• Title/Summary/Keyword: Gradient elution

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Diagnostic FAB-MS Spectra of Green Tea Components (고속원자충격질량분석에 의한 녹차성분 검색)

  • Moon, Dong-Cheul;Lee, Jeong-Hee;Lee, Yong-Moon
    • YAKHAK HOEJI
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    • v.36 no.3
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    • pp.205-211
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    • 1992
  • A simple dignostic method using Fast Atom Bombardment mass spectrometry was applied to the characterization of green tea flavonols from the eluates of Sepahadex LH-20 column chromatography. From the ethyl acetate extracts, crude mixture of flavonol fraction(Fr.$1{\sim}4$) were separated by the stepwise gradient elution with 30, 45, and 60% aqueous acetone. Procyanidine B analogues were found to be typical constituents of Fr. 1. Main components of Fr. 2 were catechins and gallo-catechins. Fr. 3 contained mainly ester type compounds, catechin-gallates, gallocatechin-gallates with their analogues. Fr. 4 was contaminated with some phthalate esters.

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Study on the Purification of Transforming Growth Factor-$\beta$ in Canine Platelets (개 혈소판에서 변형성장인자 베타의 분리에 관한 연구)

  • Kweon Oh-Kyeong;Hong Sung-Hyeok
    • Journal of Veterinary Clinics
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    • v.11 no.1
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    • pp.389-392
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    • 1994
  • To purify transforming growth factor type beta(TGF-$\beta$) in canine platelets, Sephadex G-75 gel filtration and semipreparative HPLC were carried out. The column of $2.0 {\times}120cm$ was used for gel filtration and one inch semipreparative column filled with SP-Toyopeal for HPLC. Electrophoresis and bioassay using African green monkey kidney cell were used for identification of TGF-$\beta$ Crude TGF-$\beta$ of 2.75mg was extracted from 5.2g of the platelets by the treatment of acid/ethanol. In gel filtration of crude TGF-$\beta$, 4 peaks were observed at the detection of spectrophotometer at 280nm. Electrophoresis and bioassay identified the 3rd peak TGF-$\beta$. Linear gradient elution from 0 to 3M NaCl in sornipreparative HPLC showed TGF-$\beta$ at 1.5M NaCl. Gel filtration was less expensive and useful method for the purification of TGF-$\beta$.

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Determination of Icariin in Epimedii Herba by High Performance Liquid Chromatography (고속액체크로마토그라피에 의한 음양곽 중 Icariin의 정량)

  • Shin, Kuk-Hyun;Kang, Sam-Sik;Chung, Sun-Gan;Cho, Eui-Hwan
    • Korean Journal of Pharmacognosy
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    • v.20 no.1
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    • pp.21-24
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    • 1989
  • A new method for quantitative determination of icariin in Epimedii Herba by high performance liquid chromatography was established. A reversed-phase system with $a\;{\mu}Bondapak\;C_{18}$ column using methanol in water(15% to 70%, gradient elution) as a mobile phase was developed. Icariin and spinosin as an internal reference were detected at 350 nm and the analysis was successfully carried out within 30 min.

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Determination of Chiisanoside in Acanthopanax Species by High Performance Liquid Chromatography

  • Kang, Jong-Seong;Linh, Pham Tuan;Cai, Xing Fu;Lee, Jung-Joon;Kim, Young-Ho
    • Natural Product Sciences
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    • v.9 no.2
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    • pp.45-48
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    • 2003
  • The content of chiisanoside in the Acanthopanax Species was determined by reversed-phase high performance liquid chromatographic method. Chiisanoside was separated from the other components in the plant extracts using Zorbax 300 SB $C_{18}$ column with gradient elution of acetonitrile. Identification of chiisanoside was carried out by comparison in the LC/MS spectrum of separated peak from extract with that of standard. By HPLC analysis in this experiment, Acanthopanax species could be classified into two groups based upon the content of chiisanoside-one with low concentration of chiisanoside, such as A. senticosus and A. koreanum, and another with high concentration of chiisanoside, such as A. senticosus f. inermis, A. Divaricatus var. albeofructus, and A. chiisanensis.

Characterization of Thermal Products of Alpha-Tocopherol

  • Chung, Hee-Young
    • Preventive Nutrition and Food Science
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    • v.9 no.4
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    • pp.295-299
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    • 2004
  • Alpha-tocopherol was thermally oxidized and degraded at high temperatures and the resulting products were chromatographically separated and identified by LC-MS. Alpha-tocopherol dissolved in glycerol was heated at 200^{\circ}C for 30 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: a mixture of acetonitrile and methanol (3:2), and of acetonitrile, methanol, 2-propanol, chloroform and methylene chloride (3:2:5:0.5:0.5) in a gradient mode. The isolated thermal. products of alpha-tocopherol were more viscous than alpha-tocopherol, and dark brown in color. Major thermal degradation products of alpha-tocopherol were identified by LC-MS, and the structures of thermal products were proposed. Alpha-tocopherol and its thermal degradation products were degraded into fragments, mainly at the non-aromatic parts. The degradation products of alpha-tocopherol. were combined with oxidized product (tocopherylquinone) to make thermal. products through dimerization.

