• Journal of Life Science
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• v.17 no.4 s.84
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• pp.476-481
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• 2007

The methanolic roots bark extract of Cudrania tricuspidata (Carr.) Bureau was chromatographed, which yielded three xanthones 1-3 by tyrosinase inhibitory activity-guided fractionation. The structures were fully characterized by analysis of physical and spectral data. Among them, furano prenylxanthone 3, never reported as tyrosinase inhibitor, showed potent activity with $IC_{50}$ value of $16.5{\mu}M$, and appeared to inhibit the polyphenol oxidase activity of tyrosinase in an uncompetitive inhibitor($K_i=1.6{\mu}m$) when L-tyrosine was used as a substrate. Moreover, potent inhibitor furano prenylxanthone 3 had an extended lag time of 310 sec at $20{\mu}M$, while lag time of kojic acid as positive control was prolonged with 350 sec at the same concentration.

• Journal of Life Science
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• v.22 no.8
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• pp.1092-1098
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• 2012

This study was carried out to discover the skin wrinkle reducing components in the seeds of Arctium lappa. The isolation of a methylene chloride-soluble fraction of 70% ethanol extract from the seeds of Arctium lappa using a procollagen type-1 synthesis and MMP-1 activity resulted in the isolation and identification of four lignin compounds: arctiin, arctigenin, matairesinol, and diarctigenin. All structures were confirmed via NMR and MS spectroscopic data. To determine cell viability and procollagen type-1 synthesis, human dermal fibroblasts were treated with 10-100 ${\mu}M$. As a result, none of the four compounds showed cytotoxicity up to 50 ${\mu}M$. We also investigated their procollagen type-1 synthesis and MMP-1 inhibition activity and found that arctiin had the highest activity in terms of both procollagen synthesis and MMP-1 inhibition among all four compounds. Putting all the data together, we suggest that arctiin be used in cosmetics as an anti-wrinkle material.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.855-863
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• 1999

To develop new natural antioxidants, antioxidative activity of ethanol (75%) extracts from 50 edible or medicinal plants were examined on lard and palm oil by Rancimat method ($120^{\circ}C$, 20 L/hr). The extracts from Rhus verviciflua STOKES showed comparatively strong antioxidative activity on test. Of the solvents used for extraction, chloroform extract exhibited the strongest antioxidant activity. AI (antioxidant index: induction period of oil containing extract/induction period of control oil) of chloroform extract was higher than that of commercial antioxidant, such as BHT, BHA and ${\delta}-tocopherol$. Free phenolic acid fraction (200 ppm) of the chloroform extract from 75% EtOH extract of Rhus verniciflua STOKES (RCF) showed stronger activity than that of BHT, BHA, and ${\delta}-tocopherol$ at the same concentration. RCF-11 and RCF-13 fractions separated by silicagel column chromatography from the RCF showed stronger activity than other fractions by the Rancimat method.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.189-195
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• 1997

The structural basis of Iysine specificity of Achromobacter protease I (API) was investigated by means of site-directed mutagenesis. The precursor protein in which Glu190, one of the two candidates for determining Iysine specificity, was substituted by glutamine, aspartic acid or leucine was processed autocatalytically to attaln full pretense activity with lysine specificity. The substitution of the other candidate, Asp225, for asparagine or leucine produced no mature active forms of pro-API. The precursor protein of the mutant D225E slowly matured autocatalytically. The lysylendopeptidase activity of the mature D225E was 0.25% of that of native API, and this reduced activity is mainly due to a decrease in the affinity of the enzyme for lysine. These results suggest that Asp225 plays a critical rol in restricted substrate specificity as a lysylendopeptidase. However, D225E exhibited no measurable activity for synthetic ornithine substrate. Since the hydroxyl group of Ser194 in this mutant retained essentially the same reactivity to DFP or PMSF as that in native API, it can be noted that a methylene unit longer side chain of residue 225 is not compensated by a methylene unit shorter side chain at subsite P1 in the bound substrate.

• Applied Biological Chemistry
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• v.43 no.1
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• pp.72-77
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• 2000

The repeated silica gel colum chromatographies of EtOAc fraction, showing anticonvulsant activity, obtained from MeOH extracts of Schizandra chinensis B. fruits led to isolation of a sesquiterpenoid, four lignans and a sterol glycoside. Their chemical structures were determined to be chamigrenal, gomisin A, gomisin H, gomisin N. schizandrin and daucosterol. Among them, schizandrin and daucosterol inhibited GABA degrative enzymes, succinic semialdehyde dehydrogenase and succinic semialdehyde reductase, respectively. It is postulated that the schizandrin and daucosterol are able to elevate the neurotransmitter GABA levels in central nervous system by inhibitory action on GABA degrative enzymes and act as anticonvulsant drugs.

