• 한국연초학회지
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• 제32권2호
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• pp.70-76
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• 2010

A simple and sensitive automatic amino acid analyzer method for the determination of free amino acids in tobacco was described. Sample preparation consisted of a single step of extraction with 0.1 mol HCl at ambient temperature in 60 min by sonication, followed by filtration of an aliquot. Automated amino acid analyzer was used to construct a post-column ninhydrin reaction unit to monitor amino acids separated by liquid chromatography using a series of eluting buffers. By optimization of sample preparation, separation of 19 amino acids was achieved. Limits of quantitation was 0.01 mg/g, coefficients of variation ranged from 0.5 % to 8.9 % and recoveries range from 85 % to 106 %. The method was applied to the analysis of amino acids contents of tobacco leaves in different varieties.

• 한국식품조리과학회지
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• 제23권1호통권97호
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• pp.150-155
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• 2007

This work was conducted to obtain a rapid, accurate, and precise procedure for free amino acids analysis in Doenjang with HPLC-OPA (high performance liquid chromatography using-phthalaldehyde) and AAA (automatic amino acid analyzer) methods. Different sample extraction procedures among water, 0.1 M perchloric acid, and 0.1% meta-phosphoric acid were also compared. The optimal extraction solvent was 0.1% meta-phosphoric acid for both the HPLC-OPA and AAA methods. Good recoveries for glycine and methionine were observed using the 0.1% meta-phosphoric acid extraction with HPLC-OPA method. Method precisions (% relative standard deviation) for the free amino acids ranged for 1.62% to 8.27%, in which the HPLC-OPA method with water extraction showed the lowest value at 1.62%. Inhibition rates of the free amino acids in Doenjang were greatest with an addition of NaCI at a 1% concentration.

• 한국식품영양과학회지
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• 제20권1호
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• pp.89-93
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• 1991

For the investigation of major taste components in loquat(Eiobotrya japonica) flesh its conte-nts and compositions of free sugars organic aicds and free amino acids were analyzed Major free sugars of the fully ripened loquat were fructose glucose and sucrose and their contents were 3,71, 3.42 and 0.46%(w/w) respectively. The content of total sugar 13.7% was 2 times higher than that of the unripe fruit. The content of total organic acid was about 0.2% (w/w) and major organic acids were malic acid -89mg% formic acid -32mg% and oxalic acid -26%mg% Thirteen kinds of free amino acids from the fully ripened loquat were confirmed. Major free amino acids were aspartic acid valine glutamic acid serine alanine and histidine and their contents were in the range of 18-30mg%.

• 약학회지
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• 제8권2호
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• pp.48-53
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• 1964

At the different growing stages of Fagopyrum esculentum Moench planted at the green house and out doors, the contents of free amino acids in the whole plants,were determined quantitatively by spot-extract colorimetric method (J. Awapara method) using the chromatograms obtained by the ion-exchange resin and paper chromatographic method. And the contents of carbohydrate in the whole plant were determined by Bertrand method. The results were summarized as follows. 1. Almost same kinds of free amino acids were detected in the both plants. 2. Concentrations of most amino acids was increased progressively during growth; further growth was accompanied by decreased concentrations. 3. Rate of growth and increasing of total amino acid content of green house plant is greater than that of out dorrs plant. 4. At the same stages of gwoth, total free amino acid content of green house plant is higher than that of out doors plant but sugar content is lower. 5. There was rapidly increasing of sugar content and decreasing of total free amino acid content except asparagine during mature of seeds.

• 한국균학회지
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• 제11권2호
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• pp.85-89
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• 1983

The aims of this study were to investigate various components and their physiological activities of Sarcodon aspratus (Berk.) S. Ito which grows wildly in Korea, belonging to the family Thelephoraceae. The analysis of the powered carpophore of this fungus by TLC and an amino acid autoanalyzer revealed that it contained twenty-one free amino acids and that twenty­two total amino acids were identified in its acid hydrolysate. These amino acids were also quantified.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.163-166
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• 2016

Hydrophobicity is the key concept to understand the water plays in protein folding, protein aggregation, and protein-protein interaction. Traditionally, the hydrophobicity of protein is defined based on the scales of the hydrophobicity of residue, assuming that the hydrophobicity of free amino acids is maintained. Here, we explore how the hydrophobicity of constituting amino acids in protein rely on the protein context, in particular, on the total charge and secondary structures of a protein. To this end, we calculate and investigate the hydration free energy of three short proteins based on the integral-equation theory of liquids. We find that the hydration free energy of charged amino acids is significantly affected by the protein total charge and exhibits contrasting behavior depending on the protein total charge being positive or negative. We also observe that amino acids in the ${\beta}-sheets$ display more enhanced the hydrophobicity than amino acids in the loop, whereas those in the ${\alpha}-helix$ do not clearly show such a tendency. And the salt-bridge forming amino acids also exhibit increase of the hydrophobicity than that with no salt bridge. Our results provide novel insights into the hydrophobicity of amino acids, and will be valuable for rationalizing and predicting the strength of water-mediated interaction involved in the biological activity of proteins.

