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Journal of Chemistry
Volume 2017, Article ID 7365263, 9 pages
Research Article

Photodynamic Efficiency of Xanthene Dyes and Their Phototoxicity against a Carcinoma Cell Line: A Computational and Experimental Study

1Departamento de Química e Física Molecular, Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
2Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, SP, Brazil
3Escola de Engenharia Industrial Metalúrgica de Volta Redonda, Departamento de Ciências Exatas, Universidade Federal Fluminense, Volta Redonda, RJ, Brazil

Correspondence should be addressed to Paula Homem-de-Mello; rb.ude.cbafu@ollem.aluap, Rommel B. Viana; rb.moc.oohay@vblemmor, Janice R. Perussi; rb.psu.csqi@ecinaj, and Albérico B. F. da Silva; rb.psu.csqi@ocirebla

Received 19 August 2016; Accepted 21 November 2016; Published 12 February 2017

Academic Editor: Teodorico C. Ramalho

Copyright © 2017 Suelen T. G. Buck et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The aim of this study is to assess the insights of molecular properties of the xanthene dyes [fluorescein (FL), Rose Bengal (RB), erythrosin B (EB), and eosin Y (EY)] to correlate systematically their photodynamic efficiency as well as their phototoxicity against a carcinoma cell line. The phototoxicity was evaluated by comparing the values of the medium inhibitory concentration (IC50) upon HEp-2 cells with the xanthene corresponding photodynamic activity using the uric acid as a chemical dosimeter and their octanol-water partition coefficient (). RB was the more cytotoxic dye against HEp-2 cell line and the most efficient photosensitizer in causing photoxidation of uric acid; nevertheless it was the only one characterized as being hydrophobic among the xanthenes studied here. On the other hand, it was observed that the halogen substituents increased the hydrophilicity and photodynamic activity, consistent with the cytotoxic experiments. Furthermore, the reactivity index parameters, electric dipole moment, molecular volume, and the frontier orbitals were also obtained by the Density Functional Theory (DFT). The lowest dipole moment and highest molecular volume of RB corroborate with its highest hydrophobicity due to heavy atom substituents like halogens, while the halogen substituents did not affect expressively the electronic features at all.