Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GLYCOSIDES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources

Determination of iridoid glycosides by micellar electrokinetic capillary chromatography-mass spectrometry with use of the partial filling technique.

A fast and easy method was sought for determination of the iridoid glycosides catalpol, ketologanin, verbenalin, loganin, 8-epi-loganic acid, geniposidic acid and 10-cinnamoyl catalpol in plant samples. The method involved micellar electrokinetic capillary chromatography (MEKC) coupled on-line to mass spectrometry. The partial filling technique and electrospray ionization were used. Seven iridoid glycosides could be separated with use of MEKC under basic conditions. However, 8-epi-loganic acid and geniposidic acid could not be detected simultaneously with the five neutral iridoid glycosides by mass spectrometry. Therefore, only the neutral iridoid glycosides were screened from plant samples. Catalpol, verbenalin, loganin and possibly 10-cinnamoyl catalpol were found in an examination of seven plant species in the genera Plantago, Veronica, Melampyrum, Succisa, and Valeriana. Aucubin, which was not included in the sample mixture used in method development because of overlapping with catalpol in MEKC, was also detected. The limits of detection for the iridoid glycosides, both at the UV and at the mass spectrometer, are given.

Chromatography, Micellar Electrokinetic Capillary↗

On-line identification of further flavone C- and O-glycosides from sugarcane (Saccharum officinarum L., Gramineae) by HPLC-UV-MS.

HPLC-UV-MS (APCI-MS/MS and CID/MS) was utilised for the identification of eight additional flavone glycosides from sugarcane (Saccharum officinarum L., Gramineae) extracts of bagasse, leaves and juice ('garapa'). Relevant information about substitution patterns was obtained through UV detection using post-column addition of shift reagents, while tandem MS provided structural information confirming the proposed structures of the C-glycosides vitexin, orientin, luteolin-8-C-(rhamnosylglucoside), 4',5'-dimethyl-luteolin-8-C-glycoside and the isomeric pair schaftoside-isoschaftoside, besides the O-glycosides tricin-7-O-neohesperidoside and tricin-7-O-glycoside.

Chromatography, High Pressure Liquid↗

Glycosides derived from Hemidesmus indicus R. Br. root inhibit adherence of Salmonella typhimurium to host cells: receptor mimicry.

For centuries, indigenous plants have been used against enteritis but their molecular targets and mode of action remain obscure. The present study was carried out to elucidate the protective and therapeutic role, if any, of glycosides from Hemidesmus indicus against S. typhimurium-induced pathogenesis. Studies were carried out in a human intestinal cell line (Int 407) and a murine macrophage cell line (P388D1) in order to evaluate its potency in local as well as systemic infections. The inhibitory role of the glycosides present in Hemidesmus indicus root extract (GHI) were tested by pre-coating the cells (both Int 407 and P388D1) with GHI prior to infection, and by neutralizing the wild-type bacteria with GHI before cell infection. In both cases, GHI protected the host cells from the cytotoxic effects of the wild S. typhimurium. This suggests that the biologically significant sugars (hexose, hexosamine, fucose and sialic acid etc) present in GHI might be mimicking host cell receptor saccharides and thereby blocking the bacterial ligands from binding to the host cells. Int 407 cells infected with wild-type bacteria had a diffused adherence pattern after 4 h incubation, but this typical character was not observed in cells infected with GHI-treated bacteria and the cells were normal in appearance at 4 h. After 18 h cells infected with wild-type bacteria were hypertrophoid with a disintegrated membrane and wrapped in a bacterial coat, whereas cells infected with treated bacteria had comparatively less morphological changes and few defective shrunken rods adhered locally. This suggests that the glycosides can change the adherence pattern of S. typhimurium from diffused to local. Treated bacteria had less adherence and invasion capability in Int 407 as well as P388D1 cells. The results show the decreased ability of adherence of GHI-treated S. typhimurium was due to a loss of surface hydrophobicity. A nonspecific binding between S. typhimurium and the glycosides was confirmed using ELISA. In summary, the glycosides of H. indicus root inhibited S. typhimurium induced pathogenesis nonspecifically, by reducing bacterial surface hydrophobicity and perhaps also by mimicking host cell receptors, thereby blocking its attachment to host cell and further pathological effects.

