Synthesis and antibacterial evaluation of 3,3′-diindolylmethane derivatives

Various 3,3′-diindolylmethane (DIM) derivatives were synthesized and the antibacterial activity of these compounds were tested against ten bacterial strains and their minimum inhibitory concentration (MIC) values were determined. The MIC values of derivatives 3a – d and 5a – e were ranging from 125 to 500 μg/mL. Among these derivatives, 2-(di(1 H -indol-3-yl)methyl)phenol ( 5a ) and 3-((1 H -indol-3-yl)(pyridin-3-yl)methyl)-1 H -indole ( 5d ) exhibited potent activity, showing MIC values 6.5–62.5 μg/mL against Gram positive and Gram negative bacteria. Hemolytic assay of these active DIM derivatives did not show considerable toxic effect on the normal human erythrocytes.