• Journal of Applied Biological Chemistry
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• v.59 no.2
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• pp.103-106
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• 2016

The leaves of eggplant (Solanum melongena L.) were extracted with 80 % aqueous MeOH, and the concentrated extract was partitioned with n-hexane, EtOAc, n-BuOH, and water fractions. From the n-BuOH fraction, five compounds were isolated through the repeated silica gel, octadecyl silica gel, and Sephadex LH-20 column chromatographies. On the basis of physic-chemical and spectroscopic data including mass spectrometry, infrared spectroscopy, and nuclear magnetic resonance, they were identified to be caffeic acid (1), chlorogenic acid (2), cryptochlorogenic acid (3), panasenoside (4), and (6R,7E,9R)-4,7-megastigmadien-3-one-9-${\beta}$-${\small{D}}$-glucopyranoside (5). Compounds 3 and 4 were isolated for the first time from the leaves of S. melongena L. in this study.

• Journal of Applied Biological Chemistry
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• v.59 no.2
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• pp.155-158
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• 2016

The fruits of Prunus davidiana were extracted with 80 % aqueous methanol at room temperature. The concentrated extract was partitioned as ethyl acetate (EtOAc), n-butyl alcohol, and water fractions. From the EtOAc fraction, three triterpenoids were isolated through the repeated silica gel ($SiO_2$) and octadecyl $SiO_2$ column chromatographies. Based on physico-chemical and spectroscopic data including nuclear magnetic resonance, mass spectrometry, and infrared, the compounds were identified to be ursolic acid (1), corosolic acid (2), and ${\alpha}-amyrin$ (3).

• Journal of Applied Biological Chemistry
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• v.55 no.2
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• pp.103-107
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• 2012

Acanthopanax sessiliflorus Seeman fruits (Araliaceae) were extracted at room temperature with 70% aqueous ethanol (EtOH). The concentrated extract was partitioned with ethyl acetate (EtOAc), n-butyl alcohol, and $H_2O$, successively. From the EtOAc fraction, four compounds were isolated through the repeated silica gel and octadecyl silica gel (ODS) column chromatographies. According to the results of physico-chemical and spectroscopic data including NMR, IR, and gas chromatography/mass spectrometer, the chemical structures of the compounds were determined as stigmasterol (1), linoleic acid (2), ${\beta}$-sitosterol (3), and stigmast-5-en-$3{\beta}$,$7{\beta}$-diol (4).

• Journal of Applied Biological Chemistry
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• v.57 no.2
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• pp.165-170
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• 2014

The stems of Viburnum erosum were extracted with 80% MeOH. The concentrated extract was partitioned with EtOAc, n-BuOH, and $H_2O$. From the EtOAc and n-BuOH fractions, four compounds were isolated through the repeated $SiO_2$, octadecyl silica gel, and Sephadex LH-20 column chromatographies. Based on NMR, MS, and IR spectroscopic data, the chemical structures were determined as betulinic aldehyde (1), koaburside (2), (6R,7E,9R)-9-hydroxymegastigma-4,7-dien-3-one-9-O-${\beta}$-D-glucopyranoside (3), and byzantionoside B (4). All the compounds were isolated for the first time from the stems of Viburnum erosum.

• Natural Product Sciences
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• v.13 no.2
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• pp.152-159
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• 2007

To demonstrate anti-hyperlipidemic activity of the 19${\alpha}$-hydroxyursane-type triterpenoid (19${\alpha}$-HUT)-rich fraction, this fraction was prepared from the extract of Rubus crataegifolius leaves. This fraction was found to have anti-hyperlipidemic effect in a high fat diet-induced rat model from the observation of reduction of abdominal fat pad weights, atherogenic index and hypercholesterolemia at 30 and 60 mg/kg (p.o.) The 19${\alpha}$-HUT fraction was subjected to SiO$_2$, ODS, and/or Sephadex LH-20 column chromatography to yield a new triterpenoid (1) called pomolic acid ester along with nine known triterpenoids which are all 19${\alpha}$-HUTs: euscaphic acid (2), tormentic acid (3), 23-hydroxytormentic acid (4), kaji-ichigoside F$_1$ (5), rosamultin (6), niga-ichigosides F$_1$ (7) and F$_2$ (8), suavissimoside F$_1$ (9) and coreanoside F$_1$ (10). The structure of compound 1 was established as 28-O-formyl-3,19-dihydroxyurs-12-en-28-oic acid on the basis of 2D-NMR spectroscopic data and mass spectrum. Compound 1 was isolated for the first time from natural sources.

• Natural Product Sciences
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• v.16 no.2
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• pp.116-122
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• 2010

A high-performance liquid chromatography (HPLC) with diode array detector (DAD) and electrospray ionization mass spectrometry (ESI-MS) was established for the simultaneous determination of five representative metabolites of the iridoid and phenolic classes from Rehmannia glutinosa. The optimal chromatographic conditions were obtained on an ODS column (5 mm, $4.6{\times}250\;mm$) with the column temperature at $25^{\circ}C$. The mobile phase was composed of water and acetonitrile using a gradient elution with the flow rate 0.3 mL/min. Detection wavelength was set at 205 nm. All calibration curves showed good linear regression ($r^2$ > 0.997) within test ranges. Limits of detection (LOD) and quantitation (LOQ) values were lower than 0.123 and $0.373\;{\mu}g/mL$, respectively. The developed method provided satisfactory precision and accuracy with overall intra-day and inter-day variations of 0.09 - 0.76% and 0.16 - 1.41%, respectively, and the overall recoveries of 99.03 - 102.67% for all of the compounds analyzed. In addition, effectiveness of diverse extraction methods was compared to each other for the development of standard analytic method. The verified method was successfully applied to the quantitative determination of five representative metabolites in twenty-one commercial Rehmannia glutinosa samples from different markets in Korea and China. The analytical results showed that the contents of the five analytes vary significantly with sources.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1214-1220
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• 2008

