• 제목/요약/키워드: Protecting group

검색결과 259건 처리시간 0.025초

The p-Hydroxyphenacyl Photoremovable Protecting Group

  • Richard S. Givens;Lee, Jong-Ill
    • Journal of Photoscience
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    • 제10권1호
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    • pp.37-48
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    • 2003
  • A review of the background and development of the p-hydroxyphenacyl group (pHP) as a photoprotecting group for biological substrates is chronicled. The pHP group has promise as an efficient, rapid phototrigger for the study of very fast biological processes. Applications include the release of neurotransmittors and second messengers, enzyme switches and nucleotides.

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One-pot Synthesis of Cinnamylamines with Various Protecting Groups from Cinnamyl Ethers

  • Jung, Young-Hoon;Kim, Ji-Duck
    • Archives of Pharmacal Research
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    • 제24권5호
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    • pp.371-376
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    • 2001
  • The reaction of various alkyl cinnamyl ethers with CSI afforded the corresponding cinnamylamines with various protecting groups, such as -NHMoc, -NHiPoc, -NHCbz, -NHPnz, -NHTroc and -NHAloc. In the case of cinnamyl t-butyl ether and cinnamyl p-methoxybenzyl ether, the corresponding cinnamyl carbamates were formed via a different reaction pathway from the above.

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The Influence of Protecting Groups on the β-Sheet Structure Stability of Protected Peptides

  • 이진식;이동진
    • Bulletin of the Korean Chemical Society
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    • 제16권7호
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    • pp.591-594
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    • 1995
  • The influence of protecting groups on the β-sheet-structure-stability of protected peptides was studied in organic solvents. α-amino groups, carboxyl groups and side chain functional groups of model peptides were protected by suitable groups commonly used in peptide synthesis. The difference of the solubilities of model peptides was investigated by the solvent-titration method by using IR absorption spectra. The β-sheet structure of model peptide in CH2Cl2 was easily disrupted by increasing the amounts of DMSO. The β-sheet-structure-stabilizing potentials of each protecting group showed similar behaviors except Npys, Mts and Z2. The result exhibits that the < SPβ > values of protected peptides are almost independent of the kinds of their protecting groups.

Stability and in Vivo UV-Protecting Efficacy of Emulsions Stabilized with Cinnamoyl Surfactants

  • Park, Seok Ho;Kwon, Kyeongnan;Kim, Jin-Chul
    • Korean Chemical Engineering Research
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    • 제56권2호
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    • pp.143-150
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    • 2018
  • Oil-in-water emulsion was prepared using cinnamoyl surfactants as emulsifiers. Cinnamoyl surfactants used in the present study were polyoxyethylene (20) sorbitan monolaurate-cinnamic acid conjugate (TW20CA), polyoxyethylene (20) cetyl ether-cinnamic acid conjugate (CE20CA), and polyoxyethylene(20) oleyl ether-cinnamic acid conjugate (OE20CA). The emulsion stabilized with TW20CA was the most stable, possibly because the polyoxyethylene segment of TW20CA would sterically stabilize the oil droplets effectively. In vivo UV protecting efficacy of surfactant and emulsion was investigated by determining the minimum amount of UV light (MAUL) to induce a black point on the back of hairless mice (HRM2). The mean MAUL of PARSOL, OE20CA, and emulsion stabilized with TW20CA was $1046.5mJ/cm^2$, $1163mJ/cm^2$, and $1308.5mJ/cm^2$, respectively. The high UV-protecting efficacy of the emulsion could be ascribed to not only the UV-absorbing property of cinnamoyl group but also the UV-scattering property of the oil droplets.

