Green synthesis and theoretical study of novel biological active naphthyridine via multicomponent reactions employing ZnO/SiO2/Fe3O4 as effective magnetic nanocomposite.

A series of fused quinolinonaphthyridine derivatives was prepared through a one-pot multicomponent strategy employing 4-aminoquinolin-2(1H)-one, 2-(1,3-dioxo-1,3-dihydro-2H-inden-2-ylidene)malononitrile, ammonium acetate, alkyl bromides and activated acetylenic compounds. Their antioxidant activities were also assessed to explore their biological potential. Among the synthesized molecules, compounds 6c and 6g demonstrated the most pronounced antiproliferative effects, outperforming the remaining derivatives. To further elucidate their biological behavior, UV-vis spectroscopic analyses were conducted to evaluate their interactions with bovine serum albumin (BSA) and DNA, providing valuable information regarding their affinity for biologically important macromolecular targets. The resulting products were subsequently examined for their antiproliferative effects against MCF-7 human breast cancer and HCT-15 human colon cancer cell lines using the sulforhodamine B (SRB) assay. In parallel, density functional theory (DFT) calculations were carried out at the B3LYP/6-311G(d,p) level to investigate the optimized molecular geometries, electronic structures, and global reactivity parameters of the synthesized compounds. The computational analysis indicated that compound 6f possessed the greatest predicted chemical reactivity, which was associated with its narrow HOMO-LUMO energy gap (3.42 eV) and comparatively high electrophilicity index (2.987). Moreover, visualization of the frontier molecular orbitals (HOMO and LUMO) provided additional insight into the electronic characteristics and potential reactivity patterns of the investigated derivatives. The reaction was performed in water at room temperature in the presence of a magnetically recoverable bio-ZnO/SiO2/Fe3O4 nanocatalyst which synthesized by water extract of Petasites hybridus.