Preliminary study to obtain some fluoroquinolone-tetracycline hybrids

Objective: This paper aimed to synthesize hybrids of fluoroquinolones with tetracycline class representatives and conduct their preliminary characterization.
Methods: A reaction between tetracycline representatives (doxycycline, tetracycline), formaldehyde (acting as a molecular connector) and fluoroquinolone representatives (ciprofloxacin, moxifloxacin, and norfloxacin) was attempted through a classical reflux synthesis with an electrical heating source (heating mantles) and a microwave-assisted reflux synthesis. One synthesis group also used cupric chloride dihydrate as a catalyst. The samples were analyzed using Differential Scanning Calorimetry, Electrospray Ionization Mass Spectrometry, or High-Performance Liquid Chromatography.
Results: The results indicated the formation of a compound different from the parent components in the case of doxycycline-norfloxacin and possibly tetracycline-norfloxacin hybrids.
Conclusions: Both synthesis methods yielded similar results. The influence of the catalyst did not seem to have been significant. The synthesis method is simple and one-step, using non-toxic solvents. Future studies involving molecular docking and microbiology could be employed to further explore the mechanism of action and the microbiological effects of the hybrids.