• Journal of Animal Science and Technology
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• 제60권9호
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• pp.23.1-23.9
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• 2018

Background: Aging trials are conducted to determine characteristics associated with dry- and wet-aging processes of beef from delivered cows grown in Okinawa, i.e., dams that have finished giving birth (Okinawan delivered cow beef). Changes in free amino acids, hardness, and other factors were analyzed in round of Okinawan delivered cow beef during dry- and wet-aging processes along with a comparison with characteristics of beef imported from Australia. Results: Functional amino acids did not increase during both dry- and wet-aging processes. However, proteinogenic amino acids increased significantly (P < 0.05) and hardness tended to decrease during both dry- and wet-aging processes. On comparison between dry- and wet-aging processes by analysis of variance, drip and cooking losses were significantly lower during the dry-aging process than during the wet-aging process. However, there was no significant difference in free amino acids or hardness in this comparison. Conclusion: There was no significant difference between dry- and wet-aging methods for all studied variables related to free amino acids or hardness in this study.

• Journal of Plant Biology
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• 제4권1호
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• pp.9-11
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• 1961

A comparative investigation of free amino acids content in healthy check and virus diseased leaves of Chinese date tree, Zyzyphus jujuqa Mill var. inermis Rhed, was carried out by authors throughout the growing season of 1959 and 1960 from June to October. The methods of qualitative analysis of free amino acids aplied in this experiment is followed by Moore and Stein. Free amino acids determined in this experiment are shown in Fig. 1 and Table 1. As the figure and the table are shown, three more amino acids such as glutamine, asparagine and histidine are detected in the diseased material. The additional amino acids which are known as diamines in diseased leaves are conspicuous. It is presumed that the diamine might be incresed by the self-reproduction of the virus in cooporation with certain enzymes which are carrying out the protein metabolism in the host protoplast in contrast with the healthy checks which is carrying out normal protein metabolism. From the histological poing of view, the facts of phloem degeneration or necrosis in diseased leaves, it seems to interrupt to move free amino acids from roots to leaves and it possibly takes place an excessive production of NH3 which is diaminated by the metabolism of nitrogen compounds in such conditioned leaves. Therefore, it is also presumed that additional diamino acids are accumulated in diseased leaves. There are no change of amino acids are accumulated in diseased leaves. There are no change of amino acids in both materials of this plant throughout the growing season qualitatively, and this result agress with the paper of Knight.

• Journal of Plant Biology
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• 제6권4호
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• pp.5-10
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• 1963

농촌에서 식용으로 사용하는 두종의 죽순에 대하여 함유하는 아미노산을 생장부위에 따라 정성분석하였다. 대체로 한 종류가 함유하는 아미노산은 5종 내지 15종이었으며 축순의 생장과정에 따라 함유된 아미노산의 종류는 명명 상위하였다. 식용 죽순에 함유된 필수 아미노산의 종류는 4종에서 9종임을 정성분석 할 수 있었다. 식용죽순에 잇어서도 다른 식물성 식품과 같이 영양가치가 있음을 알아 내었다. 선단부 보다 기부에 아미노산의 종류가 많이 분석된 것은 기부에서 부터 질소대사가 촉진되어 간다는 것을 추측케 하였다.

• 한국환경성돌연변이발암원학회지
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• 제24권2호
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• pp.67-72
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• 2004

To find active components in Ganoderma lucidum, their free amino acid and free amino acid derivatives were analyzed. After extracting with hot water, the extracts were filtrated by three steps. So, supernatants below 10,000 dalton were obtained. Filtrates were derivativated with PITC (phenylthiocarbamyl) derivative reagent and PITC amino acid was obtained. Then, they were analyzed by RP-HPLC. 13 amino acids were analyzed in cultured Korean Nok-kak ji (one of Ganoderma lucidum), 15 amino acids in cultured Korean Ganoderma lucidum, 12 amino acids wild Ganoderma lucidum, 16 amino acids in cultured Taiwan Ganoderma lucidum.