Showing papers on "Glucoside published in 1990"
TL;DR: The definite structure and chemical stability of a new glucoside of L-ascorbic acid (AA) which was enzymatically glucosylated with rat intestinal and rice seed alpha-glucosidases were reported.
Abstract: The definite structure and chemical stability of a new glucoside of L-ascorbic acid (AA) which was enzymatically glucosylated with rat intestinal and rice seed alpha-glucosidases were reported. The stability of this AA derivative in water under aerobic conditions was proved by its remarkable resistance against enhanced oxidative degradation by heat, Cu2+ ion or ascorbate oxidase, and it was found to have no reducing activity toward radicals. These properties were obviously distinguishable from those of AA. This glucoside was effectively hydrolyzed by alpha-glucosidases which possessed the ability to synthesize itself, resulting in the liberation of AA activity. The conjugate was composed of equimoles of AA and glucose. Nuclear magnetic resonance spectra, mass spectra, pH profiles of ultraviolet spectra and pK(a) value of 3.10 supported the coupling of alpha-glucose to the 2-position of AA. From these results, its structure was assigned 2-O-alpha-D-glucopyranosyl-L-ascorbic acid, being distinct from 6-O-alpha-D-glucopyranosyl-L-ascorbic acid formed with Aspergillus niger alpha-glucosidase. These findings indicate that the 2-O-glucoside formed by regioselective transglucosylation withstands oxidative degradation even in aqueous solutions and it can be used as an available active AA source for multicomponent liquid products.
119 citations
TL;DR: It is concluded that mammalian α-glucosidase is able to form a very stable and nonreducing form of glucosylated AA through a specific transGLucosylation reaction distinct from that of microbial α- glucOSidase.
113 citations
TL;DR: The structure of Hellicoside was deduced from chemical and spectral evidence to be 3,4,7-trihydroxy-β-phenethyl-O -β-d -glucopyranosyl-(1 → 3)-4- O -caffeoyl-β-, d -glocopyranoide as discussed by the authors.
76 citations
TL;DR: The amounts of p-hydroxybenzoic acid glucoside, picein, catechin and cell wall-bound ferulic acid were considerably reduced in mycorrhizas from axenic culture, whereas the hydroxystilbenes piceatannol, its glucosides and worhapontin were not significantly reduced.
Abstract: The occurrence and amount of soluble and insoluble phenolics in mycorrhizal and non-mycorrhizal roots of Picea abies (L.) Karst, were investigated, p-Hydroxybenzoic acid glucoside, picein, piceatannol and its glucoside, isorhapontin, catechin and ferulic acid could be identified by high-performance liquid chromatography in mycorrhizas of Picea abies-Lactarius deterrimus and Picea abies-Laccaria amethystea. Both types were collected from axenic cultures and the latter also from a spruce stand. The same phenolics occurred in non-mycorrhizal short roots from sterile cultures. However, the amounts of p-hydroxybenzoic acid glucoside, picein, catechin and cell wall-bound ferulic acid were considerably reduced in mycorrhizas from axenic culture, whereas the hydroxystilbenes piceatannol, its glucoside and worhapontin were not significantly reduced. Pure mycelia of Laccaria amethystea (Bull.) Murr, and Lactarius deterrimus Groger were also analysed for phenolic compounds. Both fungal species contained none of the identified phenolics. The results are discussed with respect to mycorrhization in different mycorrhizal types.
59 citations
TL;DR: The fungus Cunninghamella elegans ATCC 36112 formed predominantly glucoside conjugates of the phenolic derivatives of FA, which suggests that this fungus has the potential to detoxify FA.
