Antimicrobial activity of new dumbbell-shaped phenothiazine cinnamides

Herein, we report the synthesis and in vitro antibacterial and antifungal activities for twelve ( E )-3-(10-(4-(10 H -phenothiazin-10-yl)phenyl)-10 H -phenothiazin-3-yl)- N -phenyl acrylamides ( 1–12 ). Structures of the compounds were established using IR, 1 H NMR, mass and elemental analysis. These compounds exhibited promising activity against bacterials rather than fungal strains used. All the compounds inhibited the Gram-negative E. coli (ATCC 25922) and compounds 3 , 5 , 7 , 8 and 12 also inhibited Gram-negative Pseudomonas (ATCC 27853) species in nano molar concentrations. Disc diffusion and micro-dilution (for MIC) methods were employed in estimating their in vitro antibacterial and antifungal activities. Ciprofloxacin and ketoconazole were used as the respective internal standards.