Picture of two heads

Open Access research that challenges the mind...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs. Strathprints provides access to thousands of Open Access research papers by University of Strathclyde researchers, including those from the School of Psychological Sciences & Health - but also papers by researchers based within the Faculties of Science, Engineering, Humanities & Social Sciences, and from the Strathclyde Business School.

Discover more...

Degradation of bidentate-coordinated platinum(II)-based DNA intercalators by reduced l-glutathione

Kemp, S. and Wheate, N.J. and Pisani, Michelle J. and Aldrich-Wright, J.R. (2008) Degradation of bidentate-coordinated platinum(II)-based DNA intercalators by reduced l-glutathione. Journal of Medicinal Chemistry, 51 (9). pp. 2787-2794. ISSN 0022-2623

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

We have examined the interaction of [(5,6-dimethyl-1,10-phenanthroline)(1S,2S-diaminocyclohexane)platinum(II)]2+ (1, 56MESS), [(5-methyl-1,10-phenanthroline)(1S,2S-diaminocyclohexane)platinum(II)]2+ (2, 5MESS), [(5,6-dimethyl-1,10-phenanthroline)(1R,2R-diaminocyclohexane)platinum(II)]2+ (3, 56MERR), and [(5,6-dimethyl-1,10-phenanthroline)(ethylenediamine)platinum(II)]2+ (4, 56MEEN) with reduced l-glutathione and l-methionine. Both thiols degrade all four complexes, mainly by displacing the ancillary ligand and forming a doubly bridged dinuclear complex. The degradation half-life of all the complexes with methionine is >7 days, indicating that these reactions are not biologically relevant. The rate of degradation by glutathione appears to be particularly important and shows an inverse correlation to cytotoxicity. The least active complex, 4 (t1/2 glutathione: 20 h), degrades fastest, followed by 3 (31 h), 2 (40 h), and 1 (68 h). The major degradation product, [bis-μ-{reduced l-glutathione}bis{5,6-dimethyl-1,10-phenanthroline}bis{platinum(II)}]2+ (5, 56MEGL), displays no cytotoxicity and is excluded as the source of the anticancer activity. Once bound by glutathione, these metal complexes do not then form coordinate bonds with guanosine. Partial encapsulation of the complexes within cucurbit[n]urils is able to stop the degradation process.