Chiral CE method has been developed for quantitative determination of d-amino acid
modulators of NMDA glutamate receptor; d-serine and d-aspartate along with l-glutamate
and l-aspartate in biological samples. These ligands are suggested to be involved
in regulation of NMDA receptor related brain functions, such as neurogenesis, neuronal
plasticity, and memory formation. For sensitive determination of the amino acids LIF
detection was chosen, and a fluorogenic reagent, 7-fluoro-4-nitro-2,1,3-benzoxadiazole
was used for derivatization. An amino-modified beta-CD, 6-monodeoxy-6-mono(3-hydroxy)propylamino-beta-CD
(HPA-beta-CD) was applied as chiral selector. Determinations were accomplished in
a polyacrylamide coated capillary and reverse polarity was used for the analysis of
the negatively charged analytes. The method was optimized and validated; 6 mM HPA-beta-CD
in 50 mM HEPES buffer, pH 7 was appropriate to achieve baseline separation of the
analytes. The limit of quantification with acceptable accuracy is 0.05 muM for both
d-amino acids. The method was used for the determination of d-aspartate and d-serine
content in various brain regions of adult mice.
