Aloe Vera Extract-Mediated CuO NPs as Catalysts for the Synthesis of 4-Hydroxy-3-Methoxybenzaldehyde-Connected Piperidine Derivatives and Their Antibacterial Activity

We have designed an easy, affordable, and eco-friendly technique for Schiff base preparation of vanillin-coupled piperidine analogues using CuO NPs as a catalyst. Using a green chemistry strategy using copper oxide nanoparticles (CuO NPs) as a catalyst, a unique one-pot synthesis of Schiff base vanillin-linked piperidine derivatives (2, 2a-2j) may be generated, with a potential yield in a short reaction time. The CuO NPs were synthesized with the aloe vera extract. The newly synthesized piperidin-4-ylidene analogues were investigated using FT-IR, NMR (H-1, C-13), mass spectra, and elemental analysis. The morphology of piperidine derivatives was studied using XRD and TEM. The compound 2a-2j was evaluated for antibacterial activity against gram +ve and gram -ve bacteria. Compound 2d is exceptionally active against (5.0 mu g/mL, E. coli), and 2c is very effective against (4.0 mu g/mL, L. plantarum) when compared to reference drug and other Schiff base of vanillin-associated piperidine derivatives. Finally, we concluded the compounds 2c and 2d have strong antibacterial activity and can be used as antibacterial drugs in the future.

Automated summary

We have developed a green and efficient approach for synthesizing Schiff base vanillin-linked piperidine derivatives using CuO NPs as a catalyst. The CuO NPs were synthesized from aloe vera extract. The newly synthesized compounds showed strong antibacterial activity, especially compound 2d against E. coli and compound 2c against L. plantarum. These findings suggest that compound 2c and 2d have potential as antibacterial drugs in the future.