• 제목/요약/키워드: thymidine

검색결과 419건 처리시간 0.032초

핵산유도체의 비대칭촉매 가능성연구 (Synthesis of Pyrimidine Nucleosides as a Potential Asymmetric Catalysts)

  • 윤인권;백기현
    • 자연과학논문집
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    • 제9권1호
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    • pp.95-104
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    • 1997
  • 본 연구에서는 thymidine으로부터 시작하여 3'-OH과 5'-OH의 각각의 변형, 동시의 변형을 통해 크게 5종의 amino thymidine 골격의 촉매를 합성하였다. 다양한 thymidine 화합물들이 새로운 키랄 보조체로서의 촉매효과를 위해 우선 3'-OH 자리에 mono-methylamino thymidine과 dimethylamino thymidine을 합성하고, 이들의 합성과정을 응용하여 5'-OH을 Ac-O로 변환한 5'-acetyl-3'-dimethylamino thymidine과 5'-OH를 TBS로 변환하고 up위치의 azido화합물인 5'-TBS-3'-Up-tBOC methylamino thymidine을 합성하였다. 그리고, 5'-OH를 amino group으로 변환하고 3'-OH를 -Me로 변환한 화합물 3'-acetyl-5'-tBOC-amino thymidine을 합성하였다.

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Methyl Methanesulfonate Stimulated $^3H$-Thymidine Uptake in Synchronized HeLa $S_3$ Suspension Cells Pretreated with Thymidine Analogs

  • Park, Sang-Dai
    • 한국동물학회지
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    • 제19권3호
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    • pp.113-122
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    • 1976
  • 非同時化시킨 HeLa $S_3$ 細胞에 있어 MMS에 의한 $^3 H$-Thymidine Uptake率은 MMS의 頻度증가에 따라 직선적으로 감소하며, BUdR 혹은 IUdR과 二重處理할 경우 그 감소율은 더욱 증가한다. MMS에 의한 $^3 H$-Thymidine Uptake은 thymidine 二重 處理후 얻은 同時化된 HeLa $S_3$ 細胞의 $G_2$ 時期에서 檢出된다. BUdR과 IUdR은 MMS에 의한 $^3 H$-Thymidine Uptake率을 더욱 증가시키며 IUdR은 BUdR에 비해 더효과적인 感受性 物質로 판명되었다.

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호수 생태계에서 세균 생산량 측정 방법의 비교 (Comparison of Methods for the Measurement of Bacterial Production in a Lake Ecosystem)

  • 김명운;강찬수;김상종
    • 미생물학회지
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    • 제28권4호
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    • pp.318-323
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    • 1990
  • The bacterial secondary production was measured at 6 sites of Lake Soyang in October, 1989 by $^{3}$H-thymidine incorporation rate. Verfication for the method of bacterial secondary production measurement showed that $^{3}$H-thymidine incorporated into DNA, RNA and protein by average percentage of 38.45, 42.27 and 20.07%, respectively. THe more increased incoporated $^{3}$H-thymidine, the more increasde DNA fraction, but protein fraction was generally low. Incorporation of rate of /usp 3/H-thymidine. $^{3}$H-leucine into protein correlated with protein fraction of incorporated $^{3}$H-thymidine. Conversion factors were calculated as follows; $1.83*10 ^{20}$ cells/moles of thymidine incorporated/hr and 1.69*10$^{22}$ cells/moles of leucine incorporated/hr.

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돼지 미성숙 난포란의 체외성숙에 미치는 Thymidine 처리 효과 (Effect of Thymidine on $In$ $Vitro$ Maturation of Immature Porcine Follicular Oocytes)

