Synthesis, spectroscopic characterization and biological evaluation of unsymmetrical aminosquarylium cyanine dyes. Issue 14 (15th July 2017)

• Record Type: Journal Article
• Authors: Friães, Sofia; Silva, Amélia M.; Boto, Renato E.; Ferreira, Diana; Fernandes, José R.; Souto, Eliana B.; Almeida, Paulo; Ferreira, Luis F. Vieira; Reis, Lucinda V.
• Is Part Of: Bioorganic & medicinal chemistry. Volume 25:Issue 14(2017)
• Page Start: 3803
• Page End: 3814
• Publication Date: 2017-07-15
• Subjects: Unsymmetrical aminosquarylium cyanine dyes -- Singlet oxygen -- Caco-2 cells -- HepG2 cells -- Cell viability -- Photosensitizers; Bioorganic chemistry -- Periodicals; Pharmaceutical chemistry -- Periodicals; Biochemistry -- Periodicals; Chemistry, Clinical -- Periodicals; Chemistry, Organic -- Periodicals; Chimie bio-organique -- Périodiques; Chimie pharmaceutique -- Périodiques; 615.19
• DOI: 10.1016/j.bmc.2017.05.022
• Languages: English
• ISSNs: 0968-0896

Abstract

Graphical abstract: Highlights: New unsymmetrical aminosquarylium cyanine dyes were synthesized. The quantum yield of singlet oxygen formation for new dyes was measured. In vitro toxicity of dyes was evaluated on Caco-2 and HepG2 cells lines. Photosensitizing potential of new synthesized dyes was evaluated. Dyes with very low oxygen singlet yield still induce significant phototoxicity. Abstract: New unsymmetrical aminosquarylium cyanine dyes were synthesized and their potential as photosensitizers evaluated. New dyes, derived from benzothiazole and quinoline, were prepared by nucleophilic substitution of the corresponding O -methylated, the key intermediate that was obtained by methylation with CF3 SO3 CH3 of the related zwitterionic unsymmetrical dye, with ammonia and methylamine, respectively. All three news dyes herein described displayed intense and narrow bands in the Vis/NIR region (693–714 nm) and their singlet oxygen formation quantum yields ranged from 0.03 to 0.05. In vitro toxicity, in Caco-2 and HepG2 cells, indicated that dark toxicity was absent for concentrations up to 5 µM (for the less active dye) or up to 1 µM (for the two more active dyes). The three dyes present potential as photosensitizers, differing in irradiation conditions and period of incubation in the presence of irradiated dye. The less active dye needs a longer irradiation period to exhibit phototoxicity which is only evident after longer period of contact with cells (24 h). However, the remaining two more active dyes produce higher phototoxicity, even at shorter incubation periods (1 h), with shorter irradiation time (7 min). Although in different extents, these dyes show promising in vitro results as photosensitizers.