Showing papers on "Disaccharide published in 1981"

The uptake and hydrolysis of disaccharides by fast-and slow-growing species of Rhizobium

Abstract: Slow growing strains of rhizobia appear to lack both uptake systems and catabolic enzymes for disaccharides. In the fast-growing strains of rhizobia there are uptake mechanisms and catabolic enzymes for disaccharide metabolism. In Rhizobium leguminosarum WU 163 and WU235 and R. trifolii WU290, sucrose and maltose uptake appears to be constitutive whereas in R. meliloti WU60 and in cowpea Rhizobium NGR234 uptake of these disaccharides is inducible. There is evidence that there are at least two distinct disaccharide uptake systems in fast-growing rhizobia, one transporting sucrose, maltose and trehalose and the other, lactose. Disaccharide uptake is via an active process since uptake is inhibited by azide, dinitrophenol and carbonyl cyanide m-chlorophenylhydrazone but not by arsenate. Bacteroids of R. leguminosarum WU235 and R. lupini WU8 are unable to accumulate disaccharides.

Vaccine stabilizer containing L-glutamic acid and L-arginine

Abstract: An improved stabilized liquid live viral vaccine contains a live virus, partially hydrolyzed gelatin, a monosaccharide or disaccharide, a cell culture medium, L-glutamic acid, L-arginine and sufficient physiologically acceptable acidic buffer to maintain the pH at from about 6.0 to about 6.5.

Uptake and metabolism of sucrose by Streptococcus lactis.

Abstract: Transport and metabolism of sucrose in Streptococcus lactis K1 have been examined. Starved cells of S. lactis K1 grown previously on sucrose accumulated [14C]sucrose by a phosphoenolpyruvate-dependent phosphotransferase system (PTS) (sucrose-PTS; Km, 22 microM; Vmax, 191 mumol transported min-1 g of dry weight of cells-1). The product of group translocation was sucrose 6-phosphate (6-O-phosphoryl-D-glucopyranosyl-1-alpha-beta-2-D-fructofuranoside). A specific sucrose 6-phosphate hydrolase was identified which cleaved the disaccharide phosphate (Km, 0.10 mM) to glucose 6-phosphate and fructose. The enzyme did not cleave sucrose 6'-phosphate(D-glucopyranosyl-1-alpha-beta-2-D-fructofuranoside-6'-phosphate). Extracts prepared from sucrose-grown cells also contained an ATP-dependent mannofructokinase which catalyzed the conversion of fructose to fructose 6-phosphate (Km, 0.33 mM). The sucrose-PTS and sucrose 6-phosphate hydrolase activities were coordinately induced during growth on sucrose. Mannofructokinase appeared to be regulated independently of the sucrose-PTS and sucrose 6-phosphate hydrolase, since expression also occurred when S. lactis K1 was grown on non-PTS sugars. Expression of the mannofructokinase may be negatively regulated by a component (or a derivative) of the PTS.

Bausteine von Oligosaccchariden, XXXIII1) Synthese von β-glycosidisch verknüpften L-Rhamnose-haltigen Disacchariden

Abstract: Das 2,34-Tri-O-benzyl-α-L-rhamnopyranosylbromid (4) ist eine reaktive Halogenose, die sich bei Gegenwart eines Silbersilicatkatalysators mit Sacchariden, die eine reaktive Hydroxylgruppe enthalten in guter Selektivitat zu β-glycosidisch verknupften Disacchariden umsetzen last. Die β(1 4)- und β(1 3)-verknupften Disaccharide der L-Rhamnose 6, 17 und 27 mit L-Rhamnose und D-Galactose als Hydroxylkomponenten wurden auf diesem Wege dargestellt. Durch Entblockierung wurden die freien Disaccharide 8, 19 und 31 erhalten. Building Units for Oligosaccharides, XXXIII1) Synthesis of β-Glycosidically Linked Disaccharides of L-Rhamnose The 2,3,4-tri-O-benzyl-α-L-rhamnopyranosyl bromide (4) is a reactive halogenose which in the presence of a silver silicate catalyst reacts with saccharides containing a reactive hydroxyl group to dive a β-glycosidically linked disaccharide with good selectivity. The three β(1 4) and β(1 3) linked disaccharides of L-rhamnose 6, 17, and 27 were made in this way with either L-rhamnose or D-galactose as hydroxyl group component. Subsequent deprotection gave the free disaccharides 8, 19 and 31 respectively.

Lactases and their Applications

Abstract: Lactose or milk sugar is a disaccharide found in the milk of mammals. Lactose itself is not sweet, it has a low solubility and it cannot be absorbed directly from the intestine. Lactase splits lactose into glucose and galactose, which have a sweetening power of about 0–8 relative to sucrose; they are 3–4 times more soluble than lactose and are easily absorbed from the intestine.

