β Scribed by Peter Marfey
No coin nor oath required. For personal study only.
l-fluoro-2,4-dinitrophenyl-5-L-alanine amide has been synthesized in high yield (76%) from 1,5-difluoro-2,4-dinitrobenzene and L-AIa-NH2. This compound contains a reactive fluorine atom which can be used for the reaction with a mixture of L-and D-amino acids. The resulting diastereomers which are obtained in quantitative yield can be separated and estimated by HPLC. With the five amino acids studied (Ala, Asp, Glu, Met and Phe), L-diastereomers were eluted from the reverse-phase column before D-diastereomers. This behavior can be explained by a stronger i ntramolecular hydrogen bonding in the latter diastereomer. When artificial mixtures of the five amino acids containing known proportions of L-and D-isomers were derivatized with the reagent and the reaction products analyzed by HPLC, it was possible to determine the relative content of each isomer in a nanomole range.
π SIMILAR VOLUMES
A highly sensitive fluorescent labeling reagent, 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride (DMS-Cl), for determination of amino acids by HPLC has been developed. DMS-Cl reacted with amino acids in the basic medium to produce the corresponding fluorescent sulfonamides (excit