Synthesis and Antimicrobial Activity of Novel Fluoroquinolone with Geranyl Amine Moiety

The rapid emergence and global spread of antimicrobial resistance necessitate the development of novel antibacterial molecules. A promising strategy is the fusion of conventional drugs with fragments of natural compounds possessing various biological activity. In this study, we report the synthesis and antimicrobial activity of a novel fluoroquinolone carrying acyclic monoterpene moiety derived from geranyl amine. Compound 7 was obtained with a yield of 75% and characterized by NMR, HRMS, IR, UV, and single-crystal X-ray diffraction. The antimicrobial activity of the synthesized fluoroquinolone was assessed against MSSA and MRSA S. aureus clinical isolates, as well as Candida species and filamentous fungi. While exhibiting antibacterial activity lower than that of moxifloxacin against MSSA isolates (MIC 0.25–1 μg/mL), the compound demonstrated comparable or up to four-fold higher potency against MRSA isolates. The molecular docking confirmed the high binding affinity of compound 7 for DNA gyrase with the binding energy of −11.59 kcal/mol. In addition, moderate antifungal activity was observed against filamentous fungi (MIC 125–250 μg/mL). Thus, a novel fluoroquinolone represents a promising starting point for the design of antimicrobials for the treatment of staphylococcal infections complicated by fungal pathogens.