Synthesis, spectral properties of rhodanine complex merocyanine dyes as well as their effect on K562 leukemia cells

Two rhodanine complex merocyanine dyes 9a and 9b were synthesized and their structures were confirmed by 1H NMR, IR, MS, HRMS and UV–Vis spectra. From the spectral properties of the two dyes, it could be found that the λmax of the dyes showed hypsochromic shifts with the increase of permittivity in protonic solvents, and bathochromic shifts with the increase of refractive index in non protonic solvents. The interactions of two dyes with DNA or BSA were also studied under physiological conditions. The results showed that the quantum yield of DNA-dye 9a was up to 29.5 times compared with free dye 9a. Dyes 9a and 9b were researched in Photodynamic Therapy (PDT) as well. It was demonstrated that supplementation of dye 9a or 9b as photosensitizers for PDT in K562 cells decreases the survival rate.

► The two rhodanine complex merocyanine dyes were synthesized.
► The spectral properties of two dyes were investigated in different solvents.
► The interaction of two dyes and DNA or BSA was studied.
► Using the dyes as photosensitizers for PDT could decrease K562 cells’ survival rate.