Animals↗

Screening for pregnane glycosides with immunological activities from the stems of Stephanotis mucronata by high-performance liquid chromatography/tandem mass spectrometry.

The stems of the Chinese traditional medicine Stephanotis mucronata were screened for immunologically active pregnane glycosides using high-performance liquid chromatography (HPLC) coupled with electrospray ionization tandem mass spectrometry. In the mass spectra of pregnane glycosides, predominant [M+Na]+ ions were observed and used to determine the molecular masses, while fragmentation reactions of the [M+Na]+ ions were recorded to provide information on the primary sequences of oligosaccharide chains in terms of classes of monosaccharide. Fragment ions from the side-chain cleavage of aglycone portions can provide mass information about side-chain substitutions. To further confirm the fragment ion structures, Fourier transform ion cyclotron resonance tandem mass spectrometry (MSn) with low-energy collision-induced dissociation was performed using samples collected from HPLC fractions, which provided accurate elemental compositions of fragment ions. Based on fragmentation patterns and comparison with standards, ten pregnane glycosides were identified as stemucronatosides C, D, F, and G, mucronatosides A, B, and C, stephanoside E, and two glycosides that are identified in the S. mucronata extracts for the first time. The latter two pregnane glycosides are 12-O-cinnamoyldeacetylmetaplexigenin-3-O-6-deoxy-3-O-methyl-beta-D-allopyranosyl-(1 --> 4)-beta-D-cymaropyranosyl-(1 --> 4)-beta-D-cymaropyranoside and 12-O-cinnamoyl-20-O-acetyl (20S)-pregn-6-ene-3beta,5alpha,8beta,12beta,14beta,17beta,20-heptaol 3-O-beta-D-thevetopyranosyl-(1 --> 4)-beta-D-cymaropyranosyl-(1 --> 4)-beta-D-cymaropyranoside.

Chromatography, High Pressure Liquid↗

Investigation of cardiac glycoside levels in human post mortem blood and tissues determined by a special radioimmunoassay procedure.

Even after the introduction of radioimmunological methods the question of a cardiac glycoside causing or contributing to the death of a patient can not be answered satisfactorily. By means of a special radioimmunoassay procedure for digoxin as well as for the structurally related methyl- and acetylderivatives we measured the concentrations in human blood and post mortem tissues. We investigated the glycoside contents in the blood of intravenously digitalised (Novodigal) al) patients before and after death. At autopsy blood specimens were taken from the heart and the femoral vein. We found an increase of the glycoside level up to a highly toxic range (7--15 ng/ml) especially in the heart blood. Thus post mortem blood levels of digoxin and its derivatives are not suitable for a final decision in alleged cases of fatal poisonings. Measuring various concentrations in tussues and body fluids of the above cardiac glycosides mentioned revealed the kidney concentration to be of high value in confirming a digitalis poisoning. This organ and the heart show the highest tissue concentrations. Interpretations of fatal digitalis poisonings should be based on the additional knowlege of these concentrations. Individual cardiac glycosides may be analyzed by a combination of thin layer chromatography and radioimmunoassay.

Cardiac Glycosides↗

Studies on a plasma cardiac glycoside assay based upon displacement of 3-H-ouabain from Na+-K+-ATPase.

We tested an assay system introduced for plasma glycoside measurements, basing on the displacement of 3-H-ouabain from Na+-K+-ATPase by unlabeled glycoside. ATPase preparations from hog, cat and guinea pig were used. Displacements were performed using 20 cardiac glycosides, genins and derivatives with different cardiac activity. Most of the glycosides and derivatives do not induce a continuous 3-H-ouabain displacement from the ATPase, but a very steep increase of unbound 3-H-ouabain between 10-minus 7 and 2 times 10-minus 7 M. Therefore this assay system shows a satisfactory discrimination only in a short concentration range. This behavior and a relatively low sensitivity make the ATPase displacement assay problematic for clinical and pharmacokinetical plasma glycoside measurements.

Adenosine Triphosphatases↗

Studies on the production of daunomycinone-derived glycosides and related metabolites in Streptomyces coeruleorubidus and Streptomyces peucetius.

