Amino acids binding to Zn 2+-cyclen molecular receptor in aqueous solution.
Potentiometric titrations and (1) H NMR spectroscopic studies of amino acids binding to the [ZnL](2+) -complex where L=cyclen in aqueous solution provide information concerning complexing species identity, their stability, and coordination mode declaration. The amino acids form stable ternary [ZnL(HL(n))](2+) and [ZnL(L(n))](+) complexes. The observations indicate bidentate coordination mode of the deprotonated amino acids, involving both the amine and the carboxylate functions to the [ZnL](2+) complex in pH region of about 7.5-9.5. The determined stability constants indicate that [ZnL](2+) complex is a very efficient receptor for simple amino acids such as glycine and alanine.
Vargová
Z
Z
Department of Inorganic Chemistry, Institute of Chemistry, University of P.J.Šafárik, Moyzesova 11, 04154 Košice, Slovak Republic. zuzana.vargova@upjs.sk
Balentová
E
E
Walko
M
M
Arabuli
L
L
Hermann
P
P
Lukeš
I
I
D000596:Amino Acids / Q000378:metabolism*; D000080027:Cyclams; D006571:Heterocyclic Compounds / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D011522:Protons; D012996:Solutions; D017186:Titrimetry; D015032:Zinc / Q000378:metabolism*
D000596:Amino Acids; D000080027:Cyclams; D006571:Heterocyclic Compounds; D011522:Protons; D012996:Solutions; C038072:cyclen; D015032:Zinc