• Preventive Nutrition and Food Science
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• v.12 no.3
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• pp.131-134
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• 2007

The kinetic analyses for thermal products of alpha-, gamma- and delta-tocopherols during heating as functions of temperature and time were studied. Alpha-, gamma- and delta-tocopherols dissolved in glycerol were heated at $100{\sim}200^{\circ}C$ for $5{\sim}60$ min. The thermal products were separated by hexane extraction and analyzed by HPLC using a reversed phase ${\mu}-Bondapak$ $C_{18}-column$ with two kinds of elution solvents in a gradient mode. The formation kinetics of thermal products of tocopherols followed a first-order kinetic model. The formation rate of thermal products of tocopherols was dependent on heating temperatures and heating times. The activation energy and enthalpy for the thermal products of ${\gamma}-and$ ${\delta}-tocopherols$ were higher than those for ${\alpha}-tocopherol$ as in the case of the oxidative degradation kinetics of tocopherol. The magnitude order of the activation energy was ${\gamma}->{\delta}->{\alpha}-tocopherol$.

• Korean Journal of Pharmacognosy
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• v.21 no.2
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• pp.148-152
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• 1990

Seven flavonol glycosides from the EtOAc fraction of Ginkgo biloba leaves were identified by high performance liquid chromatography. Separation by reversed phase chromatography on $Lichrosorb^{\circledR}$ RP-18 column was achieved by isocratic elution. The content of the major acylated flavonol glycoside, kaempferol 3-0-[$6'-O-{p}-coumaroyl-{\beta}-_D-glucosyl(1{\rightarrow}2)-{\alpha}-_L-rhamnoside$] was about 8.0% and 0.55% for EtOAc fraction and MeOH extract, respectively.

• Korean Journal Plant Pathology
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• v.13 no.1
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• pp.63-68
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• 1997

In the screening of antiviral materials produced by actinomycetes, an isolate named B25 was fond to produce an antibiotic substance ASA, which showed a strong inhibitory activity against tobacco mosaic virus (TMV) infection. ASA was purified from culture broth of B25 by silica gel column chromatography, preparative TLC, and reversed phase HPLC. Also MS, IR, UV spectrum, and melting point of ASA were determined and analysed. ASA was white powder soluble in dimethyl sulfoxide, chloroform, and ethyl acetate, having absorption peaks at 223 and 328 nm in UV-VIS spectrum, and had a molecular weight of 548. ASA showed strong inhibitory effect on TMV infection when it was applied as a mixture of TMV to the upper surface of leaves of a local lesion host (Nicotiana tabacum c. Xanthi-nc). It also showed antimicrobial effect against yeast and some phytopathogenic fungi.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.635-639
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• 1998

The thermal degradation pattern of $\alpha$-, ${\gamma}$-and $\delta$-tocopherols in glycerol was investigated during heating at 100~25$0^{\circ}C$ for 5-60 min in the absence of oxyge. The tocopherols and thermally decomposed products were separated by HPLC with a reversed phase $\mu$-Bondapak C18-column. The degradation pattern of $\alpha$-tocopherol during the heating in the absence of oxygen was different from those of ${\gamma}$-and $\delta$-tocopherols. But the degradation patterns of ${\gamma}$-and $\delta$-tocopherols were similar to each other. The residual content of $\alpha$-tocopherol during the heating in the absence of oxygen decreased to the range 12~65% and those of ${\gamma}$-and $\delta$-tocopherols decreased to the range 4~96%. The thermal degradation of tocopherols in the absence of oxygen was less than that in the presence of oxygen.

• YAKHAK HOEJI
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• v.37 no.3
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• pp.286-289
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• 1993

UV and high performance liquid chromatographic methods for the quantitative analysis of methyl 5-hydroxy-dinaphtho [1,2-2',3'] furan-7,12-dione-6-carboxylate(MHDDC) in urine and blood were developed. The correlation coefficients of the calibration curves of MHDDC in chloroform, methanol and dioxane solution were 0.999, 0.997 and 0.998, respectively. MHDDC was resolved within 15 min and had a detection limit of 2-5ng at S/N=3 by using a reversed-phase column with two solvents (MeOH, HAc).

