• Korean Journal of Pharmacognosy
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• v.41 no.2
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• pp.136-140
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• 2010

This study was carried out to utilize non-toxic solvents instead of harmful solvents for the TLC(Thin Layer Chromatography) identification test of herbal medicines. It is recommended not to use harmful solvent such as chloroform at a viewpoint of clean analysis. In this study, we revised the identification test of 10 items in the Korea Pharmacopoeia(KP) and the Korean Herbal Pharmacopoeia(KHP) such as Cornus officinalis S. containing the harmful solvents on the developing solvent and established identification test that is utilized non-toxic solvents by HPTLC(High Performance Thin Layer Chromatography).

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.848-854
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• 1999

Inhibitory compounds of angiotensin converting enzyme (ACE) were separated from Doenjang (traditional Korean fermented soybean paste). Water extracts from Doenjang which showed ACE inhibitory activity were separated with gel permeation chromatography (GPC), in which two fractions with high ACE inhibitory activities were obtained. The first fraction from GPC was further isolated by semi-preparative reverse phase preparative-HPLC (high performance liquid chromatography) and 2-dimensional electrophoresis/thin layer chromatography (TLC). The purified spot had molecular weight of 759 daltons and ninhydrin-positive non-peptide. The second fraction from GPC was also further isolated by semi-preparative reverse phase HPLC and $NH_2-column$ HPLC. One fraction with high ACE inhibitory activity was purified and characterized. Molecular weight of this fraction by LC-MS was 272.34 daltons. The active fraction was identified as Arg-Pro with ACE $IC_{50}$ of $92\;{\mu}M$.

• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.273-281
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• 2007

Ceramide is involved in cell death as a lipid mediator of stress responses. In this study, we developed an improved method of ceramide quantification based on added synthetic ceramide and thin layer chromatography (TLC) separation, and applied to biological samples. Lipids were extracted from samples spiked with N-oleoyl-D-erythro-sphingosine ($C_{17}$ ceramide) as an internal standard. Ceramide was resolved by TLC, complexed with fatty-acidfree bovine serum albumin (BSA), and deacylated by ceramidase (CDase). The released sphingosine was derivatized with o-phthalaldehyde (OPA) and measured by high performance liquid chromatography (HPLC). The limit of detection for ceramide was about 1-2 pmol and the lower limit of quantification was 5 pmol. Ceramide recovery was approximately 86-93%. Ceramide concentrations were determined in biological samples including cultured cells, mouse tissues, and mouse and human plasma. TLC separation of ceramide provides HPLC chromatogram with a clean background without any interfering peaks and the enhanced solubility of ceramide by BSAceramide complex leads to the increased deacylation of ceramide. The use of an internal standard for the determination of ceramide concentration in these samples provides an accurate and reproducible analytical method, and this method can be applicable to diverse biological samples.

• Textile Coloration and Finishing
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• v.10 no.6
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• pp.27-32
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• 1998

도시 Traditionally, dyes extracted from onion shells have been used as natural pigments but dyeing methods with reproducibility have not been developed. In this study, the dyes were analyzed by high performance thin layer chromatography(HPTLC) to obtain the ratio of pigments in water and ethyl acetate extract. Furthermore, the present study was also carried out to obtain the information characteristic of wavelength which proportionally decrease for continuous dyeing reaction. Scanning of water extract showed 4 peaks by the mobile phase of benzene/ethyl acetate/acetic acid(40/10/5) and the peak 1 exhibited yellow color with the maximal absorption spectra of 306nm and 309nm while ethyl acetate extract showed 9 peaks in the same mobile phase. The water extract after ethyl acetate extraction was adjusted to 0.5 of O.D.(optical density) at 550nm by adding of water and compared wavelength of the pigments from 200 to 600nm to find the proportional decrease of wavelength. As the result, it showed that wavelength of 306nm could be the standard of dyeing monitoring points.

• Bulletin of the Korean Chemical Society
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• v.18 no.3
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• pp.316-318
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• 1997

A general and universal detection method, which can be used in high performance liquid chromatography (HPLC) and flow injection analysis (FIA) system for the determination of any metal ions complexing with ethylenediaminetetraacetic acid (EDTA), is demonstrated. Pulsed amperometric detection scheme is applied in a flow-through thin layer electrochemical cell at an Au working electrode. Fluctuation of peak current level at the same flow rate of carrier solution is minimized at this solid working electrode, whereas not at a dropping mercury electrode. Removal of dissolved oxygen can be omitted with this detection method, which is a required step for cathodic detection methods. Also, a group of metal ions can be determined selectively and indirectly with this detection scheme.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.679-682
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• 2008

