• Title/Summary/Keyword: 4A

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Structure elucidation of a newly isolated saponin from Clerodendrum serratum (L) Moon

  • Bhujbal, Santosh S.;K.Nanda, Rabindra;S.Deoda, Ramesh;Kumar, Dinesh;Kewatkar, Shailesh M.;S.More, Laxmikant;J.Patil, Manohar
    • Advances in Traditional Medicine
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    • v.10 no.4
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    • pp.319-321
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    • 2010
  • Plant saponins are widely distributed amongst plants and have a wide range of biological properties. Icosahydropicenic acid, $C_{51}H_{80}O_{19}$ ((4S,6bS)-8a-((4,5-dihydroxy-6-methyl-3-((3R)-3,4,5-trihydroxy-6-methyl-tetrahydro-2H-pyran-2-yloxy)-tetrahydro-2H-pyran-2-yloxy)carbonyl)-2-hydroxy-4, 6a, 6b, 11, 14b-pentamethyl-11-(2-methylprop-1-enyl)-3-(3,4,5-trihydroxy-6-(hydroxymethyl) - tetrahydro-2Hpyran-2-yloxy)-1, 2, 3, 4, 4a, 5, 6, 6a, 6b, 7, 8, 8a, 9, 10, 11, 12, 12a, 14, 14a, 14b-icosahydropicene-4-carboxylic acid), a new saponin was first time isolated from the roots of Clerodendrum Serratum (L) Moon (Verbenaceae). The structure elucidation of the compound was carried out by $^1H$ NMR and DART-MS studies.

Synthesis and Antibacterial Activity of New Tetrazole Derivatives (새로운 Tetrazole유도체의 합성과 항균활성)

  • Mulwad, V.V.;Pawar, Rupesh B;Chaskar, Atul C
    • Journal of the Korean Chemical Society
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    • v.52 no.3
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    • pp.249-256
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    • 2008
  • 3-Acetyl/Formyl 4-hydroxy-2H(1)-benzopyran-2-one on treatment with malonitrile and ethyl cyanoacetate yielded 1,1-dicyano-2-[4/-hydroxy-2/H(1)-benzopyran-2/-one-3/-yl] ethene/propene 2a-h and ethyl-2-cyano-3-[4/-hydroxy-2/H (1)-benzopyran-2/-one-3/-yl] propenoate/butenoate 3a-h respectively. The 1,3 dipolar reaction of 2a-h with NaN3 gave the tetrazole derivative 4a-h. 3a-h on cyclization with PPA gave 3-cyano-2H,5H-pyrano [3, 2-c] benzopyran-2,5-diones 5a-h which on 1,3 dipolar reaction with NaN3 to gave 3-(1/H-tetrazol-5/-yl)-2H,5H-pyrano[3, 2-c] benzopyran-2,5-diones 6a-h. The structures of the compounds have been established on the basis of the spectral and analytical data. All the compounds were screened for their antimicrobial activities and have been found to exhibited significant antibacterial activities. Compounds 2h and 4h showed the activity 50g/mL.

ON CONTACT THREE CR SUBMANIFOLDS OF A (4m + 3)-DIMENSIONAL UNIT SPHERE

  • Kwon, Jung-Hwan;Pak, Jin--Suk
    • Communications of the Korean Mathematical Society
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    • v.13 no.3
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    • pp.561-577
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    • 1998
  • We study (n+3)-dimensional contact three CR submanifolds of a Riemannian manifold with Sasakian three structure and investigate some characterizations of $S^{4r+3}$(a) $\times$ $S^{4s+3}$(b) ($a^2$$b^2$=1, 4(r + s) = n - 3) as a contact three CR sub manifold of a (4m+3)-dimensional unit sphere.

