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)

Oleuropein, an intensely bitter glucoside, was isolated from green olives. Hydrolysis products obtained from oleuropein in sufficient quantity for further tests were: (i) beta-3,4-dihydroxyphenylethyl alcohol prepared by acid hydrolysis of oleuropein; (ii) elenolic acid obtained by methanolysis of oleuropein, isolation of the intermediate acetal, and subsequent acid hydrolysis; and (iii) oleuropein aglycone formed by the action of beta-glucosidase on the parent glucoside. Mass spectral verification of the isolated compounds and ultraviolet absorption data are given. Oleuropein and its aglycone had similar threshold levels for detection of bitterness, whereas elenolic acid and beta-3,4-dihydroxyphenylethyl alcohol were not judged to be bitter.
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PMID:Preparation of antimicrobial compounds by hydrolysis of oleuropein from green olives. 476 96

Leaves of the privet tree, Ligustrum obtusifolium, contain a large amount of oleuropein, a phenolic secoiridoid glycoside, which is stably kept in a compartment separate from activating enzymes. When the leaf tissue is destroyed by herbivores, enzymes localized in organelles start to activate oleuropein into a very strong protein denaturant that has protein-crosslinking and lysine-decreasing activities. These activities are stronger than ever reported from plant systems and have adverse effects against herbivores by decreasing the nutritive value of dietary protein completely. We report here that strong oleuropein-specific beta-glucosidase in organelles activates oleuropein by converting the secoiridoid glucoside moiety of oleuropein into a glutaraldehyde-like structure, which is also an alpha,beta-unsaturated aldehyde. Oleuropein activated by beta-glucosidase had very strong protein-denaturing, protein-crosslinking, and lysine-alkylating activities that are very similar to, but stronger than, those of glutaraldehyde. Aucubin, another iridoid glycoside, had similar activities after beta-glucosidase treatment. We also detected polyphenol oxidase activity in organelles that activate the dihydroxyphenolic moiety to have protein-crosslinking activities. These data suggest that the privet tree has developed an effective defense mechanism with oleuropein, a unique multivalent alkylator ideal as a protein-crosslinker. Our results that iridoid glycosides are precursors of alkylators may elucidate the chemical bases that underlie various bioactivities and ecological roles of iridoid glycosides.
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PMID:Enzymatic activation of oleuropein: a protein crosslinker used as a chemical defense in the privet tree. 1043 Sep 12

Oleuropein hydrolysis products, obtained both by endogenous beta-glucosidase and almond commercial one, were investigated by classic methodologies and by 1HNMR experiments. We found that both presence and relative amount of the different compounds in the reaction mixture are stricly related to the used enzyme.
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PMID:Highlights in oleuropein aglycone structure. 1571 52

Oleuropein (Chemical Abstracts Service registry number 32619-42-4), a bitter-tasting secoiridoid glucoside commonly found in leaves of the olive tree as well as in olives (Olea europaea L.), was found to be hydrolyzed by the beta-glucosidase (EC 3.2.1.2.1) produced by oleuropeinolytic Lactobacillus plantarum-type strains. Three strains, designated B17, B20, and B21, were isolated from the brine of naturally ripe olives not treated with alkali. These strains were rod-shaped forms, grown at a pH 3.5 limit, and tolerated 1% oleuropein and 8% NaCl in the growth medium. The beta-glucosidase produced hydrolyzed 5-bromo-4-chloro-3-indolyl-beta-d-glucopy-ranoside as well as oleuropein. The presence of 2% glucose in the medium inhibited activity by 40 to 50%, depending on the bacterial strain. Chromatographic analysis of the trimethylsilyl derivatives of the products obtained after 7 days of incubation at 30 degrees C of strain B21 showed all the hydrolysis products of oleuropein, i.e., aglycone, iridoid monoterpen, and 3,4-dihydroxyphenylethanol (hydroxytyrosol). Oleuropein and its aglycone after 21 days of incubation decreased to trace levels with the simultaneous increase in concentration of beta-3,4-dihydroxyphenylethanol.
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PMID:Hydrolysis of Oleuropein by Lactobacillus plantarum Strains Associated with Olive Fermentation. 1634 42