• Journal of Plant Biology
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• v.18 no.2
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• pp.53-58
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• 1975

Three varieties of soybean, Chungtaik, Hillkong, and Endaedu which have been recommended to cultivate widely in Cheju Island, were chosen to study their amino acid metabolism in order to determine their nutritional values. 1) The total nitrogen contents of these soybeans were decreased in the order of Chungtaik, Hillkong, and Endaedu, indicating that the last variety is undesirable for a recommened formae even under a favorable condition of cultivation. The Hillkong variety may well be recommended for cultivation for a source of lipid rather than protein. 2) From analysis fo free amino acids, it was found that Hillkong contained normal amounto f vaious amino acids but Endae여 contained them in very abnormal fashion suggesting that an improved scheme of fertilization is necessary. Data from Chungtaik indicated it was excessively supplied with N fertilizer. 3) The amino acid contents of proteins extracted from these soybeans showed that Chungtaik contained less number of amino acids in its protein than the other two. The distribution of these amino acids appeared normal in Hillkong but quite irregular in Endaedu. In conclusion, both Chungtaik and Hillkong could be recommended for cultivation, the former as a protein source, the latter a lipid source of foods. Endaedu, however, may be liable to further research before it will be recommend for cultivation.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1298-1309
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• 1999

The nutritional value of protein varies between feedstuffs. It is possible to feed animals using crystalline amino acids as a sole nitrogen source, but in practice only some limiting amino acids are added to the diet. In order to use feedstuffs efficiently, it is important to determine exact amino acid requirements. Reported values differ widely because the requirements are affected by various factors. In this report, therefore, the factors affecting amino acid requirements are reviewed as follows: 1) availability of dietary amino acids, conversion factors of nitrogen to protein, interaction of amino acids, and strain, sex and age of animals; 2) amino acid requirements for maximum performance and maintenance, usefulness of non-essential amino acids; 3) plasma amino acid concentration as a parameter to determine amino acid requirements; and 4) nitrogen excretion to reduce environmental pollution. These factors should be considered, it is to improve the dietary efficiency, which is to reduce excess nitrogen excretion for environmental pollution.

• Bulletin of the Korean Chemical Society
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• v.24 no.4
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• pp.467-472
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• 2003

Optically pure α-mono- and α, α-disubstituted β-amino acids were conveniently prepared in four steps and in 27-40% overall yields from the correspondingly substituted racemic β-hydroxy acids that can be readily obtained from diethyl malonate. In the synthesis, (S)-phenylethylamine has been used as a resolving agent and as a source of the amino group in the β-amino acids.

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3387-3390
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• 2012

In this research work the potentialities of microemulsion bulk liquid membrane for the selective transport of L-tryptophan (L-Trp) and L-tyrosine (L-Tyr) are investigated at 298.15 K. Reversed micelle formed by sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in dichloroethane, was used as mobile carrier to transport amino acids between a source and a receiving aqueous phase. The effects of pH, surfactant concentration and initial amino acid concentration on the extraction efficiency and transfer rate of the amino acids were studied. It is verified that for a mixture of two amino acids, L-Trp can be extracted selectively by using this type of the bulk liquid membrane with optimized condition.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.124-127
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• 2008

The behavior of Penicillium camembertii and Geotrichum candidum growing in submerged pure cultures on simple (glutamate) or complex (peptones) substrates as nitrogen and carbon sources and lactate as a second carbon source was examined. Similar to the behavior previously recorded on a simple substrate (glutamate), a clear differentiation between the carbon source and the energy source was also shown on peptones and lactate during P. camembertii growth, since throughout growth, lactate was only dissimilated, viz., used for energy supply by oxidation into $CO_2$, whereas peptides and amino acids from peptones were used for carbon (and nitrogen) assimilation. Because of its deaminating activity, G candidum preferred peptides and amino acids to lactate as energy sources, in addition to being assimilated as carbon and nitrogen sources. From this, on peptones and lactate, G candidum grew faster than P. camembertii (0.19 and 0.08 g/l/h, respectively) by assimilating the most readily utilizable peptides and amino acids; however, owing to its lower proteolytic activity, the maximum biomass was lower than that of P. camembertii (3.7 and 5.5 g/l, respectively), for which continuous proteolysis and assimilation of peptides were shown.

• Korean Journal of Environmental Agriculture
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• v.35 no.2
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• pp.104-110
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• 2016

BACKGROUND: There is lack of comprehensive compositional data of the amino acid profile of spinach with regard to different cultivars. A more detailed knowledge in this aspect will be of benefit in the future selection of spinach genotypes with improved nutritional quality.METHODS AND RESULTS: The effects of cultivar type (Jeoncheonhu, Sagyejul, Namdongcho and Mustang) and harvest time (79^th, 116^th and 145^th days after sowing or DAS) on the concentrations of free amino acids in field-grown spinach (Spinacia oleracea) were examined. About 35 different free amino acids were detected and quantified by the amino acid analyzer. Glutamic acid and proline were identified as the major amino acids, while α -aminoadipic acid and α-aminobutyric acid were present in much lower concentrations. Spinach constituted 1468.4 mg/100 g total free amino acids (TAA), of which essential amino acids, neutral/acidic amino acids and sulphur containing amino acids constituted around 15, 45 and 2% of the TAA, respectively. The most limiting amino acids among the leafy vegetables - cysteine was recorded only in Mustang harvested at 116 DAS. Free amino acid contents did not differ significantly among the spinach cultivars and also at different harvest times.CONCLUSION: The data show that, either of the spinach cultivars, preferably Mustang harvested on or after 116 DAS can serve as a significant source of nutritionally relevant amino acids to meet the demand of the growing populations.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.5
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• pp.371-376
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• 2014

