• Microbiology and Biotechnology Letters
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• v.49 no.4
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• pp.566-575
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• 2021

Galactose and soybean meal were selected as the best carbon and nitrogen sources, repectively, for the efficient production of α-glucosidase inhibitor (AGI) and 1-deoxynojirimycin (DNJ) by a newly isolated Bacillus subtilis MORI. The optimal concentrations of the galactose and soybean meal for the production of AGI and DNJ were investigated by response surface methodology. For the production of AGI, the optimal galactose and soybean meal concentrations were 4.3% (w/v) and 3.2% (w/v), respectively, and for DNJ, 4.5% (w/v) and 3.0% (w/v), respectively. The nearly identical optimal concentrations of galactose and soybean meal for the production of both AGI and DNJ indicated a close correlation between the production of AGI and DNJ. The maximum production of AGI (50,880 GIU/ml) and DNJ (824 ㎍/ml) obtained from the statistically optimized medium in a jar fermenter was 2.33 and 2.38-fold, respectively, higher than those (21,798 GIU/ml and 346 ㎍/ml, respectively) of the pre-optimized medium. The production of both AGI and DNJ was greatly increased by jar fermentation (AGI of 38,524 GIU/ml and DNJ of 491 ㎍/ml) compared with flask fermentation.

• The Korean Journal of Food And Nutrition
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• v.35 no.4
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• pp.276-281
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• 2022

Antioxidant activities and α-glucosidase inhibitory activities of Taraxacum officinale solvent fractions were measured. Extraction yields (relative to raw material) of 50% ethanol, hexane, ethyl acetate, butanol, and water were found to be 10.29, 2.61, 5.54, 2.15, and 0.96%, respectively. Polyphenol and flavonoid contents were high in ethyl acetate extract of Taraxacum officinale at 56.88 mg gallic acid/g and 33.27 mg gallic acid/g, respectively. DPPH, hydroxyl radical scavenging activity, and SOD-like activity measurement (IC₅₀%) of Taraxacum officinale 50% ethanol extract, hexane, butanol, ethyl acetate, and water fractions were 22.64, 18.65, 10.29, 20.81, 20.46 mg/mL, 24.68, 10.69, respectively. It was found to be 9.66, 15.81, 13.77 mg/mL, 32.84, 17.09, 12.73, 33.63, and 33.91 mg/mL, and was high in the ethyl acetate layer. Results showed that α-glucosidase inhibitory activities of Taraxacum officinale solvent fraction were 25.75, 15.93, 35.87, 15.96, and 2.88% for 50% ethanol extract, hexane, butanol, ethyl acetate, and water fractions, respectively.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.25-32
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• 2021

Phytochemicals include plant-derived natural products that promote and improve the human metabolism and physiological activity, and there is a lot of research to find the value of the molecules is in progress. Likewise, we obtained 288 fractions of Capsicum annuum L. extract in less than 20 h using HPLC/SPE/HPLC coupling experiment through Sepbox system, an effective separation system to search for active substances in natural resources and ensure efficacy and reliability. Therefore, this experiment allowed rapid identification of biologically active molecules from the extract compared to traditional separation processes. Of the above fractions, eight fractions showed the α-glucosidase inhibitory (AGI) activity and subsequent LC-MS analysis revealed one of the active molecules as luteolin 7-O-glucoside. In addition, we proved the increase in AGI activity according to deglycosylation of flavonoid glycoside. Therefore, this study suggests that the Sepbox system can quickly separate and identify active components from plant extract, and is an effective technique for finding new active substances.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1643-1650
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• 2013

A non linear QSAR model was constructed on a series of 57 xanthone and curcuminoide derivatives as ${\alpha}$-glucosidase inhibitors by back-propagation neural network method. The neural network architecture was optimized to obtain a three-layer neural network, composed of five descriptors, nine hidden neurons and one output neuron. A good predictive determination coefficient was obtained (${R^2}_{Pset}$ = 86.7%), the statistical results being better than those obtained with the same data set using a multiple regression analysis (MLR). As in the MLR model, the descriptor MATS7v weighted by Van der Waals volume was found as the most important independent variable on the ${\alpha}$-glucosidase inhibitory.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.191-199
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• 2020

