Glutamic acid isolation

More recently, Jenkins and Ciereszko (321) noted that glutamic acid isolated from the cellular proteins of the N.R.R.L. 571 strain of B. subtilis, is the L form. This strain used for the production of DGP, was cultivated on Sauton s medium containing DL-aspartic acid instead of glutamic acid. 

In the 1950s, a group of coryneform bacteria which accumulate a large amount of L-glutamic acid in the culture medium were isolated (21). The use of mutant derivatives of these bacteria offered a new fermentation process for the production of many other kinds of amino acids (22). The amino acids which are produced by this method are mostiy of the T.-form, and the desired amino acid is singly accumulated. Therefore, it is very easy to isolate it from the culture broth. Rapid development of fermentative production and en2ymatic production have contributed to the lower costs of many protein amino acids and to their availabiUty in many fields as economical raw materials. 

Crotonoside. Crotonoside, also caHed isoguanosine, (45) has been isolated from Croton tiglium (4). Ip administration of [2- C]crotonoside to rats results in incorporation into nucleic acids (qv). It inhibits the inducible binding sites, inhibits glutamic acid dehydrogenase, and accumulates cAMP. 

In subsequent experiments (66), this locked substrate was used to obtain evidence for the hypothesis (67) that enzyme-bound y-glutamyl phosphate 14 is an intermediate in the enzyme-catalyzed reaction. All attempts to isolate this acyl phosphate 14 have failed (66), presumably because of the marked tendency of this intermediate to cyclize to pyrrolidonecarboxyUc acid, 15, and to hydrolyze to glutamic acid. 

Nodularia spwnigena has also been shown to produce a peptide with hepato-toxic activity. The more recent reports come from Australia (76), the German Democratic Republic (77), Denmark (78), Sweden (79), and Finland (80,81). Recently structure information on Nodularia toxin has been presented by Rinehart (97) for waterbloom material collected in Lake Forsythe, New Zealand, in 1984 by Eriksson et al. (81) from waterbloom material collected in the Baltic Sea in 1986, and Runnegar et al. (82) for a field isolate from the Peel Inlet, Perth, Australia. Structure work by Rinehart, Eriksson, and Runnegar all indicate that the peptide is smaller than the heptapeptide toxins. Rinehart s work (97) indicates the toxin is a pentapeptide with a similar structure to the heptapeptides and containing fi-methylaspartic acid, glutamic acid, arginine, dehydrobutyrine, and ADDA (MW 824). 

Hundreds of different natural amino acids have been found and isolated. In some cases, they are quite complex and have a variety of functions. The preparation and isolation of amino acids occurs either from biological material or via chemical synthesis. Several amino acids, such as glutamic acid and methionine, are now prepared on a scale of 100,000 tons per year. 

A group at the Bach Institute in Moscow was able to isolate a flavine pigment (an isoalloxacine derivative) from the polymer obtained by heating a mixture of three amino acids (glutamic acid glycine lysine = 8 3 1) this exhibited photochemical acivity (e.g., redox reactions such as electron transfer to acceptors with lower Eo values) under both aerobic and anaerobic conditions (Kolesnikov and Kritsky, 1999). 

Crystallization remains the primary means of controlling the polymorphic or solva-tomorphic state of a compound, and various groups have examined the influences of processing parameters on the identity and quality of the isolated form. Seeding was used to reduce the size of the metastable zone of eflucimibe, and thereby control the identity of the desired polymorphic identity of the product through a reduction in concomitant crystallization [16], Process improvements have been developed that were found to improve the filterability and enhance the bulk density of ranitidine Form-1 [17], while the variation of process parameters used in an oscillatory baffled crystallizer enabled better selection to be made between the metastable a- and /i-forms of (z.)-glutamic acid [18]. 

Because synthetic products are isolated as the barium or, more frequently, the calcium salt of leucovorin, common acid-base titrations are not reported. If this type of titration or one in which the cation is exchanged were feasible, the results would require careful interpretation because impurities containing the glutamic acid moiety would respond similarly to leucovorin when the carboxyl groups are being analyzed. 

As early as 1905 Abderhalden (Al) isolated from the hydrolyzate of the nondiffusible fraction of human urine four amino acids, i.e., leucine, alanine, glycine, and glutamic acid, and detected two others phenylalanine and aspartic acid. Some amino acids derived from this fraction have been quantitatively determined by Albanese et al. (A3) who found in the amount of the nondiffusible fraction corresponding to one liter of urine as much as 32.8 mg tryptophan, 18.0 mg phenylalanine, 16.2 mg methionine, 15.2 mg cystine, 13.1 mg arginine, 6.7 mg histidine, and 3.9 mg tyrosine. 

In the course of studies on aminoaciduria in Fanconi s syndrome, Dent (Dl) isolated from the urine of the subject investigated a simple peptide identified as serylglycylglycine. Carsten (Cl) found in normal urine several peptides containing in every case one of the dicarboxylic amino acids. He discovered also two tetrapeptides, one of them consisting of equimolar amounts of aspartic acid and glycine, and the second composed of glycine, alanine, and glutamic acid in the ratio 2 1 1. The first of these tetrapeptides was also found in the urine of a patient with rheumatoid arthritis. 

