• YAKHAK HOEJI
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• v.54 no.4
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• pp.316-321
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• 2010

Adefovir dipivoxil which was originally developed by Gilead Sciences has been used as treatments of HIV and HBV, especially a therapeutics for HBeAg positive and negative chronic patients. We developed highly efficient purification method using reverse phase column chromatography for mass production and a stable amorphous Adefovir dipivoxil using solid dispersion method. Reverse phase column chromatography led to highly pure product, more than 99.7% by HPLC and can be used for mass production compared with normal column chromatography. Solid dispersion method containing watersoluble polymer and Isomalt showed improved stability of amorphous Adefovir dipivoxil against heat and moisture.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.307-314
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• 1990

Brassinosteroid-like substances in two japonica type Korean rices were investigated. The extracts from the shoots at the maximum tillering stage were purified by solvent fractionation, silica gel adsorption chromatography, Sephadex LH-20 chromatography, charcoal adsorption chromatography, preparative TLC, Bondesil chromatography and HPLC of normal phase and reverse phase, successively. Biological activity of each purification step were monitored by the rice lamina inclination test. Two cultivars tested in this experiment produced brassinosteroids and endogenous brassinosteroids showing similiarity between two cultivars.

• Natural Product Sciences
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• v.24 no.4
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• pp.288-292
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• 2018

High-performance countercurrent chromatography (HPCCC) coupled with reversed-phase highperformance liquid chromatography (RP-HPLC) method was developed to isolate dihydrophaseic acid 3'-O-${\beta}$-D-glucopyranoside (DHPAG) from the extract of Nelumbo nucifera seeds. Enriched DHPAG sample (2.3 g) was separated by HPCCC using ethyl acetate/n-butanol/water system (6:4:10, v/v/v, normal-phase mode, flow rate: 4.0 mL/min) to give 23.1 mg of DHPAG with purity of 88.7%. Further preparative RP-HPLC experiment gave pure DHPAG (16.3 mg, purity > 98%). The current study demonstrates that utilization of CCC method maximizes the isolation efficiency compared with that of solid-based conventional column chromatography.

• Korean Journal of Medicinal Crop Science
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• v.9 no.1
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• pp.21-25
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• 2001

Major saponins in ginseng were analysed using reverse phase high performance liquid chromatography with binary mobile phase gradient control system instead of normal phase column. The optimum condition were as following : reverse phase column; ${\mu}{\beta}ondapak\;C_{18}$ column (Waters, $3.9mm{\times}300\;mm,\;5{\mu}m$), methyl cyanaide/water binary mobile phase gradient control system, solvent flow rate; 1.5 ml/min, and UV($203{\mu}m$ ) detector. The complete separation of ginsenoside $Rb_1,\;Rb_2,\;Rc,\;Rd,\;Re,\;Rf\;and\;Rg_1$ was achieved within 55 min. The Regression coefficients of the calibration curves for seven ginsenosides were 0.99.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.204-210
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• 2001

Paclitaxel can be produced in high yield and with a high degree of purify from plant cell cultures of Taxus chinensis. The complete purification method was systematically established and described. This method was an efficient procedure for the purification of paclitaxel from crude paclitaxel, consisting or reverse-phase chromatography, followed by a normal-phase chromatography. The two-stage HPLC purification scheme serves as an effective and economical approach for resolving paclitaxel from complex mixtures of taxoids, with high purify (>99%) and low impurities (<0.1%). The process is readily scalable to a pilot plant and eventually to a production environment where multikilogram quantities of material are expected to be produced. The process has been optimized to minimize solvent usage, complexity, and operating costs.

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.282-286
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• 2010

To isolate a calcium-binding peptide from chlorella protein hydrolysates, chlorella protein was extracted and hydrolyzed using Flavourzyme, a commercial protease. The degree of hydrolysis and calcium-binding capacity were determined using trinitrobenzenesulfonic acid and orthophenanthroline methods, respectively. The enzymatic hydrolysis of chlorella protein for 6 hr was sufficient for the preparation of chlorella protein hydrolysates. The hydrolysates of chlorella protein were then ultra-filtered under 5 kDa as molecular weight. The membrane-filtered solution was fractionated using ion exchange, reverse phase, normal phase chromatography, and fast protein liquid chromatography to identify a calcium-binding peptide. The purified calcium-binding peptide had a calcium binding activity of 0.166 mM and was determined to be 700.48 Da as molecular weight, and partially identified as a peptide containing Asn-Ser-Gly-Cys based on liquid chromatography/electrospray ionization tandem mass spectrum.

