Oxidative cleavage of DNA by pentamethine carbocyanine dyes irradiated with long-wavelength visible light

• Published in: Bioorganic & medicinal chemistry letters Vol. 24; no. 1; pp. 214 - 219
• Main Authors: Mapp, Carla T., Owens, Eric A., Henary, Maged, Grant, Kathryn B.
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier 01.01.2014
• Subjects: Carbocyanines - chemistry; Chemistry; Chemistry, Medicinal; Chemistry, Organic; Coloring Agents - chemistry; DNA - chemistry; DNA Cleavage; Life Sciences & Biomedicine; Molecular Structure; Oxidation-Reduction; Pharmacology & Pharmacy; Physical Sciences; Science & Technology; Spectrophotometry, Ultraviolet; Ultraviolet Rays; Carbocyanine; BINDING MODES; Photodynamic therapy; SINGLE; YOYO; Photocleavage; Red light; Tri-cationic; CYANINE DYES; Benz[e]indolium; AGGREGATION; light emitting diode; bp; O; DNA base pairs; singlet oxygen; YO; reactive oxygen species; thiazole orange; OH; PDT; ground state triplet molecular oxygen; calf thymus; LED; (3-bromopropyl)trimethylammonium bromide; CT; hydroxyl radical; ROS; TO; TMAB; oxazole yellow
• ISSN: 0960-894X; 1464-3405
• DOI: 10.1016/j.bmcl.2013.11.035

Here we report the synthesis of seven symmetrical carbocyanine dyes in which two nitrogen-substituted benz[e]indolium rings are joined by a pentamethine bridge that is meso-substituted with chlorine or bromine versus hydrogen. The heteroatom of benz[e]indolium is modified with a phenylpropyl, methyl, or cationic quaternary ammonium group. In reactions containing micro molar concentrations of halogenated dye, irradiation at 575, 588, 623, or 700 nm produces good photocleavage of plasmid DNA. UV-visible spectra show that the carbocyanines are in their H-aggregated and monomeric forms. Scavenger experiments point to the involvement of singlet oxygen and hydroxyl radicals in DNA photocleavage. (C) 2013 Elsevier Ltd. All rights reserved.