DNA Interaction Studies and In Vitro Cytotoxicity of Newly Synthesized Steroidal Imidazolidinones

New steroidal imidazolidinone derivatives (7–9) were synthesized after reacting steroidal thiosemicarbazones with oxalyl chloride in absolute ethanol. After characterization by spectral and analytical data, the interaction studies of compounds (7–9) with DNA were carried out by UV–vis, fluorescence spectroscopy, circular dichroism, molecular docking and gel electrophoresis. The compounds bind to DNA preferentially through electrostatic and hydrophobic interactions with Kb; 2.31 × 104 M−1, 2.57 × 104 M−1 and 2.16 × 104 M−1, respectively indicating the higher binding affinity of compound 8 towards DNA. Gel electrophoresis demonstrated that the compounds 7–9 show strong interaction during the cleavage activity with pBR322 DNA. The docking study suggested the intercalation of imidazolidinone moiety of steroid derivative in minor groove of DNA. During in vitro cytotoxicity, compounds 7–9 revealed potential toxicity against the different human cancer cells (MTT assay). Apoptotic degradation of DNA in presence of compounds 7–9 was analyzed by agarose gel electrophoresis and visualized by ethidium bromide staining (comet assay). FACS analysis shows that the compound 8 bring about cell cycle arrest at 7 μM concentration.