• Title/Summary/Keyword: HPLC Chromatography

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A Comparison of Sampling and Analytical Methods for Airborne Isocyanates (공기중 이소시아네이트류의 측정 및 분석방법에 관한 비교연구)

  • 변혜정;윤충식;백남원
    • Journal of Environmental Health Sciences
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    • v.22 no.2
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    • pp.32-42
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    • 1996
  • This study was performed to evaluate accuracy and precision of filter method and impinger method for analyzin airborne isocyanates in mixture (2, 6-TDI, HDI, 2, 4-TDI, MDI). Filter method was performed using the OSHA Method 42 and impinger method using the NIOSH Method 5521. The samples were analyzed by high performance liquid chromatography-ultraviolet detector (HPLC-UVD). After the optimum operating conditions for each method were investigated, samples with various concentration levels were quantified at the conditions. The precision was expressed by the pooled coefficient of variation(C.V.) and the accuracy by overall accuracy. The results are summarized as follows: 1. The optimum condition of filter method was determined at 35/65 ACN/buffer (0.01 M ammonium acetate) in mobile phase. And in case of impinger method, it was at 30/70 ACN/buffer(0.2 M sodium acetate). The effect of concentrations of acetate on the separation of the peaks was not significant, but, the effect of ACN/buffer ratio was significant. 2. The correlation coefficients for the two methods were above 0.9 in all isocyanate compounds. Average recovery efficiencies for 2, 6-TDI, HDI, 2, 4-TDI and MDI in filter method were 92.4%, 102.6%, 87.3% and 101.0%, respectively. Those in impinger method were 106.6%, 106.7%, 99.0% and 103.6%, respectively. As a result, the recovery efficiency of impinger method was higher than those of filter method in analyzing isocyanate compounds. 3. The pooled coefficients of variations of the methods were slightly higher than expected. The overall accuracies of the methods were within $\pm 25%$ for each isocyanate compound. Since these results satisfy NIOSH criteria, the accuracy of the experiment is appropriate. 4. As seen above, impinger method is more efficient than filter method. But, there are many disadvantages in impinger method. Therefore, solid sorbent such as a glass fiber filter must be developed in order to have the high efficiency not less than that of impinger method in the future.

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Chemical Constituents of Saposhnikovia divaricata (방풍의 화학 성분)

  • Kim, So-Jun;Chin, Young-Won;Yoon, Kee-Dong;Ryu, Min-Youl;Yang, Min-Hye;Lee, Je-Hyun;Kim, Jin-Woong
    • Korean Journal of Pharmacognosy
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    • v.39 no.4
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    • pp.357-364
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    • 2008
  • The roots of Saposhnikovia divaricata Schischk. (Umbelliferae) have been known to possess analgesic, anti-inflammatory, anti-parasitic and anti-bacterial activities, and used for curing headaches, fever and arthralgia. In this study, we aimed to isolate active constituents to provide phytochemical data for the quality control of this plant. Nine coumarins, eight chromones, three sterols and a coumarolignan were isolated from EtOAc-soluble fraction of the roots of S. divaricata through repetive column chromatography method using silica gel, ODS gel, Sephadex-LH 20, MPLC and HPLC. By analyses of spectroscopic data and comparison of their data with those of published values, the compounds were identified as 3'-O-angeloylhamaudol (1), ${\beta}$-sitosterol (2), marmesin (3), phellopterin (4), anomalin (5), imperatorin (6), xanthotoxin (7), deltoin (8), bergapten (9), stigmasterol (10), ledebouriellol (11), hamaudol (12), 8'-epicleomiscosin A (13), xanthoarnol (14), cimifugin (15), 5-O-methylvisamminol (16), daucosterol (17), 4'-O-${\beta}$-D-glucosyl-5-O-methylvisamminol (18), nodakenin (19), sec-O-glucosylhamaudol (20), prim-O-glucosylcimifugin (21). Among them, 8'-epicleomiscosin (13) was firstly reported from Umbelliferae family and xanthoarnol (14) and nodakenin (19) were isolated from this plant for the first time.

