• Korean Journal of Pharmacognosy
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• v.45 no.2
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• pp.141-146
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• 2014

In this study, we investigated on antioxidative activities and tyrosinase inhibitory activities of methanol extract and its fractions from roots of Arctium lappa. The total phenolic compound and flavonoid content of the ethylacetate fraction was found to be 818.29 mg/g and 360.59 mg/g as the highest content. In the measurement of DPPH radical scavenging ability and tyrosinase inhibitory activity, the ethylacetate fraction was higher than the other fractions and the extract. In addition, comparative analysis of phenolic compounds by liquid chromatography-mass spectrometry (MS)/MS system under the multiple-reaction monitoring (MRM) with negative-ion electrospray ionization mode. The main phenolic compounds in the extract and fractions of roots from Arctium lappa were cynarin and chlorogenic acid. The main phenolic compound of the ethylacetate fraction was cynarin. n-Butanol fraction had a significantly higher chlorogenic acid content than other samples. In conclusion, DPPH radical scavenging ability and tyrosinase inhibitory activity of the cynarin-riched ethylacetate fraction showed the highest activity.

• Preventive Nutrition and Food Science
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• v.4 no.4
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• pp.221-225
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• 1999

Antioxidative compounds contained in roasted safflower seeds were investigated. Six phenolic compounds, N-feruloylserotonin, N-(p-coumaroyl) serotonin, matairesinol, 8'-hydroxyarctigenin, acacetin 7-Ο-β-D-glucoside(tilianine) and acacetin were isolated and identified from the extract of seeds. The inhibitory effects of six phenolic compounds on 1,1-dipheny1-2-picrylhydrazyl(DPPH) radical and lipid peroxidation induced by H₂O₂/FeSO₄in rat liver microsomes were determined. Two serotonins showed more potent DPPH radical scavenging activity, and a stronger inhibitory effect on the lipid peroxidation than that of α-tocopherol. In addition, acacetin and matairesinol also considerably inhibited lipid peroxidation, while 2-hydroxy-arctigenin and tilianine were inactive. These results suggest that phenolic compounds, including serotonins, lignans and flavonoids in the roasted safflower seeds can be used as potential dietary natural antioxidants.

• Korean Journal of Pharmacognosy
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• v.44 no.3
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• pp.220-223
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• 2013

In the course of screening tyrosinase inhibitory activity, total methanolic extract and EtOAc-soluble fraction of Smilax china leaves showed significant inhibitory activity. Further fractionation and isolation of the EtOAc-soluble fraction resulted in 12 phenolic compounds, which were identified as 4-hydroxybenzoic acid (1), 3,4-dihydroxybenzaldehyde (2), 3,4-dihydroxybenzoic acid (3), 3,4-dihydroxyacetophenone (4), 3-hydroxy-4-methoxy benzoic acid (5), trans-p-hydroxycinnamic acid (6), cis-p-hydroxycinnamic acid (7), trans-resveratrol (8), cis-resveratrol (9), dihydroresveratrol (10), moracin M (11) and kaempferol (12). Compounds 1-11 were first reported from this plant. Among the isolated compounds, compounds 2, 8, 9 and 12 showed strong inhibition on tyrosinase activity.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.81-86
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• 2019

A yellow resin (gamboge) from Garcinia hanburyi has been widely used as folk medicine due to its antibacterial and antitumor activities. We isolated four ${\alpha}$-glucosidase inhibitory compounds from the methanol extract of gamboge. The compounds (1-4) were identified as gambogoic acid (1), moreollic acid (2), gambogic acid (3), and 10-methoxygambogenic acid (4), respectively through spectroscopic data including 2D-NMR and HREIMS. All compounds were examined in the enzyme inhibition assay against ${\alpha}$-glucosidase to identify their inhibitory potencies and kinetic behavior. All compounds (1-4) showed enzyme inhibition against ${\alpha}$-glucosidase, but the activity was significantly affected by the methoxy group on C-10 of ring A and pentenyl pyran moiety of ring D. For example, compound 1 ($IC_{50}=41.4{\mu}M$) bearing pyran ring eight times effective that 4 ($IC_{50}=350.6{\mu}M$) having geranyl group itself. Most active compound was found out to be gambogoic acid (1) which was analyzed most abundant metabolite in gamboge by LC-ESI-MS/MS. In kinetic study, compounds 1 and 2 were proved as noncompetitive inhibitors.

• 한국약용작물학회:학술대회논문집
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• 2010.10a
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• pp.430-430
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• 2010

In this study ethanol extracts of aerial part of Geranium thunbergii Sieb. et Zucc. was investigated for their ability to inhibit a-glucosidase, and thus was fractionated using two organic solvents, including dichloromethane, ethyl acetate. The ethyl acetate-soluble fraction, which manifested potent enzyme inhibitory properties, was then followed by tracking down the active compound by combining HPLC micro-fractionation to an enzyme assay in 96-well plate. The ${\alpha}$-glucosidase inhibitory activity profile showed that two peaks exhibited potent inhibitory activity, and then the structural analyses of the two peaks were carried out by HPLC-UV-MS. The main ${\alpha}$-glucosidase inhibitory compounds in the ethyl acetate-soluble fractions of ethanol extracts of Geranium thunbergii Sieb. et Zucc. were tentatively identified as geraniin and kaempferol-7-rhamnoside.