Strains of Streptomyces coeruleorubidus ISP 5145, JA 10092 and 39-146, differing mutually in antibiotic activity, were found to produce identical spectrum of metabolites (at least nine antibiotically active glycosides, 13-dihydrodaunomycinone, epsilon-rhodomycinone and a larger number of unidentified compounds); only trace quantities of daunomycin and daunomycinone could be detected. A fraction of glycosides with a higher RF (0.4-0.7), isolated from strain 39-146, could be transformed to daunomycin by mild hydrolysis and to daunomycinone by total hydrolysis. Streptomyces peucetius IMI 101 335 differed from Streptomyces coeruleorubidus in an increased production of epsilon-rhodomycinone and a lower content of glycosides; the zone of daunomycin was most pronounced among the glycoside spots. Streptomyces coeruleorubidus 39-146 exhibited the highest activity in a medium containing 3.5% soluble starch, 3.0% soybean meal, 0.3% NaCl and 0.3% CaCo3; glucose was a more useful carbon source for the remaining strains. The activity of Streptomyces coeruleoribidus was inhibited by 1-propanol, Na-propionate, 5,5-diethylbarbiturate and bacitracin. Ferrous sulphate stimulated the production of glycosides only in strain JA 10092, decreasing simultaneously the production of aglycones.

Chromatography, Thin Layer↗

Determination of iridoid glycosides in larvae and adults of butterfly Melitaea cinxia by partial filling micellar electrokinetic capillary chromatography-electrospray ionisation mass spectrometry.

The iridoid glycosides, methyl catalpol, asperuloside, verbenalin, cinnamoyl catalpol, catalpol and aucubin, were studied from both larvae and adults of butterfly Melitaea cinxia. Special emphasis in the study was put on finding a correlation between the iridoid glycoside content in butterflies and plants. An optimised partial filling micellar electrokinetic capillary chromatographic-electrospray ionisation mass spectrometric (PF-MECC-ESI-MS) method was employed for the separation and identification of the six iridoid glycosides. In this work, the isolation and determination of catalpol and aucubin from extracts of both larvae and adults of Melitaea cinxia butterflies is demonstrated. The PF-MECC-ESI-MS method, using the [M+Na]+, [M+Li]+ and/or [M+NH(4)]+ adducts in ESI-MS, was used for quantification of aucubin and catalpol in the insects. In addition, the identification of all analytes was attempted by direct infusion MS/MS analysis. LOQ values for the iridoid glycosides varied between 10 mg/l (for verbenalin) to 50 mg/l (for catalpol and aucubin) corresponding to 0.1% of the samplés dry mass. A correlation was noticed between the concentrations of iridoid glycosides in plants and the concentrations in larvae feeding on them.

Aging↗

Spatial organisation of four enzymes from Stevia rebaudiana that are involved in steviol glycoside synthesis.

The sweet steviol glycosides found in the leaves of Stevia rebaudiana Bert. are derived from the diterpene steviol which is produced from a branch of the gibberellic acid (GA) biosynthetic pathway. An understanding of the spatial organisation of the two pathways including subcellular compartmentation provides important insight for the metabolic engineering of steviol glycosides as well as other secondary metabolites in plants. The final step of GA biosynthesis, before the branch point for steviol production, is the formation of (-)-kaurenoic acid from (-)-kaurene, catalysed by kaurene oxidase (KO). Downstream of this, the first committed step in steviol glycoside synthesis is the hydroxylation of kaurenoic acid to form steviol which is then sequentially glucosylated by a series of UDP-glucosyltransferases (UGTs) to produce the variety of steviol glycosides. The subcellular location of KO and three of the UGTs involved in steviol glycoside biosynthesis was investigated by expression of GFP fusions and cell fractionation which revealed KO to be associated with the endoplasmic reticulum and the UGTs in the cytoplasm. It has also been shown by expressing the Stevia UGTs in Arabidopsis that the pathway can be partially reconstituted by recruitment of a native Arabidopsis glucosyltransferase.

Arabidopsis↗

4-Methylumbelliferyl-glycosides as fluorescence probes of sugar-binding sites on lectin molecules: spectral properties and dependence of fluorescence on polarity and viscosity.

