• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.569-572
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• 2004

• Plant Biotechnology Reports
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• 제3권2호
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• pp.139-145
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• 2009

DNA methylation is known to play an important role in the regulation of gene expression in eukaryotes. In this study, we isolated NtMET1 from Nicotiana tabacum cv. Havana (SR1) and obtain transgenic plants that reduced MET1 expression level with the double-strand RNA (dsRNA) MET1 gene. Transgenic tobacco plants showed dwarf and abnormal flower development when compared with the wild type. Using methylation-sensitive amplified polymorphism (MSAP) analysis, the patterns of cytosine methylation in transformed plants and the wild type were compared. MseI/HpaII selection primers showed an interesting polymorphism, and 153 DNA bands of interest were detected. Among these, 30 selective fragments were sequenced and analyzed with a BLAST search by successful MSAP modifications. The homology search showed that the transposons and tandem repeated sequences were related to the phenotypes. These results suggested that the decreased degree of methylation by dsRNA strategy caused abnormal growth and development in N. tabacum.

• 대한화학회지
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• 제62권1호
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• pp.19-23
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• 2018

케르세틴의 메틸화된 대사체인 람나진과 옴부인은 항암제와 항염증제로서의 개발 가능성이 높은 물질이다. 본 연구에서는 케르세틴 수산기의 선택적인 메틸화를 통하여 기존의 합성법이 알려지지 않은 람나진의 합성법을 개발하였다. 그리고 케르세틴의 메틸화된 대사체 중의 하나인 옴부인의 기존 합성법의 문제점을 수정한 새로운 합성법을 제시하였다.

• Bulletin of the Korean Chemical Society
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• 제12권6호
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• pp.625-628
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• 1991

Using uniform flat plate-like samples of ZSM-5 zeolites, diffusion coefficients were measured volumetrically for the diffusion of xylene, ethyltoluene and diethylbenzene by direct measurement of sorption rate. Toluene disproportionation over H(100)-, K(72)-and Cs(82)-ZSM-5 at 773 K and toluene methylation, toluene ethylation and ethylbenzene ethylation over Cs(75)-ZSM-5 at 623 K were carried out. The selective formation of para xylene during the toluene disproportionation, presumably due to the increased tortuosity over Cs-ZSM-5, could be explained by smaller diffusion coefficient in Cs-ZSM-5 than in K-and H-ZSM-5. The para selectivity increased in the order; toluene methylation < toluene ethylation < ethylbenzene ethylation. As the chain length of the alkyl substituent in dialkylbenzenes is increased, the para selectivity of the products was improved. It may be attributed to the differences in the ratios of diffusion coefficient of para products to that of ortho ones. Diffusion coefficient of m-xylene was about 1 order of magnitude smaller than that of o-xylene.

• Asian-Australasian Journal of Animal Sciences
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• 제33권2호
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• pp.203-211
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• 2020

Objective: Staphylococcus aureus (S. aureus) is one of the major microorganisms responsible for subclinical mastitis in dairy cattle. The present study was designed with the aim to explore the DNA methylation patterns using the Fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) techniques in a S. aureus-infected mouse model. Methods: A total of 12 out-bred Institute of Cancer Research female mice ranging from 12 to 13 weeks-old were selected to construct a mastitis model. F-MSAP analysis was carried out to detect fluctuations of DNA methylation between control group and S. aureus mastitis group. Results: Visible changes were observed in white cell counts in milk, percentage of granulocytes, percentage of lymphocytes, CD⁴⁺/CD⁸⁺ ratio (CD⁴⁺/CD⁸⁺), and histopathology of mice pre- and post-challenge with S. aureus. These findings showed the suitability of the S. aureus-infected mouse model. A total of 369 fragments was amplified from udder tissue samples from the two groups (S. aureus-infected mastitis group and control group) using eight pairs of selective primers. Results indicated that the methylation level of mastitis mouse group was higher than that in the control group. In addition, NCK-associated protein 5 (Nckap5) and transposon MTD were identified to be differentially methylated through secondary polymerase chain reaction and sequencing in the mastitis group. These observations might play an important role in the development of S. aureus mastitis. Conclusion: Collectively, our study suggests that the methylation modification in Nckap5 and transposon MTD might be considered as epigenetic markers in resistance to S. aureus-infected mastitis and provided a new insight into S. aureus mastitis research in dairy industry and public health.

• Bulletin of the Korean Chemical Society
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• 제12권4호
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• pp.392-397
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• 1991

A stereocontrolled synthesis of (${\pm}$)-isocomene (1) via selective monoketalization of tricyclo[6.3.0.$0^{1.5}$]undeca-4,7-dione(13) was reported. Grignard reaction of bicyclic enone 10, which was prepared from 2-methyl-1,3-cyclopentadione, gave the 1,4-addition product 11. The subsequent aldol condensation product 12 was converted to mesyl derivative 13. Transformation from 13 to the desired product 19 was achieved by a series of reactions, i.e., the selective monoketalization at C-4 carbonyl group, the elimination of a mesyl group, Birch alkylation, methylation at C-6, the reduction of carbonyl group, the dehydration of alcohol 18, and hydrolysis of the ketal group.