The purpose of this study was to isolate novel lactic acid bacteria to ferment mulberry leaf extract (MLE) and to investigate its anti-diabetic effect. Lactobacillus plantarum SG-053 isolated from gatkimchi was selected to ferment MLE because it exhibited high α-glucosidase inhibitory activity (96.8%) and enhanced the content of 1-deoxynojirimycin (DNJ), an anti-diabetic substance, in fermented MLE up-to 2.2 times. MLE fermented with L. plantarum SG-053 (FMLE) showed growth promoting activity against L6 myotubes and increased the gene expressions of IRS-1, PI3K p85α, and GLUT-4 up-to 1.4, 2.2, and 1.4 times, respectively, and 2-deoxyglucose uptake up-to 40.7%. In rat skeletal muscle tissue, the expressions of PI3K p85α and GLUT-4 increased by 6.4 and 2.1 times, respectively. These results suggest that L. plantarum SG-053 could enhance the DNJ content of MLE by fermentation and that FMLE is effective in ameliorating insulin resistance via activation of the insulin signaling pathway.

• Korean Journal of Medicinal Crop Science
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• v.21 no.4
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• pp.301-305
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• 2013

This study was performed to select adequate plant materials for developing a natural ${\alpha}$-glucosidase inhibitor by analyzing ${\alpha}$-glucosidase inhibition activity in fronds and rhizomes of three Dryopteridaceae species: Cyrtomium fortunei, Polystichum polyblepharum, and P. lepidocaulon. The highest ${\alpha}$-glucosidase inhibitor obtained from frond of P. lepidocaulon ($4.16{\mu}g{\cdot}mL^{-1}$), and rhizome of C. fortunei ($1.84{\mu}g{\cdot}mL^{-1}$), showed much higher inhibition activity than acarbose ($1413.70{\mu}g{\cdot}mL^{-1}$). The biomass required to inhibit ${\alpha}$-glucosidase by 50% was 0.04 ~ 0.35mg for frond and 0.03 ~ 0.10mg for rhizome, and P. lepidocaulon required the least amount of fronds and P. lepidocaulon the least rhizomes. In frond, ${\alpha}$-glucosidase inhibition activity was the highest in water fraction of C. fortunei ($20.2{\mu}g{\cdot}mL^{-1}$), and n-butanol fraction of P. lepidocaulon ($9.33{\mu}g{\cdot}mL^{-1}$) and P. polyblepharum ($5.10{\mu}g{\cdot}mL^{-1}$). In rhizome, it was the highest in n-butanol fractions of C. fortunei ($19.76{\mu}g{\cdot}mL^{-1}$) and P. polyblepharum ($4.47{\mu}g{\cdot}mL^{-1}$), and ethylacetate fraction of P. lepidocaulon ($5.46{\mu}g{\cdot}mL^{-1}$). The frond biomass required for 50% ${\alpha}$-glucosidase inhibition was the lowest in the water fraction of C. fortunei (1.43mg), and n-butanol fractions of P. lepidocaulon (1.10mg) and P. polyblepharum (0.66mg). The required biomass of rhizome was the lowest in the water fraction of C. fortunei (1.59mg), and n-hexane fractions of P. lepidocaulon (0.04mg) and P. polyblepharum (0.15mg). The result of this study suggested that the three Dryopteridaceae species had high ${\alpha}$-glucosidase inhibition activity with small biomass, which might have high value as materials for economical anti-diabetic medication.

• Journal of Life Science
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• v.18 no.7
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• pp.1005-1010
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• 2008