  • 민성훈;박흠대
    • Reproductive and Developmental Biology
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    • 제36권1호
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    • pp.71-77
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    • 2012
  • The objective of this study was to examine the effect of thymidine treatment during $in$ $vitro$ maturation (IVM) of porcine follicular oocytes on blastocyst development. Porcine oocytes were treated with thymidine (10 mM, 20 mM and 30 mM) for 2 or 6 hr in the preiods of IVM I and/or II. The survival rates of the blastocysts in the 6 hr treatment groups of 10 mM and 20 mM during IVM I period were significantly higher than those of control group ($p$<0.05). However, the survival rate of the blastocysts in the 2 hr treatment group of 20 mM during IVM II period was significantly higher than control group ($p$<0.05). Furthermore, the survival rate of the blastocysts in the 6 hr treatment group of 30 mM during IVM II period was significantly lower than control group ($p$<0.05). Consistent with the previous result, blastocyst development of both IVM I and II treatment group was also showed as similar pattern. Total and apoptotic cell numbers of blastocysts derived from thymidine treated porcine oocytes were examined by using Tunel assay. The results showed that there was no significant differences in total cell number of blastocysts between thymidine treated and untreated groups. However, apoptosis-positive cells in the thymidine treated group (6 hr IVM I) were significantly lower than those of other groups ($p$<0.05). Taken together, these results indicate that high quality oocytes were selected by DNA synthesis mechanism according to high concentration thymidine treatment during porcine oocyte maturation. Therefore, we concluded that presumptive selected oocytes by thymidine treatment during maturation periods improved the further embryo development and embryonic quality of IVF embryos by decreasing the incidence of apoptosis in preimplantation porcine embryos.

Thymidine Production by Corynebacterium ammoniagenes Mutants

  • Song, Kyung-Hwa;Kwon, Do-Young;Kim, Sang-Yong;Lee, Jung-Kul;Hyun, Hyung-Hwan
    • Journal of Microbiology and Biotechnology
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    • 제15권3호
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    • pp.477-483
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    • 2005
  • Corynebacterium ammoniagenes ATCC 6872, which does not accumulate pyrimidine nucleoside or nucleotide, was metabolically engineered to secrete a large amount of thymidine. Characteristics of 5-fluorouracil resistance ($FU^r$), hydroxyurea resistance ($HU^r$), trimethoprim resistance ($TM^r$), thymidylate phosphorylase deficiency ($deoA^-$), inosine auxotrophy ($ino^-$), 5-fluorocytosine resistance ($FC^r$), thymidine kinase deficiency, and thymidine resistance ($thym^r$) were successively introduced into mutant strains KR3 and DY5T9-5, and shake-flask cultures were able to accumulate 408.1 mg/l and 428.2 mg/l of thymidine, respectively, as a major product. The mutant strains did not accumulate thymine at all and accumulated less than 10 mg/l of other pyrimidine nucleosides, such as cytosine, cytidine, and deoxycytidine, as byproducts.

Relative Photoreactivity of 5,7-Dimethoxycoumarin and cis-syn 8-MOP $<\array{4^{\prime},5\\5^{\prime},6}>$ Thd Monoadduct to Thymidine in a Dry Film State

  • Shim, Sang-Chul;Kang, Ho-Kwon
    • Bulletin of the Korean Chemical Society
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    • 제7권4호
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    • pp.289-293
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    • 1986
  • The photocycloaddition reactivity of 5,7-dimethoxycoumarin (DMC) to thymidine is much higher than that of cis-syn 8-methoxypsoralen $<\array{4^{\prime},5\\5^{\prime},6}>$ thymidine monoadducts, due to the steric effect. The different rate is also due to the relative reactivity of the singlet rather than the triplet excited state of the compounds. The biadducts of 8-methoxypsoralen and thymidine are first splitted into 4',5'-monoadducts and thymidine, not into 3,4'-monoadducts and thymidine by 254 nm light.

Ag-NORs 염색법과 [3H]thymidine incorporation법에 의한 caffeine의 NIH3T3 세포증식 억제효과 비교측정 (Comparison of Ag-NORs stain and [3H]thymidine incorporation in antiproliferative effect of caffeine on NIH3T3 cells)

  • 김성호;이차수
    • 대한수의학회지
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    • 제30권4호
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    • pp.459-464
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    • 1990
  • Inhibitory effect of caffeine on NIH3T3 cell proliferation was studied by using [$^3H$]thymidine incorporation and a modified one-step silver staining technique. The latter technique shows argyrophilic nucleolar organizer region-associated proteins (Ag-NORs), which are seen in nuclei as black dots. The result was compared with the counts of [$^3H$] thymidine incorporation. The results were summarized as follows; 1. The Ag-NORs numbers of NIH3T3 cells were $6.81{\pm}1.38$ at 24 hrs, $7.13{\pm}1.26$ at 48 hrs, $8.50{\pm}2.04$ at 72 hrs after incubation. 2. The numbers of Ag-NORs were significantly decrease in caffeine treated groups (p<0.01). 3. The counts of [$^3H$] thymidine incorporation were similar to the result of using Ag-NORs staining technique. It is concluded that Ag-NOR is a rapid, simple and compatible method to quantitate cell proliferation as compared with [$^3H$]thymidine incorporation.