The spectral properties of 4-methylumbelliferyl-glycosides (MeUmb-glycosides) were investigated in order to assess their usefulness as probes of the microenvironment of sugar binding sites on lectin molecules. It was shown that the abnormally high values for fluorescence polarization of free MeUmb-glycosides (from 0.07 to 0.251) were due neither to their molecular size nor to the blockade of their movement, but to the short lifetimes (less than 0.55 ns) of the excited state of these compounds. Working essentially with two MeUmb-monosaccharides and one MeUmb-disaccharide (MeUmb-alpha-D-galactopyranoside, MeUmb-beta-D-galactopyranoside, and MeUmb-2-acetamido-2-deoxy-3-O-(beta-D-galactopyranosyl)-beta-D- galactopyranoside) which were solubilized in various solvents, it was demonstrated that solvent polarity and viscosity definitely affected the fluorescence intensity of MeUmb-glycosides. A low-polarity medium reduced this intensity, and high viscosity enhanced it. The implications of these findings are discussed in relation to the variations in the fluorescence intensity of MeUmb-glycosides when these compounds were bound to lectins.

Binding Sites↗

Binding and precipitation of lectins from Erythrina indica and Ricinus communis (agglutinin I) with synthetic cluster glycosides.

We recently reported that tri- and tetraantennary complex type oligosaccharides with nonreducing terminal galactose residues and the triantennary asialofetuin glycopeptide can bind and precipitate certain galactose specific lectins (L. Bhattacharyya, and C.F. Brewer (1986) Biochem. Biophys. Res. Commun. 141, 963-967; L. Bhattacharyya, M. Haraldsson, and C.F. Brewer (1988) Biochemistry 27, 1034-1041). The present study investigates the binding interactions of two of these lectins, those from Erythrina indica and Ricinus communis (Agglutinin I), with mono-, bi-, and triantennary synthetic cluster glycosides, which have little structural resemblance to complex type oligosaccharides other than they possess nonreducing terminal galactose residues (R.T. Lee, P. Lin, and Y.C. Lee (1984) Biochemistry 23, 4255-4261). The enhanced affinities of the bi- and triantennary glycosides relative to the monoantennary glycoside for the two lectins are consistent with an increase in the probability of binding due to multiple binding residues in the multiantennary glycosides. The triantennary glycoside is capable of precipitating the two lectins, and quantitative precipitation data indicate that it is a trivalent ligand. The results show that the binding and precipitation activities of complex type oligosaccharides with these lectins is due solely to the presence of multiple terminal galactose residues and not to the overall structures of the oligosaccharides.

Chemical Precipitation↗

Interaction of cardiac glycosides and Na,K-ATPase is regulated by effector-controlled equilibrium between two limit enzyme conformers.

The paper describes the dissociation parameters of the complexes between [3H]-digitoxin and Na,K-ATPase (Na+ + K+-activated, Mg2+-dependent ATP phosphohydrolase, E.C. 3.6.1.3) from pig cardiac muscle and brain cortex formed and dissociated in the presence of different combinations and concentrations of the enzyme effectors ATP, Mg2+, Na+ and K+. Systematic variation of effector-ligation of Na,K-ATPase allowed production of glycoside complexes with two enzyme conformers only, which showed either rapid or slow dissociation kinetics. Appropriate changes of enzyme ligation allowed the interconversion of the two conformer types. Biphasic, rapid and slow glycoside release was not bound with the presence of two Na,K-ATPase isozymes, but caused by the enzyme ligation-determined coexistence of the two conformers of Na,K-ATPase. The rate constants for the rapid and slow glycoside release were within the complexes of each dissociation type much alike indicating uniform isomerization kinetics of the two conformers even when differently liganded. Taken together, the observations indicated the effector-controlled isomerizations of two conformers of Na,K-ATPase possessing different geometries of the glycoside binding domain. Present findings and relevant literature data were integrated in a circular, consecutive and simultaneous model for induced conformation changes that accounted for the regulation of the interaction of cardiac glycosides and Na,K-ATPase through an effector-controlled equilibrium between two limit enzyme conformers.

Adenosine Triphosphate↗

Formation of genotoxic metabolites from anthraquinone glycosides, present in Rubia tinctorum L.

