Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inhibition of alpha-glucosidase is a therapeutic approach for diabetes. In this study, a method based on online liquid chromatography-diode array detection-tandem mass spectrometry and biochemical detection (LC-DAD-MS/MS-BCD) was developed to screen and identify alpha-glucosidase inhibitors from selected beverage extracts, including pu-erh tea ( Camellia sinensis var. assamica), eagle tea ( Litsea coreana Levl.), and radix glycyrrhizae ( Glycyrrhiza uralensis Fisch.). As a result, two components, (-)-epigallocatechingallate (EGCG) and (-)-epicatechingallate (ECG), as potent alpha-glucosidase inhibitors, were found in pu-erh tea. The IC(50) values of EGCG and ECG on alpha-glucosidase (EC 3.2.1.20, from Saccharomyces cerevisiae ) were 175.1 and 246.9 microM, respectively, and both were lower than that of acarbose (IC(50) = 3553.0 microM), a commercial alpha-glucosidase inhibitor. Kinetic studies revealed that both EGCG and ECG inhibited alpha-glucosidase activity in a noncompetitive manner. The study suggests that the developed LC-DAD-MS/MS-BCD system is a powerful tool for rapid screening and identification of alpha-glucosidase inhibitors in complex samples and that EGCG and ECG may be good candidates as alpha-glucosidase inhibitors.
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PMID:Inhibition of three selected beverage extracts on alpha-glucosidase and rapid identification of their active compounds using HPLC-DAD-MS/MS and biochemical detection. 2044 96

The EtOAc extract of the roots of Glycyrrhiza uralensis exhibited alpha-glucosidase inhibitory activity. Bioassay-guided fractionation resulted in the isolation of an active prenylflavonoid, glycyrrhisoflavone. Its structure was elucidated by NMR and MS analyses. A simple method to prepare glycyrrhisoflavone from the 95% EtOH extract of the roots of G. uralensis was developed by combination of Diaion HP-20 column chromatography (CC), silica gel CC, and preparative HPLC. An HPLC-PDA method was developed for quantitative determination of glycyrrhisoflavone in the roots of G. uralensis. The sample was extracted with MeOH and analyzed using a reversed-phase column with isocratic elution with CH3CN-H2O (0.06% trifluoroacetic acid) (42:58) at a flow rate of 1.2 mL/min, a column temperature of 40 degrees C, and a detection wavelength of 260 nm. The method allowed the determination of glycyrrhisoflavone in the concentration range of 5-500 microg/mL. The relative standard deviation values of the precision and repeatability were 0.3% and 2.0%, respectively. The limits of detection and quantification were 0.5 microg/mL and 5 microg/mL, respectively. The relative recovery rate was 100.2 +/- 1.8%. Based on the validation results, the HPLC determination method was found to be precise, accurate, and time conservative. This method was applied successfully to nine different root samples of G. uralensis. The amounts of glycyrrhisoflavone in these samples were 15-93 mg/100 g of dried powdered plant material.
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PMID:Bioassay-guided isolation and quantification of the alpha-glucosidase inhibitory compound, glycyrrhisoflavone, from Glycyrrhiza uralensis. 2073 38

Natural products have been extensively investigated for antidiabetic therapy. Many of the natural products have direct or indirect effect in diabetes pathways as enzyme inhibitors. The most involved mechanisms are inhibition of intestinal alpha-glucosidase and alpha-amylase, lens aldose reductase, oxidative stress protection, inhibition of formation of advanced glycation end products, inhibition of aldose reductase, lowering plasma glucose levels, altering enzyme activity of hexokinases and glucose-6-phosphate, synthesizing and releasing of insulin, postprandial hyperglycemia inhibition, stimulation of GLUT-4, decreasing activity of G6P, lowering the level of skeletal hexokinases, etc. The following medicinal plants products or extracts showed promising effects as enzyme inhibitors: Abelmoschus moschatus, Alangium salvifolium, Azadirachta indica, Bidens pilosa, Boerhaavia diffusa, Capsicum frutescens, Cassia alata, Eclipta alba, Embellica officinalis, Ficus carica, Gentiana Olivier, Glycyrrhiza glabra, Gymnema sylvestre, Hordeum vulgare, Ipomoea aquatica, Juniperus communis, Mangifera indica, Momordica charantia, Ocimum sanctum, Punica granatum, and Zingiber officinale. Some of the group of phytochemicals isolated with enzyme inhibition activities are Alkaloids, sesquiterpene and saponins, polysaccharides, flavonoids, dietary fibers, ferulic acid, tannins, limonene, and oleuropeoside. This review will provide very useful material to enhance the efficiency of rational antidiabetic drug design.
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PMID:Enzymes inhibitors from natural sources with antidiabetic activity: A review. 3041 83