Background: To investigate the multicomponent organic synthesis of the biologically important
spiro-oxindoles, spiro-acenaphthoquinone and spirochromenes scaffolds by using Amberlite
IRA-400 Cl resin as catalyst in an aqueous medium.
Methods: Three-component synthesis of spiro components has been achieved by the reaction of isatin/
acenaphthoquinone/ninhydrin, activated methylenes, and 1,3-dicarbonyl compounds under catalytic
amount of Amberlite IRA-400 Cl resin in an aqueous medium. This protocol is significant due to its
environmentally benign nature, efficiency, and easy handling.
Results: A large number of spiro heterocyclic compounds have been synthesized by using efficient
and environmentally benign Amberlite IRA-400 Cl resin catalyst. The synthesized compounds have
displayed considerable antimicrobial activities against human pathogenic bacteria and fungi. The in
silico studies revealed that these compounds are good antimicrobial agents as it showed lower binding
energy and higher binding affinity towards the active binding pocket in the receptors transglycosylase
of bacteria and glucoamylase of fungi.
Conclusion: A number of spirochromene, spiroacenaphthylene and spiro-oxindoles derivatives have
been synthesized using Amberlite IRA-400 Cl resin as catalyst in water medium. Selective synthesized
compounds 4h, 4j, 6d and 6g have been proved to be antimicrobial agent against the entire test
pathogens compared to commercial agents. Molecular docking studies revealed that even at a low
concentration with exhibit lower binding energies and higher binding affinity in order to maintain the
stable protein-ligand binding complex with the enzymes transglycosylase of bacteria and glucoamylase
of fungi proves the compounds are possess strong antimicrobial property.