Rubia tinctorum L., a medicinal plant used for the treatment of kidney and bladder stones, contains a characteristic spectrum of 9,10-anthraquinone derivatives, which are substituted in only one of the aromatic benzo rings. The majority of the anthraquinones present in the plant itself or in plant extracts are glycosides. We investigated the metabolism of two such glycosides, alizarinprimeveroside (AlP) and lucidinprimeveroside (LuP). AlP given orally to rats was metabolized to alizarin (Al) and 1-hydroxyanthraquinone (1-HA). The reductive cleavage of AlP was also observed after treatment of this compound with rat liver enzymes (S9) and NADPH. 1-HA has been reported to induce unscheduled DNA synthesis (UDS) in primary rat hepatocytes (PRH) and intestinal and liver tumors in rats after chronic treatment. The in vitro genotoxicity of 1-HA was confirmed by our present investigations. We also observed that the glycoside AlP was active at inducing UDS in PRH, but the compound was inactive in the Salmonella/microsome assay. Oral administration of LuP to rats resulted in the excretion of lucidin and rubiadin. When LuP was treated with rat liver extract and NADPH, the compound was reduced to rubiadinprimeveroside (RuP), which was hydrolyzed to rubiadin. We have recently shown that lucidin is highly genotoxic in a battery of short-term tests. We now report that rubiadin is also highly genotoxic in Salmonella typhimurium. However, in contrast to lucidin, it requires metabolic activation. In the UDS assay in PRH, rubiadin was even more potent than lucidin and equal to the positive control DMBA. In addition, the glycoside LuP is active in the Salmonella/microsome assay as well as in the UDS assay. The present work demonstrates that the uptake of the anthraquinone glycosides AlP and LuP leads to the rodent carcinogen 1-HA, and to the highly genotoxic compounds lucidin and rubiadin. This extends our previous studies and supports our suggestion that the therapeutic use of Rubia tinctorum may involve a carcinogenic risk.

Animals↗

The glycosidic precursor of (Z)-5-ethylidene-2(5H)-furanone in Halocarpus biformis juvenile foliage.

A new glycosidic lactone, (5R,6R)-5-(1-hydroxyethyl)-2(5H)-furanone beta-D-glucopyranoside, has been identified as the principal precursor of (Z)-5-ethylidene-2(5H)-furanone in juvenile foliage of the New Zealand tree Halocarpus biformis. Three related lactone glycosides were isolated in smaller amounts, together with the known phenolic glycosides pyroside, arbutin and picein. The principal lactone glycoside underwent facile elimination of glucose, in neutral or basic conditions, to yield (Z)-5-ethylidene-2(5H)-furanone and its E-isomer. This lactone glycoside was also detected in foliage of H. bidwillii and H. kirkii.

Animals↗

Cytostatic and cytotoxic activity of synthetic genistein glycosides against human cancer cell lines.

Genistein, the principal soy isoflavone, is a molecule of great interest as an innovative chemotherapeutic agent or as a lead-compound in anticancer drug design. To enhance intrinsic activity of genistein and to explore its pharmacophoric potential, its glycosidic derivatives were synthesized. On the basis of structural features and calculated lipophilicity coefficient (ClogP) the derivatives were classified as hydrophilic (i.e. those containing free sugar moiety) or lipophilic (i.e. those with alkylated or acylated sugar hydroxyls). The in vitro cytostatic and cytotoxic studies showed hydrophilic glycosides to be practically inactive against human cancer cell lines when compared to the free aglycone. On the contrary, lipophilic glycosides were significantly more active than the parent isoflavone although the correlation between ClogP and the activity was not clear. On the basis of GI50 and LC50 values two of the most active glycosides were found to be several times more potent in their cytostatic and cytotoxic effect than genistein. Additionally all lipophilic glycosides were revealed to exhibit different mode of action in comparison to genistein. It may suggest that these compounds do not undergo rapid biodegradation, either in culture media or inside cells, and exert their biological effects primarily as intact molecules.

Anticarcinogenic Agents↗

Central nervous system depressant action of flavonoid glycosides.

