Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.21 (beta-glucosidase)
3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eight novel toxoflavin glycosides, which are potential prodrugs in antibody directed enzyme prodrug therapy (ADEPT), were synthesized. The structures of all toxoflavin glycosides were characterized by (13)C NMR spectroscopy, elemental analysis, and MS. Their enzymatic hydrolysis activities were tested against beta-glucosidase (EC.3.2.1.21).
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PMID:Study on glycosylated prodrugs of toxoflavins for antibody-directed enzyme tumor therapy. 1741 11

Andrographolide (1), the cytotoxic agent of the plant Andrographis paniculata, was subjected to semi-synthetic studies leading to a series of new derivatives, a novel family of glucosidase inhibitors. Nicotination of 3,19-hydroxyls in 15-alkylidene andrographolide derivatives (9) was favorable to alpha-glucosidase inhibition activity. Among them, 15-p-chlorobenzylidene-14-deoxy-11,12-didehydro-3,19-dinicotinateandrographolide (11c) was a very potent inhibitor against alpha-glucosidase with an IC50 value of 6 microM. However, all compounds concerned for beta-glucosidase showed no inhibition. All compounds synthesized were characterized by the analysis of NMR, IR, HRMS spectra and the stereochemistry of 2 was confirmed by X-ray analysis.
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PMID:Synthesis of andrographolide derivatives: a new family of alpha-glucosidase inhibitors. 1742 67

Nine novel monoterpene alkaloid derivatives (3(a)-(c), 4(a)-(c), 5(a)-(c)) were prepared as a reaction of genipin 2 with L-amino acid methyl hydrochlorides utilized the reaction of reductive amination. Genipin was obtained by beta-glucosidase, catalyzed hydrolysis of the iridoid glucoside geniposide 1. The chemical structures were confirmed by 1D-, 2D-NMR and MS.
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PMID:Synthesis of monoterpene alkaloid derivatives from the iridoid glucoside geniposide. 1798 95

A new strain, GS603, having beta-glucosidase activity was isolated from soil of a ginseng field, and its ability to convert major ginsenoside Rb(1) to minor ginsenoside or gypenoside was studied. Strain GS603 was identified as an Intrasporangium species by phylogenetic analysis and showed high ginsenoside-converting activity in LB and TSA broth but not in nutrient broth. The culture broth of the strain GS603 could convert ginsenoside Rb(1 )into two metabolites, which were analyzed by TLC and HPLC and shown to be the minor ginsenoside F(2) and gypenoside XVII by NMR.
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PMID:Microbial conversion of ginsenoside Rb1 to minor ginsenoside F2 and gypenoside XVII by Intrasporangium sp. GS603 isolated from soil. 1816 39

A glycosynthase approach was attempted to glycodiversify macrolide antibiotics, using DesR, a family-3 retaining beta-glucosidase involved in the self-resistance mechanism of methymycin production. STD-NMR was used to probe enzyme-substrate interactions. Analysis of competitive STD-NMR experiments between erythromycin A and a chromogenic substrate (pNP-beta-d-glucose) with the hydrolytically inactive nucleophile mutants led us to discover a family of unprecedented glycosidase inhibitors. Analysis of kinetic data with wild-type DesR determined that erythromycin is a competitive inhibitor of the glucosidase (IC50 = 2.8 +/- 0.3 microM and Ki = 2 +/- 0.2 microM) with respect to the hydrolysis of pNP-beta-d-glucose. Comparable inhibitory data was obtained for clarithromycin; however, the inhibitory effect of azithromycin was weak and no significant inhibition was observed with methymycin or d-desosamine. This report documents significant inhibition of glycosidases by macrolide antibiotics and provides insight into the design of novel glycosidase inhibitors based on the macrolactone ring of macrolide antibiotics.
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PMID:Glycosidase inhibition by macrolide antibiotics elucidated by STD-NMR spectroscopy. 1863 10

Some novel 2-aryl-3-[5-deoxy-1,2-O-isopropylidene-alpha-D-xylofuranose-5-C-yl] thiazolidin-4-ones were synthesized by the three-component condensation of an amino sugar 1, an aromatic aldehyde 2, and mercaptoacetic acid 3 in the presence of DCC and DMAP at room temperature. Two diastereoisomers 4 and 5 were afforded as the main products in totally isolated yields of 25.4-70%. The reaction was carried out with almost no observed stereoselectivity except in the case of 2c, which showed a moderate stereoselectivity. The structures of the new compounds were determined by NMR spectroscopy and mass spectrometry (MS), and the configuration of the newly generated chiral carbon (C-2) in the thiazolidin-4-one ring was tentatively assigned based on the X-ray crystallographic structure of 5d and the comparison of their corresponding NMR signals. The antitumor (human cervical cancer cells) activity and the inhibition against the glycosidases (alpha-glucosidase, beta-glucosidase, alpha-amylase) have been evaluated for the new compounds, some of which exhibited antitumor activity.
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PMID:Synthesis and biological activity of novel thiazolidin-4-ones with a carbohydrate moiety. 1880 19

