• 약학회지
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• 제52권1호
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• pp.67-72
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• 2008

The use of doxorubicin, which is one of the most effective anticancer agents, is often limited by occurrence of acquired resistance in tumor cells. GSH has been shown to be involved in the development of this drug resistance. Transcription factor Nrf2 governs the expression of GSH synthesizing glutamylcysteine ligase (GCL), as well as multiple phase 2 detoxifying enzymes. Here we show that Nrf2 is one of factors determining doxorubicin sensitivity. Nrf2-deficient fibroblasts (murine embryonic fibroblasts, MEF) were more susceptible to doxorubicin mediated cell death than wild-type cells. Doxorubicin treatment elevated levels of Nrf2-regulated genes including NAD(P)H: quinone oxidoreductase (Nqo1) and GCL in wild-type fibroblasts, while no induction was observed in Nrf2-deficient cells. Doxorubicin resistance in human ovarian SK-OV cells was reversed by treatment with L-buthionine-sulfoxamine (BSO), which is depleting intracellular GSH. Finally, transfection of SK-OV cells with Nrf2 siRNA resulted in exacerbated cytotoxicity following doxorubicin treatment compared to scrambled RNA control. These results indicate that the Nrf2 pathway, which plays a protective role in normal cells, can be a potential target to control cancer cell resistance to anticancer agents.

• Mycobiology
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• 제43권1호
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• pp.43-48
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• 2015

The medicinal fungus Phellinus linteus, in the family Hymenochaetaceae, has been used as a traditional medicine for the treatment of various diseases. In this study, the chemical constituents of the culture broth of P. linteus were investigated. P. linteus was cultured in potato dextrose broth medium, and the culture broth was extracted with ethyl acetate. The ethyl acetate-soluble portion was concentrated and subjected to ODS column chromatography, followed by Sephadex LH-20 column chromatography. Six compounds (1~6) were purified by preparative reversed-phase high-performance liquid chromatography. Spectroscopic methods identified their structures as caffeic acid (1), inotilone (2), 4-(3,4-dihydroxyphenyl)-3-buten-2-one (3), phellilane H (4), (2E,4E)-(+)-4'-hydroxy-${\gamma}$-ionylideneacetic acid (5), and (2E,4E)-${\gamma}$-ionylideneacetic acid (6). Compounds 1, 2, and 3 exhibited potent dose-dependent antioxidant activity.

• Fisheries and Aquatic Sciences
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• 제5권3호
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• pp.150-155
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• 2002

Marine bacteria producing algicidal substance against Cochlodinium polykrikoides was screened and isolated from seawater. Metabolite of marine bacteria Micrococcus sp. LG-5 showed strong algicidal activity against C. polykrikoides. C. polykrikoides was inhibited above $90\%$ at $5\%$ solution of the metabolite within 24 hrs. Algicidal substance from the metabolite was extracted with ethyl acetate, and then purified by PTLC and reversed-phase HPLC. Algicidal activity of purified compound against C. polykrikoides was above $90\%$ at 3.7, 11.0 and 33.0${\mu}g/mL$ concentration after 12, 9 and 3 hrs, respectively. Ninety percent inhibition of other red tides, Gymnodinium sanguineum and Gyrodinium impudicum was observed when treated with 3.7${\mu}g/mL$ of purified compound within a period of 12 hrs. The microscopic view of red tides treated with purified compound showed the deformations such as cell node cuts and swelling of cells.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.765-769
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• 2014

An analytical methodology was developed for qualitative and quantitative impurity profiling of the coloring agent Sudan III by high-performance liquid chromatography (HPLC)-diode array detection (DAD). The impurities in commercial Sudan III were characterized by comparison of their retention times and UV spectra with those of authentic standards. Four impurities regulated by International Committees in Sudan III were quantified by HPLC-selective UV detection. The impurities in Sudan dye were successfully separated on a reversed phase C18-column within 25 min and sensitively detected by UV spectrometry at two selective wavelengths. Method validation was conducted to determine linearity, precision, accuracy, and limit of quantification (LOQ). The linear dynamic range extended from 0.002 to 4.0%, with a correlation coefficient (R2) greater than 0.995. The LOQs of the impurities ranged from 8.04 to $54.29{\mu}g/mg$. Based on the established method, the levels of regulated impurities in five commercial Sudan III dyes were determined.

• 한국수산과학회지
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• 제49권2호
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• pp.137-145
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• 2016

This study screened the biological activity of an acidified gill extract of the Manila clam Ruditapes philippinarum including antimicrobial, hemolytic, membrane permeabilization, and DNA-binding activity, and purified the antimicrobial material. The acidified gill extract showed potent antimicrobial activity against Bacillus subtilis and Escherichia coli without significant hemolytic activity, but showed no membrane permeabilization or DNA-binding ability. An antimicrobial material was purified from the acidified gill extract using C₁₈ reversed-phase and cation-exchange high-performance liquid chromatography (HPLC). Treatment of the purified material with trypsin completely abolished all of the antibacterial activity against Bacillus subtilis, suggesting that the purified material is a proteinaceous antibiotic. The molecular weight of the purified material was 2571.9 Da, but no primary structural information was obtained due to N-terminal blocking. A future study should confirm the primary structure. Our results suggest that the Manila clam gill contains proteinaceous antibiotics that have a role in first-line defense. This information could be used to better understand the Manila clam innate immune system.

