Showing papers on "Glucoside published in 1984"
TL;DR: Steroid glycosides and the unique glycosidase activity of the colonic microflora form the basis of a new colon-specific drug-delivery system, and hydrolysis of the prodrugs by beta-glucosidase and fecal homogenates in vitro released free steroids.
Abstract: Steroid glycosides and the unique glycosidase activity of the colonic microflora form the basis of a new colon-specific drug-delivery system. Drug glycosides are hydrophilic and, thus, poorly absorbed from the small intestine. Once such a glycoside reaches the colon it can be cleaved by bacterial glycosidases, releasing the free drug to be absorbed by the colonic mucosa. This concept was illustrated with dexamethasone 21-beta-D-glucoside (1) and prednisolone 21-beta-D-glucoside (2), two prodrugs that may be useful in treating inflammatory bowel disease. Hydrolysis of the prodrugs by beta-glucosidase and fecal homogenates in vitro released the free steroids. Glucosides 1 and 2 were administered to rats intragastrically to determine when and where the free steroids were released. Unmodified dexamethasone (3) and prednisolone (4) were also given to rats intragastrically to compare absorption of the glucosides with the free steroids. Both glucosides were found to reach the rat lower intestine in 4-5 h, where they were rapidly hydrolyzed, releasing the free steroids. Delivery of steroid 3 (via glucoside 1) was more specific than that of steroid 4 (via glucoside 2): nearly 60% of an oral dose of glucoside 1 reached the cecum, whereas less than 15% of glucoside 2 reached the cecum. When free steroids 3 and 4 were administered orally, they were almost exclusively absorbed in the small intestine: less than 1% of an oral dose of each reached the cecum.
180 citations
TL;DR: Three new C6-C2 natural alcohols, rengyol (1), rengoxide (2), and rengylone (3), have been isolated from Forsythiasuspensa fruits, along with a novel glycoside, forsythoside E (4), a new sugar ester, 4-caffeoylrutinose, and a known quinol glucoside, cornoside (5).
Abstract: Three new C6–C2 natural alcohols, rengyol (1), rengyoxide (2), and rengyolone (3), have been isolated from Forsythiasuspensa fruits, along with a novel glycoside, forsythoside E (4), a new sugar ester, 4-caffeoylrutinose, and a known quinol glucoside, cornoside (5). Chemical and spectroscopic studies have established the structures of these new constituents.
72 citations
TL;DR: Melampyrum arvense and M. cristatum contain aucubin, 8-epiloganin and melampyroside, a new natural iridoid glucoside: gardoside methyl ester as discussed by the authors.
62 citations
TL;DR: Loganin, loganic acid, and periclymenoside have been isolated from Lonicera perriclymenum and the identity of the others have been determined by chemical transformations and interpretation of the spectral data as mentioned in this paper.
Abstract: Loganin (1), loganic acid (2), and periclymenoside (3) have been isolated from Lonicera periclymenumL. The structure of the new compound 3 and the identity of the others have been determined by chemical transformations and interpretation of the spectral data.
61 citations
TL;DR: Cyclodopa glucoside ( = (2S)-5-(β-D-glucopyranosyloxy)-6-hydroxyindoline-2-carboxylicacid; 1a) is prepared from betainin via a base exchange reaction.
Abstract: Cyclodopa glucoside ( = (2S)-5-(β-D-glucopyranosyloxy)-6-hydroxyindoline-2-carboxylicacid; 1a) is prepared from betainin (2a) via a base exchange reaction. Its purification and physical properties are described. The compound is N-formylated in dilute HCOOH solution. Cyclodopa glucoside is contained in considerable amount in redbeet juice varying from 0.07 to 1.9 mmol/kg or from 12 to 46% relative to teh content of betanin. Teh occurrence of free cyclodopa glucoside supports its role as intermediate in betanin biosynthesis.
44 citations
TL;DR: In this paper, the glucosyl group of aryl glucoside was transferred to an alcoholic hydroxyl group in high yield using a two-phase system consisting of water and an organic solvent immiscible with water.
