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 415 records · Page 23Linked to original sources
PubMedDate not supplied

Characterisation of soy isoflavones and screening for novel malonyl glycosides using high-performance liquid chromatography-electrospray ionisation-mass spectrometry.

HPLC combined with electrospray ionisation (ESI)-MS and photodiode array detection has been employed to study the isoflavone components of soy. All of the known soy isoflavones separated by HPLC were identified and characterised, and three novel isoflavones were detected and screened out. These minor isoflavones were deduced to be isomers of 6"-O-malonyl isoflavone glycosides, based on the ESI-MS and UV data, in which the malonyl group is attached at a position other than the 6" position of the glycosyl moiety of the molecule. These novel malonyl glycosides are as thermally labile as the 6"-O-malonyl glycosides, being converted into known isoflavone glycosides after heating in aqueous ethanol. The advantages of HPLC-ESI-MS in detection of novel isoflavones from plant extracts are reviewed.

Chromatography, High Pressure Liquid↗
PubMed2003

Acaricidal effects of cardiac glycosides, azadirachtin and neem oil against the camel tick, Hyalomma dromedarii (Acari: Ixodidae).

The cardiac glycoside, digitoxin, from Digitalis purpurea L (Scrophulariaceae), a cardiac glycosidal (cardenolide) extract from Calotropis procera (Ait) R Br (Asclepiadaceae), azadirachtin and neem oil from Azadirachta indica A Juss (Meliaceae) were tested for their effects against larvae and adult stages of the camel tick, Hyalomma dromedarii Koch (Acari: Ixodidae). The contact LC50 values of the first three materials against adults were 4.08, 9.63 and >40.7 microg cm(-2), respectively, whereas the dipping LC50 values of the four materials were 409.9, 1096, >5000 and >5000 mg litre(-1), respectively. Contact and dipping LC50 values of the extract and azadirachtin against larvae were 6.16, >20.3 microg cm(-2) and 587.7 and >2500 mg litre(-1), respectively. Azadirachtin had no effects on egg production or feeding of adults up to 5000 mg litre(-1); however at 2500 mg litre(-1), it caused significant reduction in feeding activity of larve, prolonged the period for moulting to nymphal stage, and caused 60% reduction in moultability. Results of the two cardiac glycoside materials are comparable with those of several commercial acaricides. The risks and benefits associated with the use of cardiac glycosides are considered.

Animals↗
PubMed2003

Biological activities of synthetic saponins and cardiac glycosides.

Comparisons of the biological activities of diosgenyl (DIO) beta-D-xylopyranosyl- (1 --> 2)-alpha-D-glucopyranoside (2DXalpha) and beta-D-glucopyranosyl- (1 --> 3)-beta-D-glucopyranoside (3GLbeta) or methyl glycyrrhetinate (GAM) 2DXalpha and 3GLbeta with those of the other DIO- or GAM- glycosides confirmed our assumption that both haemolytic and antifungal activities of DIO-glycosides (steroid saponins) generally parallel each other, while almost all haemolytic GAM-glycosides (triterpenoid saponins) have no antifungal activity. By comparisons of digitoxigenyl (DIG) 2DXalpha, beta-D-xylopyranosyl- (1 --> 2)-beta-D-glucopyranoside (2DXbeta) and 3GLbeta with the other DIG-glycosides, the previous supposition on DIG-diglycosides (cardiac diglycosides) has been developed into the assumption that those having a (1 --> 4), (1 --> 3) or (1 --> 2)beta sugar linkage show stronger anti-ATPase and antiviral activities than those with a (1 --> 6) or (1 --> 2)alpha linkage.

Adenosine Triphosphatases↗
PubMed2002

Antioxidant properties of silybin glycosides.