The pharmacological effects on the central nervous system (CNS) of a range of available flavonoid glycosides were explored and compared to those of the glycosides 2S-hesperidin and linarin, recently isolated from valeriana. The glycosides 2S-neohesperidin, 2S-naringin, diosmin, gossipyn and rutin exerted a depressant action on the CNS of mice following i.p. injection, similar to that found with 2S-hesperidin and linarin. We demonstrate in this work that these behavioural actions, as measured in the hole board, thiopental induced sleeping time and locomotor activity tests, are unlikely to involve a direct action on gamma-aminobutyric acid type A (GABA(A)) receptors. The corresponding aglycones were inactive, pointing to the importance of the sugar moieties in the glycosides in their CNS depressant action following systemic administration. The pharmacological properties of the flavonoid glycosides studied here, in addition to our previous results with hesperidin and linarin, opens a promising new avenue of research in the field.

Animals↗

Azido glycoside primer: a versatile building block for the biocombinatorial synthesis of glycosphingolipid analogues.

A lactoside primer, 12-azidododecyl beta-lactoside, was synthesized via the Koenigs-Knorr method by glycosylation of 1,12-dodecyldiol with perbenzoylated lactosyl bromide. The presence of the 2-O-acyl substituent in the donor gave the beta-lactoside, and an excess of acceptor ensured monoglycosylation of the diol. Mesylation of the omega-hydroxyl group in the aglycon, followed by displacement of the mesylate with azide and subsequent O-debenzoylation gave the desired omega-azidododecyl beta-lactoside. The azido glycoside primer was examined in mouse B16 melanoma cells for its feasibility as a building block for oligosaccharide biosynthesis. Uptake of the azido glycoside primer by B16 cells resulted in the sialylation of the galactose residue of the primer to give a glycosylated product having the same glycan as in ganglioside GM3. After 24 h incubation of B16 cells with the primers, the amount of sialylated omega-azidododecyl beta-lactoside primer was 75% of the amount of sialylated n-dodecyl beta-lactoside. However, after 48 h incubation, both primers gave equal amounts of the sialylated products. Interestingly, the remaining azido glycoside primer after 48 h incubation was 5.6-fold greater than that of the alkyl primer, indicating degradation of the alkyl primer to a larger extent than the omega-azido glycoside primer. The facile chemical synthesis and the efficient uptake in cells make the azido glycoside primer a versatile building block for the biocombinatorial synthesis of glycolipid oligosaccharides.

Animals↗

Synthesis of 3-O-sulfoglucuronyl lacto-N-neotetraose 2-aminoethyl glycoside and biotinylated neoglycoconjugates thereof.

The 2-aminoethyl glycoside of pentasaccharide 3-O-sulfo-GlcA(beta-1-->3)Gal(beta-1-->4)GlcNAc(beta-1-->3)Gal(beta-1--> 4)Glc(beta (1) and its conjugates with biotin and biotinylated polyacrylic acid were synthesized as molecular probes to investigate the recognition of the HNK-1 epitope containing carbohydrates by proteins. Key steps in the first of two investigated schemes for the preparation of the target compound 1 were (a) assembling of the pentasaccharide backbone (compound 10) by glycosylation of selectively substituted allyl glycoside of the trisaccharide GlcNAc(beta-1-->3)Gal(beta-1-->4)Glc(beta with glucuronyl-galactose glycosyl donor, (b) transformation of the allyl aglycon in 10 into 2-azidoethyl one (to give 11), (c) selective deprotection of the OH group at C-3 of the GlcA residue in 11 via saponification, intramolecular formation of 6,3-lacton (13) and its methanolysis, and (d) subsequent O-sulfation. The alternative scheme with the use of 2-azido-ethyl glycoside of the trisaccharide GlcNAc(beta-1-->3)Gal(beta-1-->4)Glc(beta instead of the allyl glycoside 6 was less effective due to smaller yield at the step of pentasaccharide synthesis. Additionally to 1 the 2-aminoethyl glycosides of the oligosaccharides GlcA(beta-1-->3)Gal(beta-1-->4)GlcNAc(beta-1-->3)Gal(beta-1-->4)Glc(beta, 3-O-sulfo-GlcA(beta-1-->3)Gal(beta, and GlcA(beta-1-->3)Gal(beta were also synthesized.

Acrylic Resins↗