A difficulty in explaining the mechanism whereby archaeal lipid membrane vesicles (archaeosomes) deliver entrapped protein antigens to the MHC class I cytosolic pathway from phagolysosomes of antigen-presenting cells has been the observation that they tend not to fuse. Here, we determine that archaeosomes, composed of archaeal isoprenoid mixtures of glyco and phospholipids, can be highly fusogenic when exposed to the pH and enzymes found in late phagolysosomes. Fusions were strictly dependent on acidic pH and the presence of alpha- or beta-glucosidase. Resonance energy transfer (RET) assays demonstrated that fusion conditions induced lipid mixing of archaeosome lipids with self-unlabeled archaeosomes. Because PC/PG/cholesterol liposomes by themselves did not fuse, it was possible to unequivocally show a fusion of rhodamine-labeled liposomes with archaeosomes by fluorescence microscopy and to demonstrate lipid mixing between labeled liposomes and archaeosomes by the RET assay. Radiotracer and (1)H NMR studies revealed that glycolipids in fused archaeosomes were not degraded significantly by glucosidase treatment during fusion. Rather, the glucosidases dramatically induced small archaeosomes to rapidly and visually aggregate at pH 4.8, but not 6.8, thus bringing membranes together appropriately as a first step in the fusion process. (1)H NMR was used to demonstrate that conditions causing aggregation correlated with binding of glucosidase to the archaeosomes. Binding at acidic pH occurred by the electrostatic interaction of positively charged glucosidase with the anionic phospholipids, although the interaction also occurred with the gentiobiosyl lipids. The data indicate a mechanism of membrane-membrane fusion for archaeal glycolipid membranes induced by glycosidase and illustrate the importance for inclusion of glycolipids in compositions of vesicles designed to deliver protein antigens to the cytosol for MHC class I presentation.
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PMID:Glycosidase-induced fusion of isoprenoid gentiobiosyl lipid membranes at acidic pH. 1902 7

New substrates, 2-(2'-benzothiazolyl)-phenyl (BTP) cellooligosaccharides with degree of polymerization (d.p.) 2-4 (BTPG(2-4)) were synthesized for the screening of microbial cellulolytic activity in plate assays. The substrates were very efficient that was shown for several cellulolytic bacteria, including yeast-like isolates from Kamchatka hot springs. Three tested bacterial strains and eighteen of 30 of the yeast isolates showed ability to degrade cellulose with cellobiohydrolase, beta-glucosidase and endo-cellulase activities measured with standard substrates. The structures of 2-(2'-benzothiazolyl)-phenyl oligosaccharides were solved by NMR- and mass-spectrometry. The usefulness of the 2-(2'-benzothiazolyl)-phenyl substrates were also shown during purification of the B. polymyxa cellulolytic complex, which consists of at least three types of the enzymes: cellobiohydrolase, endo-beta-d-glucanase and beta-glucosidase.
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PMID:Novel precipitated fluorescent substrates for the screening of cellulolytic microorganisms. 1915 Apr 71

A new polyhydroxylated pyrrolizidine alkaloid designated as pochonicine (1) was isolated from a solid fermentation culture of the fungal strain Pochonia suchlasporia var. suchlasporia TAMA 87. The structure of 1 was determined using NMR and MS techniques as (1R*, 3S*, 5S*, 6S*, 7R*, 7a S*)-5-acetamidomethyl-3-hydroxymethyl-1,6,7-trihydroxypyrrolizidine. Pochonicine (1) showed potent inhibition against beta-N-acetylglucosaminidases (GlcNAcases) of various organisms including insects, fungi, mammals, and a plant but no inhibition against beta-glucosidase of almond, alpha-glucosidase of yeast, or chitinase of Bacillus sp. The GlcNAcase inhibitory activity of pochonicine (1) was comparable to nagstatin, a potent GlcNAcase inhibitor of natural origin.
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PMID:Pochonicine, a polyhydroxylated pyrrolizidine alkaloid from fungus Pochonia suchlasporia var. suchlasporia TAMA 87 as a potent beta-N-acetylglucosaminidase inhibitor. 1977 96

It has been reported that icariin and icariside II, two flavonoid glycosides coming from herba epimedii, which have a closely structural relationship, show some pharmacological effects such as preventing osteoporosis, cancer and depression. The content of natural icariside II is very low in herba epimedii, but it is the main component in vivo after the administration of herba epimedii. More icariside II can be obtained from icariin by enzymatic hydrolysis method than by traditional isolation method. This study focuses on finding a simple and feasible method to prepare icariside II from icariin by enzymatic hydrolysis, so as to meet the request for further pharmacologic actions study. Icariin was obtained successively with 90% ethanol extraction, isolation on macroporous resin and purification on silica gel chromatography. Enzymatic hydrolysis conditions were tested for the bioconversion of icariin into icariside II by orthogonal array design. The structures of isolated icariin and produced icariside II were identified by UV, IR, ESIMS, (1)H NMR, (13)C NMR, and DEPT spectroscope. Enzymatic hydrolysis experiment showed that icariin could be transformed into icariside II with the action of beta-glucosidase and the optimum reaction conditions were determined as follows: 50 degrees C, 0.2 M disodium hydrogen phosphate and citric acid buffer system (pH6.0), the ratio of icariin/enzyme is 1:1 and reaction time 5 h. By using this enzymatic condition, 95.5 mg icariside II (with the purity of 99.1%) was obtained eventually by transforming 200 mg icariin.
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PMID:Preparation of icariside II from icariin by enzymatic hydrolysis method. 2002 90


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