Determination of Individual Lanthanide Elements by Neutron Activation Using a New Comparator Technique

  • Lee, Chul;Yim, Yung-Chang;Chung, Koo-Soon
    • Nuclear Engineering and Technology
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    • v.4 no.2
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    • pp.83-89
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    • 1972
  • The contents of the individual lanthanide elements are determined by neutron activation using a new comparator technique, which employs the short-lived radio-isotope of 56Mn as a neutron flux monitor. The total rare earths are separated as a group from the monazite sample before irradiation. After irradiation the rare earths are separated from each other by gradient elution with ammonium alpha-hydroxyisobutyrate using a cation-exchange column. The contents of 14 individual rare earths, from lutetium to lanthanum, are deter-mined.

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Identification and HPLC Quantification of a Phytoecdysone and Three Phenolic Glycosides in Lamium takesimense Nakai

  • Nugroho, Agung;Park, Kyoung-Sik;Seo, Dong-Jin;Park, Hee-Juhn
    • Natural Product Sciences
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    • v.24 no.4
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    • pp.241-246
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    • 2018
  • The herbs of Lamium takesimense Nakai (Lamiaceae) is used to treat spasmodic and inflammatory disease. The four polar compounds, ecdysterone, isoacteoside, rutin and lamiuside C, were isolated and identified from the BuOH fraction of the L. takesimense MeOH extract. HPLC quantification was performed on a Capcell Pak C18 column ($5{\mu}m$, $4.6mm{\times}250mm$) with a gradient elution of $H_2O$ and 0.05% acetic acid in MeOH. The HPLC method was validated in terms of linearity, sensitivity, stability, precision, and accuracy. The quantitative level in plant material was determined as the following order: lamiuside C (4, 3.75 mg/g dry weight) > ecdysterone (1, 1.93 mg/g) > isoacteoside (2, 1.32 mg/g) > rutin (3, 0.97 mg/g).

Quantitative determination of pseudoephedrine in human plasma by reversed-phase liquid chromatography-electrospray ionization mass spectrometry

  • Kim, Jin-Ki;Cho, Jung-Hye;Woo, Jong-Soo;Kim, Chong-Kook
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.394.2-394.2
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    • 2002
  • A sensitive and selective reversed-phase LC-ESI-MS method to quantitate pseudoephedrine in human plasma was developed and validated. Phenacetin was used as an internal standard. Samples were prepared simply by acetonitrile precipitation without an evaporation step. Chromatographic separation was achieved on a XTerra MS C18 column ($150{times}2.1$ mm I.D.. 3.5 $\mu\textrm{m}$ particles). using gradient elution with 0.5% (v/v) trifluoroacetic acid (TFA) in water and 0.5% (v/v) TFA in methanol at a flow-rate of 0.1 ml/min. (omitted)

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Simultaneous Determination of Curcumin and Glycyrrhizin Contents by High-performance Liquid Chromatography in Two Different Oriental Herbal Preparations of Kamijadowhan

  • Kim, Eun-Young;Choi, Seung-Hun;Kwon, Oh-Seung
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.389.1-389.1
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    • 2002
  • A high-performance liquid chromatographic method was developed to determine the quantities of curcumin and glycyrrhizin in two different oriental herbal preparations of Kamijadowhan (KMD. NKMD). Two compounds were separated in less than 10 min with a Nova-Pak $C_{18}$ column ($3.9{\times}150$ mm ($5{\mu}$ particle size) by linear gradient elution using 0.03% (v/v) phosphoric acid-acetonitrile (60:40. v/v% at 0 min; 40:60 v/v% at 6 mini as the mobile phase at a flow-rate of 0.8 ml $min^{-1}$. (omitted)

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Quantitative analysis of cordycepin in Cordyceps militaris under different extraction methods

  • Choi, Jungwon;Paje, Leo Adrianne;Kwon, Baekjun;Noh, Jaekyu;Lee, Sanghyun
    • Journal of Applied Biological Chemistry
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    • v.64 no.2
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    • pp.153-158
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    • 2021
  • Cordyceps militaris (CM) is one of the most important medicinal mushrooms known to possess various biological activities. Cordycepin (CP) is a bioactive compound present in the fruiting bodies of CM and is known to have anti-tumor, anti-metastatic immunomodulatory and anti-inflammatory activities. In this study, we aim to analyze CP quantitatively under various CM extraction conditions. CP was measured using high-performance liquid chromatography, quantified using a reversed phase column using a gradient elution system of water and acetonitrile, and detected with a UV absorbance wavelength of 260 nm. The CP content of CM was the highest in 100% ethanol extract of the fruiting bodies and 60% ethanol extract of the mycelium. This study provides an efficient analysis method to determine the optimal extraction conditions for CP that can be used as a basis for developing functional foods and pharmaceutical products derived from CM.