Studies on the characterization of the linkage-region between polysaccharide chain and core protein in bovine corneal proteokeratan sulfate.

Abstract: 1) A new method of enrichment of the linkage-region in corneal proteokeratan sulfate is described, which consists of desulfation of peptidokeratan sulfate, followed by chromatography on Con A-Sepharose 4B and enzymatic degradation with beta-D galactosidase and beta-N-acetyl-D-glucosaminidase. 2) After permethylation, hydrolysis, reduction with sodium borohydrid and acetylation gas chromatography/mass spectrometry analyses were performed. The followings products could be detected as their peracetates: 2,3,4-tri-O-methylfucitol; 2,3,4,6-tetra-O-methylmannitol; 3,4,6-tri-O-methylmannitol; 2,4-di-O-methylmannitol; 2,3,4,6-tetra-O-methylgalactitol; 2,4,6-tri-O-methylgalactitol; 2,4-di-O-methylgalactitol. 3) The results point to the presence of a branched linkage region in the proteokeratan sulfate molecule with one mannose as the branching point and two mannose residues as the starting point of two disaccharide chains.

Chemical and Biochemical Studies on Carbohydrate Esters. IX. Antitumor Effects of Selectively Fatty Acylated Products of Maltose

Abstract: Selective fatty acylation of maltose was carried out by heating an equimolar mixture of the disaccharide and an appropriate acid chloride in pyridine. The resulting crude product was chromatographed to furnish two preparations, termed maltose-[mono]- and-[high]-esters ; the former preparation was an isomeric mixture of monoesters among which the 1-, 6-, and 6'-isomers were presumably predominant, and the latter consisted of di-, tri-, and poly-esters, as indicated by gas-liquid and thin-layer chromatographies. The antitumor effects of the maltose-[mono]-esters of stearic, palmitic, myristic, lauric, and caprylic acids towards Ehrlich ascites carcinoma in mice were tested by the total packed cell volume method, by intraperitoneal injection. The stearic, palmitic, and myristic esters proved to be effective, while the lauric and caprylic esters exhibited a slight effect and no effect, respectively. The antitumor effect of the maltose-[mono]-stearate upon the same tumor was compared with that of the analogous derivative of sucrose by survival bioassay (intraperitoneal administration) at various doses. Both compounds showed similar antitumor results, giving especially marked effects at the dose of 50 mg/kg/day×5. These two compounds also exerted moderate growth-inhibitory effects against solid sarcoma 180 in mice when they were administered subcutaneously ; in the case of sucrose-[mono]-stearate, intramuscular injection was also effective. The maltose-[high]-esters of stearic, palmitic, and myristic acids failed to exert marked activity upon this solid tumor by either administration route.

The metabolism of 3‐phenoxybenzyl alcohol, a pyrethroid metabolite, in plants

Abstract: The metabolism and conjugation of 3-phenoxybenzyl alcohol, a plant metabolite of permethrin and cypermethrin, have been examined in abscised cotton leaves. Mature cotton leaves were treated by petiole uptake of an aqueous solution of [α-14C]-3-phenoxybenzyl alcohol. Initially there was rapid formation of a compound identified as the glucosyl 3-phenoxybenzyl ether. Subsequently more polar compounds were formed and these were shown to be disaccharide conjugates of the alcohol with glucose and pentose sugars. The alcohol and its mono- and disaccharide conjugates were shown to undergo interconversion in cotton leaves, and evidence was obtained from experiments with [14C]glucose for the ready exchange of the glucose units on the conjugates with free glucose in the leaves. No larger carbohydrate conjugates of 3-phenoxybenzyl alcohol were detected under the conditions used.

Effect of penicillin G on release of peptidoglycan fragments by Neisseria gonorrhoeae: characterization of extracellular products.

Abstract: The effect of penicillin G (penG) on the turnover and release of peptidoglycan (PG) by Neisseria gonorrhoeae RD5 was investigated. We previously showed that exponentially growing gonococci (labeled in the glycan moiety with glucosamine and muramic acid and in the peptide with diaminopimelic acid) turn over ca. 35% of their PG per generation. In current studies, addition of penG accelerated the rate of PG hydrolysis by more than twofold and resulted in a corresponding increase in the amount of soluble PG fragments found in the medium. This increase of soluble PG was accounted for mainly by the release of nonreducing (anhydro-muramyl-containing) disaccharide peptide dimers (molecular weight, about 2,000) and trimers that were composed of subunits, linked not by peptide cross-linking bonds, but probably only by glycosidic bonds. The enhanced release of these products suggested that penG, directly or indirectly, stimulates the activity of a glycan-splitting, gonococcal PG:PG-6 muramyl transferase (transglycosylase). PG monomers that were released in the presence of penG were identical, both qualitatively and quantitatively, to the monomers released as a result of turnover in the absence of penG and consisted of anhydro-muramyl-containing disaccharide tripeptides and tetrapeptides. PenG-treated bacteria consistently released slightly less free disaccharide and free peptides than did control cultures, implying a penG-associated depression in the activity of the gonococcal N-acetylmuramyl-L-alanine amidase. In addition to stimulating the release of PG fragments, penG was also associated with greatly enhanced release from cells of glucosamine-containing non-PG macromolecule(s).

