Interactions between copper (II) ions and l-threonine, l-allo-threonine and l-serine in aqueous solution

Grenouillet, Pierre; Martin, René-Paul; Rossi, A; Ptak, Marius

doi:10.1016/0005-2795(73)90292-4

Cited by 32 publications

(18 citation statements)

References 24 publications

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“…The pK a value of the b-alcoholato-group incorporated in the Cu(II) complex (log b 1110 ) log b 111-1 ) is 10.3 which is in good agreement with that reported in literature [30].…”

Section: Complex Formation Equilibria Involving Amino Acidssupporting

confidence: 89%

Complex Formation Reactions of (2,2′-dipyridylamine)copper(II) with Various Biologically Relevant Ligands. The Kinetics of Hydrolysis of Amino Acid Esters

Shoukry

2005

Transition Met Chem

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Binary and ternary copper(II) complexes involving 2,2¢-dipyridylamine (DPA) and various biologically relevant ligands containing different functional groups are investigated. The ligands used are dicarboxylic acids, amino acids, peptides and DNA unit constituents. The ternary complexes of amino acids, dicarboxylic acids or peptides are formed by simultaneous reactions. The results showed the formation of 1:1 complexes with amino acids and dicarboxylic acids. The effect of chelate ring size of the dicarboxylic acid complexes on their stability constants was examined. Peptides form both 1:1 complexes and the corresponding deprotonated amide species. The ternary complexes of copper(II) with DPA and DNA are formed in a stepwise process, whereby binding of copper(II) to DPA is followed by ligation of the DNA components. DNA constituents form both 1:1 and 1:2 complexes with Cu(DPA) 2+ . The concentration distribution of the complexes in solution was evaluated. [Cu(DPA)(CBDCA)], [Cu(DPA)(malonate)] and [Cu(DPA)(oxalate)] were isolated and characterized by elemental analysis, i.r. and magnetic measurements. Spectroscopic studies of [Cu(DPA)(malonate)] revealed that the complex exhibits square planner coordination with copper(II). The hydrolysis of glycine methyl ester (MeGly) is catalyzed by the Cu(D-PA) 2+ complex. The reaction has been studied by a pH-state technique over the pH range 5.8À6.8 at 25°C and I=0.1 mol dm )1 . The kinetic data fits assuming that the hydrolysis proceeds in two steps. The first step, involving coordination of the amino acid ester by the amino and carboxylic group, is followed by the rate-determining attack by the OH ) ion. The second step involves equilibrium formation of the hydroxo-complex, Cu(DPA)(MeGly)(OH), followed by intramolecular attack.

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“…The pK a value of the b-alcoholato-group incorporated in the Cu(II) complex (log b 1110 ) log b 111-1 ) is 10.3 which is in good agreement with that reported in literature [30].…”

Section: Complex Formation Equilibria Involving Amino Acidssupporting

confidence: 89%

Complex Formation Reactions of (2,2′-dipyridylamine)copper(II) with Various Biologically Relevant Ligands. The Kinetics of Hydrolysis of Amino Acid Esters

Shoukry

2005

Transition Met Chem

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“…Therefore one can conclude that the apparent CuH À1 L complex is in fact an intermediate, metastable CuL(OH) species, which yields a Cu(OH) 2 precipitate with time. This interpretation is also consistent with a low acidity, and therefore low availability, of similarly positioned hydroxyl groups in serine and threonine, which deprotonate in their binary Cu(II) complexes only above pH 10 [28][29][30]. The parameters of EPR spectra for this complex, stabilised in a glycol mixed solvent, are consistent with a chelate ring, containing a nitrogen donor and a hydroxide ion (indistinguishable from a deprotonated alcohol) [18][19][20][21].…”

Section: Cu(ii) Complexation By Hepessupporting

confidence: 75%

Cu(II) complexation by “non-coordinating” N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES buffer)☆

Sokołowska

Bal

2005

Journal of Inorganic Biochemistry

116

107

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“…The pKa value of the β-alcoholato-group incorporated in the Cu(II) complex (Log β 1110 -Log β 111-1) is 10.55. This is in good agreement with that reported in literature for the Cuthreonine complex [12,13,35] The pKa value of the coordinated alcohol group in the ethanolamine complex (8.14) is considerably smaller than of the threonine complex. This could be explained according to the reaction scheme where the alcohol group in ethanolamine is coordinated to copper center, where the OH group in threonine remains attached prior to deprotonation.…”

Section: Amino Acid Complexessupporting

confidence: 92%

Complex formation equilibria of imipenem with some transition metal ions. Ternary complex formation reactions involving Cu(II) with imipenem and various bio-relevant ligands

Shoukry

2013

Eur. J. Chem.

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KEYWORDSImipenem is one of the β-lactam antibiotics (β-lactamase inhibitors), which are reported to be the most important class of drugs that are capable of inhibiting the bacterial enzyme to protect the β-lactam antibiotic from destruction. In view of the biological importance of imipenem as drug, the ligation behavior of imipenem is studied in order to get an idea about its potentiality towards some transition metals in in-vitro systems. The binary complex formation equilibria with the metal ions Cu(II), Ni(II), Co(II), Mn(II), and Zn(II) were investigated potentiometrically. The effects of dioxane as a solvent, on the protonation constant of imipenem and the formation constants of Cu(II)-imipenem complexes were discussed. The ternary copper(II) complexes involving imipenem and various biologically relevant ligands containing different functional groups, as amino acids, amides, dicarboxylic acids and DNA constituents were investigated. The stability constants of the complexes are determined. The mechanisms of complex formation are speculatively discussed based on the calculated stability constant values. The ternary complexes are formed by simultaneous reactions. The concentration distributions of various species formed in solution were also evaluated as a function of pH.

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Interactions between copper (II) ions and l-threonine, l-allo-threonine and l-serine in aqueous solution

Cited by 32 publications

References 24 publications

Complex Formation Reactions of (2,2′-dipyridylamine)copper(II) with Various Biologically Relevant Ligands. The Kinetics of Hydrolysis of Amino Acid Esters

Complex Formation Reactions of (2,2′-dipyridylamine)copper(II) with Various Biologically Relevant Ligands. The Kinetics of Hydrolysis of Amino Acid Esters

Cu(II) complexation by “non-coordinating” N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES buffer)☆

Complex formation equilibria of imipenem with some transition metal ions. Ternary complex formation reactions involving Cu(II) with imipenem and various bio-relevant ligands

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