Logo: to the web site of Uppsala University

Herein, an efficient synthesis of spiro-indoline-pyrano[3,2- c ]quinolines derivatives of spiroxindolines by the water-mediated three-component condensation reaction of 2-hydroxyquinoline-4-one 1(a-b) , isatin derivatives 2(a-n) , and malononitrile 3 in the presence of water-soluble and phase transfer Tetrabutylammonium bromide (TBAB) catalyst is described. The present protocol shows features such as excellent yield of product, mild reaction condition, reusable reaction medium with catalyst and low E-factor. This blossomed the reaction with the green synthetic condition and provide a safe and clean alternative for the synthesis of spiropyrano[3,2- c ] quinolines derivatives. All the synthesized compounds were screened against the pancreatic alpha-amylase. Many of those synthesized compounds possess noticeably good alpha-amylase inhibitory action. From the activity profile, analogous 4g and 4h were found to be more active than the others with IC 50 values ranges for alpha-amylase inhibition (IC 50 = 73.82 -76.65 mu g/ml) in comparison with the standard acarbose (IC 50 = 79.64 +/- 0.46 mu g/ml). Molecular docking results showed key interactions of 4g, 4h and acarbose with alpha-amylase, compound 4g shows H-bonding interaction with GLN63, HIS101 and compound 4h shows H-bonding interaction with ASP300. In silico ADMET prediction was carried out to check the physicochemical properties of the synthesized compound.