• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1307-1314
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• 2015

Leukemia inhibitory factor (LIF) is a member of the IL-6 cytokine family, having pleiotropic actions such as maintaining stem cell pluripotency and enabling blastocyst implantation. Because the action of LIF is mediated by a ligand-receptor interaction with the LIF receptor (LIF-R), an antagonist for LIF-R has been developed to inhibit LIF-induced signaling. In this study, we present a novel method for the production and purification of an antagonist to human LIF-R (hLA). His-tagged hLA was expressed in E. coli, and simple purification methods without any endopeptidase cleavage were designed. In addition, we determined the optimal temperature conditions for enhancing the production of soluble hLA. Finally, the bioactivity of His-tagged hLA was examined using STAT3 phosphorylation and receptivity of human endometrial ECC-1 cells. Our strategy provides a rapid and efficient method to produce biologically active recombinant hLA.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1843-1847
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• 2010

An efficient method for the preparation of 1,4-disubstituted 1,2,3-triazole compounds is described using polymeric quaternary ammonium salts having azide or alkyne functionality to remove unreacted excess starting molecules (azide/alkyne). Copper metal could easily be removed by simple filtration with a short $Na_2SO_4$/silica cartridge, affording highly regioselective products in high yield and excellent purity without the need for work-up, extraction and chromatographic purification.

• Journal of Ginseng Research
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• v.14 no.2
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• pp.217-220
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• 1990

Two lignanes, Comp.-I, mp 108-1$0^{\circ}C$ and Comp.-II 50-52$^{\circ}$were isolated from Korea ginseng extract by repeated column chromatographic purification. Comp.-I was identified as gomisin-N and Comp.-II as gomisin-A by spectrometric analysis, both of which have already been described as the anti-hepatotoxic lignan components of Schizandra chinesis Bail.

• BMB Reports
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• v.37 no.1
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• pp.59-74
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• 2004

The study of whole patterns of changes in protein expression and their modifications, or proteomics, presents both technological advances as well as formidable challenges to biological researchers. Nutrition research and the food sciences in general will be strongly influenced by the new knowledge generated by the proteomics approach. This review examines the different aspects of proteomics technologies, while emphasizing the value of consideration of "traditional" aspects of protein separation. These include the choice of the cell, the subcellular fraction, and the isolation and purification of the relevant protein fraction (if known) by protein chromatographic procedures. Qualitative and quantitative analyses of proteins and their peptides formed by proteolytic hydrolysis have been substantially enhanced by the development of mass spectrometry technologies in combination with nanoscale fluidics analysis. These are described, as are the pros and cons of each method in current use.

• Korean Journal of Pharmacognosy
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• v.4 no.4
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• pp.167-172
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• 1973

Five crystalline substances, which are positive to$L_{IEBERMAN}-B_{URCHARD}$ reaction, were isolated from the unsaponifiable fraction of the fresh leaves of Betula latifolia $K_{OMAROV}$ (Betulaceae)by silica gel column chromatographic purification. Compound $A\;(C_{29}H_{50}O,\;mp\;136^{\circ}), \;B\;(C_{30}H_{52}O_3,\;mp\;165^{\circ}), \;C\;(C_{30}H_{52}O_4,\;mp\;237^{\circ}), \;D\;(C_{30}H_{52}O_3,\;mp\;196^{\circ})\;and\; E\;(C_{30}H_{52}O_4,\;mp\;121^{\circ})$ were isolated. Compound B was characterized as a new tetracyclic triterpenoid. Compounds A, C and D were identified as ${\beta}-sitosterol$, betulatriterpene C, and betulafolienetriol, respectively.

• Journal of Food Hygiene and Safety
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• v.9 no.2
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• pp.89-94
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• 1994

A simple, safe, and sensitive gas chromatographic method using packed column and electron capture detector to analyze 2, 4-D herbicide in imported lemon, grapefruit, and orange was described and its usefulness evaluated. In this scheme of analysis the acid herbicide was converted into its alkyl esters by an one-step reaction prior to analysis. The herbicide in the fruits was extracted with ethyl acetate and partitioned against dichloromethane for purification, and the extracts finished partitioning were derivatized with alcohol, using sulfuric acid as a catalyst to form the corresponding alkyl derivatives. The analytical scheme studiedwas found to be applicable for the herbicide in the fruits without a column clean-up procedure. The mean recoveries of the herbicide for lemon samples fortified at 0.1 mg/kg and 1.0 mg/kg were 93% and 95%, respectively. The detection limit was 0.5 $\mu\textrm{g}$/kg for 2.4-D methyl ester.

• YAKHAK HOEJI
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• v.40 no.1
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• pp.36-40
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• 1996

Chemical constituents of Uncaria hooks were studied. Four compounds were isolated from the ether soluble fraction by chromatographic purification process. They were ident ified as isocorynoxeine-N-oxide, anti-isorhynchophylline-N-oxide, physcion and ursolic acid by spectral evidences. Their contents analyzed by HPLC or GC method were physcion 0.04%, ursolic acid 0.26%, isocorynoxeine-N-oxide 0.04% and anti-isorhynchophylline-N-oxide 0.03% respectively. Isocorynoxeine-N-oxide was not reported in nature so far.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.48-51
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• 2014

${\alpha}$-Neoagarooligosaccharide (${\alpha}$-NAOS) hydrolase was purified from Cellvibrio sp. OA-2007 by using chromatographic techniques after hydroxyapatite adsorption. The molecular masses of ${\alpha}$-NAOS hydrolase estimated using SDS-PAGE and gel filtration chromatography were 40 and 93 kDa, respectively, and the optimal temperature and pH for the enzyme activity were $32^{\circ}C$ and 7.0-7.2. ${\alpha}$-NAOS hydrolase lost 43% of its original activity when incubated at $35^{\circ}C$ for 30 min. The enzyme hydrolyzed neoagarobiose, neoagarotetraose, and neoagarohexaose to galactose, agarotriose, and agaropentaose, respectively, and produced 3,6-anhydro-L-galactose concomitantly; however, it did not degrade agarose.

• YAKHAK HOEJI
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• v.34 no.1
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• pp.34-39
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• 1990

The alkaloidal constituents of Commelina communis(Commelinaceae) were investigated. From the ether soluble alkaloidal fraction, three ${\beta}-carboline$ type alkaloids were isolated by chromatographic purification process. Their chemical structures were identified as $1-carbomethoxy-{\beta}-carboline$, norharman and harman from the physicochemical data, which were newly isolated from this plant.

• Proceedings of the Ginseng society Conference
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• 1978.09a
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• pp.13-17
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• 1978

This paper is concerned with the studies on the effective components of anti-oxidant activity, with a view to demonstrate the anti-aging activity of Korean ginseng. Feeding the extract of Korean ginseng or its effective component to mice inhibited strongly the induction of lipid peroxidation produced by ethanol intoxication. From the extract of Korean red ginseng, one effective component Compound A, mp.143, $C_6H_6O_3$ was isolated by chromatographic purification and its chemical structure was determined as 2-meth-y1-3-hydroxy-${\gamma}-pyrone(maltol).$