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 <b>7</b> 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 <i>S. aureus</i> clinical isolates, as well as <i>Candida</i> 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 <b>7</b> 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.