Showing papers on "Glucoside published in 1999"
TL;DR: It is suggested that quercetin glucoside is actively absorbed from the small intestine, whereas quercettin rutinoside is absorbed fromThe colon after deglycosylation, suggesting that Absorption of other food components might also be enhanced by attachment of a glucose group.
Abstract: Flavonoids are antioxidants present in plant foods. They occur mainly as glycosides, i.e. linked with various sugars. It is uncertain to what extent dietary flavonoid glycosides are absorbed from the gut. We investigated how the nature of the sugar group affected absorption of one major flavonoid, quercetin. Quercetin linked with glucose, i.e. quercetin glucoside and quercetin linked with rutinose, i.e. quercetin rutinoside, both occur widely in foods. When we fed these compounds to nine volunteers, the peak concentration of quercetin (Cmax) in plasma was 20 times higher and was reached (Tmax) more than ten times faster after intake of the glucoside (Cmax = 3.5 ± 0.6 μM (mean ± SE); Tmax < 0.5 h) than after the rutinoside (Cmax = 0.18 ± 0.04 μM; Tmax = 6.0 ± 1.2 h). The bioavailability of the rutinoside was only 20% of that of the glucoside. We suggest that quercetin glucoside is actively absorbed from the small intestine, whereas quercetin rutinoside is absorbed from the colon after deglycosylation. Abso...
507 citations
TL;DR: The results showed that one or two tryptophan residues oxidized by N‐bromosuccinamide per enzyme molecule was sufficient to inhibit the enzyme activity completely, thus indicating that the tryptophile residues play an important role in the catalytical processes of the enzyme reaction.
Abstract: The beta-D-glucosidase produced by Thermomyces lanuginosus-SSBP was purified to apparent homogeneity. The purified enzyme consisted of two identical subunits with a native molecular mass of 200 kDa. The purified beta-D-glucosidase only hydrolysed the glucoside substrates containing a terminal, non-reducing beta-D-glucose residue and was active on both aryl-beta-glucoside and cellobiose. This enzyme also exhibited less, but significant alpha-D-glucosidase activity and was capable of hydrolysing beta-1,6-linked diglucosides and gentiobiose. The Kapp m, V(max) and k(cat) values for p-nitrophenyl-beta-D-glucopyranoside were calculated to be 0.075 mM, 12.12 units/mg of protein and 44.44 glucose molecules released/s respectively. The beta-D-glucosidase retained its full activity after a 30 min incubation at 50 degrees C but was inactive after the same treatment at 70 degrees C. The enzyme appeared to be stable when the pH of the storage buffer was above 5.0. Maximal beta-D-glucosidase activity occurred at 65 degrees C and pH 6.0. This enzyme was competitively inhibited by glucose, cellobiose and salicin with K(i) values of 0.55, 0.52 and 0.81 mM respectively. The presence of Hg(2+) and N-bromosuccinimide inhibited the enzyme activity completely at 2 mM, while cysteine enhanced beta-D-glucosidase activity.
151 citations
TL;DR: Polyphenol-rich fractions of Cowania mexicana and Coleogyne ramosissima showed significant inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) and were found to exhibit anti-tumor promoting activity in two-stage mouse skin carcinogenesis using 7,12-dimethylbenz[a]anthrac
80 citations
Journal Article•
TL;DR: UV filter biosynthesis appears to be activated at or near birth, and in the lens, the newly formed double bond is rapidly reduced through this deamination-reduction process.
