Antimicrobial properties of ortho-ortho direct-linked phenolic oligomers

Antimicrobial properties of the ortho-ortho direct-linked phenolic oligomers prepared by the oxidative polymerization of substituted phenols using horseradish peroxidase and hydrogen peroxide were evaluated with respect to their molecular structure. The antimicrobial activity was increased by the oligomerization in some cases, but their effectiveness was slightly inferior to that of the corresponding ortho linked methylene-bridged phenolic oligomers. The p-cresol oligomer, p-ethylphenol oligomer, p-methoxyphenol oligomer, m-cresol oligomer and 3,4-dimethylphenol oligomer exhibited lower MIC values against some gram-positive bacterial strains and fungal strains than the corresponding monomeric phenols.