Glutamic acid, purification

Fig. 7. 45 Glutamic acid purification process including all variables and available data...

In addition some leucine and glutamic acid are obtained their purification is described in the handbook cited. 

Recently, both enantiomers each of cis- and tran5 -5-butyl-2-heptylpyrrolidine (10c) have been synthesized from glutamic acid by an excellent method with high diastereomeric and enantiomeric purity (417). The thiolactam (293) prepared from L-glutamic acid was reacted with benzyl 2-(trifluoromethylsul-fonyloxy)oetanoate to yield the rather unstable salt (294), which without purification was treated with triphenylphosphine and A-methylpiperidine to afford... 

A soln of 130 (0.17 g, 0.34 mmol) and TFA (2.0 mL, 26 mmol) in CH2CI2 (4mL) was stirred at rt for 3h. The volatiles were removed in vacuo, and the residue was dissolved in H20 (15 mL). The resulting soln was frozen and lyophilized to give 131 as a mixture of diastereomers, and as a cream colored hygroscopic powder yield 151 mg (97%) mp 89-92°C. Attempted further purification via RP-chromatography on Sephadex LH-20, with H20 as the mobile phase, resulted in extensive hydrolysis to free glutamic acid and benzoin, as determined by isolation and coelution with authentic samples on TLC. 

The introduction of a glutamic acid (E bold), after each RADI 6 repeat was made to allow cleavage by endoproteinase Glu-C, which cleaves C-terminal to glutamate. A cellulose binding domain (CBD) (Table 1) was selected as the affinity tag, as CBDs bind strongly and specifically to cellulose which is a relatively cheap and abundant purification matrix. The main problem encountered was the low level of peptide recovered. Theoretically, 1 g of fusion protein should give 267mg of peptide, but only 10.1 mg of peptide was recovered after RP-HPLC. 

Wheat Protein Isolate occurs as a powder. It is produced by acidic deamidation of gluten that converts glutamine and asparagine to their nonamidated derivatives, glutamic acid and aspartic acid, followed by several purification measures. Alternatively, gluten can be solubilized in an acidic or alkaline medium, and the dissolved protein is then separated and purified by filtration or centrifugation. 

Preparative Methods both enantiomers of dihydro-5-(hydroxymethyl)-2(3H) furanone and their trityl derivatives are commercially available but expensive. The simplest and by far most popular method for preparing (5)-dihydro-5-(hydroxymethyl)-2(3H)-furanone (2) consists of enantiospecific deamination of L-glutamic acid and subsequent selective reduction of the resulting carboxylic acid (13) (eq 1). Purification of the intermediate acid (13) by crystallization and not by distillation is recommended in order to secure an excellent optical yield (>98% ee). Likewise, (f )-dihydro-5-(hydroxymethyl)-2(3//)-furanone (1) (>98% ee) can be obtained from o-glutamic acid. As the latter is considerably more expensive than its natural antipode, an appealing option is to convert the (5)-lactone into its enantiomer (eq 2)P Also available and equally useful is an inversion route to (f )-dihydro-5-(trityloxymethyl)-2(3H)-furanone (5) by way of the Mitsunobu reaction (eq 3). ... 

From glutamic acid, MSG of more than 99 % purity is obtained by neutralization and purification. It consists of odourless white crystals. In aqueous solution, MSG tastes sweet-salty with a detection threshold of 0.01-0.03 % or 100-300 ppm [2, 10]. 

The polypeptides were glycosylated via reaction of the pendant glutamic acids (and C-termini) with either P-D-galactosylamine or A -(e-aminocaproyl)-p-D-galactosylamine. The detailed procedure for modification of the polypeptides and purification of the glycopolypeptides has been previously reported (26). 

Electrodialysis uses stacks of pairs of anion- and cation-exchange membranes in deionizing water and in recovery of formic, acetic, lactic, gluconic, citric, succinic, and glutamic acids from their sodium and potassium salts in fermentation broths.114 This may have an advantage over processes that involve purification through calcium salts. Electrodialytic bipolar membranes have been used to recover concentrated mineral acids from dilute solution.115 They can be used to convert sodium chloride to hydrogen chloride and sodium hydroxide in a process that avoids the use of chlorine.116 Soy protein has been precipitated by... 

PZ-2 Gly-Ala-Gly-Gln-Gly-Glu-Ala purification contains both glutamine and glutamic acid similar electrophoretic mobility to DNA makes it poor drag-tag... 

A synthetic immunogen, poly-(L-tyrosine-L-glutamic acid)-poly-DL-alanine-poly-L-lysine has been used to raise immunoglobulin M in rabbits and cattle. The immobilized antigen has then been used in the purification of the immunoglobulin. 

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