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A new water soluble Zn‐salophen derivative as a receptor for α‐aminoacids: Unexpected chiral discrimination
Author(s) -
Dalla Cort Antonella,
De Bernardin Paolo,
Schiaffino Luca
Publication year - 2009
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20614
Subject(s) - chemistry , moiety , steric effects , carboxylate , enantiomer , hydrogen bond , zinc , titration , stereochemistry , phenylalanine , ammonium , medicinal chemistry , inorganic chemistry , molecule , organic chemistry , amino acid , biochemistry
A new water soluble zinc‐salophen complex with appended D ‐glucose moieties was synthesized and characterized. Its binding properties toward six aminoacids were investigated by UV‐vis spectrophotometric titrations. Association constants showed to be unfavorably affected by increasing steric hindrance of the side chain. Quite surprisingly, different association constants were measured for the L and D enantiomers. These data suggest that aminoacids are bound via two interactions, zinc‐carboxylate coordination and two hydrogen bonds between the ammonium group of the aminoacid and two oxygen atoms of one D ‐glucose moiety. Such conclusion is supported by the result of semiempirical (PM3) calculations. Notably, the K L / K D value of 9.6 observed for the association of phenylalanine rivals with the highest values found for the chiral recognition of aminoacids in water. Chirality, 2009. © 2008 Wiley‐Liss, Inc.