Calotropis gigantea Assisted Synthesis of Zinc Oxide Nanoparticle Catalysis: Synthesis of Novel 3‐Amino Thymoquinone Connected 1,4‐Dihyropyridine Derivatives and Their Cytotoxic Activity

The synthesis of biologically active 1,4-dihyripyridine derivatives using a Calotropis gigantea leaf powder and ZnO NPs used as catalyst under solvent-free conditions at room temperature via grinding method has been established in a single-stage, mild, and environmentally friendly green process. The procedure is fast and effective and produces high yields. Three cancer cell lines were used to assess the cytotoxic activity of 1,4-dihyropyridine derivatives. The cytotoxicity of 1,4-dihyropyridine compound 1f (HepG2, LC50-0.50 μM, MCF-7, LC50-0.64 μM, and HeLa, LC50-0.52 μM) was found to be highly active. The synthesized derivatives demonstrated their safety by causing substantially less cytotoxicity in normal cell lines HEK-293, LO2, and MRC5 with IC 50 > 100  g/mL. As a result, compound 1f could serve as a high-impact molecule for the production of anticancer drugs in the future.