• Title/Summary/Keyword: Natural ester

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A Novel Prosapogenin from the Methanolyzate of Melandrium Crude Saponins

  • Woo, Eun-Hee;Woo, Won-Sick
    • Korean Journal of Pharmacognosy
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    • v.22 no.4
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    • pp.211-214
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    • 1991
  • Two compounds were isolated from the methanolyzate of the butanol-soluble fraction obtained from the whole plants of Melandrium firmum (Caryophyllaceae) and identified as $3-{\beta}-D-glucuronopyranosylmelandrigenin$ methyl ester and $2{\beta},\;21{\beta}-dihydroxy-16,\;23-dioxo-28-norolean-13(18)-ene$.

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Expression of Cholesteryl Ester Transfer Protein cDNA using Recombinant Vaccinia Viruses

  • Jang, Moon-Kyoo;Ahn, Byung-Yoon;Huh, Tae-Lin;Bok, Song-Hae;Park, Yong-Bok
    • BMB Reports
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    • v.28 no.3
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    • pp.216-220
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    • 1995
  • cDNA for human cholesteryl ester transfer protein (CETP), a potent atherogenic plasma protein that redistributes the neutral lipids among lipoproteins, was expressed in recombinant vaccinia virus-infected cells (CV-1). Two insertion vectors regulated by different promoters were constructed. The vectors were introduced into human thymidine kinase-negative ($TK^-$) 1438 cells infected with wild-type vaccinia virus (WR strain). Recombinant viruses were selected with 5-bromodeoxyuridine (BUdR) and X-gal and identified with DNA dot blot analysis (vSC11-CETP and vTM1-CETP). The CETP cDNA insert in the recombinant vaccinia virus genome was identified by Southern blot analysis. Transcription of CETP cDNA in CV-1 cells infected with recombinant vaccinia virus was monitored by Northern blot analysis using the CETP cDNA as a probe. Positive signals were detected at 1.8 kb in cells infected with vSC11-CETP and at 2.3 kb in cells infected with vTM1-CETP. The recombinant vaccinia virus-infected CV-1 cells were shown to produce functional CETP when the culture medium was subjected to the CETP assay.

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Suberitenone B: A Novel Inhibitor of Cholesteryl Ester Transfer Protein (CETP) with an Unprecedented Skeletal Class from the Antarctic Sponge Suberites sp.

  • Shin, Jongheon;Seo, Youngwan;Rho, Jung-Rae;Baek, Eunjoo;Kwon, Byoung-Mog;Jeong, Tae-Sook;Bok, Song-Hae
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.04a
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    • pp.64-64
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    • 1995
  • Cholesteryl Ester Transfer Protein (CETP) mediates the transfer of cholesterol ester and triglyceride between high-density lipoprotein (HDL) and other low-density lipoproteins, therefore, it might influence HDL levels. The levels of HDL is closely related to the atherogenic diseases in human and there were several reports that the trasgenic mice expressing CETP had much worse atherosclerosis than non-expressing control one. Therefore, selective inhibitors of CETP have the potential to be used as antiatherosclerotic agents. Continued screening for potent inhibitors of CETP led to the isolation of Suberitenone B from marine sponge. Suberitenone B, sesterterpenoids of a new skeletal class have been isolated from the sponge Suberites sp. collected from King George Island the Antartic. The structure of the metabolite has been determined by NMR experiments and chemical methods.

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A New Analog of Antimycin from Streptomyces sp. M03033

  • Seo, Young-Wan;Cho, Ki-Woong;Rho, Jung-Rae;Mo, Sang-Jun;Shin, Jong-Heon
    • Journal of Microbiology and Biotechnology
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    • v.11 no.4
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    • pp.663-667
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    • 2001
  • A new secondary metabolite was isolated from the culture broth and mycelium of Streptomyces sp. collected from marine sediment. The structure of this compound was determined to be N-formylantimycic acid methyl ester, an acyclic derivative of antimycin, on the basis of combined chemical and spectral methods. The structure-activity relationship of antimycins is discussed.

