Premium
Photobiological Properties of Positively Charged Methylene Violet Analogs
Author(s) -
Houghtaling Melissa A.,
Perera Rushika,
Owen Katherine E.,
Wagner Stephen,
Kuhn Richard J.,
Morrison Harry
Publication year - 2000
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/0031-8655(2000)0710020ppopcm2.0.co2
Subject(s) - bathochromic shift , chemistry , photochemistry , titration , methylene blue , singlet oxygen , absorption spectroscopy , covalent bond , methylene , absorption (acoustics) , nuclear chemistry , medicinal chemistry , organic chemistry , oxygen , fluorescence , photocatalysis , catalysis , physics , quantum mechanics , acoustics
O ‐Methyl methylene violet (OMeMV), O ‐methyl bromomethylene violet (OMeBrMV) and O ‐methyl iodomethylene violet (OMeIMV) have been prepared in order to test their potential utility as anti‐viral and anti‐tumor phototoxic dyes. Rates of photosensitized toxicity of KB cells with 633 nm irradiation are (×10 −19 photon −1 ): 2.4, 2.2, 1.9 and 0.17 for OMeIMV, OMeBrMV, methylene violet (MV) and OMeMV, respectively. Rates of photosensitized inactivation of Sindbis virus in phosphate‐buffered saline with 633 nm irradiation are (×10 −18 photon −1 ): 3.3, 1.8, 0.99, 0.15 for MV, OMeIMV, OMeBrMV and OMeMV, respectively. Quantum efficiencies for singlet oxygen formation were determined as OMeIMV, 0.64; OMeBrMV, 0.40; OMeMV, 0.054. Titration of the dyes with double‐stranded (ds)DNA resulted in bathochromic shifts and hypochromic effects in the visible absorption spectra. Association constants for interaction of the methylated dyes with dsDNA of ∼1 × 10 5 M −1 were determined by Scatchard analysis of equilibrium dialysis and UV absorption titration data. Photolysis of the halogenated dyes with DNA under argon led to covalent bond formation with the nucleic acid; there was no evidence of covalent binding in the dark.