Urea and thiourea scaffolds have been successfully used in drug design in recent years ⁽¹⁾. The formation of thiazolidines by reaction of propargyl amine with isothiocyanates under harsh conditions has been previously reported. Also, these new molecules have attracted great attention because their biological activity ⁽²⁾.

The coordination with different metals like gold or silver seem to show a better biological activity ⁽³⁾, hence, these metal centers were coordinated to the thiourea and to the heterocyclic compounds.

The reactions between propargylamines and isothiocyanates (Scheme 1), when the stoichiometry was 2:1, showed the formation the thiourea-thiazolidine compounds. These new molecules have coordination atoms such as sulfur and nitrogen where metal atoms can be linked, improving their biological activity. On the other hand, these atoms could work recognizing different target cells leading to higher selectivity for these compounds.

Scheme 1

Thiourea-thiazolidine compounds were coordinated to gold and silver atoms with 1:1 or 2:1 stoichiometry (Scheme 2).

Scheme 2

Finally, these compounds were tested with HeLa cells through the MTT assay. The results had not been as successfully as expected. Only silver compounds showed good cytotoxic values as anticancer compounds. Gold compounds have lower IC₅₀ valuables than their respective organic ligands, but more studies should be perform to improve the complexes in order to developed better candidates for the treatment of cancer.

Graphic 1

References

1. Yao, J.; Chen, J.; He, Z.; Sun, W.; Xu, W. Bioorg. Med. Chem. 2012, 20, 2923–2929.
2. Liu, Y.; Jing, F.; Xu, Y.; Xie, Y.; Shi, F.; Fang, H.; Li, M.; Xu, W. Biorg. Med. Chem. 2011, 19, 2342-2348.
3. O. Rackham, S.J. Nichols, P.J. Leedman, S.J. Berners-Price, A. Filipovska. From Biochemical Pharmacology. 2007, 74(7), 992-1002.