HPLC Methods for Determination of d-Aspartate and N-methyl-d-Aspartate
d-Amino acids are stereoisomers or optical isomers of naturally occurring l-amino acids and thus possess the same chemical structure, but may differ in their biological/physiological properties. Until a half century ago, d-amino acids had been considered to be unnatural substances found only in microorganisms. However, improvements in analytical instruments and methods have revealed that d-amino acids are present in invertebrates and vertebrates, including humans, and that they possess important physiological functions. d-Aspartate (d-Asp) and its methylated form N-methyl-d-aspartate (NMDA) possess neuroendocrine properties in many species. Several methods have been developed for determination of d- and l-enantiomers of amino acids by high performance liquid chromatography (HPLC). We report here improved HPLC methods for the specific determination of d-Asp and NMDA in biological tissues.
Key wordsd-aspartate N-methyl-d-aspartate N-methyl-l-aspartate HPLC
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