Physicochemical and photodynamic antimicrobial chemotherapy studies of mono- and tetra-pyridyloxy substituted indium(III) phthalocyanines

The synthesis and photophysicochemical properties of mono- and tetra-pyridyloxy substituted indium (III) phthalocyanines (InPcs) are presented in this study. General trends are described for quantum yields of fluorescence, triplet, singlet oxygen and photodegradation as well as lifetimes of fluorescence and triplet state of these compounds. The complexes exhibited high singlet oxygen quantum yields (Phi(Delta)) ranging from 0.44 to 0.66 in DMF, and from 0.44 to 0.69 in DMSO and Phi(Delta) = 0.31 for the quartenized tetra substituted InPc which is soluble in water. The triplet quantum yields (Phi(T)) ranged from 0.77 to 0.95 in DMF and from 0.77 to 0.94) in DMSO. The tetra substituted photosensitizers do not differ in their inactivation of bacteria with over 8 log reduction of viable bacteria when compared with the mono substituted photosensitizer which could only manage a 1 log reduction. (C) 2014 Elsevier B.V. All rights reserved.