Novel enantioselective receptors for N-protected glutamate and aspartate.
A series of chiral bisthiourea macrocycles 1-4 have been prepared and their binding properties with various dicarboxylate salts have been examined by using NMR titration and isothermal calorimetry experiments. Macrocycle 1, in particular, favours the 1:1 binding of N-protected L-glutamate and aspartate, but favours 1:2 binding of the corresponding D-amino acids in polar solvents (dimethyl sulfoxide and acetonitrile). The macrocycles, however, do not bind carboxylates at all in the less competitive solvent chloroform. The binding properties of these macrocyles are sensitive to small structural changes as demonstrated by the altered binding properties of macrocycles 2-4 compared with 1.
Ragusa
Andrea
A
School of Chemistry, University of Southampton, Southampton, SO17 1BJ, UK.
Rossi
Sara
S
Hayes
Joseph M
JM
Stein
Matthias
M
Kilburn
Jeremy D
JD
D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008958:Models, Molecular; D011487:Protein Conformation; D017459:Receptors, Amino Acid / Q000737:chemistry*; D017470:Receptors, Glutamate / Q000737:chemistry*; D013237:Stereoisomerism
D017459:Receptors, Amino Acid; D017470:Receptors, Glutamate; C031959:aspartic acid receptor