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Effective Amidation of Carboxylic Acids Using (4,5-Dichloro-6-oxo-6H-pyridazin-1-yl)phosphoric Acid Diethyl Ester

  • Kang, Seung-Beom;Yim, Heung-Seop;Won, Ju-Eun;Kim, Min-Jung;Kim, Jeum-Jong;Kim, Ho-Kyun;Lee, Sang-Gyeong;Yoon, Yong-Jin
    • Bulletin of the Korean Chemical Society
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    • v.29 no.5
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    • pp.1025-1032
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    • 2008
  • (4,5-Dichloro-6-oxo-6H-pyridazin-1-yl)phosphoric acid diethyl ester (3a) are efficient and selective coupling agents for the amidation of carboxylic acids. Amidation of aliphatic and aromatic carboxylic acids with aliphatic and aromatic amines using 3a under mild condition gave chemoselectively the corresponding amides in good to excellent yield. Three protected-dipeptides were also synthesized from N-BOC-Phe and O-Me-amino acid hydrochlorides using 3a under mild condition.

Anticomplement Activities of Oleanolic Acid Monodesmosides and Bisdesmosides Isolated from Tiarella polyphylla

  • Park, Si-Hyung;Oh, Sei-Ryang;Jung, Keun-Young;Lee, Im-Seon;Ahn, Kyung-Seop;Kim, Jae-Gil;Lee, Jung-Joon;Lee, Hyeong-Kyu
    • Archives of Pharmacal Research
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    • v.22 no.4
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    • pp.428-431
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    • 1999
  • Seven known oleanolic acid glycosides (1-7) were isolated form the MeOH extract of Tiarella polyphylla. The structures were identified to be 3-O-($\beta$-glucopyranosyl) oleanolic acid (1), 3-O-[$\beta$-D-glucopyranosyl-(1 3)-$\beta$-D-glucopyranosyl] oleanolic acid (2), 3-O-D-[$\beta$-D-glucopyranosyl-(1 2)-$\beta$-D-glycopyranosyl] oleanolic acid (3), 3-O-[$\beta$-D-glucopyranosyl-(1 3)-$\beta$-D-glucopyranosyl] oleanolic acid 28-O-$\beta$D-glucopyranosyl ester (4), 3-O-[$\beta$-D-glucopyranosyl-(1 2)-$\beta$-D-glucopyranosyl] oleanolic acid 28-O-$\beta$-D-glucopyranosyl ester (5), 3-O-[a-L-rahmnopyranosyl-(1 3)-$\beta$-D-glucururonopyranosyl] oleanolic acid (6), and 3-O-[$\alpha$-L-rhamnopyranosyl-(1 3)-$\alpha$-D-glucuronopyranosyl] oleanolic acid 28-O-$\alpha$-D-glucopyranosyl ester (7) on the basis of physicochemical and spectral data. These triterpene glycosides were tested for the anti-complement activity and hemolytic activity. Bisdesmosidic saponins, 4, 5, and 7, showed anti-complement activity; in contrast, monodesmosidic saponins, 1-3, and 6, showed direct hemolytic activity. Methyl esterified monodesmosidic saponins showed anti-complement activity at a low concentration and hemolytic activity at a high concentration.

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Fluorine Labeling in Biosynthetic Studies (I) : Synthesis of Fluorfarnesols

  • Park, O-Sook
    • Archives of Pharmacal Research
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    • v.9 no.4
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    • pp.237-242
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    • 1986
  • The Synthesis of E, E, E-12-fluorofarnesol and E, Z-6-fluorofarnesol which are key intermediates for the study of biosynthesis of some sesquiterpenes, is described. E, E-Farnesyl acetate is treated with selenium dioxide to give E, E, E-12-hydroxy farnesyl acetate, whih is transformed by DAST into E, E, E-12-hydroxy farnesyl acetate, which is transformed by DAST into E, E, E,-12-fluorofarnesylacetate. The latter compound is hydrolyzed to E, E, E,-12-fluorofarnesol. The reformatsky reaction of 6-methyl-5-hepten-2-one with ethyl bromofluoroacetate affords ethyl 2-fluoro-3-hydroxy-3, 7 dimethyl-6-octanoate. This ester is acetylated and eliminated to give ethyl (Z)-2-fluoro-3, 7-dimethylocta-2, 6-dienoate, which is transformed to allyl bromide via allylic alcohol. The allyl bromide is treated with dianion of methyl acetate to give-keto ester. The $\beta$-keto ester is converted to diethyl phosphoryloxy compound. The conjugate addition of lithium dimethylcuprate to the latter compound gives fluoro ester, which is treated with DIBAL to afford E, Z-6-fluorofarnesol.

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