• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.643-647
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• 2004

Natural antimicrobial substance from peanut (Arachis hypogaea) shells was isolated and structurally elucidated. Peanut shells were extracted with methanol (MeOH) and concentrated in vacuo, MeOH extract was solvent-fractionated with ethyl acetate (EtOAc) and various buffer to obtain EtOAc acidic, neutral, and phenolic fractions. EtOAc neutral fraction, which showed antimicrobial activity, was purified through silica gel adsorption column, Sephadex LH-20 column, ODS column, and high performance liquid chromatographies, and its active substance was isolated and identified as pratensein (3',5,7-trihydroxy-4'-methoxyisoflavone) by spectroscopic methods of proton-nuclear magnetic resonance, mass spectrometry, and nuclear overhauser enhancement spectroscopy.

• Archives of Pharmacal Research
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• v.23 no.5
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• pp.441-445
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• 2000

Achiral-chiral column switching HPLC assay was developed to allow the separation and quantification of the enantiomers of terbutaline in human plasma by means of fluorescence detection. Plasma samples were prepared by solid-phase extraction with sep-pak silica, followed by HPLC assay. The enantiomers of terbutaline and the internal standard were separated from the biological matrix on a silica column, and the two enantiomers were resolved and quantified on a Sumichiral OA-4900 column. The two columns were connected by a switching valve equipped with silica trap column, The trap column was used to concentrate the terbutaline in the eluent from the achiral column before back flushing onto the chiral phase. For each enantiomers, the assay was linear between 2.5-125 ng/$m\ell$ (r=0.9999) and detection limit was 1.0 ng/$m\ell$ .

• FOCUS: LIFE SCIENCE
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• no.1
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• pp.5.1-5.3
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• 2024

The document discusses the regeneration of Partisil/Partisphere ion-exchange columns in chromatography. It mentions that column efficiency can diminish with use due to the accumulation of sample and/or mobile phase impurities at the head of the column. This can lead to a change in back pressure, lower column efficiency, and sometimes a change in selectivity. The document outlines a procedure that may restore column performance. The document also provides everyday practices to enhance the lifetime of a column. These include using only high-purity HPLC solvents and buffers, using freshly prepared mobile phases and buffers, filtering mobile phases to remove particulates, using appropriate sample clean-up procedures, using a guard column or pre-column filter, and working within the pressure and flow rate limitations of the column. For the regeneration of Partisil/Partisphere SAX, SCX, WAX, and WCX columns, the document suggests passing 20 column volumes of various mobile phases through the column. These include a buffer wash, distilled water, an acid wash, a chelating wash, a methanol wash, and a buffer for separation. The document emphasizes that not all of these wash steps are required for every column clean-up and that some chromatographers require only a combination of certain steps.

• Microbiology and Biotechnology Letters
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• v.26 no.6
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• pp.558-561
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• 1998

In the screening for lipid peroxidation inhibitors from edible mushroom, Agrocybe cylindracea, a bioactive compound AG 8 was isolated. The AG 8 was purified from methanol extract of its fruit body by Diaion HP-20 column chromatography, ethyl acetate extraction, and silica gel column chromatography, consecutively. Based on various NMR studies including $^1$H irradiation and HMBC experiments, the AG 8 was identified as MTA, 5'-deoxy-5'-methylthioadenosine. This compound inhibited lipid peroxidation with an $IC_{50}$/ value of 3.2 $\mu\textrm{g}$/$m\ell$. The MTA was isolated for the first time from basidiomycetes.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.204-210
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• 1997

The ethyl acetate (EtOAc) extracts from needles of Pinus densiflora were showed antimicrobial activities against bacteria, yeast and fungi. The antimicrobial active substance of EtOAc extracts were successively purified with solvent fractionation, silica gel adsorption column chromatography and Sephadex LH-20 column chromatography. The purified active substance was isolated as crystals and identified as benzoic acid by $MS,\;^{1}H-NMR\;and\;^{13}C-NMR$. The amount of benzoic acid was 0.608 mg per gram of fresh needle of Pinus densiflora.

• Microbiology and Biotechnology Letters
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• v.28 no.2
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• pp.92-96
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• 2000

Aspergillus sp. F184 was isolated from soil for the development of new xanthine oxidase inhibitor. This xanthine oxidase inhibitor was sequentially purified by filtration, HP-20 adsorption column chromatography, ethyl acetate extraction, silica gel column chromatography and crystallization, and was named as YUX 104. YUX 104 was identified to be 5,6-epoxy-2-hydroxy-3-methyl-2-cyclohexene-1,4-dione(terreic acid) by NMR and mass spectroscopic sudies.

• Microbiology and Biotechnology Letters
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• v.8 no.2
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• pp.125-133
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• 1980

A microorganism which produced D-glucose isomerase was identified to be similar to Streptomyces antibioticus on the morphological, cultural and physiological characteristics except the spore chain and the utilization of sucrose. D-xylose grown cells of Streptomyces sp. strain K-17 were disrupted by grinding with sea sand. D-glucose isomerase was partially purified with the fractionation by ammonium sulfate, Mn-treatment, DEAE-cellulose column chromatography, DEAE-sephadex (A-50) column chromatography and gel filtration of sephadex G-200. The enzyme was purified about 380 fold with 25 ％ recovery.

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.44-48
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• 1990

Alkalophilic sp. YC-335 isolated from soil was capable of producing large amount of cyclodextrin glycosyltransferase (CGTase) in culture broth. This enzyme was successively purified 52.9 folds with 17.8 yield by ethanol precipitation, DEAE-Toyopearl column chromatography and Sephadex G-100 column chromatography. The purified enzyme have a molecular weight of approximately 75,000 estimated by SDS polyaerylamide gel electrophoresis. The optimum pH and temperature for the enzyme activity were 6.0 and 5$0^{\circ}C$, respectively. The enzyme stable between pH 6 and 10, and up to 5$0^{\circ}C$. The thermostability of the enzyme was increased up to 6$0^{\circ}C$ by the addition of 15mM CaCl$_2$.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.191-196
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• 1998

The MeOH extract from root of Pulsatilla koreana was showed antimicrobial activities against bacteria and yeast. The antimicrobial active substances of MeOH extract were successfully purified with solvent fractionation, silica gel adsorption column chromatography and Sephadex LH-20 column chromatography. The purified two active substances were isolated by HPLC and identified as 4-hydroxy-3-methoxycinnamic acid and 3,4-dihydroxycinnamic acid by MS, $^{1}H-NMR$ and $^{13}C-NMR$.

• KSBB Journal
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• v.18 no.6
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• pp.511-516
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• 2003

The methanol extract from leaves of Catalpa ovata 6. DoN showed DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity, and its antioxidative compounds were studied. The ethyl acetate-soluble neutral fraction from the methanol extract was successively purified with silica gel adsorption column chromatography, Sephadex LH-20 column chromatography and HPLC. Three antioxidative compounds were isolated and identified as piperitol, pinoresinol and lariciresinol by HR-MS and NMR spectroscopic analyses. The DPPH radical-scavenging activity of the identified compounds decreased in the order of lariciresinol > pinoresinol > piperitol.