Reduction of trans-dichloro- and trans-dibromo-tetracyanoplatinate(IV) by L-methionine
(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:
https://lup.lub.lu.se/record/b4ea22b1-846b-48dd-ac00-c016e58a1199
- author
- Shi, Tiesheng LU ; Berglund, Johan and Elding, Lars Ivar LU
- organization
- publishing date
- 1997-06-21
- 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 < 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.}}, 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}}, }