Role of soy lecithin combined with soy isoflavone on cerebral blood flow in rats of cognitive impairment and the primary screening of its optimum combination

  • Hongrui Li;Xianyun Wang;Xiaoying Li;Xueyang Zhou;Xuan Wang;Tiantian Li;Rong Xiao;Yuandi Xi
    • Nutrition Research and Practice
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    • 제17권2호
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    • pp.371-385
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    • 2023
  • BACKGROUND/OBJECTIVES: Soy isoflavone (SIF) and soy lecithin (SL) have beneficial effects on many chronic diseases, including neurodegenerative diseases. Regretfully, there is little evidence to show the combined effects of these soy extractives on the impairment of cognition and abnormal cerebral blood flow (CBF). This study examined the optimal combination dose of SIF + SL to provide evidence for improving CBF and protecting cerebrovascular endothelial cells. MATERIALS/METHODS: In vivo study, SIF50 + SL40, SIF50 + SL80 and SIF50 + SL160 groups were obtained. Morris water maze, laser speckle contrast imaging (LSCI), and hematoxylin-eosin staining were used to detect learning and memory impairment, CBF, and damage to the cerebrovascular tissue in rat. The 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the oxidized glutathione (GSSG) were detected. The anti-oxidative damage index of superoxide dismutase (SOD) and glutathione (GSH) in the serum of an animal model was also tested. In vitro study, an immortalized mouse brain endothelial cell line (bEND.3 cells) was used to confirm the cerebrovascular endothelial cell protection of SIF + SL. In this study, 50 µM of Gen were used, while the 25, 50, or 100 µM of SL for different incubation times were selected first. The intracellular levels of 8-OHdG, SOD, GSH, and GSSG were also detected in the cells. RESULTS: In vivo study, SIF + SL could increase the target crossing times significantly and shorten the total swimming distance of rats. The CBF in the rats of the SIF50 + SL40 group and SIF50 + SL160 group was enhanced. Pathological changes, such as attenuation of the endothelium in cerebral vessels were much less in the SIF50 + SL40 group and SIF50 + SL160 group. The 8-OHdG was reduced in the SIF50 + SL40 group. The GSSG showed a significant decrease in all SIF + SL pretreatment groups, but the GSH showed an opposite result. SOD was upregulated by SIF + SL pretreatment. Different combinations of Genistein (Gen)+SL, the secondary proof of health benefits found in vivo study, showed they have effective anti-oxidation and less side reaction on protecting cerebrovascular endothelial cell. SIF50 + SL40 in rats experiment and Gen50 + SL25 in cell test were the optimum joint doses on alleviating cognitive impairment and regulating CBF through protecting cerebrovascular tissue by its antioxidant activity. CONCLUSIONS: SIF+SL could significantly prevent cognitive defect induced by β-Amyloid through regulating CBF. This kind of effect might be attributed to its antioxidant activity on protecting cerebral vessels.

크로토니테논에 대한 합성방법 (A Synthetic Approach towards Crotonitenone)

  • 김영균
    • Journal of the Korean Wood Science and Technology
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    • 제23권4호
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    • pp.98-107
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    • 1995
  • 천연물 중 casbene-type diterpenoid의 하나인 crotonitenone의 합성이 시도되었다. 합성 방법으로는 crotonitenone의 각 부분을 먼저 합성하여 이들을 합하는 방법(convergent method)을 적용하였으며, 각 부분이 최종물질에 적합한 sterochemistry를 갖게 하기 위하여 시작물질로는 chiron으로 S-(-)-citronellol과 IS-chrysanthemic acid를 사용하였다. 환구조를 형성하는데 중요한 역할을 할 TBDMS protecting group이 붙은 phosphonium salt(synthon A) 가 고압반응으로부터 고수율 (70%)로 생성되었다. 또한, 중요한 반응으로서 synthon A와 hydroxy lactone(synthon B)과의 Witting reaction이 성공적으로 이루어졌다. 그러나, TBDMS protecting group의 존재하에 이중 치환된 이중결합(disubstituted double bond)과 삼중치환된 것과의 선택적인 환원의 어려움으로 인하여 최종 물질의 합성방법이 재고되었으며 이에 대해 간단히 논하였다.

