Glutamate salt forms

The sodium salt form of glutamic acid is monosodium glutamate (MSG). The neurotoxic levels of MSG have been studied extensively in animal and human models. The available data indicate that, under normal conditions, mammals have the metabolic capacity to handle large oral doses of MSG. Glutamate salts have also been tested in exercise. 

Salt forms of glutamate (ARG-glutamate or MSG) have been used in exercise trials. 

Both studies appear to suggest that supplemental salt forms of glutamate may play a positive role in nitrogen and energy metabolism. 

If the racemic mixture consists of ionizable species, the addition of acid or base to the solution has been found to stabilize the solution (Asai and Ikegami, 1982). This has been found to be true for ionizable amino acids, e.g. the L and D forms of glutamic acid, the L and D forms of DOPA (3,4-dihydroxy-P-phenylalanine), etc. (Asai, 1985). Here both the free and the salt forms of the acid are racemic mixtures. But the salt forms are much more soluble. The reaction that takes place, for example, in the presence of NaOH is as follows ... 

Techaarpomkul et al. compared gene silencing efficiency in HeLa cells with different chitosan salt forms, including chitosan aspartate, chitosan glutamate. 

The following treatment with Cl form of a strong anion exchange material (column 2) is performed at /(//near isoelectrie point of neutral amino acids. Glutamic acid and aspartic acid are anions while alkaline amino acids are eations. As has been shown above (see discussion following equation (10)), sorption of zwitterions and co-ions of amino acids by salt forms of ion exchangers does not take place due to low thermodynamic benefit of such processes. As the result the column retains Glu and Asp anions allowing almost free pass to neutral (zwitterions) and alkaline (cations) amino acids. 

An estimation of the amount of amino acid production and the production methods are shown ia Table 11. About 340,000 t/yr of L-glutamic acid, principally as its monosodium salt, are manufactured ia the world, about 85% ia the Asian area. The demand for DL-methionine and L-lysiae as feed supplements varies considerably depending on such factors as the soybean harvest ia the United States and the anchovy catch ia Pern. Because of the actions of D-amiao acid oxidase and i.-amino acid transamiaase ia the animal body (156), the D-form of methionine is as equally nutritive as the L-form, so that DL-methionine which is iaexpensively produced by chemical synthesis is primarily used as a feed supplement. In the United States the methionine hydroxy analogue is partially used ia place of methionine. The consumption of L-lysiae has iacreased ia recent years. The world consumption tripled from 35,000 t ia 1982 to 100,000 t ia 1987 (214). Current world consumption of L-tryptophan and i.-threonine are several tens to hundreds of tons. The demand for L-phenylalanine as the raw material for the synthesis of aspartame has been increasing markedly. 

Use of the relatively small cyclopropane ring drastically reduces the potential for deleterious steric bulk effects and adds only a relatively small lipophilic increment to the partition coefficient of the drug. One of the clever elements of the rolicyprine synthesis itself is the reaction of d,l tranylcypromine (67) with L-5-pyrrolidone-2-carboxylic acid (derived from glutamic acid) to form a highly crystalline diastereomeric salt, thereby effecting resolution. Addition of dicyclohexylcarbodiimide activates the carboxyl group to nucleophilic attack by the primary amine thus forming the amide rolicyprine (68). 

Chitosan is insoluble at alkaline and neutral pH values but it can form salts with inorganic and organic acids such as hydrochloric acid, lactic add, acetic add and glutamic acid. In contrast to alginates and carrageenans in solution, the amino fundions of chitosan are protonated and the resultant soluble polysaccharide is... 

Two asymmetric carbon atoms, the or carbon in the glutamic acid portion of the molecule and the C6 carbon in the tetrahydropteridine ring, allow four possible isomers. Since synthetic procedures would undoubtedly start with L-glutamic acid, the isomeric possibilities are reduced to the dL and 1L diastereomers. Of these, the biologically more active form is the 1L separation of the diastereomers is effected by solubility differences of the calcium salts.2... 

The functionalization of folded motifs is based on an understanding of secondary and tertiary structures (Fig. 2) and must take into account the relative positions of the residues, their rotamer populations and possible interactions with residues that do not form part of the site. For example, glutamic acid in position i has a strong propensity for salt-bridge formation, and thus reduced reactivity, if there is a Lys residue available i-4 in the sequence, but the probabihty is much less if the base is i-3 [60]. Fortunately, there is a wealth of structural information on the structural properties of the common amino acids from studies of natural proteins that provides considerable support for the design of new proteins. The naturally occurring amino acids have so far been used to construct reactive sites for catalysis [11-13], metal- and heme-binding sites [14,15,19,21,22] and for the site-selective functionalization of folded proteins [24,25]. 

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