Glutamic acid ammonium salt

JECEA reviewed the safety studies of glutamate and endorsed its safety by allocating an Acceptable Daily Intake (ADI) for L-glutamic acid and its monosodium, potassium, ammonium, calcium, and magnesium salts as being "not specified." The scientific committee for food of EC concurred (40). 

Glutamic acid and its salts (especially the sodium salt) enhance the flavour of many convenience foods. Bejaars et al. (1996) described the determination of free glutamic acid in soups, meat products and Chinese food. The method involves hot water extraction of test portions followed by filtration and dilution. The extracts were treated with N,N-dimethyl-2-mercapto-ethyl-ammonium chloride and o-phtaldialdehyde to convert glutamic acid into a stable fluorescent, l-alkylthio-2-alkyhsoindole. Homocysteic acid was used as the internal standard. Separation was made on a Ci8 column, eluted with... 

A highly enantioselective synthesis of (2S)-a-(hydroxymethyl)glutamic acid, a potent metabotropic receptor ligand, has been accomplished via the catalytic Michael addition of /-butyl 2-naphthalen-l-yl-2-oxazoline-4-carboxylate to CH2=CHC02Et, using the phosphazene base (143) and the (.S )-binaphthyl quaternary ammonium salt (144) as the chiral phase-transfer reagent in CH2CI2 at — 60 °C (<97% < < ).174... 

Herbicidal properties of this compound as a commercially synthesized ammonium salt (glufosinate or HOE 39866) were first reported in 1977 ill41. This herbicide is presently marketed as BASTA by Hoechst AG. Some phosphonic and phosphinic acid analogs of glutamic acid have been known since 1959 to be inhibitors of glutamine synthetase (GS) (115). but not until 1972 was phosphinothricin found to be a potent inhibitor of GS activity (113)(Figure... 

C-Alkylation of the sodio derivative is accomplished by a technique similar to the alkylation of malonic ester. Primary halogen compounds, quaternary ammonium salts,and an alkene oxide have been used as alkylating agents. Alkylation by secondary halides has been less successful. Hydrolysis of the substituted esters to acetylated amino acids is described for leucine (64%) and phenylalanine (83%). Hydrolysis with deacylation has been used to prepare histidine (45%) and phenylalanine (67%). Glutamic acid (75%) is obtained from substituted acylaminomalonates prepared by the Michael condensation of methyl acrylate and the acylated amino esters. ... 

L-glutamic acid and its ammonium, calcium, monosodium, and potassium salts were evaluated by the Joint FAOAVHO Expert Committee on Food Additives (JECFA) in 1988 (6). Because human studies had failed to confirm involvement of monosodium glutamate in the Chinese restaurant sjmdrome or other reactions, the JECFA classified glutamic acid and its salts under the heading acceptable daily intake (ADI) not specified. The Scientific Committee for Food (SCF) of the European Commission reached a similar conclusion in 1991, and the conclusions of a subsequent review by the Federation of American Societies for Experimental Biology (FASEB) and the Federal Drug Administration (FDA) did not discount the existence of a sensitive subpopulation but otherwise concurred with the evaluations of JECFA and the SCF. 

Unlike fractions of pig-kidney protein, Neurospora crassa extracts can use L-glutamine, but not ammonium salts nor ammonium salts plus adeno-sine-5-triphosphoric acid. No synthesis of D-glucosamine is stimulated in Neurospora extracts by L-glutamic acid, L-aspartic acid, L-asparagine, L-alanine, glycine, L-valine, L-leucine, L-lysine, L-arginine, L-serine, L-cys-teine, L-citrulline, L-ornithine, butyramide, putrescine, or urea. Recently, a protein fraction has been discovered, in rat liver, that converts D-glucose... 

In practise, MSG (which corresponds to the completely dissociated form of the acid) is used almost exclusively to improve the flavour of foods. It is permitted world-wide, although in some countries and some types of foods maximum concentration limits apply. Other salts of glutamic acid that are occasionally used are potassium, calcium, and ammonium glutamates. These are not permitted world-wide. 

Magnesium hydrogen Magnesium hydrogen Dietary supplement glutamic acid and its monosodium, potassium, calcium, magnesium, and ammonium salts) MTDI70 (expressed as... 

Fig. 1.8 Asaccharolytic fermentation produces ammonia and short-chain fatty acids. This group of fermentations by oral bacteria utilizes proteins, which are converted to peptides and amino acids. The free amino acids are then deaminated to ammonia in a reaction that converts nicotinamide adenine dinucleotide (NAD) to NADH. For example, alanine is converted to pyruvate and ammonia. The pyruvate is reduced to lactate, and ammonium lactate is excreted into the environment. Unlike lactate from glucose, ammonium lactate is a neutral salt. The common end products in from plaque are ammonium acetate, ammonium propionate, and ammonium butyrate, ammonium salts of short chain fatty acids. For example, glycine is reduced to acetate and ammonia. Cysteine is reduced to propionate, hydrogen sulfide, and ammonia alanine to propionate, water, and ammonia and aspartate to propionate, carbon dioxide, and ammonia. Threonine is reduced to butyrate, water, and ammonia and glutamate is reduced to butyrate, carbon dioxide, and ammonia. Other amino acids are involved in more complicated metabolic reactions that give rise to these short-chain amino acids, sometimes with succinate, another common end product in plaque.

L-Glutamine, Gin, Glu-NH a proteogenic amino acid, the 5-amide of L-glutamic acid, M, 146.15, m.p. 185-186°C (d,), [a]gt-9.2° fc = 2 in water) or -t 46.5 °(c = 2in5M HCI). In boiling, neutral aqueous solutions or in weak acid. Gin rapidly cyclizes to the ammonium salt of pyrrolidone carboxylic acid (see Glutamic acid). 

The ammonia enters the portal vein and mixes with the metabolic nitrogen pool of the body. The fixation of this ammonia nitrogen into arginine, glutamic acid and utamine and aspartic acid represents a net contribution to nitrogen balance. The alternative fate of this ammonia is its conversion to urea prior to renal excretion. Thus the use of N-labelled ammonium salts or [ N]urea forms the basis of several common lines of clinical investigation. 

Where a nitrogenous compound is involved, the amphibolic pathways are centred around glutamate, aspartate and carbamoyl phosphate. These provide nitrogen which may be used either for the synthesis of nitrogenous compounds of many types, e.g. amino acids, proteins, nucleotides, nucleic acids, haem, or for conversion to urea or ammonium salts, in which form most of the nitrogen is excreted. 

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