Anti-adipogenic Pregnane Steroid from a Hydractinia-associated Fungus, Cladosporium sphaerospermum SW67

  • Lee, Seoung Rak;Kang, Heesun;Yoo, Min Jeong;Yu, Jae Sik;Lee, Seulah;Yi, Sang Ah;Beemelmanns, Christine;Lee, Jaecheol;Kim, Ki Hyun
    • Natural Product Sciences
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    • v.26 no.3
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    • pp.230-235
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    • 2020
  • A pregnane steroid, 3α-hydroxy-pregn-7-ene-6,20-dione (1), was isolated from a Hydractinia-associated Cladosporium sphaerospermum SW67 by repetitive column chromatographic separation and high-performance liquid chromatography (HPLC) purification. The planar structure of 1 was elucidated from the analysis of the spectroscopic data (1D and 2D NMR spectra) and LC-MS data. The absolute configuration of 1 was determined by interpretation of ROESY spectrum of 1, together with the comparison of reported spectroscopic values in previous studies. To the best of our knowledge, this is the first report of the identification of the pregnane scaffold from C. sphaerospermum, a natural source. Compound 1 was evaluated for its effects on lipid metabolism and adipogenesis during adipocyte maturation and showed that compound 1 substantially inhibited lipid accumulation compared to the control. Consistently, the expression of the adipocyte marker gene (Adipsin) was reduced upon incubation with 1. Further, we evaluated the effects of 1 on lipid metabolism by measuring the transcription of lipolytic and lipogenic genes. The expression of the lipolytic gene ATGL was significantly elevated upon exposure to 1 during adipogenesis, whereas the expression of lipogenic genes FASN and SREBP1 was significantly reduced upon treatment with 1. Thus, our findings provide experimental evidence that the steroid derived from Hydractinia-associated C. sphaerospermum SW67 is a potential therapeutic agent for obesity.

Comparison of Index Compounds Content and Antioxidative Activity of Wild Ginseng Pharmacopuncture by Extraction Methods (산양산삼약침의 추출법 별 성분 및 항산화 활성 비교)

  • Lee, Dae-yeon;Choi, Byoung-sun;Lee, In-hee;Kim, Jae-hyun;Gwon, Pil-seung
    • The Journal of Internal Korean Medicine
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    • v.39 no.3
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    • pp.313-322
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    • 2018
  • Objectives: Wild ginseng pharmacopuncture is widely used in oriental medicine. However, there is no standard method for efficiently extracting the active ingredient. In this study, in order to determine an efficient extraction method, wild ginseng was extracted by the distillation and 70% ethanol reflux methods, respectively. In comparing each extract, the index compounds were analyzed, and antioxidant activity was measured. Methods: The index compounds, ginsenoside Rg1 and ginsenoside Rb1, were detected using high performance liquid chromatography (HPLC). Antioxidative activities of total phenolic compounds, DPPH (${\alpha}$, ${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) and FRAP (ferric reducing antioxidant power) were measured to compare their bioactivities. Since saponin is known to be hemolytic, the hemolytic activity of each extract was compared. Results: The index compounds were analyzed. Nothing was detected in the wild ginseng distilled extracts (WGDE). In the wild ginseng 70% ethanol reflux extracts (WGEE), ginsenoside Rg1 was 3.66 mg/g, and ginsenoside Rb1 was 16.70 mg/g. WGEE showed higher levels than WGDE in all antioxidative activities. In the hemolytic test, the extracts showed almost no toxicity, but WGEE showed lower toxicity than WGDE. Conclusions: In this study, it was concluded that WGEE is more advantageous than WGDE in the detection of index compounds and bioactivity. However, additional studies of additional extraction methods and other bioactivity tests are needed.

Purification and Characterization of CDMHK, a Growth Inhibitory Molecule Against Cancer Cell Lines, from Myxobacterium sp. HK1 Isolated from Korean Soil

  • LEE HAN-KI;LEE IN-HYE;YIM JEE-SUN;KIM YONG-HO;LEE SANG-HEE;LEE KISAY;KOO YOON-MO;KIM SANG-JIN;JEONG BYEONG-CHUL
    • Journal of Microbiology and Biotechnology
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    • v.15 no.4
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    • pp.734-739
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    • 2005
  • Myxobacterium sp. HK1, isolated from Korean soil, degrades cellulose, differentiates to fruiting body, and its 16s rDNA has $95\%$ similarity to Polyangium sp. An anticancer molecule, CDMHK, was identified from culture broth of Myxobacterium sp. HK1, and purified by Diaion HP20, Silica gel, Sephadex LH-20 chromatography, and preparative HPLC using an YMC OSD-A C18 column. The molecular structure and formula were determined to be $C_{l2}H_{l9}N_3O_2$ (M.W 237) by MS spectrometry, 300 MHz $^{1}H\;and\;^{13}C$ NMR. The CDMHK was not active against Escherichia coli, Staphylococcus aureus, and Candida albicans. However, this molecule inhibited the growth of various cancer cell lines. The $ED_{50}$ values of CDMHK were determined to be 0.147, 0.086, 0.18, 0.166, and 0.142 $\mu$g/ml against A549, SK-OV-3, SK-MEL-2, VF498, and HCTl5 cancer cell lines, respectively. In addition, the CDMHK was able to induce apoptosis of the CCRF-CEM cancer cell line, evidenced by DNA fragmentation assay and DAPI staining.