Abstract: The fungus Cunninghamella elegans ATCC 36112 metabolized approximately 80% of the 3-14C-labeled fluoranthene (FA) added within 72 h of incubation. C. elegans metabolized FA to trans-2,3-dihydroxy-2,3-dihydrofluoranthene (trans-2,3-dihydrodiol), 8- and 9-hydroxyfluoranthene trans-2,3-dihydrodiol, 3-fluoranthene-beta-glucopyranoside, and 3-(8-hydroxyfluoranthene)-beta-glucopyranoside. These metabolites were separated by thin-layer and reversed-phase high-performance liquid chromatography and identified by 1H nuclear magnetic resonance, UV, and mass spectral techniques. The major pathway involved hydroxylation to form a glucoside conjugate of 3-hydroxyfluoranthene and a glucoside conjugate of 3,8-dihydroxyfluoranthene which together accounted for 52% of the total ethyl acetate-soluble metabolites. C. elegans initially metabolized FA in the 2,3 position to form fluoranthene trans-2,3-dihydrodiol, which has previously been shown to be a biologically active compound in mammalian and bacterial genotoxicity tests. However, C. elegans formed predominantly glucoside conjugates of the phenolic derivatives of FA, which suggests that this fungus has the potential to detoxify FA.
59 citations
TL;DR: Cultured cells of Mallotus japonicus converted exogenous o -hydroxybenzoic acid into its O -glucoside after a lag period of 8 hr during which time the aglycone was taken up rapidly by the cells, partly excreted and then re-absorbed.
47 citations
TL;DR: The enzymatic transglucosylation to synthesize a chemically stable form of l-ascorbic acid (AA) was further investigated by using commercially available enzymes, which allowed for a sufficient amount of AA-2G with ric...
Abstract: The enzymatic transglucosylation to synthesize a chemically stable form of l-ascorbic acid (AA) was further investigated by using commercially available enzymes. Among various glycosidases examined, only rice seed α-glucosidase could produce a nonreducing and stable glucoside of AA, which was identified as 2-O-α-d-glucopyranosyl-l-ascorbic acid (AA-2G). The enzyme showed the same regioselective transglucosylase activity as rat intestinal α-glucosidase that had been demonstrated by us to be effective in this reaction, although these two enzymes had different pH optima for maltose hydrolysis. The substrate specificity of rice α-glucosidase for AA-2G formation was considerably different from that of rat α-glucosidase. However, both α-glucosidases had high specificity for the α-1,4-glucosidic linkage but not α-1,6, suggesting that they can catalyze a preferential transglucosylation to the 2-position but not to the 6-position of AA. Thus, these results allows us to produce a sufficient amount of AA-2G with ric...
43 citations
TL;DR: In this article, two new phenyl glucosides, 5-(3′-glucosyl)benzoyloxygentisic acid and 2,6-dimethoxy-4-hydroxyphenol 1-glocoside were isolated together with 1-sinapoyl glucoside from the hairy roots of Swertia japonica.
37 citations
TL;DR: In this paper, a number of β-d-glucosides were isolated from sour cherry fruit pulp by liquid chromatography, after per-O-methylation, by comparison of HRGC, HRGC-MS and HRGCFTIR data with those of authentic β- d-glocosides synthesized under modified Koenigs-Knorr conditions.
34 citations
TL;DR: A new bitter acylsecoiridoid glucoside, rindosides, has been isolated from rhizomes and roots of GENTIANA SCABRA var.
Abstract: A new bitter acylsecoiridoid glucoside, rindoside, has been isolated along with a known iridoid glucoside, loganic acid, from rhizomes and roots of GENTIANA SCABRA var. BUERGERI. The structure of rindoside was established by chemical and spectral evidence.
28 citations
TL;DR: Boscialin (1), a new compound structurally related to the ionones and abscisic acid, and its 4′-O-glucoside 2 were isolated from the MeOH extract of the leaves of the African medicinal plant Boscia salicifolia as discussed by the authors.
Abstract: Boscialin (1), a new compound structurally related to the ionones and abscisic acid, and its 4′-O-glucoside 2 were isolated from the MeOH extract of the leaves of the African medicinal plant Boscia salicifolia. The structures of the two compounds were determined mainly by NMR spectroscopy and by acid hydrolysis of the glycoside.