Amino-acid neurotransmitter system dysfunction plays a major role in the pathophysiology of depression. Several studies have demonstrated the potential of amino acids as a source of neuro-specific biomarkers could be used in future diagnosis of depression. Only partial amino acids such as glycine and asparagine were determined from certain parts of rats' brain included hippocampi and cerebral cortex in previous studies. However, according to systematic biology, amino acids in different area of brain are interacted and interrelated. Hence, the determination of 34 amino acids through entire rats' brain was conducted in this study in order to demonstrate more possibilities for biomarkers of depression by discovering other potential amino acids in more areas of rats' brain. As a result, 4 amino acids (L-aspartic acid, L-glutamine, taurine and ${\gamma}$-amino-n-butyric acid) among 34 were typically identified as potentially primary biomarkers of depression by data statistics. Meanwhile, an antidepressant called Fluoxetine was employed to verify other potential amino acids which were not identified by data statistics. Eventually, we found L-${\alpha}$-amino-adipic acid could also become a new potentially secondary biomarker of depression after drug validation. In conclusion, we suggested that L-aspartic acid, L-glutamine, taurine, ${\gamma}$-amino-n-butyric acid and L-${\alpha}$-amino-adipic acid might become potential biomarkers for future diagnosis of depression and development of antidepressant.

• Fisheries and Aquatic Sciences
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• v.9 no.2
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• pp.49-56
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• 2006

We evaluated changes in the nutritional composition of Mideodeok Styela clava harvested during the months of January, March, and May 2005. Glutamic acid, aspartic acid, arginine, leucine, and lysine were the most dominant amino acids present. Ratios of essential amino acids to nonessential amino acids were comparable to those of many fish species, with values ranging from 0.55 to 0.61 and 0.66 to 0.67 for muscle of Mideodeok from Geoje and Tongyeong, respectively. Mideodeok seems to be a suitable source of important fatty acids as it contains high levels of polyunsaturated fatty acids. Eicosapentanoic acid EPA; 20:5n-3 and docosahexanoic acid DHA; 22:6n-3 were the most dominant fatty acids, ranging from 20.0 to 22.3% and 16.5 to 17.9% in muscle, and 20.3 to 23.2% and 15.2 to 18.8% in tunic, respectively. The total mineral fraction of Mideodeok was 22.2-27.3% of dry matter. Sodium, calcium, magnesium, and potassium were the most dominant minerals in both muscle and tunic.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.4
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• pp.343-352
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• 2012

Sulphur deficiency has become widespread over the past several decades in most of the agricultural area. Oilseed rape (Brassica napus L.) is a very sensitive to S limitation which is becoming reduction of quality and productivity of forage. Few studies have assessed the sulphur mobilization in the source-sink relationship, very little is known about the regulatory mechanism in interaction between sulphur and nitrogen during the short-term sulphur deficiency. In this study, therefore, amount of sulphur and nitrogen incorporated into amino acids and proteins as affected by different S-supplied level (Control: 1 mM ${SO_4}^{2-}$, S-deficiency: 0.1 mM ${SO_4}^{2-}$, and S-deprivation: 0 mM ${SO_4}^{2-}$) were examined. The amount of sulphur in sulphate (S-sulphate) was significantly decreased by 25.8% in S-deprivation condition, compare to control, but not nitrogen in nitrate (N-nitrate). The markedly increase of sulphur and nitrogen incorporated amino acids (S-amino acids and N-amino acids) was observed in both S-deficiency and S-deprivation treatments. The amount of nitrogen incorporated proteins (N-protein) was strongly decreased as sulphur availability while the amount of sulphur incorporated into proteins (S-protein) was not affected. A highly significant ($p{\leq}0.001$) relationship between S-sulphate and S-amino acid was observed whereas the increase of N-amino acids is closely associated with decrease of N-proteins. These data indicate that increase of sulphur and nitrogen incorporated into amino acids was from different nitrogen and sulphur metabolites, respectively

• Journal of the Korean Society of Food Culture
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• v.23 no.3
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• pp.397-402
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• 2008

This study was conducted to evaluate the quality characteristics of domestic as well as imported fermented skate. Three types of fermented skate products were analyzed for proximate composition, pH, VBN, ammonia-N, free amino acids, and fatty acids. The results indicated that the domestic fermented skate contained large amounts of TMAO. Also, the domestic and imported fermented skates each contained approximately 7.1 log CFU/g and $5.8{\sim}6.5$ log CFU/g of aerobic bacteria, respectively, and 585.9 mg and $384.1{\sim}398.5$ mg of total free amino acids, respectively; all samples contained high levels of taurine, anserine, lysine, alanine, glycine, proline, and ${\beta}-alanine$. For fatty acid composition, the domestic fermented skate contained 11 different types of saturated fatty acid and 16 types of unsaturated fatty acid, whereas the imported skate contained 8 types of saturated fatty acid and $10{\sim}15$ types of unsaturated fatty acid. Overall, the results suggest that domestic fermented skate is a better source of amino acids and essential fatty acids and contains more aerobic bacteria than imported fermented skate.