Synthesis, crystal structure, biological and docking studies of 5-hydroxy-2-{[(2-methylpropyl)iminio]methyl}phenolate

<b>Background:</b> Schiff base compounds are potential drugs. <b>Results:</b> A Schiff base compound prepared by condensing 2,4-dihydroxy benzaldehyde and isobutylamine was characterized for structure, thermal, physicochemical and biological properties. The keto-enol tautomerism and azomethine functionality enhances electron delocaliZation and biological activity. The compound showed good antibacterial and antifungal activity at 40 μg/ml against bacteria such as <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> and fungi like <i>Candida albicans</i> and <i>Candida tropicalis</i>. The docking study exhibits a moderate binding affinity for the GyrB protein in <i>E. coli</i> with a binding energy of -4.26 kcal/mol. <b>Conclusion:</b> The compound exhibits enhanced biological activity and suppression of cell growth at concentrations as low as 30 μg/ml. The IC₅₀ for MFC-7 was found to be 41.5 μg/ml. 5-hydroxy-2-{[(2-methylpropyl)iminio]methyl}phenolate was prepared by the self-condensation of 2,4-dihydroxybenzaldehyde and isobutylamine. It shows an extended delocalization of pi-electrons prompted by forming a 6-membered motif, which enhances its biological activity. Spectral analysis, confirmed the presence of biologically active functional groups such as azomethine and hydroxy (-OH) in the compound. The monomeric mass in the solid state was confirmed by the presence of a molecular ion peak at <i>m/z</i> = 194 (rel. int = 100%) from its mass spectrum. The powder x-ray diffraction analysis confirmed its crystalline nature and its bulk purity in the powder form and the Scherrer formula yielded an average particle size (D) of 22.1 nm The compound showed good antibacterial (<i>Escherichia coli, Staphylococcus aureus)</i> and antifungal (<i>Candida albicans, Candida tropicalis</i>) activity at the concentration of 40 μg/ml. The MIC investigations revealed that the compound suppresses cell growth at concentrations as low as 30 μg/ml. The IC₅₀ value for MCF-7 was found to be 41.5 μg/ml. The compound showed a moderate binding affinity for the GyrB protein in <i>E. coli</i> with a binding energy of -4.26 kcal/mol. The negative value of the intermolecular energy (-5.75 kcal/mol) indicates a favorable interaction with the GyrB protein leading to antibacterial effects.