Secondary metabolites from the fruit body of Phellinus linteus were evaluated for their proliferative effect on human osteoblast-like cells. 3-[4,5-Dimethylthiazole-2-y1]-2,5-diphenyl-tetraxolium bromide (MTT) assay and alkaline phosphatase (ALP) activity assay were used to assess the effect those isolates on the human osteoblast-like cell line (Saos-2). Activity-guided fractionation led to the isolation of ALP-activating phenolic compounds through the extraction of P. linteus, solvent partitioning, and repeated silica gel and octadecyl silica gel (ODS) column chromatographic separations. From the result of spectroscopic data including nuclear magnetic resonance (NMR), mass spectrometry (MS), and infrared spectroscopy (IR), the chemical structures of the compounds were determined as 4-(4-hydroxyphenyl)-3-buten-2-one(1), 2-(3',4'-dihydroxyphenyl)-1,3-benzodioxole-5-aldehyde (2), 4-(3,4-dihydroxyphenyl)-3-buten-2-one (3), 3,4-dihydroxybenzaldehyde (4), and protocatechuic acid methyl ester (5), respectively. This study reports the first isolation of compounds 1-3 and 5 from P. linteus. In addition, all phenolic compounds stimulated proliferation of the osteoblast-like cells and increased their ALP activity in a dose-dependent manner ($10^{-8}$ to $10^{-1}\;mg/mL$). The present data demonstrate that phenolic compounds in P. linteus stimulated mineralization in bone formation caused by osteoporosis. The bone-formation effect of P. linteus seems to be mediated, at least partly, by the stimulating effect of the phenolic compounds on the growth of osteoblasts.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1403-1408
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• 2000

The methanol soluble fraction of the hot water extracts from Hovenia dulcis Thunb showed antioxidative and antimicrobial activity. The methanol fraction was successively purified with solvent fractionation, silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, and octadecylsilane column chromatography. The purified active substances were isolated by high performance liquid chromatography. The isolated substances were identified as 3-methoxy-4-hydroxybenzoic acid (vanillic acid) and 3-methoxy- 4-hydroxycinnamic acid (ferulic acid) by LC-MS and GC-MS. Vanillic acid and ferulic acid showed antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria and yeast. The DPPH-radical scavenging activity of ferulic acid appeared more active than that of vanillic acid. DPPH-radical scavenging concentration of ferulic acid and vanillic acid were $14\;{\mu}g/mL\;(SC_{50})$, $100\;{\mu}g/mL\;(SC_{10})$, respectively.

• Journal of the Korean Society for Heat Treatment
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• v.31 no.4
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• pp.171-179
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• 2018

Copper powder dispersed with 4 vol.% of $Cr_2O_3$ was successfully produced by a simple milling at 210 K with a mixture of $Cu_2O$, Cu and Cr elemental powders, followed by Hot Pressing (HP) at 1123 K and 50 MPa for 2h to consolidate the milled powder. The microstructure of the HPed material was characterized by standard metallographic techniques such as XRD (X-ray Diffraction), TEM and STEM-EDS. The results of STEMEDS analysis showed that the HPed materials comprised a mixture of nanocrystalline Cu matrix and $Cr_2O_3$ dispersoid with a homogeneous bimodal size distribution. The mechanical properties of the HPed materials were characterized by micro Vickers hardness test at room temperature. The thermodynamic considerations on the heat of formation, the incubation time to ignite MSR (Mechanically induced Self-sustaining Reaction), and the adiabatic temperature for the heat of displacement reaction between the oxide-metal are made for the delayed formation of $Cr_2O_3$ dispersoid in terms of MSR suppression. The results of TEM observation and hardness test indicated that the relatively large dispersoids in the HPed materials are attributed to the significant coarsening for the high temperature consolidation; this leads to the low Vickers hardness value. Based on the thermodynamic calculation for the operating processes with a limited number of parameters, the formation kinetics and coarsening of the $Cr_2O_3$ dispersoid are discussed.

• Mycobiology
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• v.49 no.5
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• pp.461-468
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• 2021

The genus Laccaria (Hydnangiaceae, Agaricales) plays an important role in forest ecosystems as an ectomycorrhizal fungus, contributing to nutrient cycles through symbiosis with many types of trees. Though understanding Laccaria diversity and distribution patterns, as well as its association with host plants, is fundamental to constructing a balanced plant diversity and conducting effective forest management, previous studies have not been effective in accurately investigating, as they relied heavily on specimen collection alone. To investigate the true diversity and distribution pattern of Laccaria species and determine their host types, we used four different approaches: specimen-based analysis, open database search (ODS), NGS analysis, and species-specific PCR (SSP). As a result, 14 Laccaria species have been confirmed in Korea. Results regarding the species distribution pattern were different between specimen-based analysis and SSP. However, when both were integrated, the exact distribution pattern of each Laccaria species was determined. In addition, the SSP revealed that many Laccaria species have a wide range of host types. This study shows that using these four different approaches is useful in determining the diversity, distribution, and host of ECM fungi. Furthermore, results obtained for Laccaria will serve as a baseline to help understand the role of ECM fungi in forest management in response to climate change.