• Title, Summary, Keyword: ${\alpha}$-glucosidase

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Effect of Medicinal Herb Prepared through Traditional Antidiabetic Prescription on α-Glucosidase Activity and Evaluation Method for Anti-Melanogenesis Agents Using α-Glucosidase Activity (당뇨 처방에 근거한 생약재의 α-Glucosidase 활성 저해 효과 및 이를 활용한 미백 소재 평가법)

  • Kim, Mi Jin;Im, Kyung Ran;Yoon, Kyung-Sup
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.7
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    • pp.993-999
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    • 2015
  • For the purpose of investigating the in vitro antidiabetic activity of a medicinal herb and herb mixture extracts prepared through traditional antidiabetic prescription, this study examined ${\alpha}$-glucosidase inhibitory activity. Tyrosinase, a type I membrane glycoprotein, is synthesized and glycosylated in the endoplasmic reticulum (ER) and Golgi. The enzyme is subsequently transported to melanosomes, where it participates in melanogenesis. Previous studies showed that disruption of early ER N-glycan processing by an ${\alpha}$-glucosidase inhibitor suppresses tyrosinase enzymatic activity and melanogenesis. According to the results, most oriental medicinal herbal extracts were stronger than acarbose and N-butyldeoxynojirimycin, known as an ${\alpha}$-glucosidase inhibitor. Interestingly, ethyl acetate layer of enzyme hydrolyzed Cheongsimyeonjaeum had an inhibitory effect on melanin synthesis in B16F1 cells, although it did not inhibit tyrosinase activity directly. Together, ${\alpha}$-glucosidase inhibition activity could be used to evaluate anti-melanogenesis, although cross-checking with melanin inhibitory assay is recommended.

Effect of Paeonia lactiflora Extracts on ${\alpha}-Glucosidase$

  • Lee, Sung-Jin;Ji, Seung-Tack
    • Natural Product Sciences
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    • v.10 no.5
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    • pp.223-227
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    • 2004
  • This study was carried out to investigate inhibitory effect of extracts from the root of Paeonia lactiflora on postprandial hyperglycemia. Organic solvent (hexane, ethyl acetate, butanol, aqueous) extracts from the crude drug were fractionated by high performance liquid chromatography. These fractions were examined to evaluate ${\alpha}-glucosidase$ (EC 3. 2. 1. 20) inhibition by microplate colorimetric assay. Among the fractions examined, the ethyl acetate fraction from the roots of Paeonia lactiflora showed potent inhibitory effects on ${\alpha}-glucosidase$. Therefore, further fractionation of the fraction was carried out to isolate the active principles. Finally, we isolated and Purified 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG) as a active principle by activity-guided fractionation. These results suggest that the extract from the root of Paeonia lactiflora can be used as a new nutraceutial for inhibition on postprandial hyperglycemia and PGG might be a candidate for developing an ${\alpha}-glucosidase$ inhibitor.

Inhibition of $\alpha$-Glucosidase Activity by Quercetin (Quercetin에 의한 $\alpha$-glucosidase 활성 저해)

  • Lee, Dong-Sun;Kim, Jong-Guk;Lee, Sang-Han
    • Microbiology and Biotechnology Letters
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    • v.34 no.4
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    • pp.368-372
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    • 2006
  • Quercetin is a flavonoid molecule that is known to tie in various sources of natural products such as vegetables and fruits. It has been proven that quercetin plays a crucial role in the prevention of colon cancer as well as homeostasis as radical scavenger in human body. It is also well-known that glycosidases, including $\alpha$-glucosidase, are involved in a variety of degenerative metabolic disorders. In the course of screening useful $\alpha$-glucosidase inhibitors, we screened out quercetin as a $\alpha$-glucosidase inhibitor from chemical libraries. Quercetin was shown to be a reversible, slow-binding, and noncompetitive inhibitor of yeast a-glucosidase with a K$_i$ value of $6.3\times10^{-8}$ M when it was included with an enzyme mixture. Together, these results show that quercetin has potential in treating disorders including diabetes, although the further mechanistic study is needed.