Abstract: Lactase from Kluyveromyces lactis was found to have high transglucosylation activity, transferring the glucosyl group of aryl glucoside to an alcoholic hydroxyl group in high yield. Both primary and secondary alcohols can accept the glucosyl group. Transglucosylation to glycol yielded a single kind of glucoside. A very hydrophilic alcohol, such as glycerol, could not serve as a substrate in this system. Hydrophobic alcohols slightly soluble in water were glucosylated in a two-phase system consisting of water and an organic solvent immiscible with water.
40 citations
TL;DR: In this paper, the ability of the alkaloidal constituents to complex with divalent metal ions and phytosterols has been examined with a view to evaluating their significance in plant biochemistry.
39 citations
TL;DR: A malonyltransferase which catalyzes the malonylation of isoflavone 7-O-glucosides in position 6 of the glucose moiety using malonyL-coenzyme A as acyl donor has been purified 157-fold from 4-day-old roots of chick pea.
38 citations
TL;DR: The structure of an iridoid glucoside formerly designated as 5-epideoxyloganic acid, isolated from Nepeta cataria L., has been revised to (1R, 5R, 8S, 9S)-deoxyl Loganic Acid, which is renamed 1, 5, 9-epidoxyl Hoganic acid.
Abstract: On the basis of exhaustive 1H-and 13C-nuclear magnetic resonance (NMR) spectral studies and chemical transformations, the structure of an iridoid glucoside formerly designated as 5-epideoxyloganic acid, isolated from Nepeta cataria L., has been revised to (1R, 5R, 8S, 9S)-deoxyloganic acid, which is renamed 1, 5, 9-epideoxyloganic acid. The absolute configuration of this glucoside was established by its chemical conversion to an antipode of boschnialactone.
37 citations
TL;DR: The greatly restricted substrate specificity proposed the assignment of the enzyme to an exo-α-1,4-glucosidase as well as other catalytic properties, along with amino acid composition, are described in this report.
36 citations
TL;DR: EuCommiol and a new eucommiol glucoside (eucommioside II) were isolated from Aucuba japonica, besides known aucubin this paper.
TL;DR: In this article, two new glucosides 1 and 2 were isolated from a non-saponin fraction of a water extract of Red Ginseng (steamed ginseng root).
Abstract: Two new glucosides 1 and 2 were isolated from a non-saponin fraction of a water extract of Red Ginseng (steamed ginseng root). The structurs of the glucosides was elucidated by MS and by 1H and 13C NMR spectrometry. Neither glucoside was detected in White Ginseng, being artifacts formed during the processing of Red Ginseng. Since 2, an unstable epimeric mixture, is readily decomposed to give maltol, this glucoside must be an intermediate in the formation of maltol from maltose during the steaming process.
TL;DR: It is concluded that 7-hydroxyoxindole-3-acetic acid-glucoside is a natural metabolite of indole- 3-ACetic acid in Z. mays seedlings.
Abstract: Radiolabeled oxindole-3-acetic acid was metabolized by roots, shoots, and caryopses of dark grown Zea mays seedlings to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glycopyranoside with the simpler name of 7-hydroxyoxindole-3-acetic acid-glucoside. This compound was also formed from labeled indole-3-acetic acid supplied to intact seedlings and root segments. The glucoside of 7-hydroxyoxindole-3-acetic acid was also isolated as an endogenous compound in the caryopses and shoots of 4-day-old seedlings. It accumulates to a level of 4.8 nanomoles per plant in the kernel, more than 10 times the amount of oxindole-3-acetic acid. In the shoot it is present at levels comparable to that of oxindole-3-acetic acid and indole-3-acetic acid (62 picomoles per shoot). We conclude that 7-hydroxyoxindole-3-acetic acid-glucoside is a natural metabolite of indole-3-acetic acid in Z. mays seedlings. From the data presented in this paper and in previous work, we propose the following route as the principal catabolic pathway for indole-3-acetic acid in Zea seedlings: Indole-3-acetic acid --> Oxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid-glucoside.
TL;DR: In this paper, a colon-specific drug-delivery system for inflammatory bowel disease was proposed, based on the unique glycosidase activity of the colonic microflora.
