Highly cytotoxic bioconjugated gold(I) complexes with cysteine-containing dipeptides

Several gold(I) complexes with cysteine-containing dipeptides have been prepared starting from cystine by coupling different amino acids and using several orthogonal protections. The first step is the reaction of cystine, where the sulfur centre is protected as disulfide, with Boc2O in order to prot...

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Detalles Bibliográficos
Autores: Gutiérrez, Alejandro, Marzo, Isabel, Cativiela, Carlos, Laguna, Antonio, Gimeno, M. Concepción
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/123038
Acceso en línea:http://hdl.handle.net/10261/123038
Access Level:acceso abierto
Palabra clave:Bioconjugation
Cytotoxic activity
Dipeptides
Gold
Medicinal chemistry
Descripción
Sumario:Several gold(I) complexes with cysteine-containing dipeptides have been prepared starting from cystine by coupling different amino acids and using several orthogonal protections. The first step is the reaction of cystine, where the sulfur centre is protected as disulfide, with Boc2O in order to protect the amino group, followed by coupling of an amino acid ester; finally the disulfide bridge is broken with mercaptoethanol to afford the dipeptide derivative. Further reaction with [AuCl(PPh3)] gives the gold-dipeptide-phosphine species. Starting from these formally gold(I) thiolate–dipeptide phosphine complexes with the general formula [Au(SR)(PR3)] different structural modifications, such as change in the type of the amino protecting group, the type of phosphine, the number of gold(I) atoms per molecule, or the use of a non-proteinogenic conformationally restricted amino acid ester, were introduced in order to evaluate their influence in the biological activity of the final complexes. The cytotoxic activity, in vitro, of these complexes was evaluated against different tumour human cell lines (A549, MiaPaca2 and Jurkat). The complexes show an outstanding cytotoxic activity with IC50 values in the very low micromolar range. Structure–activity relationship studies from the complexes open the possibility of designing more potent and promising gold(I) anticancer agents.