• Korean Journal of Food Science and Technology
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• v.17 no.2
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• pp.55-59
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• 1985

Antioxidant activity of gingerol, a component of ginger, was studied in ${\beta}-carotene-linoleic$ acid-water emulsion system. Crude gingerol extracted from ginger was separated and purified by thin-layer chromatography (TLC) into two bands. The two bands were identified as 6- and 10-gingerol by color reactions on TLC plate, acid dehydration reaction, infrared and nuclear magnetic resonance spectrometry. The antioxidant activity of gingerols (mixture of 6- and 10-gingerol) separated from ginger was remarkable, but lower than that of BHA or BHT.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.915-920
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• 2011

Four esters of succinic and maleic acid were synthesized, separated by thin-layer chromatography (TLC), and identified using matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). A comparison of matrix materials showed that 2,6-dihydroxybenzoic acid (2,6-DHB) yielded a greater ionization efficiency than 2,5-DHB prior to TLC separation. The location of each ester sample on the TLC plate was estimated by comparing the developed plate with a duplicate plate that had been visualized by immersion in a $KMnO_4$ solution. Generally, mass spectra obtained from the $KMnO_4$-visualized plate were relatively poor. Reproducible mass spectra with high peak abundance were difficult to obtain using the 2,6-DHB matrix from crude synthetic esters extracted from the TLC plates. Significant improvements in both reproducibility and sensitivity were realized by using pencil lead as the MALDI matrix. The current methodology will be beneficial to organic chemists since it can provide a guideline for simple and rapid characterization of small organic compounds.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.558-562
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• 2004

Conditions for rapid quantification of isoflavones were studied. Rapid and clear separation of isoflavones (genistin and daidzin) was obtained using solvent system of chloroform : methanol : water : acetic acid (60 : 30 : 10 : 0.5, v/v/v/v). Quantification of each isoflavone separated by TLC was conducted by densitometry analysis. Genistin and daidzin were quantified in $0.15-1.80\;{\mu}g/{\mu}L$ range with 99% confidence. Concentrations of isoflavones in soybeans and kudzu roots originated from Korea were determined, and validity of TLC method for quantification of isoflavones was confirmed by comparison with HPLC analysis.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.1
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• pp.89-92
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• 2010

In the previous study, we reported the antioxidative activity, antiaging activity, antibacterial activity and moisturizing effect of cream containing Persicaria hydropiper L. extract. In this study, the components of Persicaria hydropiper L. extract were analyzed by TLC and HPLC. Aglycone fractions obtained from the deglycosylation reaction of ethyl acetate fraction among the Persicaria hydropiper L. extract, showed 2 bands and 2 peaks in TLC and HPLC experiments, respectively. Two components were identified as quercetin and kaempferol. TLC chromatogram of ethyl acetate fraction of Persicaria hydropiper L. extract revealed 6 bands and HPLC chromatogram showed 7 peaks, which were identified as quercetin, hyperin, isoquercitrin, quercitrin, kaempferol. In conclusion, with the antioxidative activity, antiaging activity, antibacterial activity and moisturizing effect reported previously, component analysis of Persicaria hydropiper L. extracts could be applicable to new cosmeceuticals.

• Journal of Food Hygiene and Safety
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• v.3 no.3
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• pp.105-109
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• 1988

To develop a method for detecting and e&timating the quantity of adulterant rapeseed oil in sesame oil, five kinds of sesame oils and three kinds of rapeseed oils collected from different sources were fractionated by TLC (thin layer chromatography) and separated on the basis of PN (partition number) by HPLC (high performance liquid chromatography). These obsenations indicate that the proportion of adulterant rapeseed oil when mixed minimum 4% with sesame oil can be detected.