Toward the Virtual Screening of α-Glucosidase Inhibitors with the Homology-Modeled Protein Structure

  • Park, Jung-Hum;Ko, Sung-Min;Park, Hwang-Seo
    • Bulletin of the Korean Chemical Society
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    • v.29 no.5
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    • pp.921-927
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    • 2008
  • Discovery of $\alpha$-glucosidase inhibitors has been actively pursued with the aim to develop therapeutics for the treatment of diabetes and the other carbohydrate mediated diseases. As a method for the discovery of new novel inhibitors of $\alpha$-glucosidase, we have addressed the performance of the computer-aided drug design protocol involving the homology modeling of $\alpha$-glucosidase and the structure-based virtual screening with the two docking tools: FlexX and the automated and improved AutoDock implementing the effects of ligand solvation in the scoring function. The homology modeling of $\alpha$-glucosidase from baker’s yeast provides a high-quality 3-D structure enabling the structure-based inhibitor design. Of the two docking programs under consideration, AutoDock is found to be more accurate than FlexX in terms of scoring putative ligands to the extent of 5-fold enhancement of hit rate in database screening when 1% of database coverage is used as a cutoff. A detailed binding mode analysis of the known inhibitors shows that they can be stabilized in the active site of $\alpha$- glucosidase through the simultaneous establishment of the multiple hydrogen bond and hydrophobic interactions. The present study demonstrates the usefulness of the automated AutoDock program with the improved scoring function as a docking tool for virtual screening of new $\alpha$-glucosidase inhibitors as well as for binding mode analysis to elucidate the activities of known inhibitors.

Isolation and Characterization of α-Glucosidase Inhibitor Produced by Bacillus sp. SKU31-1 Strain (Bacillus sp. SKU31-1가 생산하는 α-Glucosidase 저해제 분리 및 특성 조사)

  • Kim, Shin-Duk
    • Korean Journal of Microbiology
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    • v.50 no.4
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    • pp.381-383
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    • 2014
  • In the course of screening for ${\alpha}$-glucosidase inhibitor produced by microorganism, the active compound was isolated from the culture filtrate of Bacillus sp. SKU31-1 using a series of chromatography procedures. The structure of the active compound was elucidated as 5-amino-1-hydroxymethyl-1, 2, 3, 4-cyclohexanetetrol on the basis of spectroscopic evidence obtained and comparison with data from the literature. The active compound showed potent inhibitory activity against ${\alpha}$-glucosidase with an $IC_{50}$ value of $1.9{\mu}M$ for maltose and 4.9 mM for sucrose. A Lineweaver-Burk plot indicated that its inhibition of ${\alpha}$-glucosidase was competitive, with a $K_i$ value of 0.15 mM.

Bio-assay Guided Isolation and Identification of α-Glucosidase Inhibitors from the Leaves of Diospyros lotus (고욤나무 잎으로부터 활성유도 분획법에 의한 α-Glucosidase 저해물질 분리 및 확인)

  • Kim, Sang Jun;Kim, Ji-Ae;Kim, Da Hye;Kwak, Seol Hwa;Yu, Kang-Yeol;Jang, Seon Il;Kim, Seon-Yeong;Jeong, Seung-Il
    • Korean Journal of Pharmacognosy
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    • v.46 no.2
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    • pp.105-108
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    • 2015
  • To establish the anti-diabetic(α-glucosidase inhibitory) activity of D. lotus leaf extract, isolate and identify the constituents responsible for the activity. The methanolic extract of leaves was partitioned between water, n-butanol and ethyl acetate. Bio-assay guided fractionation, based on inhibition of ;${\alpha}$-glucosidase, allowed isolation and identification of the active components. Liquid chromatography/mass spectrometry(LC/MS), 1 H-NMR and 13 C-NMR spectra analyses demonstrated that the active compound was myricetin-3-O-;${\alpha}$-L-rhamnoside(1). Compound 1 demonstrated a strong inhibition on the α-glucosidase, in vitro and ;${\alpha}$-glucosidase inhibitory value was calculated as 98.08%, when that of a reference drug, acarbose was estimated as 83.03%. The present study indicates compound 1 could be considered as an ;${\alpha}$-glucosidase inhibitor and developed as an important antidiabetes agent for type II diabetes therapy.

2-Hydroxyquinoline and Its Structural Analogs Show Antidiabetic Effects against α-Amylase and α-Glucosidase

  • Lee, Hwa-Won;Lee, Hoi-Seon
    • Journal of Applied Biological Chemistry
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    • v.58 no.1
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    • pp.1-3
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    • 2015
  • This study investigated the inhibitory activities of 2-hydroxyquinoline and its analogs against ${\alpha}$-glucosidase and ${\alpha}$-amylase. Based on the $IC_{50}$ values of 2-hydroxyquinoline analogs tested against ${\alpha}$-glucosidase and ${\alpha}$-amylase, 2-hydroxyquinoline had potent inhibitory activity (64.4 and $130.5{\mu}g/mL$, respectively), while 2-methyl-8-hydroxyquinoline showed weakly inhibitory activity (90.7 and $215.4{\mu}g/mL$, respectively). 2-Methylquinoline demonstrated no activity against ${\alpha}$-glucosidase and ${\alpha}$-amylase. In conclusion, 2-hydroxyquinoline analogs, with the existence of a methyl group and hydroxyl on quinoline, can be useful as a new diabetes treatment.

