• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.311-315
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• 2017

${\alpha}$-glucosidase inhibitory compounds (1-4) in a 50% methanol extract of Euonymus alatus were isolated by activity-based fractionations and the structures determined on the basis of chemical and spectral characterization techniques such as $^1H$ and $^{13}C$ nuclear magnetic resonance spectroscopy, $^1H-^1H$ correlation spectroscopy (COSY), and heteronuclear multiple bond correlation (HMBC). The compounds 1-4 belong to flavonols and exhibited potent inhibitory activities against ${\alpha}$-glucosidase, with $IC_{50}$ values of 25.3, 17.1, 47.3, and $35.1{\mu}M$, respectively. All the isolated compounds were more potent than the positive control acarbose. This is the first report describing the potential hypoglycemic effect of Euonymus alatus through ${\alpha}$-glucosidase inhibition and identification of its active components.

• Food Science and Preservation
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• v.18 no.6
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• pp.923-929
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• 2011

For the purpose of investigating the in vitro antidiabetic activity of a medicinal herb mixture prepared through traditional antidiabetic prescription, the study analyzed the existence of insulin-similar components and examined ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibition activity. As a result of arranging the medicinal herb mixture extracts over the 3T3-L1 fibroblast in the concentration of $10{\mu}g/mL$, which confirmed that it included much of insulin sensitizer components as 151.7% in the differentiation of 3T3-L1 fibroblast. The inhibition activity against ${\alpha}$-amylase of the medicinal herb mixture extracts as hypoglycemic agent were 38.4, 31.5 and 16.6% in the concentration of 10.0, 1.0 and 0.1 mg/mL, respectively. The inhibition activity against ${\alpha}$-glucosidase of the medicinal herb mixture extracts were 81.3, 35.8 and 26.7% in the concentration of 10.0, 1.0 and 0.1 mg/mL, respectively. The inhibition activity against ${\alpha}$-glucosidase in the ethyl acetate fractions of the water and 80% ethanol extracts were 66.9% and 55.1%, respectively, the highest levels in the various solvent extracts.

• Culinary science and hospitality research
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• v.18 no.5
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• pp.233-242
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• 2012

Jehotang is a cold traditional Korean drink made with honey and several ingredients used in traditional Korean medicine. The ingredients include Fructus mume, Fructus amomi, Fructus tsaoko, Santalum album and honey. In this study, Jehotang and its ingredients were determined through the analysis of antioxidant activity, total phenolic content, ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory activity. In addition, quality characteristics of Jehotang made by a traditional recipe(Yeonmil) and a modern recipe(double boiling and boiling) were also compared in terms of pH, color and sugar content. Total phenolic content of extract from Fructus ammomi was found to be 120.45 mg, and Yeonmil recipe was discovered 152.66 mg equivalent of gallic acid per g of extract. DPPH free radical scavenging activity were Feuctus amomi(93.13%) and Yeonmil recipe(56.44%). The Fructus amomi extract showed the highest ${\alpha}$-glucosidase inhibitory activity(89.51%) at the concentration of $100{\mu}g/mL$. ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory activity of boiled Jehotang were 52.38% and 72.52%, respectively. These results suggest that extract of Fructus amomi has an antioxidant activity and antidiabetic effects. Yeonmil recipe is useful for antioxidant effects more than the others. Also, the double boiling recipe has an excellent antidiabetic effect.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.49-55
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• 2011

Thirty Streptomyces sp. and 200 Bacillus sp. isolated from Korean soils and traditional foods were screened for their abilities to inhibit ${\alpha}$-glucosidase and produce 1-deoxynojirimycin (DNJ). This screening identified a Bacillus sp. bacterium that strongly inhibited ${\alpha}$-glucosidase and produced high levels of DNJ from Chungkookjang, a Korean traditional food. The bacterium was characterized in terms of its biochemical and molecular biological properties such as sugar utilization, cellular quinone composition, cell wall fatty acid composition, and 16S rDNA sequence. In addition, scanning electron microscopy was used to visualize the morphology of the bacterium. These analyses identified the bacterium as B. subtilis, a bacterium with Generally Recognized as Safe (GRAS) status. The selected strain was named B. subtilis MORI.

• Food Science and Preservation
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• v.22 no.2
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• pp.290-296
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• 2015

The antioxidant and ${\alpha}$-glucosidase inhibition activities of 10 kinds of seaweeds Ecklonia cava (EC), Ecklonia stolonifera (ES), Eisenia bicyclis (EB), Capsosiphon fulvescens (CF), Sargassum fulvellum (SF), Undaria pinnatifida (UP), Sargassum thunbergii (ST), Codium fragile (CFr), Hizikia fusiformis (HF), and Enteromorpha prolifera (EP) were investigated. Among all the tested seaweed extracts, the total polyphenol and flavonoid contents of the EB extract were highest 150.81 mg/g and 77.02 mg/g, respectively. The DPPH and ABTS radical scavenging abilities of the EB ethanol extract (1 mg/mL) were 86.26% and 99.71%, respectively, and its SOD-like activity and reducing power were 21.34% and 1.710 ($OD_{700}$). The ${\alpha}$-glucosidase inhibition activities of the EC, EB, and ST were above 98% at the 0.1 mg/mL concentration. These results suggest that seaweed extracts effectively prevent the what of antioxidants and decrease the blood glucose level, and may be used to develop various functional products.