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Effect of Pyridoxine on Rifampicin Toxicity

  • Yun, Yeo-Pyo;Kim, Koan-Hoi;Kim, Hack-Seang;Chung, Jin-Ho
    • Archives of Pharmacal Research
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    • 제14권1호
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    • pp.73-77
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    • 1991
  • The effects of pyridoxine (PN) on rifampicin (RMF) toxicity were investigated by both in vivo and in vitro methods. RMF (30 mg/kg) was injected intraperitoneally and PN(150 mg/kg) was administered orally to rats for 10 consecutive days. After treatment, clinical chemistry and hematologic profiles were measured. RMF and PN plus RMF did not show any adverse effects at this in vivo experimental condition. Thymidine incorporations of mice bone marrow cells were examined in vitro. RMF showed a decrease in thymidine uptake in a dose-dependent manner, but PN showed a reversal of the thymidine uptake suppression caused by RMF (p<0.01). On the other hand, PN showed a decrease in thymidine uptake at a high concentration level.

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Theoretical Studies on the Photocycloaddition Reaction of Psoralen with Thymidine

  • Kim, Ja-Hong;Oh, Se-Woung;Lee, Yoon-Sup;Shim, Sang-Chul
    • Bulletin of the Korean Chemical Society
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    • 제8권4호
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    • pp.298-300
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    • 1987
  • The theoretical studies on the photocycloaddition reaction of 5,7-dimethoxycoumarin and 4',5'-dihydropsoralen with thymidine were carried out as a model for photosensitizing reaction of psoralen with DNA. The results are in reasonable agreement with experimental observations. The photoadducts between dimethoxycoumarin and thymidine were predicted to be $C_{4}$-cycloadducts through the cycloaddition of 3,4-pyrone double bond of dimethoxycoumarin to 5,6 double bond of thymidine. The major photoadduct of 4',5'-dihydropsoralen with thymidine has the anti head-to-head stereochemistry.

Methyl Methanesulfonate 에 의한 DNA 回復合成에 미치는 Thymidine 相似체體의 感受性 효과 (Sensitization Effects of Thymidine Analogs on Methyl Methanesulfonate Induced DNA Repair synthesis)

  • Park, Sang-Dai;Um, Kyung-Il
    • 한국동물학회지
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    • 제18권3호
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    • pp.131-140
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    • 1975
  • HeLa $S_3$ 細胞를 재료로 DNA 回復合成에 미치는 Methyl methanesulfonate(MMS)와 thymidine 相似體(BUdR, IUdR)의 이중효과를 농도와 시간변화에 따라 $^3 H$-thymidine 처리에 의한 自記放射法으로 조사한 결과는 다음과 같다. 1. MMS를 단독 처리한 경우 標識細胞의 빈도는 MMS의 농도 증가에 따라 증가한다. 이는 DNA 回復合成을 한 細胞의 빈도가 증가한 결과로 細胞當 Grain 數의 증가현상과 일치한다. 시간변화에 따른 DNA 回復合成은 MMS와 $^3 H$-thymidine 처리후 2$\\sim$3시간에 최대증가율을 보인다. 2. BUdR 또는 IUdR의 단독처리후 DNA 回復合成을 일으키지 않는다. 그러나 MMS와 이중 처리할 경우 標識細胞, DNA 回復合成細胞, 그리고 細胞當 Grain 數는 MMS 단독 처리한 경우보다 훨씬 증가한다. 따라서 이 두 물질은 MMS에 의한 DNA 回復合成을 효과적으로 증가시키는 感受性物質로 작용함이 판명되었다.

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