New soluble derivatives of the hepatoprotective flavonolignan silybin (1), namely silybin galactoside (2), glucoside (3), lactoside (4) and maltoside (5) were investigated for their radical scavenging and antilipoperoxidation properties. According to cyclic voltammetry the results show that glycosides are weaker electron donors than silybin, although it was of interest that they were found to be more potent scavengers of the 1,1-diphenyl-2-picrylhydrazyl and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)-derived radicals. The glycosides (2)-(5) were more efficient than silybin in preventing tert-butylhydroperoxide-induced lipoperoxidation of rat liver mitochondrial membranes. Furthermore, glycosides (2)-(5) were significantly more cytoprotective than silybin in tert-butylhydroperoxide-damaged rat erythrocytes and primary hepatocyte cultures. Glycosylation of silybin substantially reduced its toxic effects in primary cultured hepatocytes observed during prolonged incubation. These results suggest that silybin glycosides are suitable soluble derivatives of silybin for experimental studies and may have therapeutic potential.

Animals↗
PubMed2005

Electrospray ionization mass spectrometry for identification and structural characterization of pregnane glycosides.

Pregnane glycosides are a class of naturally occurring substances characterized by some interesting biological activities and widely distributed in the plant kingdom and in some marine organisms. Their toxicity and use in herbal drugs and folk medicines has generated great interest in the chemical characterization of these molecules. In the study reported here the potential of electrospray ionization mass spectrometry (ESI-MS) in the identification and structural characterization of pregnane glycosides was examined. ESI-MS/MS and ESI-MS(n) analyses were performed on 27 different compounds employing two mass spectrometers equipped with a triple-quadrupole or an ion-trap analyzer. The data illustrate the ability of the ESI techniques in the identification of pregnane glycosides, including the nature of the pregnane core, the kind of ester substituents, the types of sugar residues (hexose, deoxyhexose, dideoxyhexose, O-methyldeoxyhexose and O-methyldideoxyhexose), and the primary structure of the saccharide chain. From these data, a generalized fragmentation pathway was proposed by comparing the spectra acquired for all the compounds. Interestingly, similar results were obtained from the two instruments, thus demonstrating that detailed analyses of product ion spectra obtained using a triple-quadrupole mass spectrometer led to structural information comparable to those obtainable in MSn experiments using an ion trap. Different and complementary information was deduced by fragmenting the [M+H]+ or the [M+Na]+ ions, or the protonated aglycone [Agl+H]+ generated by in-source fragmentation. The present evidence clearly suggests that, in order to obtain a complete characterization of pregnane glycosides by MS, all three of these species should be accurately analyzed.

Apocynaceae↗
PubMed1996

Steroidal glycosides from Petunia hybrida L. seeds and their biological activity.

A new plant source containing steroidal glycosides of the furostane and spirostane series has been shown. Ten individual steroidal glycosides (petuniosides) of the spirostane and furostane series have been isolated from Petunia hybrida L. seeds. They differ in the structures of aglycone and oligosaccharide chain, four of them are novel compounds, and their chemical structures have been established. Petuniosides A, C, and E are 3-O-beta-D-galactopyranoside spirostane; 3-O-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside spirostane; and 3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside of (25R)-5 alpha-spirostan-3 beta-ol, respectively. Petuniosides B, D, and F are 3-O-beta-D-galactopyranoside spirostane; 3-O-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside spirostane; and 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside of (25R)-5 alpha-spirostane-2 alpha, 3 beta-diol, respectively. Petuniosides E and F are new compounds, and B, C, and D have been detected in the Petunia genus for the first time. Glycosides of the furostane series, petuniosides I and K, are derivatives of (25R)-5 alpha-spirostane-3 beta, 22 alpha, 26-triol, and K and M of (25R)-5 alpha-spirostane-2 alpha, 3 beta, 22 alpha, 26-tetraol. Petuniosides I and L are new compounds, and K and M are known, but have been detected in the Petunia genus for the first time. Growth-stimulating activity has been established for petunioside M. This glycoside has been shown to enhance cucumber resistance to cucumber green eye-sport mosaic virus.

Carbohydrate Sequence↗
PubMed1984

Cardiac glycosides and sodium/potassium-ATPase.

