Isatin derivatives bearing a fluorine atom. Part 1: Synthesis, hemotoxicity and antimicrobial activity evaluation of fluoro-benzylated water-soluble pyridinium isatin-3-acylhydrazones

[Display omitted] •1-Fluorobenzylated isatins and water-soluble pyridinium isatin-3-acylhydrazones were synthesized.•Pyridinium isatin-3-acylhydrazones exhibit low hemotoxicity.•Antimicrobial activity of the novel compounds was studied.•Compounds containing a 2-fluoro-6-chlorobenzyl fragment showed the best activity against S. aureus. A series of 1-fluorobenzylated isatins and water-soluble pyridinium isatin-3-acylhydrazones on their base were obtained. The biological evaluation of novel hydrazones showed a significant dependence of their antimicrobial activity on the position of fluorine atom in benzyl substituent. The best activity showed compounds containing a 2-fluoro-6-chlorobenzyl fragment with selective action against S. aureus. The absence of hemotoxicity of both fluorine-containing products and their some non-fluorinated analogues was shown.