Production and Characterization of an Anti-Angiogenic Agent front Saccharomyces cerevisiae K-7

  • Jeong, Seung-Chan;Lee, Dae-Hyoung;Lee, Jong-Soo
    • Journal of Microbiology and Biotechnology
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    • v.16 no.12
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    • pp.1904-1911
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    • 2006
  • The cell-free extracts of 250 yeasts were screened for their in vitro anti-angiogenic activity, to develop a new cancer metastasis inhibitor. Saccharomyces cerevisiae K-7 was selected as the producer of the anti-angiogenic agent, because it had the highest anti-angiogenic activity. The anti-angiogenic agent was produced maximally from hydrolysates of Saccharomyces cerevisiae K-7, when the yeast was cultured in yeast extract-peptone-dextrose medium at 30$^{\circ}C$ for 24 h, and cell-free extracts were than digested with pepsin for 4 h at 37$^{\circ}C$. The anti-angiogenic agent was further purified by ultrafiltration, Sephadex G-25 gel permeation chromatography and reverse-phase HPLC, and the anti-angiogenic activity of the final purified preparation was 72.7% at 10 $\mu$M/egg. The purified anti-angiogenic agent was found to originate from the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) molecule of Saccharomyces cerevisiae K-7, and its peptide sequence was Val-Ser-Trp-Tyr-Asp-Asn-Glu-Tyr-Gly-Tyr-Ser-Thr-Arg-Val-Val-Asp. In the MTT assay, the shape of the HT-l 080 cell was clearly changed to a circular type at 0.2 mM purified anti-angiogenic agent. This result indicated that the growth of the HT-I080 cell was significantly inhibited at 0.2 mM of the purified anti-angiogenic agent. The MMP activity of the treated HT-l080 cells was not affected, evidenced by the gelatin zymography, indicating that the anti-angiogenic mechanism of the purified anti-angiogenic agent is not mediated through MMP activity.

Antiviral Activity of Antibiotic Peptaibols, Chrysospemins B and D, Produced by Apiocrea sp. 14T against TMV Infection

  • Kim, Young-Ho;Yeo, Woon-Hyung;Kim, Young-Sook;Chae, Soon-Young;Kim, Kap-Sik
    • Journal of Microbiology and Biotechnology
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    • v.10 no.4
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    • pp.522-528
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    • 2000
  • A total of about 300 fungal isolates from forest havitats were screened for inhibitors of tobacco mosaic virus (TMV) infection using its local lesion host, Nicotiana tabacum cv. Xanthi nc. Ine of the isolates, 14T, showed a strong activity against TMV infection, and was identified as an Apiocrea sp. based on its morphological characterstics. Rice was an optimum culture medium for its fermentation, and two antiviral compounds, KGT 141 and KGT 142, were resolved from the rice culture through column chromatography, TLC, and HPLC. By NMR and FAB-MS, the two compounds were identified as chrysospermins B (KGT 141) and D (KGT 142), both of which are peptaibols with 19-mer amino acids possessing an acetylated N-terminus and a hydroxy-amino acid (tryptophanol) at the C-terminus. Both compounds showed inhibitory activities against TMV infection, but chrysospermin D showed the stronger activity than chrysospermin B. The former of $100{\;}\mu\textrm{g}/ml$ and 54.7% at $10{\;}\mu\textrm{g}/ml$, respectively. Furthermore, the chrysospermins were highly cytotoxic toward cancer cell lines of PC-3 (prostrate) and K562 (leukemia), and inhibited growth of the Gram-positive bacteria tested, especially the plant pathogenic bacterium Corynebacterium lilium. To the best of our knowledge, this is the first report on the inhibition of plant virus infection by antimicrobial peptaibols.

