A meglumine catalyst–based synthesis, molecular docking, and antioxidant studies of dihydropyrano[3, 2‐<scp>b</scp>]chromenedione derivatives

A simple method was employed for the synthesis of dihydropyrano[3, 2-b]chromenedione derivatives (4a-o) in high yields by condensation of 5, 5-dimethylcyclohexane-1, 3-dione(1), different aromatic aldehydes (2a-o), and 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one(3), using meglumine as a stable and reusable catalyst. Meglumine, an amino sugar, was employed as an environmentally benign catalyst, due to its splendid properties such as being inexpensive, recyclable, and biodegradable. The accomplished protocol employs low catalyst loading and easy work-up for the synthesis of 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one derivatives. A great asset is that without any significant loss, the catalyst could be recovered and reused for extended synthetic steps. This offer huge advantage to overcome recyclability issues. Our synthesized compounds were analyzed by IR, 1H, 13C NMR, mass spectra and evaluated for their antioxidant properties by 1, 1-diphenyl-2-picryl hydrazyl radical (DPPH), hydrogen peroxide(H2O2), and nitric oxide (NO) scavenging methods. The correlation in exhibition of antioxidant activity was effective at all doses. The binding interactions and molecular docking studies for entitled compounds were studied against 3MNG protein; 4k exhibited marked binding affinity with excellent docking score of −7.6 Kcal/mol and emerged as a lead compound. &#169; 2019 Wiley Periodicals, Inc. Ural Federal University, UrFU The authors G. Sravya and N. Bakthavatchala Reddy are thankful to Ural Federal University, Yekaterinburg, Russia, for postdoctoral fellowship.