mei-Jue, Yiv, Seang H., Chen, Chun-Lin, Uckun, Fatih M.
• Format: Article
• Language: English
• Subjects: Acrosome Reaction - drug effects; Animals; Anti-HIV Agents - chemical synthesis; Anti-HIV Agents - pharmacology; Biological and medical sciences; Cell Membrane - drug effects; Cervix Uteri - cytology; Cervix Uteri - drug effects; contraceptives; Dideoxynucleotides; Drug Evaluation, Preclinical; Emulsions - chemistry; Emulsions - pharmacology; Epithelial Cells - drug effects; Female; Genital system. Reproduction; HIV; HIV-1 - drug effects; Humans; Male; Medical sciences; microbicide; Pharmacology. Drug treatments; Rabbits; Sperm Motility - drug effects; Spermatocidal Agents - chemical synthesis; Spermatocidal Agents - pharmacology; Spermatozoa - drug effects; spermicide; Thymidine Monophosphate - analogs & derivatives; Thymidine Monophosphate - chemical synthesis; Thymidine Monophosphate - pharmacology; Vagina - drug effects; Vagina - pathology; Virus Replication - drug effects; ZDV; Zidovudine - analogs & derivatives; Zidovudine - chemical synthesis; Zidovudine - chemistry; Zidovudine - pharmacology
• ISSN: 1360-9947; 1460-2407; 1460-2407
• DOI: 10.1093/molehr/5.5.421

In a systematic effort to develop a microbicide contraceptive capable of preventing transmission of human immunodeficiency virus (HIV), as well as providing fertility control, we have previously identified novel phenyl phosphate derivatives of zidovudine (ZDV) with 5-halo 6-alkoxy substitutions in the thymine ring and halo substitution in the phenyl moiety respectively. Here, we describe the synthesis, characterization, and successful preclinical formulation of our lead compound, 5-bromo-6-methoxy-3′-azidothymidine-5′-(p-bromophenyl) methoxyalaninyl phosphate (WHI-07), which exhibits potent anti-HIV and sperm immobilizing activities. The anti-HIV activity of WHI-07 was tested by measuring viral p24 antigen production and reverse transcriptase activity as markers of viral replication in HIV-1 infected human peripheral blood mononuclear cells (PBMC). WHI-07 inhibited replication of HIV in a concentration-dependent fashion with nanomolar IC50 values. The effects of WHI-07 on human sperm motion kinematics were analysed by computer-assisted sperm analysis (CASA), and its effects on sperm membrane integrity were examined by confocal laser scanning microscopy (CLSM), and high-resolution low-voltage scanning electron microscopy (HR-LVSEM). WHI-07 caused cessation of sperm motility in a concentration- and time-dependent fashion. The in-vitro cytotoxicities of WHI-07 and nonoxynol-9 (N-9) were compared using normal human ectocervical and endocervical epithelial cells by the MTT cell viability assay. Unlike N-9, WHI-07 had no effect upon sperm plasma and acrosomal membrane integrity. N-9 was cytotoxic to normal human ectocervical and endocervical cells at spermicidal doses, whereas WHI-07 was selectively spermicidal. The in-vivo vaginal absorption and vaginal toxicity of 2% gel-microemulsion of WHI-07 was studied in the rabbit model. The sperm immobilizing activity of WHI-07 was 18-fold more potent than that of N-9. Over a 10 day period, there was no irritation or local toxicity to the vaginal epithelia or systemic absorption of WHI-07. Therefore, as a potent anti-HIV agent with spermicidal activity, and lack of mucosal toxicity, WHI-07 may have the clinical potential to become the active ingredient of a vaginal contraceptive for women who are at high risk for acquiring HIV by heterosexual vaginal transmission.