Abstract: Steroid glycosides and the unique glycosidase activity of the colonic microflora form the basis of a new colon-specific drug-delivery system. Drug glycosides are hydrophilic and, thus, poorly absorbed from the small intestine. Once such a glycoside reaches the colon it can be cleaved by bacterial glycosidases, releasing the free drug to be absorbed by the colonic mucosa. This concept was illustrated with dexamethasone 21-beta-D-glucoside (1) and prednisolone 21-beta-D-glucoside (2), two prodrugs that may be useful in treating inflammatory bowel disease. Hydrolysis of the prodrugs by beta-glucosidase and fecal homogenates in vitro released the free steroids. Glucosides 1 and 2 were administered to rats intragastrically to determine when and where the free steroids were released. Unmodified dexamethasone (3) and prednisolone (4) were also given to rats intragastrically to compare absorption of the glucosides with the free steroids. Both glucosides were found to reach the rat lower intestine in 4-5 h, where they were rapidly hydrolyzed, releasing the free steroids. Delivery of steroid 3 (via glucoside 1) was more specific than that of steroid 4 (via glucoside 2): nearly 60% of an oral dose of glucoside 1 reached the cecum, whereas less than 15% of glucoside 2 reached the cecum. When free steroids 3 and 4 were administered orally, they were almost exclusively absorbed in the small intestine: less than 1% of an oral dose of each reached the cecum.
TL;DR: The lactonization step is of particular significance in providing a means of cleaving the p-menthane ring to afford an acyclic carbon skeleton that can be further degraded by modifications of the well-known beta-oxidation sequence.
Abstract: Previous studies have shown that the monoterpene ketone l-[G-3H] menthone is reduced to the epimeric alcohols l-menthol and d-neomenthol in leaves of flowering peppermint (Mentha piperita L.), and that a portion of the menthol is converted to menthyl acetate while the bulk of the neomenthol is transformed to neomenthyl-β-d-glucoside which is then transported to the rhizome (Croteau, Martinkus 1979 Plant Physiol 64: 169-175). Analysis of the disposition of l-[G-3H]menthone applied to midstem leaves of intact flowering plants allowed the kinetics of synthesis and transport of the monoterpenyl glucoside to be determined, and gave strong indication that the glucoside was subsequently metabolized in the rhizome. Studies with d-[G-3H]neomenthyl-β-d-glucoside as substrate, using excised rhizomes or rhizome segments, confirmed the hydrolysis of the glucoside as an early step in metabolism at this site, and revealed that the terpenoid moiety was further converted to a series of ether-soluble, methanol-soluble, and water-soluble products. Studies with d-[G-3H]neomenthol as the substrate, using excised rhizomes, showed the subsequent metabolic steps to involve oxidation of the alcohol back to menthone, followed by an unusual lactonization reaction in which oxygen is inserted between the carbonyl carbon and the carbon bearing the isopropyl group, to afford 3,4-menthone lactone. The conversion of menthone to the lactone, and of the lactone to more polar products, were confirmed in vivo using l-[G-3H]menthone and l-[G-3H]-3,4-menthone lactone as substrates. Additional oxidation products were formed in vivo via the desaturation of labeled neomenthol and/or menthone, but none of these transformations appeared to lead to ring opening of the p-menthane skeleton. Each step in the main reaction sequence, from hydrolysis of neomenthyl glucoside to lactonization of menthone, was demonstrated in cell-free extracts from the rhizomes of flowering mint plants. The lactonization step is of particular significance in providing a means of cleaving the p-menthane ring to afford an acyclic carbon skeleton that can be further degraded by modifications of the well-known β-oxidation sequence.
TL;DR: A new flavonol glycoside, gossypetin 8- O -rhamnoside, was isolated from flower petals of Gossypium arboreum and showed antibacterial activity against Pseudomonas maltophilia and Enterobacter cloacae.
TL;DR: A characteristic phenolic glucoside of the Apiaceae was isolated from anise seeds as mentioned in this paper, its structure was established as 4-(β-d -glucopyranosyloxy)benzoic acid.
TL;DR: Two new flavanone glycosides, liquiritigenin 4′-apiosyl(1 → 2)-glucoside and liquirigenin 7,4′-diglucosides together with a known flavone, apigenin 6,8-di-C -glucose, have been isolated from licorice as discussed by the authors.
