• Macromolecular Research
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• 제12권4호
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• pp.359-366
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• 2004

The polysaccharide, (1\longrightarrow5)-$\alpha$-D-ribofuranan, was synthesized by a cationic ring-opening polymerization of 1,4-anhydro-2,3-di-O-benzyl-$\alpha$-D-ribopyranose with the aid of boron trifluoride etherate and subsequent debenzylation. This polysaccharide catalyzed the hydrolysis of ethyl p-nitrophenyl phosphate, uridylyl(3'\longrightarrow5')uridine ammonium salt, and 4-tert-butylcatechol cyclic phosphate N-methyl pyridinium. The polymer also catalyzed the cleavage of nucleic acids (DNA and RNA). The hydrolysis of ethyl p-nitrophenyl phosphate in the presence of the polymer was accelerated by 1.5 ${\times}$ 10$^3$ times relative to the uncatalyzed reaction. The catalytic activity was attributable to the vic-cis-diols of the riboses being located inside the active center that is formed by polymer chain folding; these diols form hydrogen bonds with two phosphoryl oxygen atoms of the phosphates so as to activate the phosphorus atoms to be attacked by nucleophile ($H_2O$).

• 대한화학회지
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• 제36권2호
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• pp.218-222
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• 1992

시티딘은 장미조직이 가지고 있는 시티딘 디아미나제에 의해 우리딘과 암모니아 기체를 생성한다. 이 장미조직 50mg을 암모니아 기체감응센서에 고정시켜 장미조직센서를 제조하고, 수용액 중의 시티딘을 정량하는데 최적 실험조건을 조사하였다. pH8.4, 온도 37$^{\circ}C$, 0.2M 인산 완충용액을 사용하였을 때 시티딘의 농도가 $7.0 {\times}10^{-4}$에서 $1.0{\times}10^{-2}$M까지 직선이었고, 53mV/decade의 감응기울기를 나타내었다. 검출한계는 $3.0 {\times} 10^{-4}$ M 상대표준편차는 3.4%였다. 또한 이 조직센서는 선택성이 탁월하였다.

• Bulletin of the Korean Chemical Society
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• 제28권4호
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• pp.601-606
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• 2007

The chromatographic behaviors of nucleotides (inosine 5'-monophosphate, uridine 5'-monophosphate, guanosine 5'-monophosphate, and thymine monophosphate disodium salts) on a C18 column were studied with different types of ionic liquids (ILs) as additives for the mobile phase in reversed-phase liquid chromatography (RPLC). Three ILs, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm][BF4]), and 1-ethyl-3-methylimidazolium methylsulfate ([EMIm][MS]), were used. Eluents were composed of water and methanol (90/10%, vol) with the addition of 0.5-13.0 mM of ILs. The effects of the concentration of ILs on retention and separation were investigated and discussed. The results showed that the addition of ILs affects the retention and resolution of the tested compounds. Use of 13.0 mM of [BMIm][BF4] as the eluent modifier resulted in a baseline separation of nucleotides without requiring gradient elution. This study demonstrates that ILs can be potentially applied as a mobile phase modifier in RPLC.

• 한국미생물·생명공학회지
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• 제24권4호
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• pp.472-477
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• 1996

Natural human epidermal growth factor (nhEGF) was purified from pregnant human urine by benzoic acid adsorption, DEAE-Sepharose ion exchange, and immunoaffinity chromatography. The purified nhEGF was further separated into four fractions using Bondapak C$_{18}$ HPLC system. Following characterization by Western blot analysis and double immu- nodiffusion, we found that each fraction corresponds to four derivatives of the nhEGF. For biological analysis of nhEGF, we optimized the labeling time and serum concentration for the incorporatioin of 5-bromo-2'-deoxy uridine (BrdU), a non-radioactive alternative for [$^{3}$H]-thymidine uptake, into NIH 3T3 cells. The DNA synthesis of NIH 3T3 cells was gradually increased at the nhEGF concentrations between 0.1 - 10 ng/ml in the Dulbecco's Modified Eagles Medium (DMEM) containing 0.2% Fetal calf serum (FCS). When we assayed the biological activity of four fractions, the activity of the second fraction was superior to that of the others. Based on the results from the HPLC analysis spiked with recombinant human epidermal growth factor (rhEGF) and amino acid sequencing, we concluded that the second fraction was nhEGF and the other three fractions were the derivatives of nhEGF. In addition, the proportion of nhEGF was approximately 46% is compared with that of the other three derivatives.

• Journal of Microbiology and Biotechnology
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• 제20권10호
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• pp.1393-1396
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• 2010

The attachment of sugar to flavonoids enhances their solubility. Glycosylation is performed primarily by uridine diphosphate-dependent glycosyltransferases (UGTs). The UGT from Bacillus cereus, BcGT-1, transferred three glucose molecules into kaempferol. The structural analysis of BcGT-1 showed that its substrate binding site is wider than that of plant flavonoid monoglucosyltransferases. In order to create monoglucosyltransferase from BcGT-1, the error-prone polymerase chain reaction (PCR) was performed. We analyzed 150 clones. Among them, two mutants generated only kaempferol O-monoglucoside, albeit with reduced reactivity. Unexpectedly, the two mutants harbored mutations in the amino acids located outside of the active sites. Based on the modeled structure of BcGT-1, it was proposed that the local change in the secondary structure of BcGT-1 caused the alteration of triglucosyltransferase into monoglucosyltransferase.

