Synthesis, and characterization of chitosan bearing pyranoquinolinone moiety for textile dye adsorption from wastewater.

A novel compound was synthesized by the reaction of the amino group of the chitosan with the formyl group of pyrano[3,2-c]quinoline-3-carboxaldehyde moiety, which produced chitosan modified with a Schiff base (chitosan Schiff base). The structure of the newly prepared composite was elucidated. Chitosan Schiff base was used to remove the textile anionic remazol red (RR) dye from wastewater. The kinetic data and adsorption isotherm were best fitted by the pseudo-second-order kinetic model and the Freundlich isotherm, respectively. Thermodynamic parameters were calculated. Chitosan Schiff base resulted in 100% removal of carcinogenic dye at 2 min only with qm 344.8 mg/g, and may do the same for other anionic reactive dyes, thus avoiding secondary pollution.

Synthesis and molecular docking studies of some novel Schiff bases incorporating 6-butylquinolinedione moiety as potential topoisomerase IIß inhibitors.

A series of novel pyranoquinolinone-based Schiff's bases were designed and synthesized. They were evaluated for topoisomerase IIß (TOP2B) inhibitory activity, and cytotoxicity against breast cancer cell line (MCF-7) for the development of novel anticancer agents. A molecular docking study was employed to investigate their binding and functional properties as TOP2B inhibitors, using the Discovery Studio 2.5 software, where they showed very interesting ability to intercalate the DNA-topoisomerase complex. Compounds 2a, 2c and 2f showed high docking score values (82.36% -29.98 kcal mol-1 for compound 2a, 78.18% -26.98 kcal mol-1 for compound 2c and 78.65, -28.11 kcal mol-1 for compound 2f) and revealed the highest enzyme inhibition activity. The best hit compounds exhibited highly potent TOP2B inhibitors with submicromolar IC50 at 5 µM compared to the reference doxorubicin.