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 631 records · Page 35Linked to original sources
PubMed1996

Oviposition stimulants for the monarch butterfly: flavonol glycosides from Asclepias curassavica.

The monarch butterfly, Danaus plexippus oviposits on milkweed plants, primarily within the Asclepiadaceae. Oviposition stimulants responsible for host plant recognition were isolated from Asclepias curassavica. Six flavonoid glycosides-quercetin 3-O-(2",6"-alpha-L-dirhamnopyranosyl)-beta-D-galactopyranoside, quercetin 3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-galactopyranoside, quercetin 3-O-(2"-O-alpha-L-rhamnopyranosyl)-beta-D-galactopyranoside, quercetin 3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside, quercetin 3-O-beta-D-galactopyranoside, quercetin 3-O-beta-D-glucopyranoside, and an unidentified flavonoid mixture were isolated and characterized from this plant. An additional glycoside, possibly quercetin 3-O-(2",6"-alpha-L-dirhamnopyranosyl)-beta-D-glucopyranoside, which could not be separated from the first triglycoside, was also found in some batches of plant extract. The two dirhamnosyl glycosides, the glucosylgalactose and the rutinoside were found to be active as oviposition stimulants at 0.5 g leaf equivalents.

Animals↗
PubMed1996

Structure-activity relationships of synthetic cardiac glycosides.

The antiviral, cytotoxic and anti-ATPase activities of 14 synthetic bufalyl glycosides were compared with each other. Among these glycosides, the activities of the gentiobioside and the melibioside were much weaker than those of the others. On the other hand, these three activities were found to be highly correlated with each other. These were parallel to the case of the digitoxigenyl glycosides in our previous paper.

Adenosine Triphosphatases↗
PubMed1996

Hemolytic activities of triterpene glycosides from the holothurian order Dendrochirotida: some trends in the evolution of this group of toxins.

Hemolysis and K+ loss from mouse erythrocytes, induced by triterpene glycosides and their derivatives from this order of sea cucumbers were studied. Sulfate groups, attached to position 4 of the first xylose residue and to position 6 of the third glucose residue of the branched pentaosides, having 3-O-methyl-groups in terminal monosaccharide moieties increase K+ loss. A sulfate group at C-4 of the first xylose residue increases the hemolytic activity while a sulfate at C-6 of the third monosaccharide unit decreases it. A sulfate group at C-6 of terminal 3-O-methylglucose drastically decreases the hemolytic activity and rate of K+ loss. The presence of a sulfate group at the first xylose residue in glycosides having no 3-O-methyl group at the terminal monosaccharide decreases hemolytic activity and rate of K+ loss. The presence of the 16-ketone group in aglycones having the 7(8)-double bond significantly decreases activity. These results correlate with the previously proposed trends in evolution of sea cucumber glycosides from substances having sulfate groups at C-6 of glucose and 3-O-methylglucose units to substances sulfated at C-4 of the first xylose or having no sulfate groups, and from substances with aglycone 16-ketone to substances having no oxygen functions in this position.

3-O-Methylglucose↗
PubMed1998

The stereoisomers quinine and quinidine exhibit a marked stereoselectivity in the inhibition of hepatobiliary transport of cardiac glycosides.

BACKGROUND/AIMS: Certain basic (cationic) drugs are known to interact with the hepatic transport, and renal and/or biliary clearance of cardiac glycosides. The mechanisms behind these interactions are not fully understood. In the present study our aim was to investigate the effects of the two diastereomers, quinidine and quinine, as well as the calcium antagonist verapamil, on the hepatobiliary elimination of digoxin and ouabain in the isolated perfused rat liver. METHODS: Livers from male, fasting Wistar rats were perfused by recirculation of Krebs-Henseleit bicarbonate buffer supplemented with 1% BSA. Disposition of digoxin or ouabain was studied at an initial perfusion medium concentration (Ci) of 100 or 10 nmol/l for digoxin and a Ci of 30 micromol/l for ouabain. The Ci of quinine, quinidine or verapamil was 50 micromol/l. Concentrations of the drugs in perfusion medium and bile were followed up to 2 h. RESULTS: A marked reduction in the initial medium disappearance rate of digoxin and ouabain by quinine was found, whereas quinidine did not affect the hepatic disposition of the cardiac glycosides. The stereoselective inhibition of digoxin and ouabain clearance by quinine, and not by quinidine, was shown to be due to an effect on the hepatic uptake level rather than on the metabolic conversion and/or the biliary excretion steps. An allosteric type of inhibition by the basic drugs, exerted from the inside of the cells, is inferred. This interaction may occur at the sinusoidal plasma membrane on the level of multi-specific carrier proteins for cardiac glycosides and cationic drugs, as cloned recently by various groups. CONCLUSIONS: A marked stereoselective difference was found in the effect of the stereoisomers quinidine and quinine on the hepatic uptake of digoxin and ouabain, quinine being the potent inhibitor.

