Complexes of aminophosphonates. Part 3. Copper(II) complexes of several monophosphono and diphosphono dipeptides

A novel approach for obtaining α,β-diaminophosphonates bearing structurally diverse side chains and their interactions with transition metal ions studied by ITC

“…Aminophosphonates were shown to be very effective and specic metal ion binding molecules forming biologically relevant metal complexes. 34,35 Thus, we have checked whether compounds synthesized in this work posses these abilities for selected metal ions. We decided to evaluate the interaction of Cu 2+ , Ni 2+ and Zn 2+ ions with three model compounds, which side chains contain diethylamine (2e 0 ), piperidinyl (2f 0 ) and morpholinyl (2g 0 ) moiety.…”

Complexing properties of diastereoisomers of 1-(L-methionylamino)ethylphosphonic acid

“…There are several possible ways in which Met-Ala-(P) could co-ordinate Ni 2ϩ , Co 2ϩ and Zn 2ϩ in the 1 : 2 complexes. According to Kiss et al 4 and the results in our previous papers 6, 7 we assume co-ordination to the metal via the amine, carbonyl and phosphonate groups and to Cu 2ϩ only through amine and carbonyl groups. Co-ordination is expected to occur in [CuA 2 H Ϫ1 ] 3Ϫ through two amine groups, one carbonyl group and one peptide amide group.…”

“…1 Their synthesis and properties have been reviewed by Kafarski et al 2 The acid-base and complexing properties of phosphonodipeptides were investigated for glycylaminomethylphosphonic [Gly-Gly-(P)] and 2-glycylaminoethylphosphonic acids with Cu 2ϩ , Ni 2ϩ and Co 2ϩ , 3 and for diastereoisomeric mixtures of phosphonodipeptides containing 1-aminoethylphosphonic acid Ala-(P), or 1-amino-3-methylbutylphosphonic acid, Leu-(P), with Cu 2ϩ . 4 We synthesized two series of phosphonodipeptides containing glycine (Gly), -alanine (Ala), -phenylalanine (Phe) and leucine (Leu) and aminomethylphosphonic or 1-aminoethylphosphonic acids 5 and determined their protonation and stability constants for complex formation with Co 2ϩ , Ni 2ϩ , Cu 2ϩ and Zn 2ϩ . 6,7 The protonation constants exhibited the same dependence on the amino acid side chain as for common dipeptides but the differences were not as large.…”