• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.136-140
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• 1993

New synthetic method for diethyl N-[4-{[(2,4-diamino-6-yl)methyl]-amino}benzoyl]-L-glutamate(10) which is an intermediate of methotrexate is described. p-Nitrobenzoyl-L-glutamate was obtained via a two-step sequence which involves condensation of p-nitrobenzoyl chloride with diethyl-L-glutamate and Fischer esterification reaction with ethanol. Reductive methylation of diethyl-p-nitrobenzoyl-L-glutamate were carried out by reaction with formic acid and paraformaldehyde in the presence of $PtO_2$ catalyst and yielded diethyl N-(4-methylaminobenzoyl)-L-glutamate(7). It was followed by allylation and iodoazidozation to give the diethyl-p-[N-(2-azido-3-iodopropyl)-N-methyl]aminobenzoyl-L-glutamate(9). The cyclization reaction of compound(9) with 2,4,5,6-tetraaminopyrimidine was carried out by intermolecular nucleophilic substitution to give the desired methotrexate diethylester.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.704-710
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• 2008

Glutamate availability in the argF-argR-proB${\Delta}$ strain of Corynebacterium glutamicum was increased by addition of glutamate to the cell or inactivation of the phosphoenolpyruvate carboxykinase activity and simultaneous overexpression of the pyruvate carboxylase activity to assess its effect on L-ornithine production. When glutamate was increased in an L-ornithine-producing strain, the production of L-ornithine was not changed. This unexpected result indicated that the intracellular concentration and supply of glutamate is not a rate-limiting step for the L-ornithine production in an L-ornithine-producing strain of C. glutamicum. In contrast, overexpression of the L-ornithine biosynthesis genes (argCJBD) resulted in approximately 30% increase of L-ornithine production, from 12.73 to 16.49 mg/g (dry cell weight). These results implied that downstream reactions converting glutamate to L-ornithine, but not the availability of glutamate, is the rate-limiting step for elevating L-ornithine production in the argF-argR-proB${\Delta}$ strain of C. glutamicum.

• Microbiology and Biotechnology Letters
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• v.2 no.3
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• pp.141-147
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• 1974

The cultural conditions for L-glutamate production were investigated using Brevibacterium flavum nov. sp. D2209B, the most productive strain among 5 strains reported in preceeding paper. A temperature of 3$0^{\circ}C$ and a medium volume of 30 ml per 500-flask were selected as standard culture conditions. And the following results were obtained. 1. When the concentration of acetate in the medium was below 30 g per litre, the maximum amount of L-glutamate was accumulated. 2. KH$_2$PO$_4$, MgSO$_4$, FeCI$_3$ and MnCI$_2$ were required for the L-glutamate poduction, but the concentration of those inorganic salts little effected. 3. Signifcant amount of L-glutamate was accutnulated in the limited biotin concentration less than 0.3 ug per litre. 4. The addition of malic acid or succinic acid enhanced the accumulation. 5. The L-glutamate accumulation was related to the incubation time of seed; the amount of L-glutamate accumulated was maximum by inoculating 16-20 hour incubated seed. 6. In the medium containing sufficient amount of biotin for growth, L-glutamate accumulation was stimulated by the addition of penicillin at appropreate time during incubation.

• Journal of Biomedical Engineering Research
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• v.9 no.2
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• pp.215-224
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• 1988

Block copoly(L-lactide-${\gamma}$-benzyl-L-glutamate)was synthesized from L-lactide by cationic ring opening polymerization and ${\gamma}$-benzyl-L-glutamate N-carboxy anhydride by introducing amino group terminated poly(L-lactide). L-lactide was polymerized in the presence of stannous octate at $110^{\circ}C$ and ${\gamma}$-benzyl- L-glutamate was polymerized in the presence of NaH at room temperature. The synthesized monomers and copolymers were identified by IR and NMR. The Itermal properties of the copolymers were characterized by differential scanning calorimetry and thermogravimetry. The thermal stability and melting temperature(Tm) of the block copolymers were measured and discussed. The activation energies of thermal decomposition for the block copoly(L-lactide-${\gamma}$ benzyl-L-glutamate) were evaluated from the thermogravimetric data by Freeman and Carroll method.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.699-705
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• 1997

Although it is known that neuronal cell death during development occurs by apoptosis, the mechanisms underlying excitatory amino acid-induced neuronal cell death remain poorly understood. In this study we have examined the mechanism by which L-glutamate, an excitatory amino acid neurotransmitter, induces cell death in PC12 cell lines. To characterize cell death, we employed sandwich enzyme-linked immunosorbent assay(ELISA) method for cellular DNA fragmentation, DNA agarose gel electrophoresis and chromatin staining by acridine orange and ethidium bromide after treating the PC12 cells with L-glutamate. L-Glutamate caused dose-dependent cell death with a maximum at 24 hrs after the treatment. These cellular fragmentation was blocked by pretreatment of MK-801, a noncompetitive N-methyl-D-aspartic acid(NMDA) receptor antagonist, and nerve growth factor(NGF). Analysis of DNA integrity from L-glutamate-treated cells revealed cleavage of DNA into regular sized fragments, a biochemical hallmark of apoptosis. The PC12 cells that were induced to die by L-glutamate treatment exhibited classical chromatin condensation under the light microscopy after acridine orange and ethidium bromide staining. These results suggest that apoptosis is one of the key features that are involved in L-glutamate-induced excitotoxic cell death in PC12 cells, and these cell death are mediated by NMDA receptor and depend on NGF.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1075-1081
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• 1997