Animals↗
PubMed1989

Mutagenicity of rutin and the glycosidic activity of cultured cell-free microbial preparations of human faeces and saliva.

Genotoxic testing of flavonol glycosides, which account for most of the human intake of flavonoids, is dependent on the use of enzymatic extracts that exhibit beta-glycosidic activity. This study was aimed at characterizing further the beta-glycosidic activity of cultured cell-free microbial extracts from human faeces (faecalase) and saliva (salivase). Using o-nitrophenyl-beta-D-galactoside as substrate, the optimum pH and apparent Km and energy of activation were shown to be 7.6, 3.5 x 10(-4) M and 8.65 kcal/mol, respectively, for faecalase, and 7.4, 8.7 x 10(-5) M and 3.8 kcal/mol, respectively, for salivase. Rutin (quercetin-3-O-rutinoside) was shown to be a competitive inhibitor for faecalase, whereas no inhibitory activity could be found for salivase. Enzymatic hydrolysis of rutin gave the mutagenic product quercetin that was detected in the Ames assay and using high-performance liquid chromatography.

Cell-Free System↗
PubMed1993

Microdiffusion method with solid state detection of cyanogenic glycosides from cassava in human urine.

A method for quantitative determination of cyanogenic glycosides in human urine is described. It is based on enzymatic cleavage of the glycosides, microdiffusion of the hydrogen cyanide formed, solid state detection by colour formation on a picrate-impregnated sheet, and subsequent rating of the coloured spot by the absorption of transmitted light at 540 nm with a thin-layer (TLC) densitometer. The method has been tested using normal as well as pathological urines containing glucose, protein, leucocytes, blood and bacteria. The method allows quantification of urinary linamarin above 70 mumol/litre, in 40 microliters urine. In Mozambican subjects consuming insufficiently processed cassava the mean urinary linamarin levels were 211 mumol/litre, indicating for the first time that substantial amounts of the main cyanogenic glycoside in cassava may be absorbed from the human gut and excreted intact in the urine.

Administration, Oral↗
PubMed1990

Solasodine glycosides. Selective cytotoxicity for cancer cells and inhibition of cytotoxicity by rhamnose in mice with sarcoma 180.

BEC, a standard mixture of solasodine glycosides is effective in vivo against murine sarcoma 180 (S180), whereas the aglycone solasodine at equimolar concentrations is ineffective. The efficacy of BEC against S180 in vivo can be inhibited by rhamnose. Mice which are in their terminal stage with S180 can tolerate and become symptom-free of cancer by single dose administration of BEC at concentrations of BEC three times the LD100 for normal mice. These observations suggest that the binding of solasodine glycosides on tumour cells may be mediated through the monosaccharide rhamnose, which forms part of solasonine, solamargine and di-glycosides of solasodine in BEC. Furthermore, these results provide evidence that BEC selectively destroys tumour cells relative to normal cells in vivo.

Animals↗
PubMed1982

A comparative study in vitro of physiological activity of triterpene glycosides of marine invertebrates of echinoderm type.

1. The cytostatic and antimicrobial activity of triterpene glycosides of 19 holothurian species of the Pacific tropical zone has been studied. 2. It has been demonstrated that yeast and tumor cells display a comparable sensibility to the action of triterpene oligosides of sea cucumbers. 3. Gram-positive and Gram-negative bacteria are not sensible to the action of glycosides in doses to 500 mkg/ml. 4. Triterpene glycosides-stichoposides, thelothurins and oligosides of Holothuria of genus Bohadschia are the most active in relation to fungal, yeast microflora and tumor cells.

Animals↗
PubMed1983

Differential effects on the cyanogenic glycoside content of fermenting cassava root pulp by beta-glucosidase and microbial activities.