TL;DR: In this paper, a new sinapic acid ester has been isolated and characterized as 1( E ),2( E )-di- O -sinapoyl-β-d -glucopyranoside from cotyledons of dark-grown red radish ( Raphanus sativus ) seedlings.
TL;DR: The structure of swertiaside, a new iridoid glucoside isolated from SWERTIA JAPONICA, was elucidated to be 7-epi-( M-hydroxybenzoyl)-loganicacid.
Abstract: The structure of swertiaside, a new iridoid glucoside isolated from SWERTIA JAPONICA, was elucidated to be 7-epi-( M-hydroxybenzoyl)-loganicacid.
TL;DR: Aus der Titelpflanze werden die neue Verbindung Periclymenosid (I) und die beiden bereits bekannten Bestandteile (I l) isoliert.
Abstract: Aus der Titelpflanze werden die neue Verbindung Periclymenosid (I) und die beiden bereits bekannten Bestandteile (I l) isoliert.
TL;DR: Two new lignan glucosides were isolated from the bark of Olea europaea subs africana by isolating (+)-1-acetoxypinoresinol 4″-methyl ether 4′-β- d -glucoside and (+-1-hydroxypinoreinol4′- β- d-gl glucoside.
TL;DR: The results provide evidence for a prominent role of indole-3-methanol and also for the occurrence of co-oxidation processes in wheat leaves involving indole -3-acetic acid and phenolic cosubstrates.
Abstract: Indole-3-methanol is a product of indole-3-acetic acid metabolism in wheat leaves (Triticum compactum Host., cv. Little Club). It leads either to the production of the corresponding aldehyde and carboxylic acid, to the production of a polar glucoside which releases indole-3-methanol on β-glucosidase treatment, or to an unidentified apolar product on mild alkaline hydrolysis in aqueous methanol. With reference to a published pathway of indole-3-acetic acid degradation, the results provide evidence for a prominent role of indole-3-methanol and also for the occurrence of co-oxidation processes in wheat leaves involving indole-3-acetic acid and phenolic cosubstrates.
TL;DR: The authors showed that iridoid glucosides of the suspension cultures are biosynthesized, after iridodial cation formation from 10-oxocitral (3), via 8-epiiridododial (13), 8-EPIiridotrial (14), boschnaloside (8-epIirIDotrial glucoside) (12), and dehydroiridoside (15) is conceivable.
TL;DR: From the root bark of Guettarda angelica, isolated 3- O -β- d -glucopyranosyl-quinovic acid and its aglycone, the root wood gave the same glucoside, rotundic acid, hederagenin and 3β,23dihydroxyurs-12-en-28-oic acid.
TL;DR: In this article, six methyl glucoside gallates (I-VI) were isolated, together with gallic acid 3-O-β-D-(6'-O-galloyl)-glucopyranoside (VII), from the undeground part of Sanguisorba officinalis.
Abstract: Six methyl glucoside gallates (I-VI) were isolated, together with gallic acid 3-O-β-D-(6'-O-galloyl)-glucopyranoside (VII), from the undeground part of Sanguisorba officinalis L On the basis of chemical and spectroscopic evidence, the structures of these compounds were established to be 6-O-gallate (1), 6-O-digallate (2), 4, 6-di-O-gallate (3), 2, 3, 6-tri-O-gallate (4), 3, 4, 6-tri-O-gallate (5) and 2, 3, 4, 6-tetra-O-gallate (6) of methyl β-D-glucopyranoside
TL;DR: The lactonization ofcamphor in sage resembles a similar step in the catabolism of camphor by microorganisms, but appears to be the first report of this reaction type in higher plants.
TL;DR: A new spiro-bis-γ-lactone glucoside was isolated from the leaves of Viburnum dilatatum and its structure was elucidated on the basis of spectral and chemical evidence.
TL;DR: The structure of a triterpene lactone, palustrolide, has been elucidated as 3β,23-dihydroxylupan-13β→28 lactone on the basis of physico-chemical studies as discussed by the authors.
TL;DR: A new acetylated coumarin glucoside has been isolated from the leaves of Viburnum suspensum and determined as 2′,6′- O -diacetylscopolin on the basis of spectral and chemical evidence.