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Synthesis and Antibacterial Evaluation of Some Novel 1,3,4-oxadiazol Derivatives Incorporated with Quinoline Moiety (Quinoline moiety를 가지고 있는 1,3,4-oxadiazol 유도체의 합성 및 항균활성)

  • Mandhane, Priyanka G.;Joshi, Ratnadeep S.;Khan, Wajid;Gill, Charansingh H.
    • Journal of the Korean Chemical Society
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    • v.55 no.4
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    • pp.656-661
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    • 2011
  • 5-(3,4,5-Triethoxyphenyl)-1,3,4-oxadiazole-2-thiol 6 on treatment with substituted 3-(bromomethyl)-2-chloroquinoline or 2-(p-tolyloxy)-3-(bromomethyl)quinoline 4a-j afforded the corresponding 3-((5-(3,4,5-triethoxyphenyl)-1,3,4-oxadiazol-2-ylthio)methyl)-2-chloroquinoline or 3-((5-(3,4,5-triethoxyphenyl)-1,3,4-oxadiazol-2-ylthio)methyl)-2-(p-tolyloxy)quinoline 7a-j, in the presence of $K_2CO_3$ and DMF under stirring at ambient temperature. All the synthesized compounds were further screened for their antibacterial activities. Some of our compounds showed excellent antibacterial activities against test organisms and reference standard.

Regulation of Long-Chain Acyl-CoA Synthetase 4 Expression with Progesterone and Estradiol-$17{\beta}$ (프로게스테론과 에스트라디올 $17{\beta}$에 의한 Long-Chain Acyl-CoA Synthetase 4의 발현 조절)

  • Park, Hyo-Young;Kang, Man-Jong
    • Reproductive and Developmental Biology
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    • v.35 no.3
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    • pp.215-219
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    • 2011
  • Acyl-CoA synthetase 4(ACSL4) is an arachidonate-preferring enzyme abundant in steroidogenic tissues and postulated to modulate eicosanoid production. The human and mouse ACSL4 gene are mapped on chromosome X. The female mice heterozygous for ACSL4 deficiency became pregnant less frequent1y and produced small litters, with 40% of embryos surviving gestation. In this study, we examined the regulation of ACS4 by estradiol-$17{\beta}$ and progesterone (P4) in the human endometrial cancer cell line HTB-1B. ACSL4 mRNA was increased in a dose-dependent manner. Also, expression of ACSL4 gene was up-regulated in a time-dependent manner in HTB-1B cells. However, combined treatment with progesterone and estradiol-$17{\beta}$ modestly decreased the levels of ACS4L mRNA as compared with the estradiol-$17{\beta}$ and progesterone respectively. Overall, these results suggest that the ACSL4 gene is regulated by progesterone and estradiol-$17{\beta}$ in the HTB-1B cells.

Medium Optimization for Phytase Production by Recombinant Escherichia coli Using Statistical Experimental Design

  • Choi, Won-Chan;Oh, Byng-Chul;Kim, Hyung-Kwoun;Lee, Eun-Sook
    • Journal of Microbiology and Biotechnology
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    • v.12 no.3
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    • pp.490-496
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    • 2002
  • The production of E. coli WC7 phytase from a recombinant E. coli strain was optimized using a statistical experimental design approach. Two-level complete factorial designs with seven variables were used for the media optimization. In the first optimization step, the influence of disodium succinate, yeast extract, $K_2HPO_4,\;NH_4H_2PO_4,\;MgSO_4$, NaCl, and trace elements on phytase production was evaluated. As a result, disodium succinate, yeast extract, $NH_4H_2PO_4$, NaCl, and the trace elements were found to have a positive influence on the phytase production, while $K_2HPO_4\;and\;MgSO_4$ had a negative influence. In the second step, the concentrations of disodium succinate and yeast extract were further optimized using central composite designs. The maximum phytase activity obtained was 234 U/ml using 15.9 g/1 disodium succinate, 20 g/1 yeast extract, 5 g/1 K_2HPO_4,\;10 g/1 NH_4H_2PO_4,\;1.5 g/1 MgSO_4$, 4 g/1 NaCl, and 1.5 m1/1 trace elements, which was about a 14-fold increase in comparison with that obtained using the basal medium.

Preprocessing System for Real-time and High Compression MPEG-4 Video Coding (실시간 고압축 MPEG-4 비디오 코딩을 위한 전처리 시스템)

  • 김준기;홍성수;이호석
    • Journal of KIISE:Computing Practices and Letters
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    • v.9 no.5
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    • pp.509-520
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    • 2003
  • In this paper, we developed a new and robust algorithm for a practical and very efficient MPEG-4 video coding. The MPEG-4 video group has developed the video Verification Model(VM) which evolved through time by means of core experiments. And in the standardization process, MS-FDAM was developed based on the standard document of ISO/IEC 14496-2 and VM as a reference MPEG-4 coding system. But MS -FDAM has drawbacks in practical MPEG-4 coding and it does not have the VOP extraction functionality. In this research, we implemented a preprocessing system for a real-time input and the VOP extraction for a practical content-based MPEG-4 video coding and also implemented the motion detection to achieve the high compression rate of 180:1.

