• 대한화학회지
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• 제15권5호
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• pp.256-265
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• 1971

An ESR study has been made on free radicals produced in frozen aqueous solutions (ices) of glycine, DL-${\alpha}$-alanine, DL-serine, L-cysteine, DL-leucine and DL-isoleucine by gamma-irradiation at dry ice temperature. All free radicals induced were decayed concomitant to the successive annealing but the radical species which is believed to be dominant seems to be stable even near the melting point of the ice. These dominant species were found to be identical to those resulted from direct action of radiation in the solid at room temperature. Small but significant changes in the spectra of glycine and DL-${\alpha}$-alanine were observed by varying the microwave power. These results seem to support the view that the spectra obtained were composite consisting of more than two different resonances having different power saturation characteristics. The relative contribution of unidentified resonances to the composite spectra was greater for solutions of low concentration. These resonances are assumed to be induced by indirect effects, mainly hydrogen abstraction by radiation produced hydroxyl radicals and also C-N bond cleavage by hydrated electrons.

• KSBB Journal
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• 제26권6호
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• pp.557-560
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• 2011

It has been known that Δ-desaturase (TAD5) in the biosynthetic pathway of long chain polyunsaturated fatty acids of Thraustochytrium aureumis responsible for the conversion of di-homo-${\gamma}$-linolenic acid (C20：4) into arachidonic acid (C20：4). The genetic sequence analysis on TAD5 of Thraustochytrium aureum ATCC34304 used in this study showed that it has two amino acid changes when compared to that of Thraustochytrium aureum TAD5 first reported in 2003. Accordingly, Thraustochytrium aureum ATCC34304 TAD5 was named TAD5_1. TAD5_1-inserted methylotropic Pichia pastoris was prepared and then cultured with a precursor fatty acid, di-homo-${\gamma}$-linolenic acid. GC analysis confirmed that a certain amount of the precursor fatty acid was converted into arachidonic acid. In this study, not only a recombinant Pichia pastoris with the typical activity of ${\Delta}5$-desaturase which plays an essential role in the biosynthesis of LCPUFAs was successfully made but also the preparationpotential of a recombinant Pichia pastoris strain which may synthesize eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that are important in maintaining and improving human's brain function was proposed.

• 한국식품과학회지
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• 제24권1호
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• pp.65-69
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• 1992

수출용으로 제조되고 있는 인삼엽록차에 대하여 위생적 품질개선을 목적으로 처리된 ethylene oxide(EO) 훈증제와 적정선량의 감마선 조사가 시료의 몇 가지 화학성분에 미치는 영향을 검토하였다. 인삼엽록차에 함유된 사포닌과 지방산은 상업적 조건의 EO 처리나 적정선량의 감마선 조사(5kGy 범위)에 의해 변화되지 않았다. 그러나 유리당과 아미노산에서 glucose, lysine 및 histidine은 EO 처리시 유의적으로 감소되어(p<0.05) 살균방법 중 EO gas는 감마선조사에 비해 엽록차 성분에 미치는 영향이 큰 것으로 화인되었다.

• 한국식품저장유통학회지
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• 제13권5호
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• pp.661-667
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• 2006

머위의 생리활성 기능과 이용 가능성에 관한 연구의 일환으로 머위의 잎과 줄기의 일반성분 및 영양성분을 조사하였다. 일반성분은 건물(dry basis)을 기준으로 머위 줄기는 잎보다 수분, 조지방, 조회분 및 탄수화물 함량은 높았으나, 조단백질 함량은 낮았다. 머위 잎은 D-fructose와 D-glucose의 2종의 유리당과 maltose와 lactose의 2종의 이당류가 검출되었고,줄기에서는 D-fructose와 D-glucose의 2종의 유리당과 lactose의 1종의 이당류가 검출되었다. 아미노산은 잎에서는 aspartic acid, glutamic acid, arginine, phenylalanine, leucine 순으로 검출되었으며, 줄기에서는 glutamic acid, aspartic acid, glycine, leucine 순이었다. 머위잎에는 불포화지방산인 linolenic acid를 가장 많이 함유되었고 그 다음으로 linoleic acid, palmitic acid, $\gamma$-linolenic acid순으로 검출되었다. 반면에 줄기에서는 5종의 불포화지방산이 검출되었으며 linoleic acid가 가장 많이 함유되었다. 유기산은 잎에서는 oxalic acid, succinic acid, citric acid 순으로 3종이 검출되었고, 줄기에서는 oxalic acid, malic acid, citric acid순으로 검출되었다. 머위 잎과 줄기에서 비타민 A, C와 E 3종이 검출되었다. 무기질은 머위 잎과 줄기에서 8종의 무기성분이 검출되었는데, 이 중 K이 가장 많이 함유되었다. 머위의 잎과 줄기의 일반성분 및 영양성분은 함량에서의 차이가 있을 뿐 성분은 매우 유사한 경향이었다. 이상의 결과 머위는 체내 신지대사와 생리활성을 증진시킬 수 있는 유리당, 필수아미노산 및 필수지방산을 비롯한 항산화 비타민과 무기질을 다량 함유하고 있어 머위의 식품으로서의 이용화 가치가 한 층 더 높아질 것으로 기대되어진다.

• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.819-825
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• 2002

Methanol dehydrogenase (MDH) is a key enzyme in the process of methanol oxidation in methylotrophic bacteria. However, information on MDH genes from genus Methylobacillus is limited. In this study, a 6.5-kb HindIII DNA fragment of Methylobacillus sp. SK-5 chromosomal DNA was isolated from the genomic library of the strain by using a degenerate oligonucleotide probe that was designed based on JV-terminal amino acid sequence of the MDH $\alpha$ subunit purified from the strain. Molecular analysis of the fragment revealed four tightly clustered genes (mxaFJGI) involved in the methanol oxidation. The first and fourth genes were very similar to mxaF (77% identity for nucleotides an 78% identity for amino acids) and mxaF (67% Identity for nucleotides and 68% Identity for amino acids) genes, respectively, from Methylovorus sp. SSI. Genes mxaF and mxaI encode $\alpha$ and $\beta$ subunits of MDH, respectively. The two subunits were identified from purified MDH from Methylobacillus sp. SK-5. A dendrogram constructed by comparison of amino acid sequences of MDH u subunits suggests that MxaF from Methylobacillus sp. SK-5 belongs to a subfamily cluster of MDH u subunits from $\beta$-subgroup Proteobacteria. The subfamily cluster is separated from the other subfamily that consists of $\beta$- and $\gamma$-subgroup Proteobacteria. This study provided information on mn genes from a methylotrophic bacterium in $\beta$-subgroup Proteobacteria, which would aid to better develop a gene probe to detect one-carbon metabolizing bacteria.

• 폴리머
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• 제35권6호
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• pp.558-564
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• 2011

생체적합하고 생분해성을 갖는 폴리아미노산의 하나인 폴리아스팔트산은 팹타이드 결합으로 이루어진 수용성 합성고분자로서 의료용 소재 및 다양한 응용분야의 연구가 흥미있게 진행되어 왔다. 본 연구에서는 아미노산인 GABA(${\gamma}$-aminobutylic acid)와 ${\beta}$-alanine을 곁사슬에 도입한 폴리아스팔트산 유도체 고분자를 제조하고, 이들을 서로 다른 함량의 ethylene glycol diglycidyl ether(EGDE)를 사용하여 가교시켜 고흡수성 하이드로젤을 제조하였다. 각 하이드로젤에 대해 증류수와 PBS 용액에서 기본적인 팽윤물성, 젤의 가수분해 거동과 모폴로지를 조사하였다. 제조한 하이드로젤은 수용액에서 pH와 염(salt) 농도에 의존하는 민감성 팽윤거동을 보였으며, 또한 비교적 빠른 가수분해 거동을 나타내었다.

• Journal of Animal Science and Technology
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• 제60권7호
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• pp.19.1-19.10
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• 2018

Background: A mold strain thought to be suitable for dry-aging process was isolated. The information about the scientific aspects of molds related to dry-aging beef is scarce. We, therefore, conducted aging trials to determine the characteristics of the isolated mold strain associated with dry-aging process. Specifically, during the dry-aging of beef with the mold strain, the changes in the free amino acid content, hardness, productive loss, drip and cooking loss were analyzed. These characteristics were compared with those obtained while dry-aging in the absence of a mold. Results: The isolated mold strain was identified as Mucor flavus. The free amino acid content in the mold-aging beef decreased or remained constant during the aging process. However, that in the trimming sections of the beef dramatically increased in the presence of mold. In addition, hardness of mold-aging beef gradually decreased during the aging process and finally decreased significantly. Conclusion: Amino acids such as GABA (gamma-aminobutyric acid), proline, and aspartic acid were produced by our mold strain, M. flavus during its growth on beef meat, and the mold conferred savory odors to the dry-aged beef.

• 한국수산과학회지
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• 제51권6호
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• pp.613-622
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• 2018

This study investigated changes in the quality and antioxidant activity of soy sauce with added Saccharina japonica powder (FSP). Soy sauce was prepared with acid-hydrolyzed soy sauce, brewed soy sauce, honey, ginger, garlic, dried red pepper, ${\gamma}$-aminobutyric acid (GABA)-enriched sea tangle fermented in lactic acid, and 1% or 3% S. japonica powder by soy sauce volume. The color, pH, microbiology, amino nitrogen, free amino acids, antioxidant activity, and sensory qualities of the soy sauce were evaluated. There were no significant differences in the general characteristics or antioxidant activity. However, the addition of FSP to the soy sauce enhanced the delicate flavor. Furthermore, soy sauce containing FSP had higher levels of GABA (50 mg/100 mL), a biofunctional ingredient. Therefore, the development of seasoning soy sauce with enhanced functionality seems possible.

• 대한핵의학회지
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• 제32권3호
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• pp.211-224
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• 1998

The role of scintigraphic imaging has moved from the detection of lesions to the tissue-specific characterization of lesions over the past 2 decades. Major advances in nuclear medicine imaging include: 1) positron imaging, 2) improved instrumentation, such as the use of multidetector (dual or triple head) gamma cameras for single photon emission computed tomography, and 3) development of numerous new radiopharmaceuticals for positron or single photon imaging (labeled glucose analogue, amino acids, fatty acids, hormones, drugs, receptor ligands, monoclonal antibodies, etc). These advances have resulted in a significantly improved efficacy of radionuclide techniques for the evaluation of various tumors, including those within the liver. The current role of nuclear medicine in the evaluation of focal hepatic tumors is reviewed in this article with an emphasis on the clinical applications of various tracer studies and imaging findings.

• 생약학회지
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• 제29권3호
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• pp.179-186
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• 1998

The fractions of Uncariae Ramulus et Uncus seemed to be closely related with the levels of amino acids and other components which concerns with formation and metabolism of neurotransmitters in brain. The pretreatments of methanolic extract and its fractions prohibited the pentylenetetrazole (PTZ) induced convulsion. In such cases, lowered levels of ${\gamma}-aminobutyric$ acid and glutathione in brain were significantly recovered. And also the increased levels or activities of lipid peroxide, ${\gamma}-aminobutyric$ acid aminotransferase, xanthine oxidase, aldehyde oxidase, superoxide dismutase, catalase and glutathione peroxidase by PTZ-convulsion were lowered to normal state.