Complexes of copper(II) ion with histamine-containing dipeptides: Formation constants and structure

T. Gajda, Bernard Henry, Jean Jacques Delpuech

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

The acid-base properties and copper(II) complexes of glycyl- and sarcosyl-histamine (histamine = imidazole-4-ethanamine) have been studied by pH-metric, spectrophotometric and EPR methods, and compared to those of analogous histidine-containing dipeptides on the one hand and of carcinine (β-alanylhistamine) on the other. At pH 4-9 the predominant species is the 3N-co-ordinated complex CuLH-1 (charges omitted) together with minor quantities of CuLH and CuL. The pK for metal ion-promoted deprotonation of the peptidic nitrogen is exceptionally low (pK = 3.20 and 3.66, respectively). The bis complexes CuL2 and CuL2H-1 also form in the presence of ligand in excess. Around pH 9-11 the monomeric 3N-co-ordinated hydroxo-complex CuLH-1(OH) and a polynuclear 4N-co-ordinated species are in equilibrium. The latter is assumed to be tetrameric Cu4L4H-8, with the imidazole rings as bridging bidentate units through co-ordination to both N3 and N1-pyrrolic nitrogens. At high pH ( ≈ 11) a further deprotonation results in the production of the monomeric 3N-co-ordinated hydroxo-complex CuLH-2(OH) with a pendant deprotonated N1-pyrrolic nitrogen.

Original languageEnglish
Pages (from-to)1301-1306
Number of pages6
JournalJournal of the Chemical Society, Dalton Transactions
Issue number8
DOIs
Publication statusPublished - 1993

Fingerprint

Dipeptides
Histamine
Copper
Deprotonation
Nitrogen
Ions
Histidine
Metal ions
Paramagnetic resonance
Ligands
Acids
imidazole

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Complexes of copper(II) ion with histamine-containing dipeptides : Formation constants and structure. / Gajda, T.; Henry, Bernard; Delpuech, Jean Jacques.

In: Journal of the Chemical Society, Dalton Transactions, No. 8, 1993, p. 1301-1306.

Research output: Contribution to journalArticle

@article{6a67f2df49184538b0944fcf5322b33e,
title = "Complexes of copper(II) ion with histamine-containing dipeptides: Formation constants and structure",
abstract = "The acid-base properties and copper(II) complexes of glycyl- and sarcosyl-histamine (histamine = imidazole-4-ethanamine) have been studied by pH-metric, spectrophotometric and EPR methods, and compared to those of analogous histidine-containing dipeptides on the one hand and of carcinine (β-alanylhistamine) on the other. At pH 4-9 the predominant species is the 3N-co-ordinated complex CuLH-1 (charges omitted) together with minor quantities of CuLH and CuL. The pK for metal ion-promoted deprotonation of the peptidic nitrogen is exceptionally low (pK = 3.20 and 3.66, respectively). The bis complexes CuL2 and CuL2H-1 also form in the presence of ligand in excess. Around pH 9-11 the monomeric 3N-co-ordinated hydroxo-complex CuLH-1(OH) and a polynuclear 4N-co-ordinated species are in equilibrium. The latter is assumed to be tetrameric Cu4L4H-8, with the imidazole rings as bridging bidentate units through co-ordination to both N3 and N1-pyrrolic nitrogens. At high pH ( ≈ 11) a further deprotonation results in the production of the monomeric 3N-co-ordinated hydroxo-complex CuLH-2(OH) with a pendant deprotonated N1-pyrrolic nitrogen.",
author = "T. Gajda and Bernard Henry and Delpuech, {Jean Jacques}",
year = "1993",
doi = "10.1039/DT9930001301",
language = "English",
pages = "1301--1306",
journal = "Dalton Transactions",
issn = "1472-7773",
publisher = "Royal Society of Chemistry",
number = "8",

}

TY - JOUR

T1 - Complexes of copper(II) ion with histamine-containing dipeptides

T2 - Formation constants and structure

AU - Gajda, T.

AU - Henry, Bernard

AU - Delpuech, Jean Jacques

PY - 1993

Y1 - 1993

N2 - The acid-base properties and copper(II) complexes of glycyl- and sarcosyl-histamine (histamine = imidazole-4-ethanamine) have been studied by pH-metric, spectrophotometric and EPR methods, and compared to those of analogous histidine-containing dipeptides on the one hand and of carcinine (β-alanylhistamine) on the other. At pH 4-9 the predominant species is the 3N-co-ordinated complex CuLH-1 (charges omitted) together with minor quantities of CuLH and CuL. The pK for metal ion-promoted deprotonation of the peptidic nitrogen is exceptionally low (pK = 3.20 and 3.66, respectively). The bis complexes CuL2 and CuL2H-1 also form in the presence of ligand in excess. Around pH 9-11 the monomeric 3N-co-ordinated hydroxo-complex CuLH-1(OH) and a polynuclear 4N-co-ordinated species are in equilibrium. The latter is assumed to be tetrameric Cu4L4H-8, with the imidazole rings as bridging bidentate units through co-ordination to both N3 and N1-pyrrolic nitrogens. At high pH ( ≈ 11) a further deprotonation results in the production of the monomeric 3N-co-ordinated hydroxo-complex CuLH-2(OH) with a pendant deprotonated N1-pyrrolic nitrogen.

AB - The acid-base properties and copper(II) complexes of glycyl- and sarcosyl-histamine (histamine = imidazole-4-ethanamine) have been studied by pH-metric, spectrophotometric and EPR methods, and compared to those of analogous histidine-containing dipeptides on the one hand and of carcinine (β-alanylhistamine) on the other. At pH 4-9 the predominant species is the 3N-co-ordinated complex CuLH-1 (charges omitted) together with minor quantities of CuLH and CuL. The pK for metal ion-promoted deprotonation of the peptidic nitrogen is exceptionally low (pK = 3.20 and 3.66, respectively). The bis complexes CuL2 and CuL2H-1 also form in the presence of ligand in excess. Around pH 9-11 the monomeric 3N-co-ordinated hydroxo-complex CuLH-1(OH) and a polynuclear 4N-co-ordinated species are in equilibrium. The latter is assumed to be tetrameric Cu4L4H-8, with the imidazole rings as bridging bidentate units through co-ordination to both N3 and N1-pyrrolic nitrogens. At high pH ( ≈ 11) a further deprotonation results in the production of the monomeric 3N-co-ordinated hydroxo-complex CuLH-2(OH) with a pendant deprotonated N1-pyrrolic nitrogen.

UR - http://www.scopus.com/inward/record.url?scp=37049082823&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=37049082823&partnerID=8YFLogxK

U2 - 10.1039/DT9930001301

DO - 10.1039/DT9930001301

M3 - Article

AN - SCOPUS:37049082823

SP - 1301

EP - 1306

JO - Dalton Transactions

JF - Dalton Transactions

SN - 1472-7773

IS - 8

ER -