TL;DR: The results observed here suggest that an alternate process, possibly involving intestinal microorganisms, may also be involved in the in vivo hydrolysis of pyridoxine glucoside.
Abstract: Research was conducted to evaluate the ability of a broad-specificity beta-glucosidase in mammalian tissues to catalyze the hydrolytic release of free pyridoxine from pyridoxine-5'-beta-D-glucoside, a naturally occurring form of vitamin B6 in plant-derived foods. Activity was detected in liver and intestinal mucosa using tritiated pyridoxine glucoside as a substrate. In the rat and guinea pig, enzyme activity was greater in intestine than in liver or kidney while even greater activity was detected in human intestinal tissue. Reaction rates were, however, low in all tissues. Hydrolysis of the synthetic substrate 4-methylumbelliferyl-beta-D-glucoside was also greatest in intestinal tissue. The characteristics of the enzymatic hydrolysis of pyridoxine glucoside to pyridoxine included: (i) most activity in the soluble tissue fraction, (ii) a pH optimum of approximately 6.0, and (iii) inhibition caused by the addition of sodium taurocholate. These characteristics are very similar to those of the broad-specificity beta-glucosidase in mammalian tissues with respect to the hydrolysis of a variety of naturally occurring and synthetic substrates. The apparent Km was greater than 2 mM for pyridoxine glucoside hydrolysis by intestinal preparations of each species, which is much greater than expected intestinal concentrations derived from dietary sources. In vivo studies have indicated that the intestine is involved in the metabolic utilization of dietary pyridoxine glucoside. The results observed here suggest that an alternate process, possibly involving intestinal microorganisms, may also be involved in the in vivo hydrolysis of pyridoxine glucoside.
TL;DR: A new coumarin glucoside ester, palustroside, together with two known glucosides fraxin and esculin were isolated from the aerials parts of Ledum palustre.
TL;DR: Menisdaurin this paper is a putative dihydromandelonitrile glucoside derived from the ripe fruits of Ilex aquifolium, which was later revised as (Z)-1-cyanomethylene-4R-hydroxy-6S-(β- d -glucopyranosyloxy)-2- cyclohexene known as menisdaurusin.
TL;DR: In this article, from the stem of Plrunus davidiana, naringenin and its glucoside, kaempferol and its corresponding glucosides, dihydrokaempferols and its derivatives, hesperetin, quercetin, d-catechin, β-sitosterol and β-glucoside were isolated.
Abstract: From the stem ofPrunus davidiana, naringenin and its glucoside, kaempferol and its glucoside, dihydrokaempferol, kaempferide glucoside, hesperetin glucoside, quercetin glucoside, d-catechin and β-sitosterol glucoside were isolated.
TL;DR: It was suggested that the constitutive production of cellobiase by T. clypeatus was under catabolic repression and CH probably released the repression to some extent and CH appeared not to improve enzyme titer by repressing any proteinase or stabilizing enzyme activity liberated in CH-free medium.
TL;DR: A new anthraquinone glycoside has been isolated from the roots of Rhamnus formosana together with methyllinoleate, chrysophanol, physcion, β-sitosterol, emodin, frangulin B, and stigmasterol-β- d -glucoside as discussed by the authors.
TL;DR: In this paper, a new phenolic glycoside was isolated from Hypoxis obtusa, together with the known compounds acuminoside, hypoxoside and nyasoside.
TL;DR: In this paper, a new constituent of a leaf extract of Mentha arvensis L. var. piperascens Malinv. was identified and its structure was confirmed by 13C-NMR.
Abstract: l-Menthyl-6′-O-acetyl-β-D-glucoside has been isolated and characterized as a new constituent of a leaf extract of “Wasenami,” a Japanese cultivar of Mentha arvensis L. var. piperascens Malinv. Its structure was confirmed by 13C-NMR. β-Sitosteryl-β-D-glucoside and l-menthyl-β-D-glucoside were also isolated and characterized along with the 6′-O-acetyl derivative.
