• Journal of Life Science
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• v.21 no.7
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• pp.1016-1024
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• 2011

The concentrations of bioactive material (polyphenolics and flavonoids) and the biological activities of antioxidative (DPPH [${\alpha},{\alpha}'$-diphenyl-${\beta}$-picrylhydrazyl] free radical scavenging activity, peroxidation of rat liver microsome, and Fe/Cu reducing power), ${\alpha}$-glucosidase inhibition, tyrosinase inhibition, and fibrinolytic activity were tested by in vitro experimental models using 70% methanolic extract from Ganoderma lucidum, Momordica charantia, Fagopyrum tataricum and their mixtures. The highest yield and the concentrations of polyphenolics and flavonoids were shown in the mixture extract. Mixture extract was shown to have the highest activities of ${\alpha}$-glucosidase inhibition and tyrosinase inhibition, fibrinolytic, DPPH free radical scavenging, and Fe/Cu reducing power in a concentration-dependent manner. From these results, mixture methanol extract was shown to have the most potent bioactive properties and to contain large amounts of biological materials such as polyphenolics and flavonoids. This mixture could be a good dietary supplement material candidate, such as for antidiabetic functional foods.

• Journal of Applied Biological Chemistry
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• v.43 no.3
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• pp.141-146
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• 2000

Glycosidase activities were tested from the grape berries, Vitis labruscana B. Takasumi. Among various glycosidases, $\alpha$-D-galactosidase was found to be the most active in the flesh and other glycosidases were considerably active in the order of the following: $\alpha$-D-mannosidase>$\alpha$-D-glucosidase>$\beta$-D-glucosidase>$\beta$-D-galactosidase. In the seeds, $\alpha$-D-glucosidase activity was the highest and other glycosidases such as $\alpha$-D-galactosidase, $\beta$-D-glucosidase, and $\beta$-D-galactosidase were still significantly active. The $\alpha$-D-galactosidase in the grape flesh was purified over 83-folds through salting-out with $(NH_4)_2SO_4$ and a series of chromatographies employing Sephadex G-50, Octyl-Sepharose, Q-Sepha- rose, and Biogel P-100. The enzyme was a monomer of 45 kDs as determined through SDS-PAGE and Sephacryl S-200 chromatography. The purified enzyme showed a preference of $\alpha$-D-galactose to $\beta$-D-galactose as a substrate about 5.4 times. Sulfhydryl specific reagents such as N-ethylmaleimide and iodoacetamide significantly inhibited the enzyme activity to the extents of 48 and 52% of its initial activity, respectively. The optimumpH range of $\alpha$-D-galactosidase was around 6.5-7.0. The enzyme activity increased by 46% in the presence of 1mM $Fe^{2+}$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1331-1335
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• 2009

We have studied the anti-diabetic effects of medicinal plant water extracts on hepatic glucose-regulating enzymes such as glucokinase (GK) and acetyl-CoA carboxylase (ACC). $\alpha$-Glucosidase inhibitor is usually used to prevent and treat type II diabetes; thus, anti-$\alpha$-glucosidase activity of medicinal plant water extracts was assayed. The hepatic cytosol faction of a type II diabetic animal (Goto-Kakizaki rat) was used in GK and ACC activity assays. The medicinal plants were Lycium chinense (JGP), Discorea japonica Thunb. (SY), Pyrus pyrifolia (YSB), Cornus officinalis (SSY), Paeonia suffruticosa ANDR. (MDP), Cordyceps militaris (DCH), and Acanthopanax senticosus (GSO). JGP, SY, YSB, and SSY water extracts increased the hepatic GK activity and all medicinal plant water extracts led to an increase in hepatic ACC activity. YSB, SSY, MDP, and GSO water extracts showed significantly higher anti-$\alpha$-glucosidase activity than control samples. The highest anti-$\alpha$-glucosidase activity was observed in GSO water extract and the anti-$\alpha$-glucoside activity was higher than that of Acarbose (reference $\alpha$-glucosidase inhibitor). We suggest that JGP, SY, YSB, and SSY water extracts may exert an anti-diabetic effect by enhancing the glucose metabolism and that YSB, MDP and GSO may be used as natural $\alpha$-glucosidase inhibitors in type II diabetic conditions. Increased ACC activity by plant water extracts may provide additional anti-diabetic effect.