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사염화탄소를 처리한 생쥐에서 석류종자기름의 간보호 효과 (The Liver Protecting Effect of Pomegranate (Punica granatum) Seed Oil in Mice Treated with $CCl_4$)

  • 김동희;등영건;이영미;윤양숙;권기록;박대복;박승규;이규재
    • Applied Microscopy
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    • 제36권3호
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    • pp.173-182
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    • 2006
  • 최근 석류씨 기름은 항암효과를 포함하여 다양한 효과가 있는 것으로 확인되고 있다. 본 연구는 BALB/c 생쥐에 석류씨 기름을 처리한 후 사염화탄소를 주사하여 석류씨 기름이 간 독성에 어떤 영향을 미치는지 확인하기 위하여 올리브 기름만을 처리한 대조군, 사염화탄소만을 처리한 실험군1, 및 사염화탄소를 처리한 후 석류씨 기름을 구강투여한 실험군2로 나누어 24시간 후 혈액을 채취하여 혈청내 AST (aspartate aminotransferase, SGOT), ALT (alanine aminotransferase, SGPT), total protein, albumin, total bilirubin, direct bilirubin 및 alkaline phosphatase의 함량을 측정하였고 광학현미경과 투과전자현미경으로 조직의 변화를 관찰하였다. AST와 ALT는 대조군에서 각각 $88.70{\pm}14.90$$22.00{\pm}3.12IU/L$, 실험군 1에서 $1963.70{\pm}1212.90$$4495.40{\pm}2803.60IU/L$ 그리고 실험군2에서 $432.20{\pm}260.10$$692.30{\pm}433.10IU/L$이었으며 실험군2에서의 측정값은 실험군 1에 비해 유의한 차이를 보였다(P<0.005). 간조직을 관찰한 결과 사염화탄소를 처리한 실험군1에서는 문맥을 제외한 중심정맥 주위에서 간조직의 심한 응고성 괴사가 관찰되었고, 괴사조직 가장자리 주위로 지방변성을 확인할 수 있었다. 이에 비하여 석류씨 기름을 처리한 군에서 중심정맥 주위의 간실질 조직의 괴사가 실험군1에 비하여 현저히 줄어들었고, 간세포의 지방변성은 계속 관찰되었으나 용해소체의 감소와 미토콘드리아가 실험군1에 비해서 보존되어 있는 것으로 보아 석류씨 기름이 간보호에 효과가 있는 것으로 사료된다.

Protection Process of the tert-Butyl Group as a Non-Polar Moiety of D-Serine: Unexpected Rearrangement

  • Choi, Bo-Eun;Jeong, Jin-Hyun
    • Archives of Pharmacal Research
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    • 제23권6호
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    • pp.564-567
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    • 2000
  • The use of amino acid derivatives as building blocks in peptide synthesis is increasingly being recognized as a potential route for the development of pharmaceutical agents. Side chain protection of polyfunctional amino acids such as Ser, Thr, Tyr is viewed as being particularly important. Although these derivatives are commercially listed, they are expensive and not widely available. We describe here a practical large-scale synthesis of t-butyl introduced D-serine, one of the building blocks of zoladex, a peptide drug.

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Synthesis of 2-Amino-4,6-Di-O-Benzoyl-3-O-Benzyl-1,2-Dideoxy Mannojirimycin

  • 조재익;윤신숙;천근호;Shin, Jeong E.
    • Bulletin of the Korean Chemical Society
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    • 제16권9호
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    • pp.805-808
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    • 1995
  • Diacetone-D-glucose was converted into 5-azido-6-O-benzoyl-3-O-benzyl-5-deoxy-1,2-O-isopropylidene-α-D-glucofuranose. After removal of isopropylidene and benzoyl protecting groups, hydrogenation performed reduction of azide and subsequent cyclization by reductive amination to give 3-O-benzyl-1-deoxy nojirimycin in high yield. The second azide group was introduced on 2-carbon by selective substitution reaction, and reduction of azide to amino group gave titled compound.