The Chemistry of Maltose

Abstract: Publisher Summary This chapter focuses on the reactions of maltose and illustrates some of the physical methods that have contributed to the characterization of maltose derivatives. Maltose (I), systematically named “4- O -α- d -glucopyranosyl- d -glucopyranose,” is a reducing disaccharide. The reducing groups of sugars are generally protected by glycosidation before chemical or biological transformations are carried out at other functional groups of the molecule. The selective tritylation of maltose and its derivatives has been investigated in the chapter, along with reviewing the bimolecular, nucleophilic-displacement reactions of sulfonic esters of carbohydrates. Acetates and benzoates are widely used as the characteristic derivatives of carbohydrates and for the assay and protection of hydroxyl groups. have been reviewed. 1,6-Anhydro-4- O- α- d -glucopyranosyl- β - d -glucopyranoside has proved to be a very useful starting material for the production of synthetic intermediates such as 1,2,3,2′,3′,4′,6′-hepta- O- acetyl- β -maltose, 1,6-anhydro-4′,6′ -O -benzylidene- β -maltose, and 2,3,2′,3′,4′-penta- O -acetyl-1,6-anhydro- β -maltose. The cyclic acetals of sugars constitute an important class of compounds and their value as synthetic intermediates is well recognized.

Synthesis of streptococcal Groups A, C and variant-A antigenic determinants

Abstract: The antigenic determinants of the cell wall polysaccharides belonging to the β-haemolytic Streptococci Groups A, A-variant, and C have been synthesized as the glycosides of 8-methoxycarbonyloctanol. In this form they may be used to generate artificial antigens and immunoabsorbents. The terminal disaccharide, 3-O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-α-L-rhamnopyranoside, of the Group A polysaccharide was synthesized by a Konigs–Knorr reaction between 8-methoxycarbonyloctyl 2,4-di-O-benzoyl-α-L-rhamnopyranoside (1) and 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl bromide (2) which gave the antigenic determinant (6) after removal of the blocking groups. Similarly, addition of 3,4,6-tri-O-acetyl-2-azido-2-deoxy-β-D-galactopyranosyl chloride (3) to (1) gave a disaccharide (7). The suitably blocked benzylidene acetal (11) was treated with the glactopyranosyl chloride (3) to yield the trisaccharide (12). The deblocked trisaccharide, O-(2-acetamido-2-deoxy-α-D-galactopyranosyl)-(1→3)-O-(2-acetamido-2-deoxy-α-D-galactopyranosyl)-(1→3)-α-L-rhamnopyranoside (14), is similar to the determinant of the Group C streptococcal cell wall and is also related to the Forssman antigen. The previously synthesized disaccharide glycoside, 8-methoxycarbonyloctyl 3,4-di-O-benzyl-2O-(2,4-di-O-benzoyl-α-L-rhamnopyranosyl)-α-L-rhamnopyranoside (15) was subjected to sequential chain-extension reactions with 2-O-acetyl-3,4-di-O-benzyl-α-L-rhamnopyranosyl chloride (4) to give the trisaccharide (16) and from this the slectively blocked precursor (17) from which the tetrasaccharide (18) was formed by reaction with (4). The tetrasaccharide glycoside O-(α-L-rhamnopyranosyl)-(1→2)-O-(α-L-rhamnopyranosyl)-(1→3)-O-(α-L-rhamnopyranosyl)-(1→2)-α-L-rhamnopyranoside (19) mimics the core structure of Groups A and C streptococcal polysaccharides and is identical to the sequence of the variant-A cell-wall polysaccharide.

Cell-free biosynthesis of erythroglycan in a microsomal fraction from K-562 cells.

