Multicomponent Synthesis of 2,4,5-Trisubstituted Thiazoles Using a Sustainable Carbonaceous Catalyst and Assessment of Its Herbicidal and Antibacterial Potential

Herein, a novel, biocatalyzed, and on-water microwave-assisted multicomponent methodology have been developed for the synthesis of trisubstituted thiazoles (<b>4a</b>-<b>4v</b>). The reaction was catalyzed using a sulfonated peanut shell residue-derived carbonaceous catalyst (<b>SPWB</b>). The developed catalyst was characterized using Fourier transform infrared (FTIR), a Brunauer-Emmett-Teller (BET) surface area analyzer, a field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray (EDX), and a particle size analyzer (PSA). The acidic sites have been established using acid-base back-titration methods. The molecular structures of all the synthesized compounds were validated using FT-IR, ¹H NMR, ¹³C NMR, elemental, and HRMS analyses. Herbicidal potential was evaluated by using <i>Raphanus sativus</i> L. as a model. Furthermore, the antibacterial potential of thiazoles was evaluated against <i>Staphylococcus aureus</i>, <i>Bacillus subtilis</i>, <i>Xanthomonas campestris</i>, <i>Escherichia coli</i>, <i>Micrococcus luteus</i>, and <i>Pseudomonas aeruginosa</i> bacterial strains. The compound <b>4r</b> displayed improved seed growth inhibition in <i>Raphanus sativus</i> L. versus a commercially available herbicide, <i>i.e.,</i> pendimethalin. The antibacterial activity was promising against bacterial strains (MIC: 4-64 μg/mL). The compound <b>4r</b> was the most potent against <i>P. aeruginosa</i> and <i>S. aureus</i> (MIC: 0.0076 μM) versus standard drug streptomycin (MIC: 0.0138 μM). Moreover, <i>in silico</i> studies performed with the most effective compound <b>4r</b> against <i>P. aeruginosa</i> revealed its potential binding mode within the protein binding pocket. The biological data revealed compound <b>4r</b> as a potential candidate for the development of potent herbicidal and antibacterial agents. In a nutshell, this study offers peanut shell biowaste to be a sustainable biomass for heterogeneous acid catalyst preparation and its application in the multicomponent synthesis of bioactive thiazoles, accommodating the concept of sustainable development goals and circular bioeconomy.