The sodium/potassium-ATPase complex is, according to modern research, the binding site for cardiac glycosides on the outer surface of the cell membrane and their receptor. Inhibition of this enzyme by cardiac glycosides leads for instance in the heart to a decrease or a delay in membrane sodium/potassium-ion transport, and indirectly to an increase in the intracellular ionized calcium-concentration and an increase in cardiac contractile force. According to recent observations the activity of the sodium/potassium-ATPase or its concentration, and therefore the concentration of binding sites can increase in some tissues after long term treatment with cardiac glycosides. This might explain the occasionally observed tolerance to digitalis glycosides.

Animals↗
PubMed1994

Assessing glycosidic linkage flexibility: conformational analysis of the repeating trisaccharide unit of Aeromonas salmonicida.

A detailed conformational analysis was performed for the synthetic branched trisaccharide beta-D-ManNAc-(1-->4)-[alpha-D-Glc-(1-->3)]-L-Rha 1 which represents the repeating unit of the O-antigenic polysaccharide of Aeromonas salmonicida. The study was based on 26 experimental NOE curves from 1D transient NOE experiments, employing Gaussian-shaped inversion pulses at 600 MHz. Eight of the NOE curves were interglycosidic and thus useful for an analysis of glycosidic linkage orientations. Metropolis Monte Carlo (MMC) simulations and minimum-energy calculations with the program GEGOP were used to obtain theoretical NOE curves which were compared to the experimental ones. MMC simulations with different temperature parameters of 310, 600, 900 and 2000 K allowed identification of NOEs which are sensitive towards different conformation distributions--not only different conformations--at both glycosidic linkages in 1. A comparison of trisaccharide 1 with the constituent disaccharides beta-D-ManNAc-(1-->4)-L-Rha 2 and alpha-D-Glc-(1-->3)-L-Rha 3 revealed effects of branching on glycosidic linkage flexibility. A quantitative evaluation was facilitated by the introduction of entropy-related flexibility parameters. Our study indicates a notable restriction of flexibility, especially at the (1-->3) linkage in 1. Although overall flexibility in 1 is reduced as compared to the constituent disaccharides 2 and 3, it cannot be neglected altogether. In summary, combined transient NOE experiments and MMC simulations provide a simple approach to analyse glycosidic linkage flexibility.

Aeromonas↗
PubMed1987

Absence of gene amplification in human cell mutants resistant to cardiac glycosides.

In HeLa cells, four different types of mutants resistant to cardiac glycosides viz. ouabain and SC4453, which differ from each other in cross resistance pattern, have been isolated after single-step selections [J Biol Chem 260 (1985) 6843-6850; J Biol Chem 261 (1986) 2034-2040]. Using cloned cDNA probes specific for the alpha and beta subunits of Na+/K+ ATPase, these mutants have been investigated for amplification and/or increased transcription of Na+/K+ ATPase genes. Results from dot blots, Southern and Northern hybridizations provide evidence that these mutants do not involve any amplification or increased transcription or gross structural alterations in Na+/K+ ATPase genes of their transcripts. Similar results were obtained with the mutant cells grown either in the absence or presence of cardiac glycosides, the latter conditions of which cause 3-4-fold increase in the resistant form of the enzyme within the mutant cells. These results are consistent with the inference that resistance to cardiac glycosides in these mutants may be due to specific point mutations within the structural gene(s) of Na+/K+ ATPase leading to an altered enzyme that is resistant to inhibition by different cardiac glycosides.

Cardiac Glycosides↗
PubMed1986

A dual effect of cardiac glycosides on Ca current in single cells of frog heart.

The effects of cardiac glycosides (1 microM ouabain, 50 microM dihydrooubain, 1 microM strophanthidin) on Ca current (ICa) were investigated on Cs-loaded single frog ventricular cells using the whole-cell patch-clamp technique (9). Cardiac glycosides exert both inhibitory and stimulatory effects on ICa in 20 Cs Ringer solution, but have only a stimulatory effect in 0 Cs, when the Na,K pump is blocked. The inhibitory response seems related to the inhibition of the Na,K pump by glycosides. The stimulatory effect on ICa may contribute to the positive inotropic effect of cardiac glycosides.