A fluorogenic method for measuring enteropeptidase activity: spectral shift in the emission of GD4K-conjugated 7-amino-4-methylcoumarin

  • Choi, Mal-Gi;Lee, Eung-Yeong;Chung, Hye-Shin;Jang, Sei-Heon;Lee, Chang-Woo
    • BMB Reports
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    • v.44 no.7
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    • pp.458-461
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    • 2011
  • Enteropeptidase is a serine protease secreted by the pancreas and converts inactive trypsinogen to active trypsin. Enteropeptidase cleaves the C-terminal end of the substrate recognition sequence Asp-Asp-Asp-Asp-Lys ($D_4K$). The assay for enteropeptidase has utilized $GD_4K$-conjugated 2-naphthylamine ($GD_4K$-NA) as a fluorogenic probe over the last 30 years. However, no other $D_4K$-conjugated fluorogenic substrates of enteropeptidase have been reported. Furthermore, naphthalene is known as carcinogenic to humans. In this study, we used shift in the emission spectrum of $GD_4K$-conjugated 7-amino-4-methylcoumarin ($GD_4K$-AMC) as a fluorogenic method to measure enteropeptidase activity. The kinetic analysis revealed that enteropeptidase has a $K_M$ of 0.025 mM and a $k_{cat}$ of 65 $sec^{-1}$ for $GD_4K$-AMC, whereas it has a $K_M$ of 0.5 to 0.6 mM and a $k_{cat}$ of 25 $sec^{-1}$ for $GD_4K$-NA. The optimum pH of $GD_4K$-AMC hydrolysis was pH 8.0. Our data indicate that $GD_4K$-AMC is more suitable as a substrate for enteropeptidase than $GD_4K$-NA.

High-Level Expression of Human Cytochrome P450 3A4 by Co-Expression with Human Molecular Chaperone HDJ-1 (Hsp40)

  • Ahn, Tae-Ho;Yun, Chul-Ho
    • Archives of Pharmacal Research
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    • v.27 no.3
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    • pp.319-323
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    • 2004
  • Cytochrome P450 (CYP) 3A4 is of great interest because of its important roles in the oxidation of numerous drugs and xenobiotics. HDJ-1, a molecular chaperone in human, is known to assist the correct folding of unfolded proteins. To achieve a high yield of recombinant human CYP3A4 in Escherichia coli, the CYP3A4 encoding gene was co-expressed with the chaperone HDJ-1, under the control of an inducible tac promoter in a bicistronic format. The levels of expression of the CYP3A4 in the bicistronic construct reached up to 715 nmol $(liter culture)^{-1}$ within 16 h at $37^{\circ}C$, which was about a 3.3-fold increase compared to that of the CYP3A4 alone without the HDJ-1. By co-expression with HDJ-1, the catalytic activity of CYP3A4 was also increased by -15-fold. The amount of activity increase was similar to that of the CYP production at the whole cell level. The present over-expression system may be useful for the rapid production of large amounts of active CYP3A4 in E. coli.

Functional Studies of Acyl-CoA Synthetase 4 in the Rat Liver (흰쥐 간장에 있어서 아실-CoA 합성효소4의 기능연구)

  • 정영희;문승주;강만종
    • Journal of Nutrition and Health
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    • v.36 no.4
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    • pp.376-381
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    • 2003
  • Acyl-CoA synthetase 4 (ACS4) is an arachidonate-preferring enzyme abundant in steroidogenic tissues. We examined ACS4 in rat liver, which contains a variety of pathways that use acyl-CoAs, in order to determine subcellular locations. We demonstrate that ACS4 protein was present most abundantly in the mitochondria and to a much lesser extent in the peroxisomes and microsomes. To determined the dietary effects on the level of ACS4 mRNA, northern blotting was carried out using total RNA from the livers of adult male rats fed various diets. Fasting, high fat diet, and fat-free high sucrose diet increased the hepatic level of ACS4 mRNA approximately 2-fold. Furthermore, the levels of ACS4 mRNA were induced by DEHP[Di- (2-ethylhexyl) phthalate]. These data suggest that ACS4 expression in the liver is regulated with a variety of pathways, including $\beta$-oxidation, hormone, and insulin.