The degradation of cyanogenic glycosides was studied in spontaneously fermenting cassava root pulp and in fresh pulp samples pretreated to prevent either endogenous beta-glycosidase activity, fermentation, or both. The rate of disappearance of the glycosides, as measured by hydrocyanic acid (HCN) production in situ, in membrane-sterilised media or in samples containing 1% sodium iodoacetate, was comparable with the untreated control in which 85% of the substrate was broken down within 72 h. Pretreatment of the fresh pulp with the beta-glucosidase inhibitor 1,5-gluconolactone (1%) markedly reduced the rate of disappearance of the cyanogens while inclusion of glucose in this test medium at the 3% level appeared to induce some hydrolysis. Loss of bound (glycosidic) cyanide in sterilised medium containing the glucosidase inhibitor was negligible. The results suggest that the contribution of the fermentation process in cyanide detoxification of pulped cassava roots is minimal.

Cyanides↗
PubMed1992

The Moraceae-based dart poisons of South America. Cardiac glycosides of Maquira and Naucleopsis species.

The use of cardenolide-containing Moraceae in the dart poisons of South America is reviewed. Those prepared by the Chocó Indians of western Colombia--called niaará or kieratchi--have probably been made from the latex of Naucleopsis amara and N. glabra. In Ecuador, the Colorado Indians used N. chiguila, while the Coaiquer Indians still derive a poison from the latex of N. naga and the Cayapá Indians occasionally make use of a blowgun poison, hambi, which probably also comes from a Naucleopsis species. The Kaborí (Rio Uneiuxi Makú) Indians of north-western Brazil may have utilized Maquira coriacea, but a more recent collection documents N. mello-barretoi latex as a source of their poison. The Tikuna Indians of western Brazil included leaves and bark of N. stipularis in one of their poisons. The principal cardiac glycosides present in Maquira species are strophanthidin-based and the main ones occurring in Naucleopsis species are antiarigenin- as well as strophanthidin-based. The structures of two new glycosides, isolated from dart-poison samples, have been established as strophanthidin beta-D-glucomethylosido-D-alloside and beta-D-digitoxosido-D-alloside. The former is a major component of pakurin, the crystalline glycoside mixture prepared by Santesson in 1928 from a Chocó Indian poison.

Animals↗
PubMed2005

C-Glycoside analogues of beta-galactosylceramide with a simple ceramide substitute: synthesis and binding to HIV-1 gp120.

The synthesis and HIV-1 gp120 binding of C- and aza-C-glycoside analogues of beta-galactosylceramide (GalCer) that contain a simple C-17 hydrocarbon chain as a ceramide substitute are described. Both compounds originate from stearic acid, and a carbohydrate-derived thioacetal-alcohol, and their syntheses are potentially general for beta-C-galactosides and their aza-C-partners. They showed potent and specific affinity for gp120 in an assay based on the change of surface pressure when the glycolipid monolayers were exposed to solutions of gp120. Interestingly, the aza-C-glycoside exhibited a significantly higher affinity than GalCer, whereas the C-glycoside was as active as GalCer.

Galactosylceramides↗
PubMed2004

Increased ATP content/production in the hypothalamus may be a signal for energy-sensing of satiety: studies of the anorectic mechanism of a plant steroidal glycoside.

A steroidal glycoside with anorectic activity in animals, termed P57AS3 (P57), was isolated from Hoodia gordonii and found to have homologies to the steroidal core of cardiac glycosides. Intracerebroventricular (i.c.v.) injections of the purified P57AS3 demonstrated that the compound has a likely central (CNS) mechanism of action. There is no evidence of P57AS3 binding to or altering activity of known receptors or proteins, including Na/K-ATPase, the putative target of cardiac glycosides. The studies demonstrated that the compound increases the content of ATP by 50-150% in hypothalamic neurons. In addition, third ventricle (i.c.v.) administration of P57, which reduces subsequent 24-h food intake by 40-60%, also increases ATP content in hypothalamic slice punches removed at 24 h following the i.c.v. injections. In related studies, in pair fed rats fed a low calorie diet for 4 days, the content of ATP in the hypothalami of control i.c.v. injected animals fell by 30-50%, which was blocked by i.c.v. injections of P57AS3. With growing evidence of metabolic or nutrient-sensing by the hypothalamus, ATP may be a common currency of energy sensing, which in turn may trigger the appropriate neural, endocrine and appetitive responses as similar to other fundamental hypothalamic homeostatic centers for temperature and osmolarity.

Adenosine Triphosphate↗
PubMed2006

The Ramberg-Bäcklund reaction for the synthesis of C-glycosides, C-linked-disaccharides and related compounds.