Animals↗
PubMed1993

Human skeletal muscle digitalis glycoside receptors (Na,K-ATPase)--importance during digitalization.

The aims of the present study were to evaluate in humans the putative importance of skeletal muscle digitalis glycoside receptors (Na,K-ATPase) in the volume of distribution of digoxin and to assess whether therapeutic digoxin exposure might cause digitalis receptor upregulation in skeletal muscle. Samples of the vastus lateralis were obtained postmortem from 11 long-term (9 months to 9 years) digitalized (125-187.5 micrograms daily) and eight undigitalized subjects. In intact samples from digitalized patients, vanadate-facilitated 3H-ouabain binding increased 15% (p < 0.02) from 150 +/- 18 to 173 +/- 13 pmol/g wet wt. (mean +/- SEM) after clearing receptors of bound digoxin by washing samples in excess specific digoxin antibody fragments. 3H-ouabain binding in the untreated group was 257 +/- 28 and 274 +/- 26 pmol/g wet wt. (7%, p > 0.30) before and after washing in specific digoxin antibody fragments, respectively. Thus, the present study indicates a approximately 13% occupancy of skeletal muscle digitalis glycoside receptors with digoxin during digitalization. In light of the large skeletal muscle contribution to body mass, this indicates that the skeletal muscle Na,K-ATPase pool constitutes a major volume of distribution for digoxin during digitalization. The results gave no indication of skeletal muscle digitalis glycoside receptor upregulation in response to digoxin treatment. On the contrary, there was evidence of significantly lower (37%, p < 0.005) digitalis glycoside receptor concentration in the vastus lateralis of the digitalized patients, which may be of importance for skeletal muscle incapacity in heart failure.

Aged↗
PubMedDate not supplied

Cell membrane receptors for cardiac glycosides in the heart.

Cell membranes contain special binding proteins for hormones and drugs. These binding sites ("receptors") located on the outside surface are linked to or are part of an enzyme facing the inner side of the membrane and are transducing and probably amplifying the information carried by the pharmacological agent to the cell. As the first step of their action cardiac glycosides reversibly bind with high affinity to specific receptors in cardiac cells and by this inhibit the (Na+ + K+)-ATPase, which is the enzyme system responsible for the active transmembraneous transport of sodium and potassium. It is thought that the inhibition of this active cation transport precedes the positive inotropic effect. Cardio-inactive glycosides have but low affinity to this receptor and thus do inhibit the (Na+ + K+)-activated ATPase only at very high concentrations. The characterization of the cardiac glycoside-receptor interaction in the heart reveals several factors that influence the affinity of the binding sites for the glycosides and thereby determine the sensitivity to this widely used group of potent drugs.

Adenosine Triphosphatases↗
PubMed2006

Hydrolysis of black soybean isoflavone glycosides by Bacillus subtilis natto.

Hydrolysis of isoflavone glycosides by Bacillus subtilis natto NTU-18 in black soymilk is reported. At the concentration of 3-5% (w/v), black soymilk in flask cultures, the isoflavones, daidzin, and genistin were highly deglycosylated within 24 h. Deglycosylation of isoflavones was further carried out in a 7-l fermenter with 5% black soymilk. During the fermentation, viable cells increased from 10(3) to 10(9) CFU ml(-1) in 15 h, and the activity of beta-glucosidase appeared at 8 h after inoculation and reached a maximum (3.3 U/ml) at 12 h, then decreased rapidly. Deglycosylation of isoflavone glycosides was observed at the same period, the deglycosylation rate of daidzin and genistin at 24 h was 100 and 75%, respectively. It is significantly higher than the previous reports of fermentation with lactic acid bacteria. In accordance with the deglycosylation of isoflavone glycosides, the estrogenic activity of the 24 h fermented black soymilk for ERbeta estrogen receptor increased to threefold; meanwhile, the fermented broth activated ERalpha estrogen receptor to a less extent than ERbeta. These results suggest that this fermentation effectively hydrolyzed the glycosides from isoflavone in black soymilk and the fermented black soymilk has the potential to be applied to selective estrogen receptor modulator products.

