Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Reduction of trans-dichloro- and trans-dibromo-tetracyanoplatinate(IV) by L-methionine

Shi, Tiesheng LU ; Berglund, Johan and Elding, Lars Ivar LU (1997) In Journal of the Chemical Society. Dalton Transactions 1997(12). p.2073-2077
Abstract
Reduction of trans-[Pt(CN)4 X2]2- (X = Cl or Br) as model compounds for antitumour-active platinum(IV) pro-drugs, to [Pt(CN)4]2- by L-methionine, MeSR, has been studied at 25 °C in the range 0 < pH < 12 (X = Cl) and 0 < pH < 6 (X = Br) by use of stopped-flow spectrophotometry. The stoichiometry is [Pt IV] : [MeSR] ≈ 1 : 1; the reaction products are methionine S-oxide and [Pt(CN)4]2- as identified by NMR and UV spectroscopies, respectively. The kinetics is first order with respect to the platinum(IV) and methionine concentrations and the second-order rate constants have a small pH dependence. In analogy with reduction of platinum(IV) complexes by thioglycolic acid, cysteine, penicillamine and glutathione, a mechanism is... (More)
Reduction of trans-[Pt(CN)4 X2]2- (X = Cl or Br) as model compounds for antitumour-active platinum(IV) pro-drugs, to [Pt(CN)4]2- by L-methionine, MeSR, has been studied at 25 °C in the range 0 < pH < 12 (X = Cl) and 0 < pH < 6 (X = Br) by use of stopped-flow spectrophotometry. The stoichiometry is [Pt IV] : [MeSR] ≈ 1 : 1; the reaction products are methionine S-oxide and [Pt(CN)4]2- as identified by NMR and UV spectroscopies, respectively. The kinetics is first order with respect to the platinum(IV) and methionine concentrations and the second-order rate constants have a small pH dependence. In analogy with reduction of platinum(IV) complexes by thioglycolic acid, cysteine, penicillamine and glutathione, a mechanism is postulated in which [Pt(CN)4 X2]2- is reduced by the various protolytic species of methionine in parallel reactions. In the transition state the thioether group of methionine is assumed to interact with co-ordinated halide, mediating the electron transfer to the platinum(IV) centre. The transition states for previously studied reactions between [Pt(CN)4 X2]2- and thiols are discussed in view of these results. It is concluded that methionine-containing biomolecules may compete with thiol compounds for reduction of platinum(IV) pro-drugs under acidic conditions, and also in neutral solutions with low concentrations of thiol-containing biomolecules. (Less)
Abstract (Swedish)
Reduction of trans-[Pt(CN) 4 X 2 ] 2- (X = Cl or Br) [as model compounds for antitumour-active platinum(IV) pro-drugs] to [Pt(CN) 4 ] 2- by L-methionine, MeSR, has been studied at 25 °C in the range 0 < pH < 12 (X = Cl) and 0 < pH < 6 (X = Br) by use of stopped-flow spectrophotometry. The stoichiometry is [Pt IV ] : [MeSR] ≈ 1 : 1; the reaction products are methionine S-oxide and [Pt(CN) 4 ] 2- as identified by NMR and UV spectroscopies, respectively. The kinetics is first order with respect to the platinum(IV) and methionine concentrations and the second-order rate constants have a small pH dependence. In analogy with reduction of platinum(IV) complexes by thioglycolic acid, cysteine, penicillamine and glutathione, a... (More)
Reduction of trans-[Pt(CN) 4 X 2 ] 2- (X = Cl or Br) [as model compounds for antitumour-active platinum(IV) pro-drugs] to [Pt(CN) 4 ] 2- by L-methionine, MeSR, has been studied at 25 °C in the range 0 < pH < 12 (X = Cl) and 0 < pH < 6 (X = Br) by use of stopped-flow spectrophotometry. The stoichiometry is [Pt IV ] : [MeSR] ≈ 1 : 1; the reaction products are methionine S-oxide and [Pt(CN) 4 ] 2- as identified by NMR and UV spectroscopies, respectively. The kinetics is first order with respect to the platinum(IV) and methionine concentrations and the second-order rate constants have a small pH dependence. In analogy with