TL;DR: A pronounced selectivity for the formation and/or urinary excretion of the phenobarbital N-glucosides is indicated and was comparable in both Caucasian and Oriental subjects.
TL;DR: In this paper, a chemical examination of the tannin ingredients in the leaves of the wood oil tree, Aleurites fordii HEMSLEY (Euphorbiaceae), has led to the isolation of three new ellagitannins named aleurinins A (4), B(5) and C(6), together with corilagin (1), geraniin (2) and chebulagic acid (3).
Abstract: A chemical examination of the tannin ingredients in the leaves of the wood oil tree, Aleurites fordii HEMSLEY (Euphorbiaceae), has led to the isolation of three new ellagitannins named aleurinins A (4), B(5) and C(6), together with corilagin (1), geraniin (2) and chebulagic acid (3). on the basis of chemical and spectroscpic evidence, the structures of aleurinins A (4) and B (5) have been established as ellagitannins possessing a novel cyanopropylene alcohol glucoside core, while aleurinin C (6) has been characterized as an ellagitannin based on a hydroxyacetone glucoside core.
TL;DR: A new glycoside, 6-O -β- d -glucopyranosyloxy-3-hydroxy- p -menth-1-ene, and two known compounds, o -coumaroylglucose and 5- O -feruloylquinic acid, have been isolated from the butanolic extract of Eupatorium tinifolium and identified on the basis of chemical and spectral data as discussed by the authors.
TL;DR: The formation of acyl glucuronide and glucoside of 2-(5H-[1]benzopyrano[2,3-b]pyridin-7-yl)propionic acid (pranoprofen), an anti-inflammatory drug, was studied in homogenates and microsomes of mouse tissues by using S(+)-, R(-)- and RS(+/-)-praniprofen.
Abstract: The formation of acyl glucuronide and glucoside of 2-(5H-[1]benzopyrano[2,3-b]pyridin-7-yl)propionic acid (pranoprofen), an anti-inflammatory drug, was studied in homogenates and microsomes of mouse tissues by using S(+)-, R(-)- and RS(+/-)-pranoprofen. Acyl glucuronidation occurred mainly in the liver, whereas acyl glucosidation was predominant in the kidney. Furthermore, both conjugations occurred by enzymatic transfer of glucuronic acid of uridine diphosphate glucuronic acid (UDPGA) and glucose of uridine diphosphate glucose (UDPG) to pranoprofen, respectively. No conjugation reactions were observed in the lung, plasma or gut. The amount of conjugates in the liver and kidney increased by the prolongation of the incubation times and reached the maximum at 15-30 min for glucuronidation and 45 min for glucosidation. After that, both conjugates decreased with the lapse of time. Both acyl conjugates were the least stable in the liver, then in the kidney and the most stable in the plasma. In the liver, acyl glucoside was converted to acyl glucuronide and pranoprofen in the presence of UDPGA, but only a small amount of acyl glucuronide was changed to acyl glucoside in the kidney in spite of the presence of UDPG. In the kidney, acyl glucoside decreased relative to acyl glucuronide at increasing doses for both S(+)- and R(-)-pranoprofen, but the concentration of acyl glucoside was much higher for S(+)-pranoprofen than R(-)-enantiomer 1 h after the oral administration of S(+)- and R(-)-pranoprofen. No acyl glucoside was detected in the liver and plasma. Although only a small difference in acyl glucuronidation in the liver was observed between S(+)- and R(-)-enantiomers, acyl glucosidation in the kidney occurred more predominantly for S(+)-pranoprofen than for the R(-)-enantiomer.
TL;DR: A new flavonol glycoside present in aerial parts of the fern Asplenium septentrionale has been identified as kaempferol 3-sophoroside-4′-glucoside by chemical and spectroscopic methods.
Dissertation•
11 Jun 1990
TL;DR: There was a strong inverse relationship between percent pyridoxine glucoside and bioavailability for six of the ten foods, however, wheat bran and shredded wheat had negative bioavailability while the two crucifers, broccoli and cauliflower, had high bioavailability despite a high percentage of pyrIDoxineglucoside.