• 생명과학회지
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• 제26권7호
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• pp.855-867
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• 2016

말은 인류에 의해 상대적으로 일찍 가축화된 종 중 하나로써, 경주능력, 강건성 및 항병성 등과 같은 능력을 위해 인공적으로 선택되었다. 그 결과, 현재 경주마로 많이 쓰이고 있는 서러브레드의 게놈은 운동 능력에 특화된 유전자형을 많이 갖고 있다. 최근 NGS 기술의 도래와 함께 전장게놈을 대상으로 경주마의 우수한 유전형질을 찾는 연구가 유전체학의 관점에서 진행되고 있다. 그 결과 말의 게놈에 대해서도 GWAS (Genome-wide Association study)가 적용되고 있고, 우수 경주능력을 나타내는 유전자 마커가 발굴되고 있다. 아울러, 특정 샘플의 전장 전사체를 NGS 기법으로 분석할 수 있는 RNA-Seq 기법 역시 활용되고 있는데, 이를 통하여 각 개체별, 운동 전후, 한 개체의 조직별 특정 유전자의 발현 양상과 함께 전사체의 서열 등을 확인할 수 있다. DNA 서열의 변화 없이 유전자 발현을 조절하는 강력한 인자로써 DNA methylation이 주목받고 있다. 말의 게놈에 있어서도 운동 특이적 또는 개체 특이적 DNA methylation 패턴을 보여 주었고, 이는 우수 개체 선정을 위한 마커 개발에 좋은 단서를 제공해 줄 것이다. 유전자 발현을 억제하는 miRNA와, 포유동물의 유전체 내 절반 정도를 차지하고 있는 이동성 유전인자는 기능유전체 연구에 있어서 중요한 인자들이다. 이들은 인간의 게놈에서 많이 연구가 되어 왔으나, 말에서의 연구는 현재 미미한 실정이다. 하지만, 현재까지 말에서 되어 있는 위의 두 인자에 대한 연구 현황을 알아보고, 차후 우수 마 선별 연구에 적용될 가능성을 제시하였다. 기능유전체 및 후성유전체 분석 기법이 발전함에 따라 말에서도 본 연구에서 소개된 여러 가지 분석 기법이 적용되고, 우수한 경주마를 선정하는 데 많은 도움을 줄 것으로 기대하고 있다. 이에 현재까지의 우수한 경주마를 선택하기 위한 많은 연구들 및, 말 연구에 대한 앞으로의 발전 가능성에 대해 고찰하고 토의하였다.

• Genomics & Informatics
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• 제11권1호
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• pp.2-6
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• 2013

Until recently, since the Human Genome Project, the general view has been that the majority of the human genome is composed of junk DNA and has little or no selective advantage to the organism. Now we know that this conclusion is an oversimplification. In April 2003, the National Human Genome Research Institute (NHGRI) launched an international research consortium called Encyclopedia of DNA Elements (ENCODE) to uncover non-coding functional elements in the human genome. The result of this project has identified a set of new DNA regulatory elements, based on novel relationships among chromatin accessibility, histone modifications, nucleosome positioning, DNA methylation, transcription, and the occupancy of sequence-specific factors. The project gives us new insights into the organization and regulation of the human genome and epigenome. Here, we sought to summarize particular aspects of the ENCODE project and highlight the features and data that have recently been released. At the end of this review, we have summarized a case study we conducted using the ENCODE epigenome data.

• Food Science and Biotechnology
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• 제14권2호
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• pp.259-262
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• 2005

A fraction (CMEx-AH-${\beta}$) of water-soluble polysaccharides, showing selective antitumor activities, was isolated from the mycelia of solid cultured Agaricus blazei Murill by hot-water extraction, ethanol precipitation, and series of chromatography. Chemical characteristics of CMEx-AH-${\beta}$, were as follows: carbohydrate content, 48%; monosaccharide composition, Man:Glu:Gal (2:93:5); molecular weight, $2{\times}10^5$; uronic acid content, 6.2%. Fundamental structure of CMEx-AH-${\beta}$, was deduced as ${\beta}-(1\;{\rightarrow}\;6)$-D-glucan with ${\beta}-(1\;{\rightarrow}\;3)$-D-glucosidic side chains based on results of methylation and $^{13}C$ NMR spectroscopic analyses.

• 약학회지
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• 제49권1호
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• pp.20-24
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• 2005

The synthesis of 4',5'-doubly branched carbocyclic nucleosides was accomplished in this study. The selective methylation in the 5'-position was made by Felkin-Anh controlled Grignard addition. The construction of the required 4'-quaternary carbon was carried out by using a [3,3]-sigmatropic rearrangement. Bis-vinyl 6 was successfully cyclized using a Grubbs' catalyst II. The natural pyrimidine bases (cytosine, uracil, thymine) were efficiently coupled using a Pd(0) catalyst. When the synthesized compounds were examined for their activity against several viruses such as the HIV-1, HSV-1, HSV-2 and HCMV, the cytosine analogue 13 exhibited weak antiviral activity against the HCMV.