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Melanin Synthesis Inhibition and Radical Scavenging Activities of Compounds Isolated from the Aerial Part of Lespedeza cyrtobotrya

  • Lee, Mi-Yeon;Kim, Jin-Hee;Choi, Jung-Nam;Kim, Ji-Young;Hwang, Geum-Sook;Lee, Choong-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.20 no.6
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    • pp.988-994
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    • 2010
  • The EtOAc fraction of Lespedeza cyrtobotrya showed mushroom tyrosinase inhibitory and radical scavenging activities. Four active compounds were isolated based on Sephadex LH-20 chromatography and HPLC, and the structures were elucidated, on the basis of their LC-MS and NMR spectral data, as 2-(2,4-dihydroxyphenyl)-6-hydroxybenzofuran (1), eriodictyol-7-O-glucopyranoside (2), haginin A (3), and dalbergioidin (4), respectively. Compound (1) showed mushroom tyrosinase inhibitory activity with an $IC_{50}$ value of $5.2\;{\mu}M$ and acted as a competitive inhibitor. Furthermore, $37.3\;{\mu}M$ of compound 1 reduced 50% of the melanin content on human melanoma (MNT-1) cells. The radical scavenging activities of compounds 1, 2, 3, and 4 were shown to have $IC_{50}$ values of 11.0, 24.5, 9.0, and $36.5\;{\mu}M$, respectively, in an ABTS system and $IC_{50}$ values of 42.7, 36.0, 37.7, and $61.7\;{\mu}M$, respectively, in a DPPH system. The mushroom tyrosinase inhibitory activity of the EtOAc fraction of Lespedeza cyrtobotrya was contributed by compounds 1, 3, and 4, and its radical scavenging activity was contributed by compounds 1-4.

Effect of Tripolyphosphate (TPP) on the Controlled Release of Cyclosporin A from Chitosan-coated Lipid Microparticles

  • Cheon, Ji-Woong;Shim, Chang-Koo;Chung, Suk-Jae;Kim, Dae-Duk
    • Journal of Pharmaceutical Investigation
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    • v.39 no.1
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    • pp.59-63
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    • 2009
  • Soybean phosphatidylcholine microparticles loaded with cyclosporin A (CsA) were prepared by the modified emulsion solvent diffusion and ionic gelation method, in which chitosan on the surface of the microparticles was crosslinked with various concentrations of tripolyphosphate (TPP). The morphology of the particles was characterized by scanning electron microscopy (SEM). The change of particle size and zeta-potential by chitosan on the surface of the lipid microparticles were systematically observed. The encapsulation efficiency and loading capacity of CsA in the particles were determined by high performance liquid chromatography (HPLC). In vitro release kinetics was studied using the dialysis method. In the results, the mean particle size and the zeta-potential of lipid microparticles increased when the attached chitosan was cross-linked (from 2.5 to 6.2 ${\mu}m$ and from -37.0 to +93.0 mV, respectively). The cyclosporin A-loaded lipid microparticles appeared discrete and spherical particles with smooth surfaces. The encapsulation efficiency of CsA was between 79% and 90% while the loading capacity was between 41% and 56%. In vitro release study showed that the crosslinkage of chitosan by TPP significantly delayed the release of CsA from the particles in a concentration-dependent manner. Thus, the release of CsA from the lipid microparticles could be controlled by tripolyphosphate used as a cross-linking agent.

Influence of UV-B Radiation on Photosynthesis, Growth and Pigmentation of Chondrus ocellatus (Rhodophyta) from Shallow Water

  • Taejun Han;Han, Young-Seok;Cho, Man-Gee;Park, Jin-Hee;Goo, Jae-Gun;Kang, Sung-Ho
    • Korean Journal of Environmental Biology
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    • v.21 no.4
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    • pp.368-376
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    • 2003
  • The UV-B sensitivity was tested for the intertidal species Chondrus ocellatus from Korea, by measuring photosynthesis estimated as effective quantum yield ($\Phi_{PSII}$) of photosystem II (PS II), growth and content and composition of photosynthetic pigments and UV-absorbing pigments (UVAPs). The $$\Phi_{PSII}$ of the alga decreased with increasing time of exposure to UV-B radiation, followed by fast and nearly full recovery indicating dynamic photoinhibiton. Fresh weight-based growth and pigment contents of C. ocellatus were not seriously affected by UV-B radiation. A single broad peak at 327 nm was obtained from methanol extracts of C. ocellatus, and the absorbance peak increased with increasing UV. The single peak was resolved into three peaks (311, 330 and 336 nm) by the fourth -derivative, and quantitative change in response to UV-B radiation occurred only at 330 nm. High performance liquid chromatography (HPLC) analysis of purified extracts indicated that three MAAs (mycosporine-like amino acids) are present, asterina 330, palythine and shinorine. Field observations during three growing months showed that C. ocellatus exhibit the highest amount of UVAPs in May followed by July and little trace in September, coinciding with the species' phenology. In an ecological context, dynamic photoinhibition as well as accumulation of UVAPs may enable the shallow water red alga C. ocellatus to be well adapted to high UV-B environments.