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.04a
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• pp.75-75
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• 2003

We have purified and characterized cecropin A-like antibacterial peptide from the hemolymph of immunized Galleria mellonella larvae. Acid extraction, gel filtration, preparative acid urea PAGE, and reversed-phase HPLC were used for purification of peptide. The molecular mass of the purified peptide was estimated to be 4160.68 Da by MALDI-TOF mass spectrometry. (omitted)

• Journal of Food Hygiene and Safety
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• v.11 no.2
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• pp.149-157
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• 1996

A procedure for the determination of Aflatoxins in food and grains which utilizes reversed phased liquid chromatographic (LC) analysis with postcolumn derivatization by an electrochemical cell and determination with a fluorescence detector has been evaluated. The LC mobile phase was water-acetonitrile-methanol (6+2+2) with 1mM KBr and 1 mM HNO3 which gave baseline separation for the four Aflatoxins (AfB1, AfB2, AfG1, AfG2). The electrochemical cell set at 7V, generated bromine and derivatized aflatoxins B1 and G1, The derivatives were detected by the fluorescence detector. The aflatoxins in naturally contaminated corn samples were isolated by three different cleanup procedures: the AOAC method I column(CB method), a rapid filtrate column (Romer's column), and an immunoaffinity column. The final extract were quantitated with fluordensitometric TLC and the LC postcolumn derivatization techniques. The results were quite similar, however the LC technique showed less interferences and could be automated. Samples of corn, raw peanuts, peanut butter and dried dates were also analyzed successfully with this procedure.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.1
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• pp.13-16
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• 2000

Simple procedures have been devised for purifying recombinant human interleukin-2 (hIL-2), which was expressed in Escberichia coli using sequences of glucagon molecules and enterokinase cleavage site as an N-terminus fusion partner. The insoluble aggregates of recombinant fusion protein produced in E. coli cytoplasm were easily dissolved by simple alkaline pH shift $(8\rightarrow12\rightarrow8)$. Following enterokinase cleavage, the recombinant hIL-2 was finally purified by one-step reversed-phase HPLC with high purity. The ease and high efficiency of this simple purification process seem to mainly result from the role of used glucagon fusion partner, which could be applied to the production of other therapeutically important proteins.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.501-505
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• 2010

1-Acetyl-$\beta$-carboline was isolated as an anti-MRSA agent from the fermentation broth of a marine actinomycete isolated from marine sediment. The producing strain was identified to be Streptomyces sp. by phylogenetic analysis of the 16S rRNA gene sequence. The anti-MRSA agent was isolated by bioactivity-guided fractionation of the culture extract by solvent partitioning, ODS open flash chromatography, and purification with a reversed-phase HPLC. Its structure was elucidated by extensive 2D NMR and mass spectral analyses. Combination of 1-acetyl-$\beta$-carboline with ampicillin exhibited synergistic antibacterial activity against MRSA.

• Biomolecules & Therapeutics
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• v.6 no.3
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• pp.256-260
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• 1998

-7-o-p-Fluorobenzoylchrysin was synthesized by condensing p-flouorbenzoic acid with chrysin in organic solvent, and its structure was identified by NMR, MS, UV, and IR. We also investigated the physicochemical properties, hypoglycemic effect, and the quantitative analysis method of this compound. The correlation coefficient of calibration curve on this compound was approximately 0.9945 by absorption spectrophotometry and 0.9989 by high perfornance liqid chromatography 7-o-p-Fluorobenzoylchrysin was resolved in 6.014 min by reversed-phase HPLC column with solvents consisting of methanol (80%) and 10mM phosphoric acd. Its blood glucose inhibition rate is 20.7%.