• Korean Journal of Medicinal Crop Science
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• v.20 no.4
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• pp.222-230
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• 2012

We evaluated the inhibitory effects of extracts and components of Geranium thunbergii on aldose reductase (AR) and galactitol formation in rat lenses with high levels of galactose as a part of our ongoing search of natural sources for therapeutic and preventive agents for diabetic complications. The inhibitory effects of water, methanol and ethanol extracts of G. thunbergii on rat lens AR (RLAR) were determined. Comparing inhibitory effects of various solvent extracts, ethanol extract showed RLAR inhibitory activity ($IC_{50}$ values, 5.24 and $6.39{\mu}g/m{\ell}$, respectively). The ethanol extract was fractionated to chloroform, ethyl acetate and water. Of these, the ethyl acetate fraction from ethanol extract of G. thunbergii exhibited RLAR inhibitory activity ($IC_{50}$ value, $2.64{\mu}g/m{\ell}$). In order to identify the bioactive components of ethyl acetate soluble fraction of ethanol extract from G. thunbergii, eight compounds, namely gallic acid (1), protocatechuic acid (2), p-hydroxybenzoic acid (3), brevifolin carboxylic acid (4), geraniin (5), ellagic acid (6), kaempferol-3-O-arabinofuranosyl-7-O-rhamnopyranoside (7), kaempferitrin (8) were isolated. The isolates were subjected to in vitro bioassays to evaluate their inhibitory activity on RLAR and galactitol formation in rat lenses. The ellagic tannins (5, 6) and flavonoid (7) exhibited strong inhibitory effects on RLAR. Also, these three compounds (5, 6 and 7) suppressed galactitol accumulation in rat lens under high galactose conditions, demonstrating the potential to prevent galactitol accumulation exo vivo. These results suggest that the extracts and components of G. thunbergii are a promising agent in the prevention or treatment of diabetic complications.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.335-339
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• 1999

The oxidation-reduction potentials of cosmetic raw materials, showing tyrosinase inhibitory action, and phenolic compounds structurally similar to L-tyrosine were determined by cylcic voltammetry. The voltammograms obtained could be classified ito 4 patterns (patterns 1-4). Patterns 1, characterized by oxidation and reduction peaks as a pair, was observed with catechol, hydroquinone or phenol, and pattern 2 exhibiting another oxidation peak in addition to oxidation and reduction peaks as a pair was found with arbutin, kojic acid, resorcinol, methyl p-hydroxybenzoate and L-tyrosine as the substrate of tyrosinase. Pattern 3 with an independent oxidation peak only was expressed by L-ascorbic acid, and pattern 4 with a reduction peak only at high potentials, by hinokitiol. The tyrosinase inhibitory activity of these compounds was also evaluated using the 50% inhibitory concentration ($IC_{50}$) and the inhibition constant (Ki) as parameters. Hinokitiol, classified as patterns 4, showed the highest inhibitory activity (lowest $IC_{50}$ and Ki). Hydroquinone showing the second highest activity belonged to pattern 1, which also included compounds exhibiting pattern 2 was relatively low with Ki values being in the order of 10-4 M. Although there was no consistent relationship between oxidation-reduction potentials and tyrosinase inhibitory action, the voltammetry data can be used as an additional index to establish the relationship between the structure and the tyrosine inhibitory activity.

• Korean Journal of Pharmacognosy
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• v.30 no.2
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• pp.216-221
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• 1999

The NAD(P)-linked $3{\alpha}-Hydroxysteroid$ $dehydrogenase(3{\alpha}-HSD)$ of rat liver cytosol is powerfully inhibited by the non-steroidal anti-inflammatory drugs in rank-order of their therapeutic potency, and this observation has now been developed into a rapid screen for predicting the potency of products that show anti-inflammatory effect. Five-plants were screened by using this method. Among them, BuOH-fraction of Mucuna birdwoodiana showed strong inhibitory effect on $3{\alpha}-HSD$, and three isoflavone compounds were isolated. Inhibitory activates of isolated compounds were compared.

• Natural Product Sciences
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• v.18 no.4
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• pp.233-238
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• 2012

Nine compounds (1 - 9), ${\alpha}$-linolenic acid (1), cis-5,8,11,14,17-elcosapentaenoic acid (2), phytol (3), loliolide (4), uridine (5), thymidine (6), deoxyadenosine (7), adenine (8), and adenosine (9), were isolated from the n-hexane, methylene chloride, ethyl acetate and n-butanol fractions of Capsosiphon fulvescens. The structures of these compounds were elucidated on the basis of spectroscopic evidence. Compounds 1 - 9 exhibited acetylcholinesterase (AChE) inhibitory activities with $IC_{50}$ values ranging from 114.91 to $252.40{\mu}M$, whereas 2 - 4 showed butyrylcholinesterase (BChE) inhibitory activities with $IC_{50}$ values ranging from 251.18 to $499.16{\mu}M$.

• Food Science and Biotechnology
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• v.14 no.2
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• pp.223-227
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• 2005

Anti-inflammatory assay was conducted on 20 kinds of traditional Indonesian medicinal herbs using soybean lipoxygenase (SLO) and hyaluronidase (HAse). Cinnamomun burmanni Bl showed highest anti-inflammatory activity. Ethyl acetate fraction from methanol extract of C. burmanni Bl bark showing high SLO inhibitory activity was isolated using silica gel-60 column chromatography. Two compounds were isolated and purified through preparative HPLC. Through analyses of UV, $^1H-NMR$, $^{13}C-NMR$, EI-MS and $FAB^+-MS$, compounds 1 and 2 were identified as coumarin and 2-hydroxy cinnamaldehyde, respectively, among which 2-hydroxy cinnamaldehyde showed SLO inhibitory activity of $IC_{50}\;=\;60\;{\mu}M$. Both compounds did not exhibit HAse inhibitory activity.