Liquid-assisted grinding (LAG) as sustainable high yielding method for s-triazine hybrids synthesis: their docking, <i>in vitro</i> antimicrobial and anti-biofilm studies

Abstract Liquid-assisted grinding is an exciting and superior technique suitable for exploring a novel chemical space of reactions. 4-Aryl-6-alkylamino/piperidinyl-s-triazine-2-amine derivatives were synthesized through a simple mortar and pestle using a one-step, multi-component reaction involving cyanamide, aromatic aldehydes and aliphatic amines. An excess of the appropriate liquid amines is considered a liquid-assisted additive and acts as a basic catalyst. Final products were obtained in excellent yields (94–96%). All synthesized compounds 6a–d, 7a,b and 8a–d were assessed against antimicrobial and anti-biofilm properties; compound 8a was shown to be the most effective derivative. It showed a minimum inhibitory concentration of 16 µM for both bacterial strains, Staphylococcus aureus and Escherichia coli. Additionally, it displayed substantial suppression of S. aureus biofilms, with rates ranging from 62.1% at 7.8 µg ml−1 to 82.1% at 1000 µg ml−1. To evaluate the binding stability and affinity of compound 8a with DNA gyrase and lanosterol α-demethylase, molecular docking and dynamics were performed. The results revealed that compound 8a exhibited stronger binding affinity and structural stability with DNA gyrase, as indicated by lower root mean squared deviation values and stable hydrogen bonding interactions. Electron-withdrawing groups on the s-triazine core enhance antimicrobial efficacy, with compound 8a emerging as the most potent broad-spectrum candidate. These findings suggest that compound 8a is a promising selective inhibitor of DNA gyrase, highlighting its potential for further therapeutic development.