Application of(S)-N-(4-nitrophenoxycarbonyl) phenylalanine methoxyethyl ester as a new chiral derivatizing agent for proteinogenic amino acid analysis by high-performance liquid chromatography

Abstract

Key WardsColumn liquid chromatography Indirect enantiomeric separation Chiral derivatization (S)-N-(4-Nitrophenoxycarbonyl)phenylalanine methoxyethyl ester Amino acids SummaryThe application of (S)-N-(4-nitrophenoxycarbonyl)phenylalanine methoxyethyl ester, (S)-NIFE, as a new chiral derivatizing agent for the resolution of compounds possessing an amino group is described. Its apphcabihly is demonstrated by the resolution of proteinogenic amino acid enantiomers. The diastereomeric derivatives produced were separated by reversedphase high-performance liquid chromatography. The effects of pH, excess reagent and reaction time on the derivatization kinetics, and the effects of pH and the organic modifier on the separation, were investigated.

Chirality determination of unusual amino acids using precolumn derivatization and liquid chromatography–electrospray ionization mass spectrometry

“…S-NIFE derivatives were also monitored at 254 nm. Improved enantioselectivity has been described for those CDAs that have four or five bonds between their chiral centers [34]. This ideal distance is present in GITC (four bonds), S-NIFE (four bonds), and OPA-IBLC (five bonds) whereas FDAA has six bonds (Fig.…”

“…Boc protected N-MeLeu and N-MeIle standards were obtained from BACHEM Bioscience Inc., King of Prussia, PA. N-MeLeu (23)(24) and N-MeIle (25)(26)(27)(28) were generated from their Boc protected standards by deprotection with TFA. ␤-MeOTyr (31)(32)(33)(34) were synthesized at the Department of Chemistry, Purdue University, West Lafayette, Indiana. A detailed chemical characterization of these compounds will be described in a separate paper.…”

“…Among the chiral derivatizing agents (CDAs) that have been used for indirect chromatography, Marfey's reagent N-␣-(2,4-dinitro-5-fluorophenyl)-l-alaninamide (FDAA) [21] has been most widely used for assigning the stereochemistry of amino acids in trace amounts [22][23][24][25][26][27][28][29][30][31]. Other CDAs include 2,3,4,6-tetra-O-acetyl-␤-d-glucopyranosyl isothiocyanate (GITC) [30][31][32][33], (S)-N-(4-nitrophenoxycarbonyl)phenylalanine methoxyethyl ester (S-NIFE) [34][35][36]43] and o-phthalaldehyde/isobutyryl-l-cysteine (OPA-IBLC) [22,37].…”

Liquid chromatographic enantioseparation of spin-labelled β-amino acids

“…Derivatization with (S)-NIFE took place quantitatively under mild conditions within a reasonable reaction time [45]. At room temperature, with the (S)-NIFE/amino acid ratio kept at 4 to 1, after 2 h of reaction the yields of derivatization for (+)-H-trans-POAC-OH and (−)-H-trans-POAC-OH (1) were 98.2 and 98.9%, respectively, and for (+)-H-cis-␤-TOAC-OH and (−)-H-cis-␤-TO-AC-OH (3) were 99.6 and 99.3%, respectively.…”

“…The derivatization of the investigated analytes with the applied CDAs was based on literature methods [43][44][45], which were somewhat modified. For derivatization with GITC and (S)-NIFE, analytes were dissolved in 0.4% TEA [in MeCN/water 1/1 (v/v)] and in 0.4% aqueous TEA (v/v), respectively, while for derivatization with FDAA analyte solutions were made in 1 M NaHCO 3 .…”