Abstract: Purpose To investigate UV filter synthesis in the human lens, in particular the biosynthetic origin of the second most abundant UV filter compound, 4-(2-amino-3-hydroxyphenyl)-4-oxobutanoic acid O-beta-D-glucoside. Methods Human lenses were analyzed by high-performance liquid chromatography (HPLC) after separate incubation with 3H-tryptophan (3H-Trp), beta-benzoylacrylic acid, D,L-alpha-amino-beta-benzoylpropionic acid, or D,L-3-hydroxykynurenine O-beta-D-glucoside. The effect of pH on the model compound D,L-alpha-amino-beta-benzoylpropionic acid and D,L-3-hydroxykynurenine O-beta-D-glucoside was also investigated. Results UV filters were not detected in fetal lenses, despite a 5-month postnatal lens displaying measurable levels of UV filters. In adults no radiolabel was incorporated into 4-(2-amino-3-hydroxyphenyl)-4-oxobutanoic acid O-beta-D-glucoside after 3H-Trp incubations. Beta-benzoylacrylic acid was readily reduced in lenses. D,L-alpha-amino-beta-benzoylpropionic acid and D,L-3-hydroxykynurenine O-beta-D-glucoside slowly deaminated at physiological pH and were converted to beta-benzoylpropionic acid and 4-(2-amino-3-hydroxyphenyl)-4-oxobutanoic acid O-beta-D-glucoside, respectively, after lens incubations. Conclusions UV filter biosynthesis appears to be activated at or near birth. Compounds containing the kynurenine side chain slowly deaminate, and in the lens, the newly formed double bond is rapidly reduced. These findings suggest that 4-(2-amino-3-hydroxyphenyl)-4-oxobutanoic acid O-beta-D-glucoside is derived from L-3-hydroxykynurenine O-beta-D-glucoside through this deamination-reduction process. The slowness of the deamination presumably accounts for the absence of incorporation of radiolabel from 3H-Trp into 4(2-amino-3-hydroxyphenyl)4-oxobutanoic acid O-beta-D-glucoside.
67 citations
TL;DR: Four norterpenoid glucosides have been characterized along with a sesquiterpenoid glucose glucoside from the aerial parts of Juniperus phynicea and Galega officinalis and a rare norter penoids are identified: dearabinosyl pneumonanthoside and 6-hydroxy-junipeionoloside are new natural products.
50 citations
TL;DR: The method described, which is the first allowing the direct synthesis of aromatic acid esters of flavonoid glucoside, can be applied to the acylation of other glucosides, including naringin, rutin, callistephin, and chrysanthemin.
49 citations
TL;DR: It is confirmed that mammalian cytosolic beta-glucosidase can deglycosylate some, but not all, common dietary flavonoid glycosides.
46 citations
TL;DR: From the aerial parts of Hieracium gymnocephalum the new triterpene, 21α-hydroxy-taraxasterol and flavone diglycosides luteolin 7-O-α- l -rhamnosyl(1→6)-β- d -glucoside and lutesylosyl( 1→6- β- d-glucOSide were isolated, as well as further common triterpenes, phenolic acids
44 citations
TL;DR: A DNA polymerase beta (pol. beta) inhibitor has been isolated independently from two organisms; a red perilla, Perilla frutescens, and a mugwort, Artemisia vulgaris, and it was found that the fatty acid allowed easier access of the compound to the substrate-binding site.
Abstract: A DNA polymerase beta (pol. beta) inhibitor has been isolated independently from two organisms; a red perilla, Perilla frutescens, and a mugwort, Artemisia vulgaris. These molecules were determined by spectroscopic analyses to be the cyanogenic glucoside, D-mandelonitrile-beta-D-glucoside, prunasin. The compound inhibited the activity of rat pol. beta at 150 microM, but did not influence the activities of calf DNA polymerase alpha and plant DNA polymerases, human immunodefficiency virus type 1 reverse transcriptase, calf terminal deoxynucleotidyl transferase, or any prokaryotic DNA polymerases, or DNA and RNA metabolic enzymes examined. The compound dose-dependently inhibited pol. beta activity, the IC(50) value being 98 microM with poly dA/oligo dT(12-18) and dTTP as the DNA template and substrate, respectively. Inhibition of pol. beta by the compound was competitive with the substrate, dTTP. The inhibition was enhanced in the presence of fatty acid, and the IC(50) value decreased to approximately 40 microM. In the presence of C(10)-decanoic acid, the K(i) value for substrate dTTP decreased by 28-fold, suggesting that the fatty acid allowed easier access of the compound to the substrate-binding site.
42 citations
TL;DR: In this article, the potential for flavour glycosides to be hydrolysed in the mouth during consumption has been investigated and it was shown that about 10% (0.2 µg) of the glucoside was hydrolyzed over a 2-min period due to the activity of glucosidase enzymes from the oral microflora.
41 citations
TL;DR: Anisoflavonoid glucoside was isolated from the seeds of Thai Rosewood (Dalbergiacochinchinensis Pierre), and the aglycone was shown to be 12-dihydroamorphigenin, which was named dalcochinin this paper.