• Journal of Ginseng Research
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• v.22 no.4
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• pp.284-288
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• 1998

This study was carried out to establish a new efficient method for isolation and purification of ginsenosides. Silica gel column chromatography, having been used for the isolation of ginsenosides, is advantageous to obtain a large amount of ginsenosides. However, it has a disadvantage to isolate ginsenosides to their highest purity. In addition, normal-or reverse-phase HPLC method thus far reported is confined to quantitative analysis. Especially, it has not been possible to isolate racemic 20(S)- and 20(R)-ginsenoside Rg2. In this experiment, isolation and purification of ginsenosides were accomplished by Diaion HP-20 adsorption chromatography, silica gel column chromatography, recrystalization and Prep. HPLC with or without Prep. TLC. From this study, we could establish a new efficient method for isolation and purification of 9 major and/or minor ginsenosides.

• Analytical Science and Technology
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• v.10 no.6
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• pp.445-452
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• 1997

A simple and sensitive high performance liquid chromatography for analysis of Putrescine, Spermidine and Spermine in urine is described. The benzoyl chloride derivatives of Putrescine, Spermidine and Spermine are separated on a ${\mu}$ Bondapak $C_{18}$ reverse-phase column with methanol/$H_2O$(50/50v/v) as the mobile phase. The results show that the mean level of polyamines in uterine cancer patients urine is much higher than in normal human urine.

• YAKHAK HOEJI
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• v.50 no.1
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• pp.21-25
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• 2006

Reiterated normal-phase column chromatography lead to the isolation and purification of six known compounds but for the first time from the whole plant of Sasa borealis (Hack.) Makino (Gramineae): tricin 4'-O-(erythro-${\beta}$-guaia-cylglyceryl) ether (1), tricin 4'-O-(threo-${\beta}$-guaiacylglyceryl) ether (2), tricin 4'-O-[erythro-${\beta}$-guaiacyl-(9'-O-acetyl)-glyceryl] ether (3), tricin 4'-O-[threo-${\beta}$-guaiacyl-(9'-O-acetyl)-glyceryl] ether (4), (-)-pinoresinol (5), and vanillin (6). The structures of the compounds (1-6) were established based on interpretation of high resolution NMR (COSY, HSQC, HMBC, and NOESY) spectral data. In particular, compounds 1 and 3 were diastereomers of compounds 2 and 4, respectively. These two sets of diastereomers were able to be simultaneously identified and quantified by a gradient reversed-phase HPLC method with UV photodiode array, This sensitive HPLC method is noteworthy as a simultaneous separation and identification method to test the extract of the family Gramineae which contains these compounds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.300-306
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• 2000

In the present studies, we assessed the stability of active components and toxicological safety of irradiated Angelica gigas Nakai(Danggui). In order to confirm the stability of active components in the ${\gamma}$-irradiated roots of Danggui, the quantitative analysis of decursin and decursinol angelate of ${\gamma}$-irradiated sample was carried out by high performance liquid chromatographic (HPLC) methods using reverse phase columns and normal phase columns. From the root of Danggui, decursin and decursinol angelate were isolated by a silica gel column chromatography(toluene : ether (1 : 1), Hexane : EtOAc(15 : 1)). And then the structures were confirmed in the 1H and 13C-NMR analysis. The HPLC chromatograms of decursin and decursinol angelate in ${\gamma}$-irradiated Danggui were similar with those of non-irradiated sample. In the examination of in vitro genotoxicity of the water extract from ${\gamma}$-irradiated Danggui using Salmonella reversion assay(Ames test) and micronucleus test in Chinese hamster ovary (CHO) cells, mutagenicity was not exhibited in the two assays with or without metabolic activation. These resutls suggest that active components in the ${\gamma}$-irradiated Danggui should be stable and that the safety of ${\gamma}$-irradiated Danggui could be revealed in further test in vivo.