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.35-38
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• 1990

$\alpha$-D-Glucosidase inhibitor purified in a pure form was amorphous powder which gave a single spot at Rf value 0.12-0.71 with various developing solvent systems on silica gel thin layer chromatography, and melting point was 154.3-155.3$^{\circ}C$. It was disolved in water, formic acid and ethylene glycol monoethyl ether, and was very high hygroscopic substance. Biochemical reaction of the substance was positive to phenol sulfuric acid, ninhydrin, silver nitrate-sodium hydroxide, but negative to DNS reagent. Acid hydrolysis gave fructose and acid as sole sugar and amino acid constituents respectively. Moelcular weight of the inhibitor was estimated to be 1,050 by Shphadex G-25 column chromatography.

• Food Science and Preservation
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• v.23 no.1
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• pp.80-88
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• 2016

Seven kinds (acacia, cochineal, catechu, grape peel, persimmon, gallnut and clove) of color powders obtained from natural resources and their mixtures were evaluated for their biological activities, such as antioxidant (ABTS and DPPH radicals scavenging), cholesterol absorption, and COX-2 inhibitory activities. Catechu, gallnut and clove were selected for the further studies due to its the best activities. The cholesterol absorption, COX-2 inhibitory, ${\alpha}$-amylase inhibitory and ${\alpha}$-glucosidase inhibitory activities were measured using the mixtures of catechu, gallnut and clove. The ABTS radical scavenging activity of the seven types of natural color powders were higher than the DPPH radical scavenging activity. The cholesterol absorption activity was significantly higher in cloves. The COX-2 inhibitory activity was significantly lower in acacia. The ${\alpha}$-amylase inhibitory activity was higher in catechu and gallnut, indicating that there were no significant difference between two mixtures. The ${\alpha}$-glucosidase inhibitory activity was the highest in catechu, which was higher than that of the catechu-containing mixtures. From all these results, a synergistic effect could be obtained when utilizing a mixture of powders rather than using only individual type. Since the activity of each powder was different, further studies will be required for clarifying the interactions between mixtures.

• Food Science and Preservation
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• v.23 no.2
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• pp.239-245
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• 2016

This study was conducted to compare the functionality (antioxidant, anti-diabetic, and anti-dementia activities) of the methanol extract of Allium hookeri root grown in Korea (KR) and Myanmar (MR). The total polyphenol and flavonoid contents of KR and MR were 5.27 and 4.80 mg GAE/g, and 0.35 and 0.24 mg QE/g, respectively. KR contained significantly higher levels of total polyphenols and total flavonoids than those of MR (p<0.05). The IC50 values of KR and MR were 6.53 and 5.31 mg/mL, respectively, for DPPH radical scavenging activity. However, KR had a significantly higher ABTS radical scavenging activity, $Fe^{2+}$ chelating ability, and reducing power compared with those of MR (p<0.05). In the evaluation of anti-diabetic activity, KR showed significantly higher ${\alpha}-glucosidase$ inhibition activity than acarbose and MR at whole concentrations (p<0.05). KR and MR had acetylcholinesterase inhibition activities that of 51.44% and 44.33%, respectively, at a 50 mg/mL concentration. These results suggested that roots of A. hookeri, especially KR, could be useful in improving diabetic and dementia disorders due to their high antioxidant, anti-diabetic, and anti-dementia activities.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.121-125
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• 2021

Antioxidative, anticoagulant, and α-glucosidase inhibitory effects of 60% (v/v) ethanolic extract from lotus (Nelumbo nucifera) leaves were investigated in vitro. The yield and polyphenol content of the lotus leaves extract were 35.3±1.1% and 186.2±5.2 ㎍ gallic acid equivalents/mg, respectively. The lotus leaves extract effectively scavenged free and cation radicals, and nitrite in a concentration-dependent manner, and possessed potent reducing power. The lotus leaves extract had remarkable anticoagulant and α-glucosidase inhibitory activities as a function of the extract concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.681-686
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• 2015

The purpose of this study was to measure total phenolic compounds as a measure of antioxidant activity as well as ${\alpha}$-amylase inhibitory and ${\alpha}$-glucosidase inhibitory activities as a measure of anti-diabetic efficacy in methanol extracts from 23 kinds of medicinal plants. Extracts of three medicinal plant species showing high total polyphenol contents were selected (Euonymus alatus stem, Taxus cuspidata fruit, and Eucommia ulmoides leaf). Extracts of six medicinal plant species showing over 60% DPPH radical scavenging activity were also selected [Eucommia ulmoides barks (80.10%), Lycium chinense roots (64.25%), Euonymus alatus stem (73.59%), Lespedeza cuneata (78.20%), Taxus cuspidata fruits (70.52%), and Tilia taquetii leaf and stem (67.81%)]. Regarding ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory activities acarbose showing approximately 80% inhibitory activity was selected as a control group, and six species (Eucommia ulmoides heartwood, Eucommia ulmoides bark, Euonymus alatus stem, Dioscorea batatas, Coix lachryma-jobi, and Phaseolus radiatus) showed greater than 80% ${\alpha}$-glucosidase inhibitory activity. Extracts of nine medicinal plant. species showing over 80% ${\alpha}$-amylase inhibitory activity (Pueraria thunbergiana root, Eucommia ulmoides bark, Eucommia ulmoides leaf, Lycium chinense fruits, Euonymus alatus leaf and stem, Euonymus alatus stem, Sasa borealis whole, Dioscorea batatas leaf and stem, and Tilia taquetii leaf and stem). Based on these results, medicinal plants showing high antioxidant and antidiabetic activities can be used as fundamental products in developing new medicines, as well as functional foods to prevent adult disease.