Structural scaffold of 18-crown-6 tetracarboxylic Acid for optical resolution of chiral amino acid: x-ray crystal analyses of complexes of D- and L-isomers of serine and glutamic acid.
Chem Pharm Bull (Tokyo)
; 54(4): 452-7, 2006 Apr.
Article
em En
| MEDLINE
| ID: mdl-16595944
ABSTRACT
(+)-18-crown-6 tetracarboxylic acid (18C6H4) has been used as a chiral selector for D/L-amino acids in HPLC, where L-isomer is usually eluted prior to D-isomer, except for the case of serine. To clarify why serine exhibits the reverse order for the elusion, the chiral interactions of D- and L-serines with (+)-18C6H4 were investigated by the X-ray single crystal analyses, together with the case of D- and L-glutamic acids, which exhibit the usual elution order in HPLC. The backbone structures (amino, Calpha-H and carboxyl groups) of these four amino acids showed the nearly same interaction with (+)-18C6H4 despite their different chirality. In contrast, the hydroxyl group of L-serine side chain formed a hydrogen bond with the carboxyl group of (+)-18C6H4, whereas such a interaction was not formed for the side chain of D-serine and D- and L-glutamic acids. Thus, it was shown that the exception of D/L-serine from the first elution rule of L-isomer in HPLC is due to the presence and absence of a hydrogen bond formation of its side chain OH group.
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Bases de dados:
MEDLINE
Assunto principal:
Serina
/
Ácido Glutâmico
/
Éteres de Coroa
/
Aminoácidos
Idioma:
En
Revista:
Chem Pharm Bull (Tokyo)
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Japão