TL;DR: In this article, a new approach to the preparation of dimeric (gemini) and trimeric sugar fatty acid esters has been developed, which is shown that immobilized Candida antarctica lipase (Novozyme) readily catalyzes acylation of 1,2:3,4-di-O-isopropylidene -D- galactopyranose and methyl-α-D- glucopyranoside with 2-bromomyristic acid, with the reaction rate being about three times slower than that observed with my
TL;DR: D-fructose 6-phosphate seems to be the precursor of furaneol in strawberries since, when present in the incubation medium, it produced an average increase of 125% in all furanones contents with respect to control fruits.
Abstract: The biosynthesis of 2,5-dimethyl-4-hydroxy-3(2H)-furanone (Furaneol) and its methyl ether and glucoside derivatives has been studied in strawberries. An in vitro system was used for growing this fruit, showing that the presence in the incubation medium of sucrose or hydroxyquinoline hemisulfate has no effect on the bioformation of these compounds. Strawberries in vitro grown showed an increase in furanone content with time, especially between the second and fourth days, to the same extent as field-grown fruits but at a higher rate. Among the precursors added to the incubation medium, D-fructose gave rise to an increase in furaneol and its glucoside derivative of 42. 6% and 26.3%, respectively. D-fructose 6-phosphate seems to be the precursor of furaneol in strawberries since, when present in the incubation medium, it produced an average increase of 125% in all furanones contents with respect to control fruits.
TL;DR: Distribution of pigments in the reaction center (RC) complex, chlorosomes and chlorosome-free membranes prepared from the green sulfur bacterium, Chlorobium tepidum, was analyzed and dihydrochlorobactene was decreased compared with cellular carotenes.
Abstract: Distribution of pigments in the reaction center (RC) complex, chlorosomes and chlorosome-free membranes prepared from the green sulfur bacterium, Chlorobium tepidum, was analyzed. The RC complex contained approximately 40 molecules of bacteriochlor ophyll (BChl) a per P840, half of which are estimated to be in the Fenna-Matthews-Olson (FMO) protein. Carotenes (2 molecules per P840) occupied only one third of the total carotenoids. The remaining carotenoids (4 to 5 molecules per P840) were OH-chlorobactene glucoside ester and OH-/-carotene glucoside ester. Dihydrochlorobactene was decreased compared with cellular carotenes. Furthermore, approximately 9 C670 and 1 menaquinone-7 per P840 were also found. BChl c and carotenes, whose major component is chlorobactene, were found mainly in chlorosomes, and two kinds of carotenoid glucoside esters were observed in chlorosome-free membranes.
TL;DR: An extract from the entire Ixeris denticulata f.
TL;DR: In this paper, two new isoflavonoid biosides, tectorigenin 4′-glucosyl (1→6) glucoside and iristectorigin B 7-glocosyl(1→ 6)glucose, were isolated from rhizomes of Iris carthaliniae and determined by NMR spectral analysis.
TL;DR: The structures of a new xanthone- O -glycoside, polycaudoside A, together with 2′-benzoylmangiferin, 1-methoxy-7-hydroxyxanthone, 1,2,8-trihydroxyXanthone and wubangziside are established on the basis of chemical studies and spectral evidence, including 2D NMR analyses.
TL;DR: The hexane extract of Nepeta nuda ssp albiflora led to the isolation of six known monoterpene nepetalactones, 4aa,7a,7aa-nepetalactone (1),4aa, 7a, 7aa -nepeteractone(2), 4ab,7b, 7ab-nepsetalactic acid (3), 4aa-7a-7ab-neptalic acid (4), 4a-5,9-dehydronepetal
Abstract: The hexane extract of Nepeta nuda ssp. albiflora led to the isolation of six known monoterpene nepetalactones, 4aa,7a,7aa-nepetalactone (1), 4aa,7a,7ab-nepetalactone (2), 4ab,7a,7ab-nepetalactone (3), 4ab,7a,7aa-nepetalactone (4), 4aa,7b,7ab-nepetalactone (5), 3a-hydroxy-4aa,7a,7aa-dihydron\-epe\-tal\-actone (=nepetalic acid) (6) and a dimeric 5,9-dehydronepetalactone (7) along with two known steroids b-sitosterol and sitosterol 3-one and a triterpene betulinic acid. The acetone extract of the same plant afforded compound 7 in a higher yield in addition to compounds 2 and 6, and sesquiterpene caryophyllene oxide, the iridoid glucoside 1,5,9-epideoxyloganic acid, the triterpenoids oleanolic, ursolic and betulinic acids, and sitosterol 3b-glucoside.
