Publication Type Journal Article
Title Synthesis, Structure and Cytotoxicity of a Novel Sulphanyl-Bridged Thiadiazolyl-Saccharinate Conjugate. The Relevance of S...N Interaction (HOT PAPER)
Authors Lília I. L. Cabral Elisa M. Brás Marta S. C. Henriques Catia Marques Luís M. T. Frija Luisa Barreira Jose Antonio Paixao Rui Fausto Maria Lurdes S. Cristiano
Groups CCC
Journal CHEMISTRY A EUROPEAN JOURNAL
Year 2018
Month March
Volume 24
Number
Pages 3251-3262
Abstract Reports showing that the copper concentration is considerably higher in neoplasms than in normal tissues prompted the need to develop selective copper chelators. We disclosed recently that some N-linked tetrazole-saccharinates bind selectively to copper, forming complexes that are highly cytotoxic towards cancer cells. Because tetrazole-saccharinates are photolabile, due to the photoreactivity of tetrazoles, we proposed thiadiazolyl-saccharinates as an alternative. Herein we describe the synthesis, structure, and monomeric photochemistry of a sulphanyl-bridged thiadiazolyl-saccharinate, 3-[(5-methyl-1,3,4-thiadiazol-2-yl)sulphanyl]-1,2-benzothiazole 1,1-dioxide (MTSB). The monomeric structure, charge density analysis, and characteristic infrared spectrum of MTSB were investigated theoretically, using quantum chemical calculations, and also experimentally, using matrix-isolation infrared spectroscopy. The crystal structure was investigated by combining X-ray crystallography with infrared and Raman spectroscopies. Results show that the structure of isolated MTSB is similar to that found in the crystal, with an S-N interaction clearly contributing to the structure of the molecule and of the crystal. Matrix irradiation revealed a high photostability of MTSB, compared to parent tetrazole-saccharinates and to the 5-methyl-1,3,4-thiadiazole building block, emphasizing the photostabilizing effect of the saccharyl system. Finally, in vitro toxicity assays of MTSB showed a copper concentration-dependent toxicity against cancer cells, without affecting normal cells. In particular, MTSB was most effective towards the hepatic (HepG2), neuroblastoma (SH-SY5), and lymphoma cell lines (U937). Thus, MTSB represents a promising lead for cancer chemotherapy based on chelating agents.
DOI http://dx.doi.org/10.1002/chem.201705319
ISBN
Publisher
Book Title
ISSN
EISSN
Conference Name
Bibtex ID
Observations
Back to Publications List