Plaquet et al. (PI) found in the urine of rachitic children peptides consisting of proline, hydroxyproline, and glycine, which they believed to be the products of collagen degradation. Two similar peptides containing considerable amounts of proline and hydroxyproline were isolated from the urine of a patient with rheumatoid arthritis by Mechanic et al. (Ml). One of these peptides consisted of three proline, two hydroxyproline, and nine glutamic acid residues, the second one consisted of four proline, four hydroxyproline, and one glutamic acid residues. The N-terminal amino acid in the first peptide was demonstrated to be hydroxyproline. 

By means of a procedure described above, Hanson and Fittkau (HI) isolated seventeen different peptides from normal urine. One of them, not belonging to the main peptide fraction, consisted of glutamic acid, and phenylalanine with alanine as the third not definitely established component. The remaining peptides contained five to ten different amino acid residues and some unidentified ninhydrin-positive constituents. Four amino acids, i.e., glutamic acid, aspartic acid, glycine, and alanine, were found in the majority of the peptides analyzed. Twelve peptides contained lysine and eight valine. Less frequently encountered were serine, threonine, tyrosine, leucine, phenylalanine, proline, hydroxyproline, and a-aminobutyric acid (found only in two cases). The amino acid composi-... 

B36. Broquist, H. P., and Luhby, A. L., Detection and isolation of formimino-glutamic acid from urine in folic acid deficiency in humans. Proc. Soc. Exptl. Biol. Med. 100, 349-354 (1959). 

The 2-amino-dipyrido[ 1,2-a 3, 2 -d]imidazoles (33 Glu-P-1) and (34 Glu-P-2) were first isolated from glutamic acid pyrolysates. As observed with Trp-P-1 and Trp-P-2,... 

The residue was diluted in water (5 mL) and, if necessary, the pH adjusted to 7.0 with 1 M KOH before adsorption of the product on a column of Dowex 1X8 resin (200-400 mesh, AcO form, 2 cm x 10 cm). The column was washed with water (50 mL) and then eluted with AcOH aqueous solutions (50 mL of 0.1 m, 50 mL of 0.2 m and 50 mL of 0.5 M AcOH). The ninhydrin-positive fractions were combined and dried under reduced pressure to afford (25,4/ )-4-methyl glutamic acid 2 isolated as a white solid (192 mg, 41 %) and with a high purity (>98 %). 

There is only a small selection of nonprotein amino acids that contain carbonyl groups in the form of ketone, aldehyde, and carboxylic acid moieties, as part of the side chain. The examples given in Table 6 are components of nonribosomal peptides isolated from bacteria or fungi and siderophores from bacteria. The biosynthesis of these amino acids is not clear however, some of the amino acids with carboxylic acid side chains may be traced back to the L-a-amino acids aspartic acid and glutamic acid. 

Trypsin inhibitors in cucumber were first found in a study by Walker-Simmons et /. " after wounding of leaves and treatment with proteinase inhibitor-inducing factor (PIIF). The amino acid sequence of two inhibitors isolated from Cucurhita maxima (winter squash) were determined by Wilusz et at The peptides named ITD I and ITD 111 each comprised a 29-residue sequence with six cysteine residues. The only difference between the two peptides is in position 9, which is lysine in ITD I and glutamic acid in ITD III. The reactive site is located at the peptide bond between Arg5 and Ile6. Owing to their discovery and distribution in Cucurbitaceae the inhibitor family has been named squash inhibitors. Since the initial discoveries many other members of the squash family have been found. 

Biological. Incubation of C-ring labeled endothall (10 mg/mL) by Arthwbactersp., which was isolated from pond water and a hydrosol, in aerobic sediment-water suspensions revealed that after 30 d, 40% evolved as CO2. Glutamic acid was the major transformation product. Minor products were alanine, citric, and aspartic acids and unidentified products, some of which were tentativeiy identified as phosphate esters (Sikka and Saxena, 1973). In pond water treated with endothall (2 and 4 ppm), detectable levels were found after 7 d (Sikka and Rice, 1973). Biodegradation was rapid in an Ontario soil sample. After 1 wk, 70% of endothall added was converted to carbon dioxide (Simsiman et al, 1976). 

Merremosides B (13) and D (15) exhibited antiserotonergic activity in mice with Dgo values of 10 pg/cm and 2 pg/cm, (c/., promethazine, Dgo 2 pg/cm ) (24). Intraperitoneal administration to mice of tyrianthins VI (91), VIII (scammonin VI, 68), and IX (93) resulted in antidepressant activity. Also, the activities of tryanthi-nic acids I (94) and II (95), and the macrolactones scammonins I (63) and II (64), and tyrianthins VI (91), VIII (68), and IX (93) exhibited dose-dependent protective effects against pentylenetetrazole-induced seizures. Tyrianthin VI (91) and scammonin II (64) produced relaxant effects on spontaneous contractions in the isolated rat ileum. Finally, the administration of compounds 68 and 93-95 to mouse brain slices induced increments in the release of GABA and glutamic acid 48). 

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