N-Alkyl/aryl-4-(3-substituted-3-phenylpropyl)piperazine-1-carbothioamide as dual-action vaginal microbicides with reverse transcriptase inhibition.

The growing population and health-care burden (due to STIs and HIV) imposes a particular economic crisis over resource-poor countries. Thus a novel approach as vaginal microbicides emerges as integrated tool to control both population and anti-STIs/HIV. Our continued efforts in this field led to the synthesis of fifteen N-alkyl/aryl-4-(3-substituted-3-phenylpropyl) piperazine-1-carbothioamide (12-26) derivatives as topical vaginal microbicides which were evaluated for anti-Trichomonas, spermicidal, antifungal and reverse transcriptase (RT) inhibitory activities. All compounds were also tested for preliminary safety through cytotoxicity assays against human cervical cell line (HeLa) and the vaginal flora, Lactobacillus. Docking studies were performed to gain an insight into the binding mode and interactions of the most promising compound 12 [oxo derivative], comprising of reverse transcriptase (RT) inhibitory (72.30%), spermicidal (MEC 0.01%), anti-Trichomonas (MIC 46.72 μM) and antifungal (MIC 9.34-74.8 μM) activities, along with its hydroxyl (17) and O-alkylated 4-trifluoromethylphenoxy (22) derivative, with similar activities. The stability of compound 12 in simulated vaginal fluid (SVF) and its preliminary in vivo pharmacokinetics performed in female NZ-rabbits signifies its clinical safety in comparison to marketed spermicide Nonoxynol-9.