• Journal of the Korean Wood Science and Technology
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• v.38 no.6
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• pp.579-586
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• 2010

This study was carried out to evaluate the antifungal and antioxidative activities of ethanol extracts from Magnoliaceae to investigate the possibility for the natural fungicides and food preservatives. The antifungal activities of ethanol extracts were evaluated as a hyphal growth inhibition rate using four plant pathogenic and five wood rot fungi. The high inhibition activity on the growth of fungi was shown in bark of Magnolia obovata that indicated more than 50% hyphal growth inhibition rate except Trametes versicolor, one of the white rot fungi. The antifungal activity was the highest in the ethanol extracts from M. obovata and the following was in order of M. kobus and M. sieboldii. The extract from bark in M. obovata showed higher antifungal activity than that from wood in the same species. Especially, the extracts from flower of M. denudata and M. liliflora indicated the high antifungal activities, while the other portions of same plants showed the low activities. On the other hand, a free radical scavenging method was adopted with 1,1-diphenyl-2-picrylhydrohydrazyl (DPPH) in order to test the antioxidative activities of ethanol extracts. The free radical scavenging activity was very high in the extracts from branch of Schizandra nigra and Kadsura japonica that showed more than 90% at the concentration of 100 ${\mu}g/m{\ell}$. It also turned out that the antioxidative activity of branch of S. nigra and K. japonica was similar to ${\alpha}$-tocopherol and butylated hydroxytoluene, one of the effective synthetic antioxidants. From these results, it can be suggested that the branches of S. nigra and K. japonica have the positive antioxidative activities and can be applied for the food preservatives and cosmetic ingredient.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.135-144
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• 2007

The dried barks of Maackia amurensis were ground, extracted with 95% EtOH, concentrated, and fractionated with a series of light petroleum ether, dichloromethane, ethyl acetate and water on a separatory funnel. Each fraction was concentrated, then a portion of dichloromethane and ethyl acetate soluble was chromatographed on a Sephadex LH-20 and silica gel 60 column using a various solvent system as eluents. The isolated compounds were identified by cellulose TLC, $^1H-$, $^{13}C-NMR$, COSY, NOESY, HMQC, HMBC, FAB and EI-MS. The structures were determined as: 7-O-$\beta$-D-glucopyranosyl-4'-methoxyisoflavone, 7-O-$\beta$-glucopyranosyl(1'''->6'')-$\beta$-D-glucopyranosyl-4'-methoxyisoflavone, 7-O-$\beta$-D-glucopyranosyl(1''''->6''')-$\beta$-D-glucopyranosyl(1'''->6'')-$\beta$-D-glucopyransoyl-4'-methoxyisoflavone, 7-O-$\beta$-D-glucopyranosyl-4', 6-dimethoxyisoflavone. The Free radical scavenging activity using DPPH of the isolated compounds were similar with that of BHT but lower than of $\alpha$-tocopherol.

• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.199-206
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• 2009

The aim of this study is to investigate the relations among each white stone and their characteristics through the chemical and mineralogical analysis of them excavated from around some kilns in archaeological sites. Moreover it was intended to infer the function of kilns. Nine white stones were chosen from three different archaeological sites, the each name of which is Sanyang-ri, Youngdu-ri and Gwangdae-ri in Chungcheongnam-do. In the mineralogical characteristics of thin section, eight stones containing calcite are altered and recrystallized by metasomatism and hydrothermal process, and Calcites, major component minerals of limestone, were identified by the analysis of XRD. On the basis of this result, we can infer the stones to be classified into limestone groups. One the other hand, research revealed that one of the white stones was a white pelitic stone composed of quartz, microcline and muscovite. In the analysis of chemical composition, except for the white pelitic stone eight stones are mainly composed of CaO which is major component of Calcite. Besides, as a results of correlation analysis by using a chemical compositions of major and minor elements in white stones, little did each archaeological site have the relativity. In conclusion, each archaeological site was estimated that they would use a limestone ores extracted from different deposits, and there is a high possibility that the function of these kilns is to produce quicklime.

• Journal of Applied Biological Chemistry
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• v.62 no.4
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• pp.375-384
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• 2019

The root of Panax ginseng C.A. Meyer were extracted with 70% aqueous EtOH and the concentrates were partitioned into MeOH and H₂O fractions using Diaion HP-20. The repeated SiO₂ or octadecyl SiO₂ column, and MPLC for the MeOH fraction led to isolation of four malonyl ginsenosides. The chemical structures of these compounds were determined as malonyl ginsenoside Rd (1) malonyl ginsenoside Rc (2) malonyl ginsenoside Rb2 (3) malonyl ginsenoside Rb1 (4) based on spectroscopic analyses including Nuclear magnetic resonance and HR-TOF/MS. The contents of malonyl ginsenoside Rb1 was highist as 5.44 mg/g of five years of ginseng. And malonyl ginsenoside Rd was lowest as 0.11 mg/g of six years of ginseng. Additionally, the malonyl ginsenoside Rd exhibited hepatoprotective effect against ethanol-induced hepatotoxicity in HepG2 cell line.

• Journal of Applied Biological Chemistry
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• v.62 no.4
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• pp.399-406
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• 2019

The roots of Scrophularia buergeriana were extracted with 80% aqueous Methanol and the concentrates were partitioned into EtOAc, n-BuOH, and H₂O fractions. The repeated silica gel or octadecyl SiO₂column, and medium pressure liquid chromatographies for the n-BuOH fraction led to isolation of phenylethanoid glycosides and iridoid glycosides. The chemical structures of these compounds were determined as harpagoside (1), angoroside C (2), aucubin (3) and acetoside (4) based on spectroscopic analyses including nuclear magnetic resonance and MS. A simple and efficient HPLC with UV detection method for the simultaneous determination of the four compounds (1-4) has been developed and applied to their content determination in the S. buergeriana. The roots were extracted by 80% methanol, and the contents of 1, 2, 3, and 4 were determined to 11.5, 7.6, 41.2, and 4.8 mg/g, respectively. Additionally, angoroside C (2) and acetoside (4) exhibited hepatoprotective effect against ethanol-induced hepatotoxicity in HepG2 cell line.