Enantioselective Determination of Extraterrestrial Amino Acids Using a Two-Dimensional Chiral High-Performance Liquid Chromatographic System

Abstract

A two-dimensional chiral high-performance liquid chromatographic (2D-HPLC) system has been established for the analysis of extraterrestrial amino acids. As the targets, 8 chiral amino acids (alanine (Ala), valine (Val), 2-aminobutyric acid (2AB), norvaline (nVal), N-methylalanine (N-MeAla), isovaline (iVal), 3AB and 3-aminoisobutyric acid (3AIB)) and 5 non-chiral amino acids (glycine (Gly), β-Ala, γ-aminobutyric acid (GABA), sarcosine (Sar) and 2AIB) were selected. These amino acids were tagged with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), and non-enantioselectively separated by a capillary monolithic ODS column in the first dimension. The target fractions were automatically introduced into the second dimension and further separated by Pirkle-type enantioselective columns. By using this system, the 2D-HPLC separation of 21 components in small particles of a carbonaceous chondrite (Yamato 791191, Antarctic CM2 meteorite) could be successfully performed, and all of the target amino acids were observed. The D/L ratios of the chiral molecules are almost 50/50 for all of the tested proteinogenic and non-proteinogenic amino acids.

Enantioselective Determination of Phenylalanine, Tyrosine and 3,4-Dihydroxyphenylalanine in the Urine of D-Amino Acid Oxidase Deficient Mice Using Two-Dimensional High-Performance Liquid Chromatography

“…Regarding the branched aliphatic amino acids, an anion-exchange type column, Chiralpak QN-AX provided sufficient separations of Val, allo-isoleucine, isoleucine and Leu and their Rs were 2.72-4.29 [33]. The KSAACSP-001S column was also reported to separate a variety of NBD-amino acid enantiomers [34]. In the present investigation, the 7 columns gave complete enantiomer separations of the 3 target aromatic amino acids (Phe, Tyr and DOPA).…”

“…Among these columns, the following 7 columns gave baseline enantiomer separations of all 3 target NBD-amino acids: Pirkle-type columns having amino acid derivatives as chiral selectors (Sumichiral OA-2500S, OA-3100S, OA-3200S, OA-4100SR, OA-4700SR and KSAACSP-001S columns, 1. Until now, the enantiomer separations of NBD-amino acids have been reported using various enantioselective columns including the anion-exchange type, Pirkle-type or teicoplanin bonded chiral stationary phases [32][33][34][35]. By using a Pirkle-type column, OA-2500S, 9 hydrophilic amino acids were separated and their resolution values (Rs) were 1.12-3.52 [32].…”

Multi-Dimensional High-Performance Liquid Chromatographic Determination of Chiral Amino Acids and Related Compounds in Real World Samples

“…The developmental changes of these D-amino acids are specific to the respective amino acids, and the relationships between their amounts and fermentation/aging processes are expected to be clarified. The 2D-HPLC system is also applicable to the determination of extraterrestrial amino acids [51]. As the target, non-proteinogenic chiral amino acids (2-aminobutyric acid, 3-aminobutyric acid, 3-aminoisobutyric acid, norvaline and isovaline) are also selected, because the contamination from the terrestrial environment is always the problem for proteinogenic amino acids.…”

Further characterization of carbonaceous materials in Hayabusa‐returned samples to understand their origin

“…Once carbonaceous materials are contaminated by terrestrial materials, they are difficult to distinguish from each other. In future work, we will establish a state-of-the-art analytical scheme including combustion and/or dissolution methods for the analysis of higher molecular structures, including high-precision, compound-specific measurement of amino acids with the corresponding stereoisomers (Naraoka et al 2012;Hamase et al 2014;Takano et al 2015;Sugahara et al 2018), as well as in situ molecular analysis by desorption electrospray ionization coupled with high-resolution mass spectrometry (Naraoka and Hashiguchi 2018). witness plate (silicon and fluoro rubber), by FE-SEM-EDS, STXM-XANES, and TEM.…”