Rational design of phenothiazinium derivatives and photoantimicrobial drug discovery

This review concentrates on the use of the phenothiazinium class as exemplar photoantimicrobials, due to their pre-eminence in the field and considers the various criteria required for successful activity against microbes. These include alicyclic fusion, chalcogen substitution, benzo[a] fusion and the heavy atom effect, to decrease aggregation, improve ROS production and extend absorption wavelength, as well as conventional approaches, such as increasing cationic character to improve microbial selectivity/targeting.