Utility of quaternary ammonium salts in synthesis of some novel cyanine dyes as potential antibacterial and antitumor agents

•Cyanine dyes 5–7 and 8–11 were obtained from quaternary pyridinium salt.•Compounds were screened for their antioxidant and antibacterial activity.•Some of the tested compounds exhibited promising activities.

A novel class of quaternary ammonium salts has been synthesized in high yield by a convenient procedure which cleanly afforded a new series of methine cyanine dyes 5–11. Structural spectral studies were carried out via measuring the electronic visible absorption spectra of these dyes in DMF. Structural confirmations were determined through elemental analysis, IR, 13C NMR, 1H NMR spectroscopy and mass spectral data. The newly synthesized compounds were screened for their antibacterial and antitumor activity. Among all the tested compounds, it was found that compound 5 revealed better activity against Gram positive rather than Gram negative bacteria. Also, compound 5 showed better activity as antitumor agent.