2-Hydroxy-4-methoxybenzaldehyde is a phenol found in the root bark essential oil of P. sepium that has diverse biological activities, including antibacterial, antifungal, fungicidal, antioxidant, anti-virulence, and metal chelating properties.1,2,3 It is active against Gram-positive (MICs = 100-200 ?g/ml) and Gram-negative bacteria (MICs = 125-200 ?g/ml), as well as the fungus C. albicans and the phytopathogenic fungus M. oryzae (MICs = 150 and 300 ?g/ml, respectively). 2-Hydroxy-4-methoxybenzaldehyde scavenges 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals in a cell-free assay (IC50 = 9.04 mg/ml) and acts as a metal chelator, inhibiting ferrozine-Fe2+ complex formation with an IC50 value of 2.31 mg/ml. It reduces the production of the virulence factor staphyloxanthin in clinical isolates of methicillin-resistant S. aureus (MRSA) when used at a concentration of 200 ?g/ml and decreases the expression of the MRSA virulence regulatory genes saeS, geh, crtM, and sigB.2 2-Hydroxy-4-methoxybenzaldehyde, when used in combination with the antibiotics amikacin , gentamicin, cefotaxime , vancomycin , or tetracycline , increases MRSA antibiotic sensitivity. It is also an intermediate in the synthesis of Schiff base-metal complexes with antiproliferative activity.3
1.Wang, J., Liu, H., Zhao, J., et al.Antimicrobial and antioxidant activites of the root bark essential oil of Periploca sepium and its main component 2-hydroxy-4-methoxybenzaldehydeMolecules15(8)5807-5817(2010) 2.Kannappan, A., Srinivasan, R., Nivetha, A., et al.Anti-virulence potential of 2-hydroxy-4-methoxybenzaldehyde against methicillin-resistant Staphylococcus aureus and its clinical isolatesAppl. Microbiol. Biotechnol.103(16)6747-6758(2019) 3.Tyagi, P., Tyagi, M., Agrawal, S., et al.Synthesis, characterization of 1,2,4-triazole Schiff base derived 3d-metal complexes: Induces cytotoxicity in HepG2, MCF-7 cell line, BSA binding fluorescence and DFT studySpectrochim. Acta. A. Mol. Biomol. Spectrosc.171246-257(2017)