TL;DR: Red pigments formed from geniposide and amino acids, contained in the fruit of Gardenia jasminoides Ellis, were studied and considered to be of low toxicity.
Abstract: Red pigments formed from geniposide and amino acids were studied. Geniposide, the principal iridoid glucoside contained in the fruit of Gardenia jasminoides Ellis, was hydrolysed to geniposidic acid as a precursor for the pigment. The pigments prepared anaerobically with arginine or glutamic acid under acidic conditions with a large excess of citric acid, were reddish purple and had properties governed by the electrostatic character of the amino acid. Relative molecular masses of these pigments were determined to be several thousand by gel filtration. The pigments showed good stability to heat and pH, but were gradually bleached by light. The safety of the pigments was evaluated by studing their oral acute and the 5-month oral toxicity of arginine-red pigment using mice. The pigments were considered to be of low toxicity.
TL;DR: Two new phenolic glucosides, a new γ-lactone glucoside, and adenosine were isolated from the sprouts of Crocus sativus and all structures were elucidated on the basis of chemical and spectroscopic evidence.
Abstract: Two new phenolic glucosides, a new γ-lactone glucoside, and adenosine
were isolated from the sprouts of Crocus sativus
L. The new compounds were characterized as 2,4- dihydroxy-6-methoxyacetophenone-2β-D-glucopyranoside
(1), 2,3,4-trihydroxy-6-methoxyacetopenone-3-β-D-glucopyranoside
(2) and 3-(S)-3-β-D-glucopyranosyloxybutanolide
(3), respectively. All structures were elucidated on
the basis of chemical and spectroscopic evidence.
TL;DR: Three new flavonoids have been identified in the aerial parts of Mentha longifolia, identified as tricetin 7- O -methylether 3′- O glucoside 5′-O -rhamnoside 4→4)-tricetin and tricetsyl-(1→ 4)-ramnoside.
TL;DR: It is shown that deuterium labelled 6-deoxyretzioside was incorporated into stilbericoside in Thunbergia alata, indicating that this is also a likely intermediate in the biosynthetic pathway.
TL;DR: Fushioside, a new phenylethanoid glucoside, 2-(3, 4-dihydroxyphenyl)ethyl 6-O-protocatechuoyl-β-D-glucopy-ranoside was isolated from the methanolic extract of the aerial parts of Veronica fuhsii.
Abstract: Fushioside, a new phenylethanoid glucoside, 2-(3, 4-dihydroxyphenyl)ethyl 6-O-protocatechuoyl-β-D-glucopy-ranoside was isolated from the methanolic extract of the aerial parts of Veronica fuhsii along with a known phenylethanoid glycoside, plantamajoside, and a flavone glucoside, luteolin 7-O-glucoside.
TL;DR: In this article, the transformed roots of Campanula glomerata L. var. dahurica Fish, induced by infection with Agrobacterium rhizogenes MAFF 03-01724, produced the anthocyanins cyanidin 3-glucoside and cyanide 3-rutinoside, a flavonoid rutin and a phenylpropanoid glucoside coniferin, together with the polyacetylene constituents lobetyol, lobetyolin and lobetyinin.
TL;DR: The data indicate that a glucosidase specific for DIMBOA-G comes into contact with constitutive benzoxazinone glucosides producing defensive aglycone when plants are damaged by microbial or insect attacks.
Abstract: Occurrence and properties of hydroxamic acid glucoside glucosidase were investigated in 10-day-old, autotrophic maize (Zea mays L.) in which 2,4-dihydroxy-7-methoxy-1,4- benzoxazin-3-one glucoside (DIMBOA-G) is a major benzoxazinone component. Crude extracts of both leaves and roots showed glucosidase activity for both DIMBOA-G and 2,4- dihydroxy-1,4-benzoxazin-3-one glucoside (DIBOA-G). A cation-exchange chromatography after cryoprecipitation of the extract from leaves gave a peak with both activities, and further purification by ion-exchange and hydroxyapatite chromatography gave a fraction with an apparent homogeneity, the purification being 560 fold. The Km values (mᴍ) of the purified glucosidase were 0.16 for DIMBOA-G, 0.68 for DIBOA-G and 2.96 for p-nitrophenyl-β-ᴅ-glucopyranoside. The activity on salicin and esculin was too low to be detected. The data indicate that a glucosidase specific for DIMBOA-G comes into contact with constitutive benzoxazinone glucosides producing defensive aglycone when plants are damaged by microbial or insect attacks.
