Platinum-amino-acid complexe

Although the platinum-amino-acid complexes do not show much promise as cytotoxic agents, these results demonstrated the utility of in vitro screening methods to survey the DNA-binding properties of platinum compounds in a combinatorial manner. Assuming that HMG-domain proteins are involved in the cisplatin mechanism of action, then screening based on the Pt-... 

The Pt—O bond enthalpies for a series of amino acid complexes of platinum(II) fall in the range 322-397 kJ mol-1.15 1... 

Molecular mechanics and dynamics studies of metal-nucleotide and metal-DNA interactions to date have been limited almost exclusively to modeling the interactions involving platinum-based anticancer drugs. As with metal-amino-acid complexes, there have been surprisingly few molecular mechanics studies of simple metal-nucleotide complexes that provide a means of deriving reliable force field parameters. A study of bis(purine)diamine-platinum(II) complexes successfully reproduced the structures of such complexes and demonstrated how steric factors influenced the barriers to rotation about the Pt(II)-N(purine) coordinate bonds and interconversion of the head-to-head (HTH) to head-to-tail (HTT) isomers (Fig. 12.4)[2011. In the process, force field parameters for the Pt(II)/nucleotide interactions were developed. A promising new approach involving the use of ab-initio calculations to calculate force constants has been applied to the interaction between Pt(II) and adenine[202]. 

The affinity of DMSO for platinum(ii) makes this an attractive solvent for solvolysis studies. Pt N.m.r. spectroscopy has shown that six products result from the solvolysis of cw-[PtCl2(NH3)2] in this medium, indicating a complicated mechanism. The stereochemistry and kinetics of solvolysis of the [PtCUCgly)] anion have also been probed by n.m.r. spectroscopy. Discrepancies between this and earlier work on amino-acid complexes [PtCl2(aa)] have been rationalized by further n.m.r. studies of the configurational changes involved en route to the products (4). ... 

A review11 with 123 references is given on amino acid bonding preferences in complexes of platinum and palladium. The preferences for a particular donor atom for Pd11 depends primarily on relative thermodynamic stabilities of the complexes formed. Sizes of potential chelate rings often play a crucial role in determining donor atom preferences. 

The interaction of platinum(II) complexes with various amino acids and simple peptides is relevant to understanding the biological fate of platinum anticancer agents such as mplatin, and this area has been reviewed extensively.258-261... 

B. The Reaction of Platinum Complexes with Amino-acids... 

In cytochrome-c [PtCU]2- binds to methionine 65 on the outside of the protein (64). Again the chloride is probably displaced as the reagent is applied in phosphate buffer. Dickerson and co-workers consider that the platinum is oxidized to a Pt(IV) complex but this seems unlikely as it does not occur in the reaction of [PtClJ2- with simple amino-acids. 

Cyclopentene-l-dithiocarboxylic acid, 2-amino-mctal complexes, 800 Cyclophosphazenes metal complexes, 81 Cyclotetraphosphazene, octamethyl-platinum complexes, 82 Cyclotetraphosphazenes metal complexes, 81 Cyclotriphosphorus complexes, 1058 Cysteine... 

Pinacolone, o-(diphenylphosphino)benzoyl-coordination chemistry, 401 Piperidine, IV-hydroxy-metal complexes, 797 pA a values azole ligands, 77 Plant roots amino acids, 962 carboxylic acids, 962 Plastocyanin copper binding site, 557 copper(II) complexes, 772 copper(II) site in, 770 Platinum, dichlorobis(benzonitrile)-IR spectrum, 264 Platinum, cis-dichlorodianunine-antitumor activity, 34, 979 Platinum, ethylenebis(triphenylphosphine)-reactions with 5,6-dimethyl-2,l,3-benzothiadiazole, 194 Platinum blue formation, 265 Platinum complexes acetylacetone reactions, 380 amides, 491 amidines... 

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