In this study, we investigated the inhibitory effect of four solvent fractions of Alnus firma on ${\alpha}-amylase$, ${\alpha}-glucosidase$ and aldose reductase activities. The inhibitory test showed that methanol (MeOH) extract and hexane (HX) fraction strongly inhibited pork pancreatin and salivary ${\alpha}-amylase$ activity. The MeOH extract and HX fraction of Alnus firma at the concentration of 4 mg/ml inhibited more than 70% of pancreatin and salivary ${\alpha}-amylase$ activity. The inhibitory effect of fractions has different specificities against ${\alpha}-amylase$ from pancreatin and salivary. In addition, the MeOH extract and butanol (BuOH) fraction showed the highest inhibitory activity on yeast ${\alpha}-glucosidase$ at values of $IC_{50}$ $137.36\;{\mu}g/ml$ and $115.14\;{\mu}g/ml$ respectively. The MeOH extract and BuOH fraction showed the highest inhibitory activity on yeast ${\alpha}-glucosidase$ than commercial agent such as 1-deoxynorjirimycin and acarbose. Inhibition kinetics of solvent fractions showed that ${\alpha}-glucosidase$ has been inhibited noncompetitively by the MeOH, EA and BuOH fraction. The aldose reductase from human muscle cell had been inhibited strongly by the MeOH extract and EA fraction at 57.996% and 83.293% at the concentration of $50\;{\mu}g/ml$, respectively. These findings may contribute to biological significance in that ${\alpha}-amylase$, ${\alpha}-glucosidase$ and aldose reductase inhibitory compounds could be used as a functional food and a drug for the symptomatic treatment of antidiabetic disease in the future.

• The Korean Journal of Mycology
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• v.43 no.3
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• pp.174-179
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• 2015

For development a new anti-diabetic compound from edible mushroom, antihyperglycemic ${\alpha}$-glucosidase inhibitory activities of Pleurotus ostreatus, Pleurotus cornucopiae, Pleurotus salmoneostramineus, Pleurotus eryngii and Neolentinus lepideus were investigated on its water and ethanol extracts. ${\alpha}$-Glucosidase inhibitory activity of Neolentinus lepideus fruiting body showed the highest at 86.3% in the 95% ethanol extracts and water extract from Pleurotus cornucopiae was also higher at 48.5% among water extracts. Therefore, Neolentinus lepideus which showed very high ${\alpha}$-glucosidase inhibitory activity was selected as a new anti-diabetic agent-containing mushroom and the ${\alpha}$-glucosidase inhibitor was maximally extracted when treated with 95% ethanol at $30^{\circ}C$ for 48 hr. The ethanol extracts from Neolentinus lepideus fruiting body showed dosage-dependent hypoglycemic action after administration to 120 min in the SD-rat and streptozotocin-induced diabetic SD-rat.

• 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.

• Korean Journal of Medicinal Crop Science
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• v.26 no.5
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• pp.382-390
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• 2018

Background: The plant Aster koraiensis has long been used as an ingredient in folk medicine. It has been reported that Aster koraiensis extract (AKE) prevents the progression of diabetes-induced retinopathy and nephropathy. However, although these beneficial effects of AKE on diabetes complications have been identified, the antidiabetic effects of AKE have not yet been completely investigated and quantified. In the present study, the glucose-lowering and antioxidant effects of aqueous and ethanolic AKEs were evaluated. Methods and Results: The glucose-lowering effects of aqueous and ethanolic (30%-, 50%-, and 80%-ethanol) AKEs were investigated via ${\alpha}$-glucosidase inhibitory assays. The mode of inhibition by AKEs on ${\alpha}$-glucosidase was identified through kinetic analysis. The total antioxidant capacity of each of the 4 AKEs was evaluated by assessing their conversion rate of $Cu^{2+}$ to $Cu^+$. The content of chlorogenic acid and 3,5-di-O-caffeoylquinic acid, the bioactive compounds in AKE, in each extract were analyzed by high performance liquid chromatography (HPLC). The AKEs showed potent ${\alpha}$-glucosidase inhibitory activity with mixed inhibition mode, and significant antioxidant capacity. Conclusions: These results of this study suggested that the AKEs tested had ${\alpha}$-glucosidase inhibitory and antioxidant effects. Among the extracts, the 80% ethanol extract showed the most significant ${\alpha}$-glucosidase inhibitory activity, with a half maximal inhibitory concentration ($IC_{50}$ value) of $1.65{\pm}0.36mg/m{\ell}$ and a half maximal effective concentration ($EC_{50}$ value) for its antioxidant activity of $0.42{\pm}0.10mg/m{\ell}$. It can therefore be used as a source of therapeutic agents to treat diabetes patients.