• Fisheries and Aquatic Sciences
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• 제9권1호
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• pp.30-37
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• 2006

We performed experiments on the uptake and excretion of dissolved organic phosphorus (DOP) using two toxic dinoflagellates, Alexandrium tamarense Lebour (Balech) and Gymnodinium catenatum Graham, isolated from Hiroshima Bay, Japan. ATP (adenosine triphosphate), UMP (uridine-5-monophosphate), G-6-P (glucose-6-phosphate) and Glycero-P (glycerophosphate) were used as DOP sources in preliminary uptake experiments. ATP was selected as the DOP species for the short-tenn uptake experiment because preliminary experiments showed it to be the DOP source used by both species. Although the $K_s$ values of A. tamarense and G. catenatum (5.63 and $7.61{\mu}M$, respectively) obtained from the short-term experiments for ATP were only slightly higher than those reported for dissolved inorganic phosphorus (DIP), the ${\rho}_{max}$ values (5.04 pmol/cell/h and 13.4 pmol/cell/h, respectively) were much higher. The DOP excretion rate in batch-culture experiments was estimated at 0.084 pmol/cell/h for A. tamarense and 0.012 pmol/cell/h for G. catenatum, accounting for about 30% and 25%, respectively, of the assimilated phosphorus. Our results suggest that the DIP-depleted conditions of Hiroshima Bay favor these two species by supporting their ability to use DOP.

• Natural Product Sciences
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• 제16권1호
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• pp.20-25
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• 2010

Fourteen compounds were isolated from the n-BuOH fraction of the roots of Aralia cordata (syn. = A. continentalis). Through spectroscopic method, the chemical structures were elucidated as: caffeic acid (1), protocatechuic acid (2), thymidine (3), uridine (4), methyl-$\alpha$-D-fructofuranoside (5), a mixture (3 : 1) of $\beta$-D-fructopyranoside and $\beta$-D-fructofuranoside (6), 1-methyl 1,2,3,4-tetrahydro-$\beta$-carboline-3-carboxylic acid (7), methyl-$\beta$-D-fructofuranoside (8), sucrose (9), 5-caffeoylquinic acid (chlorogenic acid) (10), 3-caffeoylquinic acid (neochlorogenic acid) (11), 4-caffeoylquinic acid (cryptochlorogenic acid) (12), 3,5-di-O-caffeoylquinic acid (13), and 1-kestose [$\beta$-D-fructofuranosyl-($2{\rightarrow}1$)-$\beta$-D-fructofuranosyl-($2{\rightarrow}1$)-$\alpha$-D-glucopyranoside] (14). Among them, compounds 5, 7, 8, and 10 - 14 were isolated from this plant for the first time.

• Biomolecules & Therapeutics
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• 제25권2호
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• pp.165-170
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• 2017

Cordyceps bassiana is one of Cordyceps species with anti-oxidative, anti-cancer, anti-inflammatory, anti-diabetic, anti-obesity, anti-angiogenic, and anti-nociceptive activities. This mushroom has recently demonstrated to have an ability to reduce 2,4-dinitrofluorobenzene-induced atopic dermatitis symptoms in NC/Nga mice. In this study, we further examined phytochemical properties of this mushroom by column chromatography and HPLC analysis. By chromatographic separation and spectroscopic analysis, 8 compounds, such as 1,9-dimethylguanine (1), adenosine (2), uridine (3), nicotinamide (4), 3-methyluracil (5), 1,7-dimethylxanthine (6), nudifloric acid (7), and mannitol (8) were identified from 6 different fractions and 4 more subfractions. Through evaluation of their anti-inflammatory activities using reporter gene assay and mRNA analysis, compound 1 was found to block luciferase activity induced by $NF-{\kappa}B$ and AP-1, suppress the mRNA levels of cyclooxygenase (COX)-2 and tumor necrosis factor $(TNF)-{\alpha}$. Therefore, our data strongly suggests that compound 1 acts as one of major principles in Cordyceps bassiana with anti-inflammatory and anti-atopic dermatitis activities.

• Food Science and Biotechnology
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• 제15권4호
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• pp.599-602
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• 2006

The effects of ethanol extract from radish seeds on gastrointestinal function in rats were investigated. Rats were divided into 2 groups of 8 rats each, the basal group and the radish seed ethanol extract group. The radish seed ethanol extract group had a significantly decreased gastrointestinal transit time, but a significantly increased fecal weight compared with the basal group. The radish seed ethanol extract group also had significantly higher duodenal villus height and greater colonic mucosal thickness than the basal group. The radish seed ethanol extract group had a greater proliferation of 5-bromo-2-deoxy-uridine (BrdU) immunoreactive cells in the gastric mucosa as well as in the mucosa and submucosa of the small and large intestine than did the basal group. Thus, radish seed ethanol extract may be useful in preventing constipation based on the observation of an increase in fecal weight, a decrease in gastrointestinal transit time, and positive changes in the intestinal mucosa.

• 방사선산업학회지
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• 제5권1호
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• pp.1-5
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• 2011

Since proteomics can be employed to compare changes in the expression levels of many proteins under particular genetic and environmental conditions, using mass spectrometry to establish radiation stimulon, we performed two-dimensional gel electrophoresis and identified E. coli proteins whose expressions are affected by high dose of ionizing radiation. After exposure to 3 kGy, it was found that 6 proteins involved in carbon and energy metabolism were reduced. Although 4 of 7 protein spots showing a significant increase in expression level were neither identified nor classified, uridine phosphorylase (Udp), superoxide dismutase (SodB), and thioredoxin-dependent thiol peroxidase (Bcp) were proven to be up-regulated after irradiation. This suggests that E. coli subjected to high doses of radiation (3 kGy) may operate a defense system that is able to detoxify reactive oxygen species and stimulate the salvage pathway of nucleotide synthesis to replenish damaged DNA.