Biological activities of phenolic oligomers (I) relationship between the degree of addition-condensation of phenolic oligomers and their antimicrobial activity

A series of methylene-bridged phenolic oligomers was prepared and the minimal inhibitory concentrations against bacteria and fungi were determined by agar dilution method. These compounds proved to be greatly effective against gram-positive bacteria and fungi. Homogeneous all ortho methylene-bridged phenolic oligomers were synthesized and the effect of the degree of addition-condensation on antimicrobial potency was examined. Of the homogeneous oligomers, tetramers were the most active against gram-positive bacteria, and trimers showed good antimicrobial activity against fungi.