Synthesis of a dihydrotestosterone-ciprofloxacin conjugate: Relationship between descriptors logP, π, R _m, and v _m and its antibacterial activity in S. aureus and E. coli

In this work a dihydrotestosterone-ciprofloxacin conjugate was synthesized. The route involved preparation of a ciprofloxacin-ethylenediamine derivative by the reaction of ciprofloxacin with ethylenediamine using a carbodiimide or boric acid as catalysts. Additionally, the ciprofloxacin derivative was bound to dihydrotestosterone hemisuccinate to form the dihydrotestosterone-ciprofloxacin conjugate in the presence of a carbodiimide. The antibacterial activity of dihydrotestosterone-ciprofloxacin, as well as ciprofloxacin-ethylenediamine and ciprofloxacin, was evaluated in vitro on S. aureus and E. coli using the dilution method and the minimum inhibitory concentration. To delineate the structural chemical requirements of the compounds ciprofloxacin, ciprofloxacin-ethylenediamine and dihydrotestosterone-ciprofloxacin conjugate as antibacterial agents on S. aureus and E. coli, other parameters such as the descriptors logP, π, R _m, and V _m were calculated. The results showed that bacterial growth of the microorganisms studied was inhibited by ciprofloxacin, ciprofloxacin-ethylenediamine and dihydrotestosterone- ciprofloxacin in a dose-dependent manner. These data suggest that functional groups involved in the structure of the studied compounds are specific for their antibacterial activity.