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

S. Kemp, N.J. Wheate, Michelle J. Pisani, J.R. Aldrich-Wright

Research output: Contribution to journalArticle

64 Citations (Scopus)

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.
LanguageEnglish
Pages2787-2794
Number of pages7
JournalJournal of Medicinal Chemistry
Volume51
Issue number9
DOIs
Publication statusPublished - 16 Apr 2008

Fingerprint

Intercalating Agents
Platinum
Glutathione
DNA
Methionine
Guanosine
Coordination Complexes
Sulfhydryl Compounds
Half-Life
Ligands
1,10-phenanthroline

Keywords

  • bidentate-coordinated platinum(II)
  • DNA intercalators
  • l-glutathione
  • biomedical sciences
  • pharmacology

Cite this

Kemp, S. ; Wheate, N.J. ; Pisani, Michelle J. ; Aldrich-Wright, J.R. / Degradation of bidentate-coordinated platinum(II)-based DNA intercalators by reduced l-glutathione. In: Journal of Medicinal Chemistry. 2008 ; Vol. 51, No. 9. pp. 2787-2794.
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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.",
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Degradation of bidentate-coordinated platinum(II)-based DNA intercalators by reduced l-glutathione. / Kemp, S.; Wheate, N.J.; Pisani, Michelle J.; Aldrich-Wright, J.R.

In: Journal of Medicinal Chemistry, Vol. 51, No. 9, 16.04.2008, p. 2787-2794.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Degradation of bidentate-coordinated platinum(II)-based DNA intercalators by reduced l-glutathione

AU - Kemp, S.

AU - Wheate, N.J.

AU - Pisani, Michelle J.

AU - Aldrich-Wright, J.R.

PY - 2008/4/16

Y1 - 2008/4/16

N2 - 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.

AB - 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.

KW - bidentate-coordinated platinum(II)

KW - DNA intercalators

KW - l-glutathione

KW - biomedical sciences

KW - pharmacology

UR - http://dx.doi.org/10.1021/jm7016072

U2 - 10.1021/jm7016072

DO - 10.1021/jm7016072

M3 - Article

VL - 51

SP - 2787

EP - 2794

JO - Journal of Medicinal Chemistry

T2 - Journal of Medicinal Chemistry

JF - Journal of Medicinal Chemistry

SN - 0022-2623

IS - 9

ER -