DL-Glutamic acid

The a-carbon of glutamic acid is chiral. A convenient and effective means to determine the chemical purity of MSG is measurement of its specific rotation. The specific optical rotation of a solution of 10 g MSG in 100 mL of 2 A/HQ is +25.16. Besides L-glutamic acid [56-86-0] D-glutamic acid [6893-26-1] and the racemic mixture, DL-glutamic acid [617-65-2] are known. Unique taste modifying characteristics are possessed only by the L-form. 

Both threo- (14) and eo f >"4-fluoro-DL-glutamic acid (/5) are noncompetitive inhibitors of glutamine synthase, an enzyme that catalyzes the synthesis of glutamine from L-glutamic acid and ammonia. This mhibibon may explain the... 

Balss et al. [26] reported enantiomeric resolution of glutamic acid, dansyl-DL-glutamic acid, and baclofen with chiral temperature gradient focusing in... 

Figure 9.7 Optimizationof chiral TGF separation of dansyl-DL-glutamic acid, (a) Ti = 13 to T2 = 40°C, (b) Ti = 11 to T2 = 30°C, (c) T = 15 to T2 = 30°C, (d) Tj = 2.5 to T2 = 15°C, (e) intensity vs. distance plots for chiral TGF separations of dansyl-DL-glutamic acid (dotted curve, resolution 2.4, is from (a), complete line curve, resolution 3.8, is from the optimized separation (d), and (f) chiral NCE electro-pherogram of the same [26].

Fig. 5 Enantiomeric HPLC analyses of the occluded additives in plate-like crystals of glycine grown in the presence of DL-glutamic acid (left to right) sample taken from the + b pole, sample from a whole crystal and sample taken from the - b pole...

B. Dawson. Acta Cryst. 6,81-7 (1953). Grystal structure DL-glutamic acid hydrochloride. 

Figure 1. Typical HPLC chromatograms of the OPA-NAC (II) derivitized amino acids detected from the spark discharge reactions. Chromatograms labeled with roman numerals I.) Amino acid standard, II.) CO2/N2 not sparked, III.) CO2/N2 + CaCOs, sparked, hydrolyzed- ascorbate. IV.) CO2/N2, sparked, hydrolyzed - ascorbate V.) CO2/N2, sparked + CaCOs, hydrolyzed + ascorbate. Amino acids I.) DL aspartic acid 2.) DL glutamic acid 3.) DL serine 4.) glycine 5.) P-alanine 6.) DL alanine 7.) a-amino isobutyric acid 8.) DL norleucine (internal standard). The D and L enantiomers of glutamic acid and serine are not separated under these chromatographic conditions.

M sec per site. Poly(acrylic acid) and poly(DL-glutamic acid) possessed no activity under similar conditions. The optimal pH observed corresponds to the pH region where partial dissociation of the carboxyl group occurs with the concurrent conformational transition to random coil. The cooperative interaction of dissociated and undissociated carboxyl group in a highly shrunken polymer molecule was proposed to explain these results. 

L-3- (3-Ethoxy-3-oxopropylthio)alanine, HL L-Aspartic acid 4-methyl ester, HL DL-Glutamic acid 5-ethyl ester, HL... 

T-Labeled water added to acetic anhydride, allowed to reach equilibrium of labeled acetic acid and acetic anhydride, N-acetylglutamic acid added, and allowed to react 10 min. at lOO DL-glutamic acid-2-3H. Y 55%. Also deuterio analog s. M. C. Hodireiter and K. A. Schellenberg, J. Labelled Compds. 5, 270 (1969). 

Synonyms Glutamic acid, diethyl ester DL-Glutamic acid, diethyl ester... 

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