reduction of platinum(IV) complexes by thioglycolic acid, cysteine, penicillamine and glutathione, a mechanism is postulated in which [Pt(CN) 4 X 2 ] 2- is reduced by the various protolytic species of methionine in parallel reactions. In the transition state the thioether group of methionine is assumed to interact with co-ordinated halide, mediating the electron transfer to the platinum(IV) centre. The transition states for previously studied reactions between [Pt(CN) 4 X 2 ] 2- and thiols are discussed in view of these results. It is concluded that methionine-containing biomolecules may compete with thiol compounds for reduction of platinum(IV) pro-drugs under acidic conditions, and also in neutral solutions with low concentrations of thiol-containing biomolecules. (Less)
Please use this url to cite or link to this publication:
author
; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Tetracyanoplatinate(IV), Methionine, Reduction, Kinetics, Reaction mechanism, Platinum(IV) prodrugs, Stopped-flow, Tetraacyanoplatinates(IV), L-methionine, Reduction, Kinetics, Reaction mechanism, anti-tumor active compounds, Platinum(IV) prodrugs
in
Journal of the Chemical Society. Dalton Transactions
volume
1997
issue
12
pages
5 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:33748498682
ISSN
1472-7773
DOI
10.1039/a608507e
language
English
LU publication?
yes
id
b4ea22b1-846b-48dd-ac00-c016e58a1199
date added to LUP
2017-01-04 11:01:50
date last changed
2022-02-21 23:20:45
@article{b4ea22b1-846b-48dd-ac00-c016e58a1199,
  abstract     = {{Reduction of trans-[Pt(CN)4 X2]2- (X = Cl or Br) as model compounds for antitumour-active platinum(IV) pro-drugs, to [Pt(CN)4]2- by L-methionine, MeSR, has been studied at 25 °C in the range 0 &lt; pH &lt; 12 (X = Cl) and 0 &lt; pH &lt; 6 (X = Br) by use of stopped-flow spectrophotometry. The stoichiometry is [Pt IV] : [MeSR] ≈ 1 :  1; the reaction products are methionine S-oxide and [Pt(CN)4]2- as identified by NMR and UV spectroscopies, respectively. The kinetics is first order with respect to the platinum(IV) and methionine concentrations and the second-order rate constants have a small pH dependence. In analogy with reduction of platinum(IV) complexes by thioglycolic acid, cysteine, penicillamine and glutathione, a mechanism is postulated in which [Pt(CN)4 X2]2- is reduced by the various protolytic species of methionine in parallel reactions. In the transition state the thioether group of methionine is assumed to interact with co-ordinated halide, mediating the electron transfer to the platinum(IV) centre. The transition states for previously studied reactions between [Pt(CN)4 X2]2- and thiols are discussed in view of these results. It is concluded that methionine-containing biomolecules may compete with thiol compounds for reduction of platinum(IV) pro-drugs under acidic conditions, and also in neutral solutions with low concentrations of thiol-containing biomolecules.}},
  author       = {{Shi, Tiesheng and Berglund, Johan and Elding, Lars Ivar}},
  issn         = {{1472-7773}},
  keywords     = {{Tetracyanoplatinate(IV); Methionine; Reduction; Kinetics; Reaction mechanism; Platinum(IV) prodrugs; Stopped-flow; Tetraacyanoplatinates(IV); L-methionine; Reduction; Kinetics; Reaction mechanism; anti-tumor active compounds; Platinum(IV) prodrugs}},
  language     = {{eng}},
  month        = {{06}},
  number       = {{12}},
  pages        = {{2073--2077}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Journal of the Chemical Society. Dalton Transactions}},
  title        = {{Reduction of trans-dichloro- and trans-dibromo-tetracyanoplatinate(IV) by L-methionine}},
  url          = {{http://dx.doi.org/10.1039/a608507e}},
  doi          = {{10.1039/a608507e}},
  volume       = {{1997}},
  year         = {{1997}},
}