TL;DR: Two new flavonoid glycosides, (2S)-5-hydroxy-7, 3'-dimethoxyflavanone-4'-O-beta-[apiosyl (1 --> 2)]glucoside (1) and rhamnazin-4'O- beta-[apioyl ( 1 --> 2]glucOSide (2) were isolated from Viscum alniformosanae.
Abstract: Two new flavonoid glycosides, (2S)-5-hydroxy-7, 3'-dimethoxyflavanone-4'-O-beta-[apiosyl (1 --> 2)]glucoside (1) and rhamnazin-4'-O-beta-[apiosyl (1 --> 2)]glucoside (2) were isolated from Viscum alniformosanae. Structures were elucidated by NMR and mass spectroscopic analysis.
TL;DR: It is clear that ethanol cannot be considered as an inert solvent for these cell cultures, and one new major compound was observed, which was isolated and identified by its spectral data as 1-O-ethyl-β-glucopyranoside.
Abstract: To study the stress and defense response of plant cell cultures of Ilex paraguariensis St. Hil., methyl jasmonate, salicylic acid, and cellulase were added, with ethanol and water used as controls. Comparison of methanolic extracts of the treated cells showed a clear decrease in the carbohydrate content of the cells relative to the controls. One new major compound was observed, which was isolated and identified by its spectral data as 1-O-ethyl-β-glucopyranoside. This compound was found especially in the cells treated with methyl jasmonate and salicylic acid, which were both dissolved in ethanol. Addition of ethanol alone also resulted in the formation of the glucoside. Addition of methanol lead to the formation of the corresponding glucoside, while n-propanol addition resulted in only a small amount of the propyl glucoside; with n-butanol, n-octanol, and n-decanol, the corresponding glucosides could not be observed. Cell growth was severely affected by addition of the higher alcohols. From the present study, it is clear that ethanol cannot be considered as an inert solvent for these cell cultures.
TL;DR: An oviposition stimulant for the cerambycid beetle, Monochamus alternatus, from an aqueous acetone extract of inner bark of Pinus densiflora, was identified as a flavanonol glucoside, (-)-2,3-trans-dihydroquercetin-3'-O-β-D-glucopyranoside.
Abstract: An oviposition stimulant for the cerambycid beetle, Monochamus alternatus, from an aqueous acetone extract of inner bark of Pinus densiflora, was identified as a flavanonol glucoside, (-)-2,3-trans-dihydroquercetin-3'-O-β-D-glucopyranoside. Two dimeric proanthocyanidins, along with polymeric proanthocyanidins, were also isolated from the extract and identified as procyanidins B-1 [epicatechin-(4 β→ 8')-catechin] and B-3 [catechin-(4α→ 8')-catechin]. In the presence of a fraction of the extract, a mixture of the polymers and either B-1 or B-3 stimulated oviposition of the female beetle. However, the glucoside, B-I, B-3 and the polymers were inactive alone.
TL;DR: Arbutin was newly found in the leaves of shirakamba, and its structures were indentified as betuloside, 3,4′-dihydroxy-propiophenone-3-β-d-glucopyranoside, salidroside, and arbutin.
Abstract: The extractive of shirakamba (Betula platyphylla Sukatchev var.japonica Hara) leaves was investigated. Four glucosides ofp-hydroxyphenyl derivatives were isolated, and their structures were indentified as betuloside (I), 3,4′-dihydroxy-propiophenone-3-β-d-glucopyranoside (II), salidroside (III), and arbutin (IV). Arbutin was newly found in the leaves of shirakamba.
TL;DR: Hydramacrosides A and B exhibited an inhibitory effect on histamine release from rat mast cells induced by an antigen-antibody reaction.
Abstract: Following the characterization of dihydroisocoumarin constituents, two secoiridoid glucoside complexes, called hydramacrosides A and B, were isolated from the leaves of Hydrangea macrophylla SERINGE var. thunbergii MAKINO. The absolute stereostructures of hydramacrosides A and B were elucidated on the basis of chemical and physicochemical evidence, which included the application of the 13C-NMR glycosylation shift rule of 1, 1'-disaccharides and the modified Mosher's method. Hydramacrosides A and B exhibited an inhibitory effect on histamine release from rat mast cells induced by an antigen-antibody reaction.