Aryl phosphate derivatives of bromo-methoxy-azidothymidine are dual-function spermicides with potent anti-human immunodeficiency virus.
Detergent-based vaginal microbicides, in addition to their high contraceptive failure rates, cause mucosal erosion and local inflammation that might increase the risk of heterosexual human immunodeficiency virus (HIV) transmission. In a systematic effort to identify a microbicide contraceptive potentially capable of preventing the sexual transmission of HIV as well as providing fertility control, a series of novel aryl phosphate derivatives of 5-bromo-6-methoxy-3'-azido-3'-deoxythymidine (AZT; zidovudine) were synthesized and examined for dual anti-HIV and sperm-immobilizing activity (SIA). Whereas AZT displayed potent anti-HIV activity (IC50 = 0.006 microM) but lacked SIA (EC50 > 300 microM), two 5-bromo-6-methoxy-aryl phosphate derivatives of AZT, compounds WHI-05 and WHI-07, exhibited potent anti-HIV activity as well as SIA. The IC50 (HIV) and EC50 (SIA) values for WHI-07 were 439-fold and 13.5-fold lower, respectively, than those for the detergent-based virucidal spermicide, nonoxynol-9 (N-9). Sperm motion kinematics using computer-assisted sperm motion analysis combined with confocal laser scanning microscopy, high-resolution low-voltage scanning, and transmission electron microscopy demonstrated that both WHI-05 and WHI-07 cause a complete and irreversible loss of sperm motility in a concentration- and time-dependent fashion without concomitantly affecting the sperm acrosomal membrane integrity. In experiments designed to assess the fertilizing capacity of treated sperm, preincubation of sperm with either compound resulted in a concentration-dependent loss of the ability to adhere to and penetrate zona-free hamster eggs as well as inhibition of binding to human zona. WHI-07 applied intravaginally prior to artificial insemination of epididymal sperm drastically reduced fertility in hormonally primed CD-1 mice. Unlike the intravaginal application of N-9, repetitive intravaginal application of WHI-07 did not damage the vaginal epithelium or cause local inflammation. Structure-function relationship analyses showed that the addition of bromo-methoxy functional groups to AZT was essential for, and the aryl phosphate derivatization contributory to, the SIA of both compounds. Compounds WHI-05 and WHI-07 may be useful as dual-function vaginal contraceptives for women who are at high risk for acquiring HIV/acquired immunodeficiency virus syndrome by heterosexual vaginal transmission.
Drug Discovery Program, Wayne Hughes Institute, St. Paul, Minnesota 55113, USA.
O J
OJ
D'Cruz
T K
TK
Venkatachalam
Z
Z
Zhu
M J
MJ
Shih
F M
FM
Uckun
D000818:Animals; D019380:Anti-HIV Agents / Q000494:pharmacology*; D006224:Cricetinae; D054306:Dideoxynucleotides; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D007700:Kinetics; D008297:Male; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D013081:Sperm Motility / Q000187:drug effects; D013084:Sperm-Ovum Interactions / Q000187:drug effects; D013089:Spermatocidal Agents / Q000494:pharmacology*; D013938:Thymidine Monophosphate / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology / Q000633:toxicity; D014779:Virus Replication / Q000187:drug effects; D015215:Zidovudine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology / Q000633:toxicity
C114569:5-Bromo-6-methoxy-5,6-dihydro-3'-azidothymidine-5'-(p-methoxyphenyl)methoxyalaninyl phosphate; C114570:5-bromo-6-methoxy-5, 6-dihydro-3'-azidothymidine-5'-(p-bromophenyl) methoxyalaninyl phosphate; D019380:Anti-HIV Agents; D054306:Dideoxynucleotides; D013089:Spermatocidal Agents; D013938:Thymidine Monophosphate; D015215:Zidovudine