title: Light induced antimicrobial properties of a brominated boron difluoride (BF(2)) chelated tetraarylazadipyrromethene photosensitizer.
abstract: Herein we describe a new antimicrobial photodynamic therapeutic (PDT) agent based upon the brominated BF(2) chelated tetraarylazadipyrromethene photosensitizer class. Bis-ammonium salt substitution of the photosensitizer promoted a rapid 10 min uptake into Gram-positive and -negative bacterial strains and pathogenic yeasts. A photosensitizer and light dose response analysis for methicillin-sensitive S. aureus showed an impressive antibacterial efficacy with 1, 2, and 5 μg/mL 6. Specifically, light activation with a dose of 16 J/cm(2) and 5 μg/mL 6 resulted in a 6.8 and 3.4 log(10) reduction of S. aureus and a clinically defined methicillin-resistant Staphylococcus aureus (MRSA) strain, respectively. Encouragingly, a broad spectrum pathogen response (using 5 μg/mL 6 and 75 J/cm(2)) was observed with 3.6 and 5.7 log(10) decreases in viable cell numbers achievable for Gram-negative bacterium E. coli and the pathogenic yeast C. albicans, respectively. The photophysical and cell eradicating characteristics of this bis-cationic PDT agent suggest that it has broad potential in antimicrobial therapeutics.
authors.affiliation: Centre for Synthesis and Chemical Biology, School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Frimannsson
authors.forename: Marco
authors.initials: M
authors.lastname: Grossi
authors.forename: Julie
authors.initials: J
authors.lastname: Murtagh
authors.forename: Francesca
authors.initials: F
authors.lastname: Paradisi
authors.forename: Donal F
authors.initials: DF
authors.lastname: O'Shea
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000935:Antifungal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001895:Boron; D001896:Boron Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects; D045744:Cell Line, Tumor; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D008027:Light; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D001896:Boron Compounds; D056831:Coordination Complexes; D017319:Photosensitizing Agents; D011758:Pyrroles; D001895:Boron