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951.
Seo EJ Curtis-Long MJ Lee BW Kim HY Ryu YB Jeong TS Lee WS Park KH 《Bioorganic & medicinal chemistry letters》2007,17(23):6421-6424
We have proven that xanthones 1-8 isolated from the root of C. tricuspidata possess highly potent alphaalpha-glucosidase inhibition properties. Compound 1 was identified as a new isoprenylated tetrahydroxy xanthone, 1,3,6,7-tetrahydroxy-2-(3-methylbut-2-enyl)-8-(2-methylbut-3-en-2-yl)-9H-xanthen-9-one (1). These are the first natural xanthones documented to exhibit such inhibition. The IC(50) values of compounds 1-8 inhibiting alpha-glucosidase activity were determined to be up to 16.2microM. Mechanistic analysis showed the xanthones 1-8 exhibited full mixed inhibition. 相似文献
952.
Doddareddy MR Choo H Cho YS Rhim H Koh HY Lee JH Jeong SW Pae AN 《Bioorganic & medicinal chemistry》2007,15(2):1091-1105
Virtual screening of the commercial databases was done by using a three dimensional pharmacophore previously developed for T-type calcium channel blockers using CATALYSTtrade mark program. Biological evaluation of 25 selected virtual hits resulted in the discovery of a highly potent compound VH04 with IC(50) value of 0.10 microM, eight times as potent as the known selective T-type calcium channel blocker, mibefradil. Search for similar compounds yielded several hits with micro-molar IC(50) values and high T-type calcium channel selectivity. Based on the structure of the virtual hits, small molecule libraries with novel scaffolds were designed, synthesis and biological evaluation of which are currently in progress. This result shows a successful example of ligand based drug discovery of potent T-type calcium channel blockers. 相似文献
953.
Chung JU Kim SY Lim JO Choi HK Kang SU Yoon HS Ryu H Kang DW Lee J Kang B Choi S Toth A Pearce LV Pavlyukovets VA Lundberg DJ Blumberg PM 《Bioorganic & medicinal chemistry》2007,15(18):6043-6053
A series of alpha-substituted N-(4-tert-butylbenzyl)-N'-[4-(methylsulfonylamino)benzyl]thiourea analogues have been investigated as TRPV1 receptor antagonists. alpha-Methyl substituted analogues showed potent and stereospecific antagonism to the action of capsaicin on rat TRPV1 heterologously expressed in Chinese hamster ovary cells. In particular, compounds 14 and 18, which possess the R-configuration, exhibited excellent potencies (respectively, K(i)=41 and 39.2 nM and K(i(ant))=4.5 and 37 nM). 相似文献
954.
955.
Ke T Jeong EK Wang X Feng Y Parker DL Lu ZR 《International journal of nanomedicine》2007,2(2):191-199
Cyclic Arg-Gly-Asp-D-Phe-Lys [c(RGDfK)] targeted poly(L-glutamic acid) (PGA)-(Gd-DO3A) conjugate with a biodegradable cystamine spacer was prepared and evaluated for in vivo detection of an angiogenesis biomarker, alpha(v)beta3 integrin, in neoplastic tissues with T1 mapping, a quantitative magnetic resonance imaging (MRI) technique. The binding activity of the c(RGDfK) containing conjugate was investigated using in vitro vitronectin assay with human prostate carcinoma DU145 cell line and Kaposi's sarcoma SLK cell line. The peptide c(RGDfK) and PGA-cystamine-(Gd-DO3A) conjugate were used as controls. The binding affinity of polymer bound c(RGDfK) was slightly lower than free c(RGDfK) peptide. The RGD targeted conjugate had higher binding affinity to the DU145 cells than the SLK cells, which was consistent to free c(RGDfK). The imaging of alpha(v)beta3 integrin with targeted PGA-cystamine-(Gd-DO3A) was evaluated in nude mice bearing DU145 and SLK xenografts at a dose of 5 micromol-Gd/kg. The targeted conjugate demonstrated higher in vivo binding affinity to the DU145 xenografts than the SLK xenografts, resulting in a significant decrease of T1 values of water protons in the periphery of the DU145 tumors as shown in the MR T1 maps. No significant decrease of T1 values was observed in the SLK tumor with the targeted conjugate and in both tumors with the non-targeted conjugate. The targeted polymeric Gd(III) chelate conjugate with a degradable spacer has the potential to be a new paradigm for safe and effective probes in molecular imaging with quantitative MR T1 mapping. 相似文献
956.