The discovery of the Ramberg-Bäcklund procedure for preparing exo-glycals from S-glycoside dioxides, developed independently in (Old) York and New York, is reviewed. The methodology is successful with glucose, galactose, mannose, xylose, fucose, ribose, altrose, 2-deoxy-arabino-hexose (2-deoxy-glucose) and daunosamine derivatives, and has been used to prepare di-, tri- and tetra-substituted exo-glycals. More recent developments, such as one-pot variants, and protecting group-free procedures, are also covered. Synthetic applications of the exo-glycals, for example, to prepare beta-glycosidase inhibitors, spirocyclic glucose derivatives, beta-C-glycosides, C-glycosyl porphyrin glycoconjugates and C-glycosyl amino acids, are also discussed. Finally, applications of the Ramberg-Bäcklund process for the synthesis of known and novel C-glycosides, and in natural product synthesis, are reviewed.

Alkenes↗
PubMed2006

A new glycosidation method through nitrite displacement on substituted nitrobenzenes.

Benzyl, benzoyl, and acetyl protected 1-OH and 1-SH glycoses in the glucose, glucosamine, galactose, mannose, and lactose series react with nitrobenzenes activated by one or two electron withdrawing substituents like nitro and cyano to afford the corresponding aryl glycosides in 50-100% yield. The S(N)Ar displacement of nitrite by 1-OH glycoses is reversible and gives predominantly the alpha-glycosides, whereas 1-SH glycoses do not anomerize and afford the beta-glycosides. Thus, the prepared dicyanophenyl gycosides are useful building blocks for the preparation of phthalocyanine-glycoconjugates via template synthesis.

Glycosides↗
PubMed2004

Inhibition of human low density lipoprotein oxidation by flavonols and their glycosides.

Antioxidative effects of the flavonols and their glycosides, i.e., quercetin (Q), quercetin galactopyranoside (QG), quercetin rhamnolpyranoside (QR), rutin (R), morin (MO), myrecetin (MY), kaempferol (K) and kaempferol glucoside (KG), against free radical initiated peroxidation of human low density lipoprotein (LDL) were studied. The peroxidation was initiated either by a water-soluble initiator 2,2'-azobis(2-amidino propane hydrochloride) (AAPH), or by cupric ion (Cu2+). The reaction kinetics were monitored either by the uptake of oxygen and the depletion of alpha-tocopherol (TOH) presented in the native LDL, or by the formation of thiobarbituric acid reactive substances (TBARS). Kinetic analysis of the antioxidation process demonstrates that these flavonols and their glycosides are effective antioxidants against AAPH- and Cu(2+)-initiated LDL peroxidation, the flavonols bearing ortho-dihydroxyl groups possess significantly higher antioxidant activity than those bearing no such functionalities, and the glycosides are less active than their parent aglycones.

Flavonols↗
PubMed2004

Capillary gas chromatographic separation of bile acid acyl glycosides without thermal decomposition and isomerization.

A direct method for the capillary gas chromatographic (cGC) separation of the acyl glycosides of bile acids was successfully attained. The free acyl glycosides were derivatized to their complete trifluoroacetyl (TFA) derivatives with N-methyl-bis(trifluoroacetamide). The highly volatile TFA derivatives were chromatographed on a short-length (10 m), narrow-bore (0.1 mm) capillary column coated with a thin film (0.1 microm) of 5% phenyl polysilphenylene-siloxane at a column temperature below 280 degrees C. Each exhibited a single, well-separated peak of the theoretical shape without any accompanying peaks due to the thermal decomposition and isomerization. The bile acid 24alpha-glucosides were always eluted faster than the corresponding 24beta-glucosides, which eluted before the corresponding 24beta-galactosides. The method could be usefully applied to biosynthetic and metabolic studies of bile acid acyl glycosides in biological materials.

Bile Acids and Salts↗
PubMed2005

Analysis of flavanone-7-O-glycosides in citrus juices by short-end capillary electrochromatography.

The separation of the major flavanone-7-O-glycoside constituents of Citrus was carried out by isocratic reversed phase capillary electrochromatography using a 75 microm i.d. silica fused column packed with 5 microm ODS silica gel. In comparison to HPLC mode, capillary electrochromatography resolution of flavanone glycosides was obtained with a high selectivity factor. Optimum separation conditions were found using a mixture of ammonium formate (pH 2.5)--acetonitrile (8:2, v/v) as the mobile phase by the short-end injection mode. Under these conditions all the investigated flavanones were baseline-resolved within short analysis time (i.e. between 5 and 10 min). A study, evaluating the intra- and inter-day repeatability as well as limit of detection and method linearity, was developed in accordance with the analytical procedures for method validation. The developed method was applied for the quantitative analysis of flavanone glycosides in commercial fruit juices (sweet orange, lemon and grapefruit).

Acetonitriles↗