Bacillus subtilis↗
PubMed2005

Effects of drought stress and nutrient availability on dry matter allocation, phenolic glycosides, and rapid induced resistance of poplar to two lymantriid defoliators.

The growth-differentiation balance hypothesis (GDBH) postulates that variation in resource availability can increase or decrease allocation to secondary metabolism, depending on how growth is affected relative to carbon assimilation. Growth and leaf area of black poplar (Populus nigra) increased substantially in response to increased nutrient availability, while net assimilation rate and photosynthesis were less strongly affected. In response, total phenolic glycoside concentrations declined, which is consistent with GDBH. Drought stress decreased net assimilation rate and photosynthesis as well as growth, while increasing total phenolic glycoside concentrations. This pattern does not follow GDBH, which predicts lower secondary metabolism when resource limitation decreases both growth and carbon assimilation. However, there was a strong negative correlation between growth and total phenolic glycoside concentration consistent with a trade-off between primary and secondary metabolism, a key premise of GDBH. Drought decreased the growth of gypsy moth (Lymantria dispar) larvae but had no effect on whitemarked tussock moth (Orgyia leucostigma). Increased nutrient availability had a positive linear effect on growth of whitemarked tussock moth, but no effect on gypsy moth. Treatment effects on gypsy moth corresponded closely with effects on total phenolic glycosides, whereas effects on whitemarked tussock moth more closely tracked changes in nutritional quality. Localized gypsy moth herbivory elicited rapid induced resistance to gypsy moth, with the effect being independent of water and nutrient availability, but did not affect whitemarked tussock moth, indicating that the effects of biotic and abiotic stress on insect resistance of trees can be species-specific.

Animals↗
PubMed1986

Fast atom bombardment and tandem mass spectrometry for structure determination of steroid and flavonoid glycosides.

The combination of fast atom bombardment (FAB) and tandem mass spectrometry (MS-MS) was tested for its applicability to generate useful structural information for steroid and flavonoid glycosides. The following compounds were investigated: quercetin, myricitrin, apigetrin, fraxin, rutin, neohesperidin, hesperidin, naringin, apiin, cymarin, digoxin, digitoxin, xanthorhamnin, and frangulin. Upon FAB, the sample molecules are desorbed as (M + H)+, (M - H)-, or as (M + Na)+ or (M + K)+. Collisional activation of (M + H)+ or (M - H)- ions in the MS-MS experiment leads to sequential losses of glycoside moieties in a manner which permits the sequence of glycosides to be established. Some glycosides occur as mixtures of homologs. Proper interpretation of the MS-MS or collisional activation decomposition spectra often allows the homology to be located. In addition to the simple and highly selective fragmentations observed in this combined experiment, FAB and MS-MS also remove interference caused by the ubiquitous matrix ions which are desorbed by FAB.

Chemical Phenomena↗
PubMed1992

Effects of alkyl glycosides incorporated into liposomes prepared from synthetic amphiphiles on their tissue distribution in Ehrlich solid tumor-bearing mice.

A study of the effects of alkyl glycosides incorporated into synthetic liposomes with respect to their stability, their in vivo distribution in Ehrlich solid tumor-bearing mice and their in vitro interaction with liver cells was undertaken. The synthetic liposomes were prepared from N,N-didodecyl-N alpha-[6-(trimethylammonio)hexanoyl]-L-alaninamide bromide (N+C5Ala2C12) and labeled with 99mTc. n-Dodecyl glucoside (DG) and n-dodecyl sucrose (DS) were used as alkyl glycosides. The stability was hardly changed by incorporation of alkyl glycosides into the liposomes in saline and serum. The uptake of DG- and DS-modified N+C5Ala2C12 liposomes decreased in liver and spleen compared with that of unmodified N+C5Ala2C12 liposomes, resulting in an increase in blood and other tissues such as tumor, duodenum and kidney, where the DS-modified N+C5Ala2C12 liposomes had a marked tendency. It was observed with electron micrographs that the size of N+C5Ala2C12 liposomes became small by incorporation of alkyl glycoside. The smaller N+C5Ala2C12 liposomes were found to result in the lower uptake in liver. The interaction of the liposomes with liver cells in vitro indicated that both DG- and DS-modified liposomes had a low affinity for liver cells compared with the unmodified liposomes and the extent of interaction of the DS-modified liposomes was weaker than that of the DG-modified liposomes.