• Biomedical Science Letters
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• v.12 no.4
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• pp.393-398
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• 2006

These studies were carried out to characterize the physiological functionalities of Codonopsis lanceolata, Cornus officinalis, and their mixtures. We investigated the antioxidative, fibrinolytic, and ${\alpha}$-glucosidase inhibitory activities of them. The antioxidative activities of Codonopsis lanceoiata and Cornus officinalis were 87% and 90%, respectively. Addition of salt to Codonopsis lanceolata and Cornus officinalis did not affect its antioxidative activities. In spite of fourfold addition of Codonopsis lanceolata to Cornus officinalis, the antioxidative activity was conserved at 90%. The fibrinolytic activities of Codonopsis lanceolata and Cornus officinalis were 0.78 plasmin unit/ml and 1.74 plasmin unit/ml, respectively. Addition of salt decreased the fibrinolytic activities of both Codonopsis lanceolata and Cornus officinalis. A mixture (3:1) of Codonopsis lanceolata and Cornus officinalis exhibited a 21% increase in activity. The ${\alpha}$-glucosidase inhibitory activities of Codonopsis ianceoiata and 100-fold diluted Cornus officinalis were 25% and 73%, respectively. The addition of salt to Codonopsis lanceolata and Cornus officinalis slightly decreased their ${\alpha}$-glucosidase inhibitory activities. According to the addition of Cornus officinalis to Codonopsis lanceoiata, the ${\alpha}$-glucosidase inhibitory activities of the resulting mixture were highly increased. We anticipate that these results will be used as basic data for the development of new bifunctional foods.

• Current Research on Agriculture and Life Sciences
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• v.31 no.4
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• pp.227-232
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• 2013

We studied antioxidant activity and inhibitory effect of ${\alpha}$-glucosidase from aqueous, ethanolic and methanolic fractions of Galla rhois. In FRAP and ORAC assay for measuring antioxidant activity, we confirmed that Galla rhois extracts had strong antioxidant activity and ethanolic and methanolic extracts were relatively stronger than aqueous extract. We used trolox as a positive control. In order to measure the inhibitory effect of ${\alpha}$-glucosidase, we compared acarbose and Galla rhois extracts. As a result of ${\alpha}$-glucosidase inhibitory assay, aqueous, ethanolic and methanolic extracts of Galla rhois showed high inhibitory activitity and ethanolic and methanolic extracts were relatively stronger than aqueous extract. The 50% inhibitory concentrations (IC50s) of acarbose, aqueous, ethanolic and methanolic fractions were 0.45 mM, $0.53{\mu}g/ml$, $0.415{\mu}g/ml$ and $0.37{\mu}g/ml$, respectively. These results suggest that Galla rhois extracts can be a clinically useful anti-diabetic ingredient, indicating that it needs to be fractionated and isolated and should be further investigated.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.239-244
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• 2009

In the current study, inhibitory activity of 8 selected Korean edible plants of Lamiaceae family against $\alpha$-glucosidases, prepared from rat small intestine acetone powder was evaluated. Total flavonoids and oxygen radical absorbance capacity (ORAC) were also investigated. Methyl alcohol extracts of Scutellaria indica (SI) had the highest $\alpha$-glucosidase inhibitory activity relevant for potentially managing hyperglycemia, followed by Clinopodium gracile (CG) and Thymus quinquecostatus (TQ). These 3 species also showed significant antioxidant activity in ORAC system. The $\alpha$-glucosidase inhibitory activity of the extracts was compared to selected phenolics. Among the standard phenolics tested quercetin which was major flavonoid in the extracts had the highest $\alpha$-glucosidase inhibitory activity. CG, TQ, and SI which had high quercetin content and ORAC values also exhibited significant sucrase inhibitory activity. Results suggested that selected 3 Korean Lamiaceae species have the potential development of effective dietary strategy for postprandial hyperglycemia and oxidative stress-linked diabetes complications.

