Oxovanadium(IV) complexes of salicyl-L-aspartic acid and salicylglycyl-L-aspartic acid.
The dipeptide and tripeptide analogues salicyl-L-aspartic acid (Sal-L-Asp) and salicylglycyl-L-aspartic acid (SalGly-L-Asp) were synthesized and their protonation and complex formation with V(IV)O2+ were studied in aqueous solution through the use of pH-potentiometry and spectroscopic (UV-Vis, CD and EPR) techniques. The phenolate terminus proved to be a good anchoring site to promote (i) the metal ion-induced deprotonation and subsequent coordination of the peptide amide group(s) in the pH range 4-5 for the dipeptide analogue, (ii) and in the pH range 5-6 in a very cooperative way for the tripeptide analogue. The results suggest that the presence of good anchoring donors on both sides of the amide groups is responsible for the cooperative deprotonation of the two amide-NH groups.
Jakusch
Tamás
T
Bioinorganic Chemistry Research Group of the Hungarian Academy of Sciences, Department of Inorganic and Analytical Chemistry, University of Szeged, POBox 440, H-6701 Szeged, Hungary.
Marcão
Susana
S
Rodrigues
Lígia
L
Correia
Isabel
I
Pessoa
João Costa
JC
Kiss
Tamás
T
D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008024:Ligands; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D014639:Vanadium / Q000737:chemistry*
D008024:Ligands; D009942:Organometallic Compounds; D014639:Vanadium; D001224:Aspartic Acid