• Molecular & Cellular Toxicology
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• 제1권2호
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• pp.87-91
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• 2005

Although 2D-PAGE has been widely used as the primary method for protein separation, difficulties in displaying proteins with an extreme values of isoelectric paint (pI), molecular size and hydrophobicity limit the technique. In addition, time consuming steps involving protein transfer and extraction from the gel-pieces can result in sample loss. Here, we describe a novel protein separation technique with capillary size-exclusion chromatography (CSEC) for rapid protein identification from human plasma. The method includes protein fractionation along with molecular size followed by in-solution tryptic digestion and peptide analysis through reversed phase liquid chromatography (RPLC) coupled to nanoflow electrospray-tandem mass spectrometry (ESI-MS/MS). Tryptic peptides are applied an a $100\;{\mu}m\;i.d.{\times}10mm$ length pre-column and then separated on a $75\;{\mu}m{\times}200mm$ analytical column at -100 nL/min flaw rate. Proteins were identified over the wide ranges of pI (3.7-12.3) when this technique was applied to the analysis of $1-2\;{\mu}L$ of human plasma. This gel-free system provides fast fractionation and may be considered a complementary technique to SDS-PAGE in proteomics.

• Natural Product Sciences
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• 제12권3호
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• pp.166-173
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• 2006

Silymarin is an antihepatotoxic substance isolated from the fruits of silybum mariamum. Possibly due to their antioxidant and membrane stabilizing properties, the compounds was shown to protect various organs and cells against a number of insults (Kvasnicka et al., 2003). Among the main silymarin components, [silybin($SB_A,\;SB_B$, isosilybin ($ISB_A,\;ISB_B$) silydianin (SD) and silychristin (SC)], silybin is the major pharmacologically active compound. Korean Pharmaceutical Codex (2nd ed.) describes silybin as the main substance of Cardus Marianus extract as supportive treatment of chronic inflammatory liver disorders. The aim of this work was to analyze silybin from various preparations containing cardus marianus extract, nicotinamide, and riboflavin (CNR). Nine commercial products were tested using reversed-phase HPLC-PDA assay. The limits of detection and quantification were $0.2\;{mu}g/ml$ and $1\;{mu}g/ml$, respectively. Calibration curve showed a good linearity ($r^2$=1.00000) in the range of $1{\sim}500\;{\mu}g/ml$ of silybin standard solutions.

• 한국해양바이오학회지
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• 제10권1호
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• pp.1-8
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• 2018

The objective of this study was to purify and characterize the ${\beta}-secretase$ inhibitor from enzymatic hydrolysates of blackfin flounder muscle, for development of a novel anti-dementia agent that may be used in the drug or functional food industries. ${\beta}-secretase$ inhibitory peptide was purified from various enzymatic hydrolysates of blackfin flounder muscle. Among six enzymatic hydrolysates, the Alcalase hydrolysate revealed highest ${\beta}-secretase$ inhibitory activity. Consecutive purification of the blackfin flounder muscle hydrolysate using Sephadex G-25 column chromatography and octadecylsilane C18 reversed phase HPLC techniques were used to isolate a potent ${\beta}-secretase$ inhibitory peptide composed of 5 amino acids, Leu-Thr-Gln-Asp-Trp (MW: 526.7 Da). The $IC_{50}$ value of purified ${\beta}-secretase$ inhibitory peptide was $126.93{\mu}M$. Results of this study suggest that peptides derived from blackfin flounder muscle may be beneficial as anti-dementia compounds in functional foods or as pharmaceuticals.

• 한국환경농학회지
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• 제29권3호
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• pp.247-256
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• 2010

A high-performance liquid chromatographic (HPLC) method was developed to determine buprofezin residues in hulled rice and fruits. The buprofezin residue was extracted with acetone and the extract was stepwise purified by liquid-liquid partition and Florisil column chromatography. For rice samples, acetonitrile/n-hexane partition was additionally employed to remove nonpolar lipids. Reversed phase HPLC using an octadecylsilyl column was successfully applied to separate buprofezin from sample co-extractives, as detected by ultraviolet absorption at 250 nm. Recovery experiment at the limit of quantitation validated that the proposed method could evidently determine the buprofezin residue at the level of 0.02 mg/kg. Mean recoveries from hulled rice, apple, pear, and persimmon samples fortified at three tenfold levels were in the range of 80.8~85.2%, 89.1~98.4%, 88.8~95.7% and 90.8~96.2%, respectively. Relative standard deviations of the analytical method were all less than 5%, irrespective of sample types. A selected-ion monitoring LC/mass spectrometry with positive electrospray ionization was also provided to sensitively confirm the suspected residue.

• 생약학회지
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• 제42권1호
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• pp.15-21
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• 2011

Scrophulariae Radix (Scrophulariaceae) has been traditionally used to treat pharyngitis, laryngitis, tonsillitis, fever, and edema. To compare the quality of the Scrophulariae Radix produced from Gyeongbuk with that from China, a quantitative analysis on the major component, E-harpagoside, was performed by reversed-phase HPLC, and a relative inhibitory activity of nitric oxide (NO) was assayed in the Raw 264.7 cells. Using a Luna $C_{18}$(2) column, we carried out quantitative analysis with a gradient of 0.1% phosphoric acid in water and acetonitrile. Our results demonstrated that the content of E-harpagoside in Gyeongbuk's Scrophulariae Radix were three times higher than that of Chinese. Moreover, the inhibitory activity of Scrophulariae Radix of Gyeongbuk's in the lipopolysaccharide (LPS)-induced NO production was higher than that of Chinese.