• Journal of Life Science
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• v.18 no.2
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• pp.206-212
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• 2008

The quorum sensing (QS) regulatory network has been the subject of extensive studies during recent years and has also attracted a lot of attention because it both positively and negatively regulates various putative virulence factors, although initially considered to be a specialized system of Vibrio fischeri and related species. In this study, to identify the novel materials which inhibit QS system of microorganisms, extracts of eighteen natural products were tested by bioassay using N-(3-oxohexanoyl)-$_L$-homoserine lactone and N-(3-oxooctanoyl)-$_L$-homoserine lactone synthesized in this experiment and an Agrobacterium tumefaciens NT1 biosensor strain containing a traI::lacZ fusion. The result indicated that the extracts of cabbage, leek, and onion exhibited the QS inhibition activity. Thus, materials contained in the extracts were isolated via recycling preparative HPLC and were purified via a JAIGEL-LS255 column. The common fraction corresponding to a peak of the 83 min point of them quenched the quorum sensing of A. tumefaciens NT1 biosensor strain in ABMM containing X-gal and was designated quorum sensing inhibitor-83 min (QSI-83). The QSI-83 exhibited the heat stability and did not inhibit the growth of A. tumefaciens NTl. Furthermore, thin layer chromatography (TLC) results suggested that these novel materials may be antagonists of N-acyl homoserine lactone or may inhibit the QS autoinducer synthesis by Pseudomonas syringae pv. tabaci.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.3114-3114
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• 2001

During the last years phytochemistry and phytopharmaceutical applications have developed rapidly and so there exists a high demand for faster and more efficient analysis techniques. Therefore we have established a near infrared transflectance spectroscopy (NIRS) method that allows a qualitative and quantitative determination of new polyphenolic pharmacological active leading compounds within a few seconds. As the NIR spectrometer has to be calibrated the compound of interest has at first to be characterized by using one or other a combination of chromatographic or electrophoretic separation techniques such as thin layer chromatography (TLC), high performance liquid chromatography (HPLC), capillary electrophoresis (CE), gas chromatography (GC) and capillary electrochromatography (CEC). Both structural elucidation and quantitative analysis of the phenolic compound is possible by direct coupling of the mentioned separation methods with a mass spectrometer (GC-MS, LC-MS/MS, CE-MS, CEC-MS) and a NMR spectrometer (LC-NMR). Furthermore the compound has to be isolated (NPLC, MPLC, prep. TLC, prep. HPLC) and its structure elucidated by spectroscopic techniques (UV, IR, HR-MS, NMR) and chemical synthesis. After that HPLC can be used to provide the reference data for the calibration step of the near infrared spectrometer. The NIRS calibration step is time consuming, which is compensated by short analysis times. After validation of the established NIRS method it is possible to determine the polyphenolic compound within seconds which allows to raise the efficiency in quality control and to reduce costs especially in the phytopharmaceutical industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.4
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• pp.562-566
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• 2003

A $\beta$-mannanase of Bacillus sp. was purified by DEAE Sephacel ion exchange column chromatography. The specific activity of the purified enzyme was 17.41 units/mg protein, representing an 84.74-folds purification of the original crude extract. For the separation of two types of hydrolysates by the action of purified $\beta$-mannanase, carbon column chromatography, sephadex G-25 column chromatography and thin layer chromatography were accomplished. Main hydrolysates were D.P value 5 and 7 containing of low D.P values. By the method of FACE (Fluorophore Assisted Carbohydrate Electrophoresis), two types of hydrolysates were identified to homo type.

• Analytical Science and Technology
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• v.7 no.1
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• pp.11-15
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• 1994

From the aerial parts of Saururus chinensis growing in Korea, four flavonoids (hyperin, isoquercitrin, quercitrin and rutin) were isolated and identified by high performance liquid chromatography, gas chromatography and thin layer chromatography. However, avicularin, which was known as one of the main constituents of flavonoid, was not detected.

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.229-235
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• 1995

The surface tension-decreasing biosurfactant was purified from Rhodotorula muciloginosa G-1. The purification procedure was the solvent extraction of culture broth. To ensure complete extraction, the sample was extracted twice with equal volume of ethylacetate. The crude solution was washed with n-hexane to remove unconsumed soybean oil. The crude sample of biosurfactant was applied to Silica gel column chromatography equilibrated with chloroform, and eluted with chloroform : methanol gradient. Serveral solvent system was used to developed the thin layer chromatography (TLC). The purified biosurfactant sample gave one spot (Rf 0.78). It was estimated that biosurfactant was glycolipid about having M.W.1,500 with standard of polyethyleneglycol by Sephadex LH-20 column chromatography.