Abstract: approved: DKJan J mes E. Leklem To test the hypothesis that vitamin B-6 bioavailability is inversely correlated with percent vitamin B-6 as pyridoxine glucoside, the bioavailability of vitamin B-6 in ten plant foods was assessed. Nine men, aged 20-33 yrs, were fed a constant diet (3.2 mg of B-6) for 49 days. Incremental 24-hr urinary 4-pyridoxic (4-PA) acid excretion in response to test doses of pyridoxine or test foods fed in addition to the basal diet was used to estimate the vitamin B-6 bioavailability. The percent bioavailability calculated from the urinary 4-PA excretion after the pyridoxine doses was: walnuts, 87; bananas, 60; tomato juice, 43; wheat bran, -46; shredded wheat, -23; spinach, 17; orange juice, 19; broccoli, 62; cauliflower, 56; and carrots, 1. There was a strong inverse relationship between percent pyridoxine glucoside and bioavailability for six of the ten foods (R = -.94, p < 0.01). However, wheat bran and shredded wheat had negative bioavailability while the two crucifers, broccoli and cauliflower, had high bioavailability despite a high percentage of pyridoxine glucoside. To evaluate different methods of in vitro measurement of bioavailable vitamin B-6 and to determine which method best predicted vitamin B-6 bioavailability measured in the feeding experiment, the ten plant foods were assayed by three different procedures. The first two methods quantified pyridoxine glucoside by a differential growth assay using S. uvarum after prior incubation with or without B-glucosidase. Pyridoxine glucoside content was lower (p<0.005) when measured by the first method which used cold buffer extraction than when measured by the second method which used hot water extraction of the foods. In the third method, foods were treated with digestive enzymes (pepsin followed by pancreatin), extracted with methanolic HCI and quantified by S. uvarum. Of the three procedures, the best correlation with food vitamin B-6 bioavailability obtained in the human feeding study was with the third method, treatment with digestive enzymes prior to quantification. IN VIVO AND IN VITRO DETERMINATION OF THE BIOAVAILABILITY OF VITAMIN B-6 FROM PLANT FOODS CONTAINING PYRIDOXINE GLUCOSIDE
Patent•
26 Apr 1990
TL;DR: A dose-dependent shift in glucuronidation and glucosidation was found for both the administrations of S(+)- and R(-)-enantiomers as well as RS(+/-)-pranoprofen.
Abstract: Following the oral administration of RS(+/-)-pranoprofen to mice at a dose of 25 mg/kg, 10.7% of the acyl glucuronide and 46.4% of the acyl glucoside of pranoprofen were excreted in the urine within 24 h. The recovery of acyl glucoside in the urine decreased relative to that of acyl glucuronide at increasing doses (100, 200 mg/kg). Following the oral administration of S(+)-pranoprofen to mice at a dose of 25 mg/kg, 5.0% of the acyl glucuronide and 56.5% of the acyl glucoside were excreted in the urine within 24 h, while 10.8% of the acyl glucuronide and 13.9% of the acyl glucoside were excreted after the oral administration of R(-)-pranoprofen, respectively. The absolute configuration of the aglycone of acyl glucuronide was almost R(-)-enantiomer (92.5-96.1%) in the 0-24 h urine, whereas that of acyl glucoside contained 15.3-24.7% of S(+)-enantiomer after the oral administration of R(-)-pranoprofen. On the other hand, only the S(+)-isomer was found as the aglycone of both acyl glucuronide and glucoside after the oral administration of S(+)-pranoprofen. The present results showed that stereoselective conjugation was observed in glucosidation in mice. Nevertheless, a dose-dependent shift in glucuronidation and glucosidation was found for both the administrations of S(+)- and R(-)-enantiomers as well as RS(+/-)-pranoprofen. Also a chiral inversion of R(-)-enantiomer to S(+)-antipode may occur slightly but significantly in mice.