• Mycobiology
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• v.41 no.3
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• pp.149-154
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• 2013

An ${\alpha}$-glucosidase inhibitor was developed from Aspergillus oryzae N159-1, which was screened from traditional fermented Korean foods. The intracellular concentration of the inhibitor reached its highest level when the fungus was cultured in tryptic soy broth medium at $27^{\circ}C$ for five days. The inhibitor was purified using a series of purification steps involving ultrafiltration, Sephadex G-25 gel permeation chromatography, strong cation exchange solid phase extraction, reverse-phase high performance liquid chromatography, and size exclusion chromatography. The final yield of the purification was 1.9%. Results of the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis indicated that the purified ${\alpha}$-glucosidase inhibitor was a tri-peptide, Pro-Phe-Pro, with the molecular weight of 360.1 Da. The IC50 value of the peptide against ${\alpha}$-glucosidase activity was 3.1 mg/mL. Using Lineweaver-Burk plot analysis, the inhibition pattern indicated that the inhibitor acts as a mixed type inhibitor.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.187-191
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• 2004

For the production of $2-O-{\alpha}-D-glucopyranosyl-L-ascorbic$ acid (ascorbic acid-2-g1ucoside, AA-2G) from ascorbic acid, the usability of spinach seed as the source of ${\alpha}-glucosidase$ having transglucosylation activity was studied. The optimum conditions for the production of AA-2G from ascorbic acid and glucose donor were investigated by using crude extract of Spinachia oleracea L. Woosung, the selected source of enzyme. The production of AA-2G was the highest with 1.053 mM when spinach seeds were grown for 2 days after germination. Maltose was the most effective glucose donor, and the optimum concentration of ascorbic acid and maltose were 175 mM and 225 mM, respectively. The optimum concentration of ${\alpha}-glucosidase$ was 60 units. The most effective buffer was sodium acetate and its optimum concentration was 175 mM. The optimum pH and temperature were 5.0 and $65^{\circ}C$, respectively. Under the optimum condition, 2.14 mM of AA-2G was produced from ascorbic acid after 50 minutes of reaction.

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.162-164
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• 2006

The roots of Codonopsis lanceolata afforded tangshenoside I(1) and $\beta$-adenosine (2) as $\alpha$-glucosidase inhibitors. Their structures were unambiguously determined by 1D and 2D NMR data including HMQC and HMBC experiments. Compounds 1 and 2 exhibited weak $\alpha$-glucosidase inhibitory activities in vitro with $IC_{50}$ of 1.4 and 9.3 mM, respectively.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.05a
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• pp.326-330
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• 2005

구기자, 구기엽, 지골피 추출물을 이용한 요구르트를 제조하여 항산화효과, ACE (angiotensin converting enzyme) 저해 효과 및 ${\alpha}-glucosidase$ 저해 활성을 시험하였다. 구기자 첨가 발효유의 Antioxidants activity는 물 추출물보다 methanol 추출물에서 더 많은 항산화 활성능을 보였으며 특히 구기엽 요구르트에서 83.85%의 높은 활성능을 보였다. 구기자와 지골피 요구르트에서는 각각 47%와 54%내외의 활성능을 나타냈다. 구기자 첨가 발효유의 ACE(angiotensin converting enzyme) 저해 효과는 원재료에서는 물 추출물이 angiotensin converting enzyme 저해능이 높았고, 구기자 요구르트의 경우 물 추출물과 methanol 추출물 모두가 angiotensin converting enzyme 저해능이 높은 것으로 나타났다. 구기자 첨가 발효유의 ${\alpha}-glucosidase$ 저해 활성은 구기자, 구기엽 및 지골피 4% 첨가 요구르트에서 methanol 추출물의 경우 각각 8.2%, 5.6%, 7.3%의 ${\alpha}-glucosidase$ 저해능을 나타냈는데 이들 모두 원재료 보다는 활성 저해능이 큰 것으로 나타났으나 물 추출물의 경우에는 활성 저해능이 거의 나타나지 않았다.