The objective of this research was to develop a glutamate enzyme sensor for rapid determinations of glutamate in samples. Glutamate oxidase was immobilized onto activated nylon, chitosan and other membranes. The enzymic and nonactin membranes were attached to an ammonia electrode to detect ammonia generated by the reaction between glutamate oxidase and glutamate. The enzyme immobilized on activated nylon membrane was stable for 2 months, and was able to perform about 250 glutamate determinations without losing activities. The enzyme immobilized on chitosan membrane had higher enzyme activity, but was not as much stable as that immobilized on nylon. The glutamate biosensor was able to accurately determine $0.1{\sim}5\;mM$ of glutamate in samples.

• Archives of Pharmacal Research
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• v.18 no.1
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• pp.8-11
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• 1995

Biodegradability of poly $Poly({\gamma}-benzyl L-Glutamate)/poly(ethylene oxide)/Poly({\gamma}-benzyl L-Glutamate)$ block copolymer (GEG) having different content of poly(ethylene oxide) (PEO) were examined using magnetite as a tracer in mice. GEG microspheres containing magnetite were injected into mice through tail vein. Biodegradability and tissue distribution of microspheres were examined by analyzing the amount of magnetite in the microspheres recollected from mice organs after specific time interval. The results showed that GEG microsphere of high content of PEO was degraded more rapidly than those of low content of PEO in the mice organs.

• Journal of Chest Surgery
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• v.22 no.3
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• pp.436-447
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• 1989

The effect of Glutamate to myocardial toxicity induced by doxorubicin was studied with 20 male rats. 20 rats divided into 4 subgroups, 1st group was taken for normal control group without any treatment, 2nd group was injected with only doxorubicin, 3rd group was injected with L-glutamate and doxorubicin, and 4thd group was injected with only L-glutamate [all injections were done intraperitoneally]. Observations were made to each group on their gross findings, body weight, and electrocardiography, complete blood count and serum level of creatine phosphokinase. The results were as follows; l. In 1st group, we found no changes. 2. In 2nd group, there were many changes which were loss of body weight, dehydration, loss of body hair, diarrhea and death, in addition, elevation of CPK-MB isoenzyme and changes in EKG due to myocardial damage, leukopenia, thrombocytopenia were also found. 3. In 3rd group, there were more toxic effects containing 2 death cases, compared to 2nd group. 4. In 4th group, we found no specific changes except weight gain. These results suggest that L-glutamate which is intermediate of Krebs cycle may worsen the doxorubicin-induced myocardial toxicity.

• Animal cells and systems
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• v.1 no.3
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• pp.467-473
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• 1997

Taurine (2-aminoethanesulfonic acid), one of bioactive amino acid in the mammalian brain, is known to exert inhibitory effects on neurons via GABA receptor. In the present study, we examined effects of taurine on glutamateinduced neurotoxicity on hippocampal neuron cell culture using cell counting method and lactate dehydrogenase (LDH) assay. After 10 d of culture, cells were stimulated with appropriate drugs. Only 43% of cultured neuronal cells survived at one day after stimulation with 500 uM L-glutamate for 10 min. Survival rate was enhanced by 82% in the presence of 10 mM taurine. LDH activity from the culture supernatant incubated with a combination of L-glutamate and taurine was less than half of that with L-glutamate alone. In the next series of experiments, interleukin-6 (IL-6) mRNA expression in cultured astrocytes was investigated using reverse tanscription-PCR (RT-PCR). IL-6 mRNA was detected in the astrocytes stimulated with L-glutamate in a dose-dependent manner, while not detected in the unstimulated control astrocytes. The expression of IL-6 mRNA caused by 10 mM glutamate was inhibited by taurine, but not by GABA. These findings demonstrated a neuroprotective action of taurine against glutamate-induced toxicity.

• Korean Journal of Veterinary Service
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• v.41 no.4
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• pp.239-244
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• 2018

Mycobacterium tuberculosis (M. tuberculosis) complex is the causative agent of tuberculosis (TB) in humans and bovine TB in mammalian hosts and grows very slowly. Selenium is a central molecule in nitrogen metabolism and an essential ingredient for all living cells and glutamic acid. The effects of selenium on the growth of M. tuberculosis, a representative slow-growing Mycobacterium species, were investigated and measured using the BacT Alert 3D System (MB/BacT System). Sodium selenate, at a final concentration of $10{\mu}g/mL$, reduced the average time-to detection (TTD) to 197.2 hours (95% confidence interval (CI), 179.6~214.8) from 225.1 hours (95% CI, 218~232.0) in the control culture media (P<0.05). The TTD did not increase with $\text\tiny{L}$-glutamate concentrations up to $10{\mu}g/mL$, but a significant reduction in the TTD was observed in the presence of $20{\mu}g/mL$ ${\text\tiny{L}}$-glutamate in culture media (P<0.05). In conclusion, selenate and ${\text\tiny{L}}$-glutamate enhance the growth of M. tuberculosis.