Abstract: Particulate membrane preparations from K-562 [human CML (chronic-myelogenous-leukaemia)-derived] cells catalyse the transfer of [3H]galactose from UDP-[3H]-galactose and [3H]N-acetylglucosamine from UDP-[3H]N-acetylglucosamine into an endogenous product that on digestion with Pronase yields long-chain glycopeptides (mol.wt. 7000--10 000) called 'erythroglycan'. Incorporation of either labelled sugar increased up to 60 min of incubation time. The labelled erythroglycan was isolated by chromatography on Sephadex G-50 and characterized by digestion with endo-beta-galactosidase from Escherichia freundii, followed by analysis on Bio-Gel P-2 and paper chromatography. This digestion gave the following four products: (1) a disaccharide with the sequence beta GlcNAc-beta Gal; (2) a trisaccharide with the sequence betaGal-betaGlcNAc-beta Gal; (3) a larger oligosaccharide containing galactose and N-acetylglucosamine; and (4) a putative protein-linkage region.

Partial Conversion of Maltose into Cyclohexane Derivatives

Abstract: 5, 6-Unsaturated disaccharide derivative prepared from maltose via its 6-iodo derivative was treated with mercuric chloride, giving α-linked pseudodisaccharide in good yield, which contains cyclohexanonederivatives as constituents. On treatment with an acetic anhydride-pyridine mixture, the cyclohexanone constituents underwent β-elimination to be changed into a sole cyclohexenone moiety. Hydrogenation of the double bond between two carbon atoms and subsequent reductive amination of the carbonyl group gave aminocyclitol-containing pseudodisaccharides.

Chemical and biochemical studies on carbohydrate esters. XI. Antitumor effects of fatty acid monoesters of D-glucose.

Abstract: 1-O-, 3-O-, and 6-O-acyl-D-glucopyranoses carrying capryloyl, lauroyl, myristoyl, palmitoyl, and stearoyl functions were tested for their in vivo and in vitro antitumor effects against Ehrlich ascites carcinoma in mice and a leukemia cell line L-5178Y by the total packed cell volume method and the tissue culture method, respectively. In the in vivo bioassay, the 1-and 3-myristate and the 6-stearate were moderately effective, while all other compounds exhibited little or no effect. These samples inhibited the growth of the cultured leukemia cells to various extents : relatively lower ID50 values were obtained with the 1-laurate, 1-myristate, 1-palmitate, 3-myristate, and 6-laurate. On the basis of these findings, the monoesters of monosaccharide appear to be less promising as antitumor agents than the analogous derivatives of disaccharide.

Alkyl glycoside of constituent unit disaccharide of acid mucopolysaccharide and oligosaccharide consisting of said disaccharide* and preparation thereof

Abstract: NEW MATERIAL:An alkyl glycoside of a constituent unit disaccharide of a compound expressed by the formula (R is lower alkyl group; Ac is acetyl group; n is an integer 0-9) and an alkyl glycoside of an oligosaccharide of said disaccharide USE:A raw material for an anticoagulant, an activator for the lipemia clearing factor and an interferon production inducer PROCESS:Hyaluronic acid or a weak base salt thereof is depolymerized in dimethyl sulfoxide containing a lower alcohol, eg methanol, in the presence of a weak base sulfate, eg pyridinium sulfate salt, at room temperature - 110 degC, preferably 80-110 degC After the reaction, an aqueous solution of an alkali is added to the reaction mixture, and the mixture is concentrated in vacuo The concentrate is then treated with an anion exchange resin column and separated into di-, tetra-, hexa-, octa- and decasaccharide fraction The separation can be confirmed by an elution curve obtained with gel filtration chromatography

Structures of O-glycosidically linked carbohydrate units of herring egg sialoglycoprotein.

Abstract: One of the major fractions of sialoglycoprotein isolated from herring eggs has been shown to contain both alkali-labile and alkali-stable carbohydrate units Homogeneous preparations of reduced disaccharide and trisaccharide were obtained Their structures, as determined by methylation analysis coupled with GLC-mass spectrometry, NMR spectroscopy and digestion with glycosidases, were beta-D-galactopyranosyl-(1 leads to 3)-N-acetyl-D-galactosaminitol and beta-D-galactopyranosyl-(1 leads to 3)-[alpha-N-acetylneuraminyl-(2 leads to 6)]-N-acetyl-D-galactosaminitol, respectively No other oligosaccharide was found among the products of alkaline borohydride treatment Glycopeptide fractions were obtained from the pronase digest of the glycoprotein The carbohydrate components of small glycopeptide fractions were either galactose and N-acetylgalactosamine or galactose, N-acetylgalactosamine and N-acetylneuraminic acid and accounted for 80% of reduced oligosaccharides obtained by alkaline borohydride treatment of the glycoprotein Threonine was the only amino acid that occurred in molar ratios relative to N-acetylgalactosamine of more than unity in these small glycopeptide fractions It was concluded that, on average, 4 carbohydrate units are attached to each peptide chain through O-glycosidic linkages between the N-acetylgalactosamine and threonine residues