Kyoung Ah Kang Rui Zhang Mei Jing Piao Min Jeong Park Ae Ran Kwon Bum Joon Kim Ho Jin You Myung Hee Chung Jin Won Hyun 《Biotechnology and Bioprocess Engineering》2007,12(2):114-120
8-Hydroxydeoxyguanosine (oh8dG) treatment induced senescence-like changes in KG-1 cells, a human acute myelocytic leukemia cell line. The oh8dG-treated cells stained positive for senescence associated β-galactosidase (SA-β-galactosidase) and had enlarged cell shape,
both of which are senescence indexes. The oh8dG-treated cells were also cell growth inhibited and arrested at G1 in the cell cycle. The accumulation of cdk (cyclin dependent kinase) inhibitors, such as p16, p21, and p27, also implies
that cellular senescence was induced in oh8dG-treated cells. However, these changes were not accompanied by cell differentiation or telomerase activity. Taken together,
we conclude that oh8dG treatment of KG-1 cells induces cellular senescence. 相似文献
957.
In this study, morphological alterations, biomass growth, and secondary metabolite production of genetically transformed hairy
roots ofPanax ginseng C. A. Meyer, were evaluated after administration of plant growth regulators. The addition of benzylamino purine and kinetin
to the culture media increased biomass formation and phenolic compound biosynthesis in the hairy roots. α-Naphthaleneacetic
acid and indole-3-butyric acid inhibited hairy root growth, however, low concentrations of indole-3-acetic acid slightly increased
hairy root growth. Low concentrations of 2,4-Dichlorophenoxyacetic acid profoundly inhibited growth of hairy roots. The addition
of plant growth regulators, such as auxin, did not increase total phenolic compounds in hairy roots that did not contain gibberellic
acid and cytokinins. Callus formation was induced in cultures suspended in liquid medium amended with benzylamino purine and
kinetin. Hairy roots regenerated from these calluses exhibited an active growth pattern with extensive lateral branching in
non-amended medium, similar to the growth pattern of the original hairy roots. 相似文献
958.
Park DS Oh HW Heo SY Jeong WJ Shin DH Bae KS Park HY 《Journal of microbiology (Seoul, Korea)》2007,45(5):409-417
Burkholderia sp. HY-10 isolated from the digestive tracts of the longicorn beetle, Prionus insularis, produced an extracellular lipase with a molecular weight of 33.5 kDa estimated by SDS-PAGE. The lipase was purified from the culture supernatant to near electrophoretic homogenity by a one-step adsorption-desorption procedure using a polypropylene matrix followed by a concentration step. The purified lipase exhibited highest activities at pH 8.5 and 60 degrees . A broad range of lipase substrates, from C4 to C18 rho-nitrophenyl esters, were hydrolyzed efficiently by the lipase. The most efficient substrate was rho-nitrophenyl caproate (C6). A 2485 bp DNA fragment was isolated by PCR amplification and chromosomal walking which encoded two polypeptides of 364 and 346 amino acids, identified as a lipase and a lipase foldase, respectively. The N-terminal amino acid sequence of the purified lipase and nucleotide sequence analysis predicted that the precursor lipase was proteolytically modified through the secretion step and produced a catalytically active 33.5 kDa protein. The deduced amino acid sequence for the lipase shared extensive similarity with those of the lipase family I.2 of lipases from other bacteria. The deduced amino acid sequence contained two Cystein residues forming a disulfide bond in the molecule and three, well-conserved amino acid residues, Ser131, His330, and Asp308, which composed the catalytic triad of the enzyme. 相似文献
959.
Ji-Suk Cho Hye Won Lee Song-Jae Lee Dong-Il Kim 《Biotechnology and Bioprocess Engineering》2007,12(4):333-339
The new technology, two-dimensional difference gel electrophoresis (2D DIGE), uses fluorescent dyes to simplify the process
of detecting and matching proteins between multiple gels by allowing for the separation of up to three separate protein samples
within the same gel. In this study, recombinant human cytotoxic T lymphocyte-associated antigen 4-immunoglobulin (hCTLA4lg)
was produced in transgenic rice suspension cell cultures and the intracellular proteins were analyzed by 2D DIGE. The highest
level of hCTLA4Ig (25.4 mg/L) was obtained five days after induction. The intracellular proteins expressed at both the growth
and induction culture stages were separated and analyzed using DeCyder software. At least 2,218 spots were detected with two-fold
thresholds and 95% confidence. We found that 29 spots increased and 20 spots decreased in their intensities during the production
of recombinant hCTLA4Ig. In addition, the 2D Western blot of hCTLA4Ig revealed that this fusion protein was expressed in a
variety of isoforms. 相似文献
960.
Hae Won Kim 《Biotechnology and Bioprocess Engineering》2007,12(1):43-47
In this brief review, basic principles and recent progresses on the development of therapeutic substitutes for major blood
components are briefly discussed with primary focus on the red cell substitutes. 相似文献