4-Methyleneglutamic acid and 4-methyleneglutamine: isolation from extracts of peanut seedlings and determination by high-performance liquid chromatography.
The non-protein amino acids, 4-methyleneglutamic acid and 4-methyleneglutamine, are isolated from aqueous extracts of peanut seedlings in good yield and high purity using a simple HCl-gradient elution from a column of cation-exchange resin followed, in some instances, by a gradient elution with acetic acid from a column of an anion-exchange resin. All of the 4-substituted glutamic acids commonly found in legume species are resolved by a combination of these two system. For analytical purposes, resolution of the acidic amino acids as their phenylthiocarbamoyl derivatives is achieved by HPLC but not by conventional ion-exchange amino acid analysis. Although 4-methyleneglutamine undergoes cyclic deamidation in acidic medium at a slower rate than glutamine, this reaction occurs to a significant extent at 22 degrees C but not a 4 degrees C during the cation-exchange chromatographic fractionation.
Winter
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Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-0606.
Powell
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Dekker
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D010367:Arachis / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D005971:Glutamates / Q000032:analysis / Q000302:isolation & purification*
D005971:Glutamates; C030977:4-methyleneglutamic acid