Inhibitory Effects of Quinoline Isolated from Ruta chalepensis and Its Structurally Related Derivatives against α-Amylase or α-Glucosidase

  • Park, Jun-Hwan;Lee, Hoi-Seon
    • Journal of Applied Biological Chemistry
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    • v.58 no.1
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    • pp.5-8
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    • 2015
  • This study was to isolate an active component of the chloroform fraction from the methanol extract of Ruta chalepensis leaves and to measure inhibitory effects against ${\alpha}$-glucosidase or ${\alpha}$-amylase. The inhibitory compound of R. chalepensis leaves was isolated using chromatographic methods and identified as quinoline. Quinoline and its structurally related derivatives were tested for their inhibitory activities by evaluating the $IC_{50}$ values against ${\alpha}$-amylase or ${\alpha}$-glucosidase and were compared with that of acarbose. Based on the $IC_{50}$ values, quinazoline exhibited the greatest inhibitory activity ($20.5{\mu}g/mL$), followed by acarbose ($66.5{\mu}g/mL$), and quinoline ($80.3{\mu}g/mL$) against ${\alpha}$-glucosidase. In case of ${\alpha}$-amylase, quinazoline had potent inhibitory activity, followed by quinoline ($179.5{\mu}g/mL$) and acarbose ($180.6{\mu}g/mL$). These results indicate that R. chalepensis extract, quinoline, and quinazoline could be useful for inhibiting ${\alpha}$-glucosidase or ${\alpha}$-amylase.

Isolation and Identification of Inhibitory Compound from Crataegi Fructus on ${\alpha}-amylase$ and ${\alpha}-glucosidase$ (산사(Crataegi Fructus) 추출물로부터 ${\alpha}-amylase$${\alpha}-glucosidase$ 저해 물질 분리 및 동정)

  • Kim, Myung-Uk;Cho, Young-Je;Kim, Jeung-Hoan
    • Applied Biological Chemistry
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    • v.50 no.3
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    • pp.204-209
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    • 2007
  • The objective of this research was to evaluate the inhibitory activities of phenolic compounds isolated from Crataegi Fructus on ${\alpha}-amylase$ and ${\alpha}-glucosidase$. The content of total phenolic compounds of water extract from Crataegi Fructus was 22.5 mg/g. The inhibitory activity of the water extract (200 ${\mu}g/ml$) from Crataegi Fructus on ${\alpha}-amylase$ and ${\alpha}-glucosidase$ was determined to be 100% and 82.6%, respectively. Isolation of inhibitory compounds was carried out on Sephadex LH-20 and MCI-gel CHP-20 column chromatography using a gradient elution procedure of increasing MeOH in $H_2O$. The chemical structure of the inhibitory compound against ${\alpha}-amylase$ and ${\alpha}-glucosidase$ was confirmed as chlorogenic acid by spectroscopic analysis of FAB-MS, NMR and IR spectrum.

Antioxidant and Alpha-Glucosidase Inhibitory Activity of Strychnos nux-vomica Extracts (마전자 추출물의 항산화 및 Alpha-Glucosidase 저해 활성)

  • Lee, Jeung-Min;Park, Jae-Hee;Park, Hae-Ryong;Park, Eun-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.9
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    • pp.1243-1248
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    • 2010
  • The physiological activities of Strychnos nux-vomica extracts were investigated through the total phenolic contents (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (RSA), comet assay, and $\alpha$-glucosidase inhibitory activity. S. nux-vomica extracts were prepared with methanol, ethanol, and acetone. The methanol extract showed the highest phenolic content (71 mg/100 g gallic acid equivalents). Pretreatment with S. nux-vomica extracts resulted in significant reductions in oxidative DNA damage at all of the concentrations tested ($1{\sim}50\;{\mu}g/mL$). The $\alpha$-glucosidase inhibitory activity of a methanol extract was 12.8% at the concentration of 1 mg/mL. Therefore, these results indicate that S. nux-vomica might be a noble potential candidate exhibiting antioxidant and $\alpha$-glucosidase inhibitory activity.