A lactic acid bacterium producing an antimicrobial substance against Escherichia coli O157:H7 was isolated from raw milk and identified as Lactobacillus amylovorus ME-1. In addition to E. coli O157 :H7, the antimicrobial substance also inhibited the growth of Bacillus cereus, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyrogenes, and Yersinia enterocolitica. The antimicrobial substance was stable at pH 2-12 and $121^{\circ}C$ for 15 min and insensitive to proteinase K, protease, amylase, and catalase. Purification of the antimicrobial substance was conducted through methanol and acetonitrile/ethylacetate extraction, ultrafiltration with a 500 Da cutoff, thin layer chromatography (TLC) with silicagel 60, and high performance liquid chromatography (HPLC) with a $C_{18}$ reverse phase column. The ${\lambda}_{max}$ of the purified antimicrobial substance was determined as 192 nm by ultra violet (UV) scanning, while the molecular weight was estimated as 453 Da based on the mass spectrum. Accordingly, the current results suggest that the antimicrobial substance from the L. amylovorus ME-1 was not a bacteriocin, but rather a new non-proteinaceous substance distinct from acidophilin, acidolin, diacetyl, and reuterin.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.55-62
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• 2014

Objectives: $^{32}P$-postlabeling assay is the most sensitive method of detecting DNA adduct formation. However, it is limited by a low sample throughput and use of radioisotopes (RI). In this study, we modified it to minimize these limitations and applied it to Z. platypus exposed to Benzo(a)pyrene (BaP) in order to investigate DNA adduct formation (effect biomarker for pollutants) in Z. platypus for assessing risk of waterborne BaP exposure. Methods: DNA hydrolysis was performed only with Micrococcal nuclease (MNase), RI reduction test was performed and the overlapping steps between thin layer chromatography (TLC) and radioisotope high-performance liquid chromatography (RI-HPLC) were omitted. The application of a modified method to Z. platypus exposed to BaP was performed. Results: The results revealed that the amount of RIs used can be reduced roughly 10-fold. Because the analysis time was shortened by 8.5 hours, the sample throughput per hour was increased compared with the previous method. The results of applying modified $^{32}P$-postlabeling assay to Z. platypus, DNA adduct formation in Z. platypus showed dose-dependency with the BaP concentration. Only BPDE-dGMP was detected as a DNA adduct. Conclusion: These results demonstrate that the modified $^{32}P$-postlabeling assay is a suitable method for detecting DNA adduct formation in Z. platypus exposed to waterborne BaP and will be useful in risk assessment of carcinogenic effect in aquatic environment due to BaP.

• Journal of Applied Biological Chemistry
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• v.44 no.1
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• pp.12-15
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• 2001

The antioxidative compounds and antioxidant contents of ginger (Zingiber officinale) rhizomes were determined. Substances reextracted using ethyl acetate from crude methanol extract of fresh ginger rhizome were separated through thin layer chromatography. Ten phenolic antioxidative bands were visualized through color reactions using ferric chloride-potassium ferricyanide and 1,1-diphenyl-2-picrylbydrazyl (DPPH). The antioxidative compounds were purified through preparative TLC and high performance liquid chromatography (HPLC), among which, five antioxidants were identified as 4-, 6-, 8-. and 10-gingerols and 6-shogaol on the basis of their molecular weights determined through LC-MS. As shown in experiments using DPPH free radicals, 6-Gingerol and PT4-HP8 (unknown) were revealed to be more efficient than BHT (butylated hydroxy toluene). Contents of gingerols were determined through reverse phase HPLC. Total gingerol contents (sum of 6-,8-, and 10-gingerols) in rhizomes of different ginger varieties varied significantly. The HG55 (collected at Wanju district in Korea) and the HG52 (imported from Brazil) showed the highest gingerol contents.

• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1259-1265
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• 2010

The filamentous cyanobacterium Arthrospira platensis strain MMG-9 was isolated from a rice field. The ability of this strain to synthesize the bioactive compound indole-3-acetic acid (IAA) was demonstrated. IAA was extracted from the culture of A. platensis strain MMG-9 and its identity was confirmed by thin-layer chromatography (TLC) as well as by high-performance liquid chromatography (HPLC). The IAA precursor L-tryptophan was required for IAA biosynthesis. Released IAA increased with the increase of the initial concentration of L-tryptophan in the medium and with the incubation time. A. platensis strain MMG-9 accumulated more IAA than it released into the medium. The bioactivity of the secreted IAA was shown by its effect on the formation of roots by Pisum sativum. There was a significant positive effect of the supernatant of cultures of A. platensis strain MMG-9 on the number of lateral roots of P. sativum, whereas a negative effect on root length was observed.

• Advances in Traditional Medicine
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• v.6 no.3
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• pp.167-173
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• 2006

A growing body of evidence supports lipid peroxidation as having a role in the pathogenesis of liver disease. Although the probable cause of damage to human hepatocytes may be multifactorial, free radicals have been implicated in a variety of liver diseases, particularly in the presence of iron overload and toxic substances such as ethanol. Consequently, antioxidants, particularly those of plant origin such as flavonoids, may help to reduce the risk of developing these diseases. Silybum (S.) marianum, a medicinal plant widely used in traditional European medicine for the treatment of liver disorders, was evaluated for antioxidant activity. Thin layer chromatography and High Performance Liquid Chromatography analyses of crude extract of the plant confirmed the presence of a number of flavonoids reported in the literature. The antioxidant activity of these flavonoids was measured through inhibition of lipid peroxidation and 1, 1-diphenyl-2- picrylhydrazyl radical scavenging. The crude plant extract showed marked antioxidant activity in both assays. These results suggest that S. marianum contains flavonoids with antioxidant activity, capable of inhibiting or scavenging free radicals, thus supporting its traditional use as a hepatoprotective agent.