Alkylation↗
PubMed1986

The rate of uptake of cardiac glycosides into human cultured cells and the effects of chloroquine on it.

HeLa cells grown on Petri dishes were either pulse labelled with various cardiac glycosides or grown in low concentrations of them for up to 2 days; either in the presence of chloroquine or not. The cells were then homogenised and the cell free homogenate layered on a continuous sucrose gradient; and the glycoside content and that of various markers measured. In another series of experiments HeLa cells were grown on plastic beads under the above conditions and then the content of glycosides and of some marker enzymes measured. The rate of internalisation of ouabain, digoxin and digitoxin from the plasma membrane preparation produced by the bead method is at 9% hr-1, similar to the rate of loss of digoxin and digitoxin from whole cells but much faster than that of ouabain. In the sucrose gradient experiments it was found that [3H]ouabain, digoxin and digitoxin all initially co-distribute with the plasma membrane marker, 5'-nucleotidase, and then leave this fraction of the homogenate at a fast rate when kept at 37 degrees, to co-distribute with the lysosomal marker, beta-hexosaminidase. At 2 degrees the ouabain remains co-distributed with the plasma membrane marker. The rate of transfer is estimated to be some 90% hr-1, much faster than previously thought. Chloroquine causes an increased retention of digoxin and digitoxin in the lysosomal fraction of the homogenate. These results are best explained by supposing that the sodium pump-glycoside complex rapidly enters a region of the peripheral cytoplasm, and that this region then controls the subsequent exit of digoxin and digitoxin from the cell. The main barrier for ouabain occurs at a stage later than this. The consequences of this model on other aspects of pump activity is discussed.

Cardiac Glycosides↗
PubMed1988

A micromethod for the estimation of oligosaccharides containing glycosidically linked sialic acid or hexoses, or both, in glycoproteins.

The peeling reaction, the process by which oligosaccharides are degraded in alkali, was used as the basis for an assay to provide structural information about glycosidically linked oligosaccharides in glycoproteins. Glycoproteins were treated with 0.05 M NaOH at 50 degrees to induce release, and subsequent degradation ("peeling"), of glycosidically linked, but not of N-glycosydically linked, oligosaccharides. Among the degradation products generated from O-linked chains were three 3-deoxy sugar acids whose formation was correlated with certain structural features of the oligosaccharides. N-Acetylneuraminic acid was released from terminal positions in the oligosaccharides, and iso- and meta-saccharinic acids were derived from the degradation of 4-O- and 3-O-substituted hexoses, respectively. All of these sugar acids were detected colorimetrically by periodate oxidation and reaction of the product with 2-thiobarbituric acid. The ability of the method to generate 3-deoxy sugar acids was tested in 8 alkali-treated glycoproteins. 3-Deoxy sugar acids were detected only in those glycoproteins whose glycosidically linked carbohydrates contained N-acetylneuraminic acid, or 3-O- or 4-O-substituted hexoses, or both. As little as 0.12 microgram of 3-deoxy sugar acid produced from 5 micrograms of human chorionic gonadotropin was sufficient for detection. This method is novel in its ability to distinguish sialylation of glycosidically linked carbohydrates. Furthermore, it combines the specificity of beta-elimination with the sensitivity of the 2-thiobarbituric acid assay in targeting degradation products of the peeling reaction as candidates for an assay method.

Glycoproteins↗