Effects of Dietary myo-Inositol,D-chiro-Inositol and L-chiro-Inositol on Hepatic Lipids with Reference to the Hepatic myo-Inositol Status in Rats Fed on 1,1,1-Trichloro-2,2-bis (p-chlorophenyl) Ethane

The effects of dietary 0.2% inositol stereoisomers on the hepatic lipids and myo-inositol (MI) status in rats fed with 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane (DDT) were investigated. Dietary MI reduced the hepatic lipids in the rats fed with DDT. Dietary D-chiro-inositol (DCI) and L-chiro-inositol (LCI) both had a promoting effect on the increase in hepatic lipids due to DDT feeding. Dietary MI enhanced the hepatic free MI level and the phosphatidylinositol/phosphatidylcholine ratio, but dietary DCI reduced the level and ratio.     

Antioxidative Effect of an Isolate from a Culture Filtrate of Aspergillus niger

D-Ins(1,3,4,5)P₄ and unnatural L-Ins(1,3,4,5)P₄ were prepared in gram-quantities from D- and L-2,6-di-O-benzyl-myo-inositol by a chemical phosphorylation and deprotection step in high yield and purity without extensive purification. The optically pure benzyl derivatives were obtained by enzyme-catalyzed resolution of racemic 2,6-di-O-benzyl-myo-inositol under acyl-transfer conditions in vinyl acetate as the acyl donor. The lipase of Candida antarctica only acetylated regio- and enantio-selectively the L-enantiomer, providing exclusively L-5-acetyl-2,6-di-O-benzyl-myo-inositol, whereas the D-enantiomer remained unchanged.     

Preparative-scale Chemo-enzymatic Synthesis of Optically Pure d-myo–Inositol-1-phosphate

d-myo-Inositol-1-phosphate was synthesized by a short and facile route from optically pure 1d-1-acetoxy-4,6-di-O–benzyl-myo–inositol, which was easily obtained by a highly regio- and enantioselective enzyme-catalyzed acetylation of 4,6-di-O-benzyl-myo-inositol.     

Syntheses of Some Derivatives of Glycosyl Pantothenic Acids,Analogues of Growth Factor for MLF Bacteria

A growth factor (TJF) for a malo-lactic fermentation bacterium (Leuconostoc sp.) has been found to be 4′-O-(β-D-glucopyranosyl)-D-pantothenic acid with structural and synthetical studies. Now other 4′-O-glycosides (β-D-ribofuranosyl, α-D-glucopyranosyl, β-D-galacto-pyranosyl, β-maltosyl and β-cellobiosyl) and 2′,4′-O-di-β-D-glucopyranoside of DL-pantothenic acid, and 4′-O-β-D-glucopyranoside of DL-pantethine were synthesized to examine their biological activities. The improved syntheses of TJF were also examined.     

Biotransformation of Cinnamic Acid,p-Coumaric Acid,Caffeic Acid,and Ferulic Acid by Plant Cell Cultures of Eucalyptus perriniana

Biotransformations of phenylpropanoids such as cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid were investigated with plant-cultured cells of Eucalyptus perriniana. The plant-cultured cells of E. perriniana converted cinnamic acid into cinnamic acid β-D-glucopyranosyl ester, p-coumaric acid, and 4-O-β-D-glucopyranosylcoumaric acid. p-Coumaric acid was converted into 4-O-β-D-glucopyranosylcoumaric acid, p-coumaric acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcoumaric acid β-D-glucopyranosyl ester, a new compound, caffeic acid, and 3-O-β-D-glucopyranosylcaffeic acid. On the other hand, incubation of caffeic acid with cultured E. perriniana cells gave 3-O-β-D-glucopyranosylcaffeic acid, 3-O-(6-O-β-D-glucopyranosyl)-β-D-glucopyranosylcaffeic acid, a new compound, 3-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcaffeic acid, 4-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, ferulic acid, and 4-O-β-D-glucopyranosylferulic acid. 4-O-β-D-Glucopyranosylferulic acid, ferulic acid β-D-glucopyranosyl ester, and 4-O-β-D-glucopyranosylferulic acid β-D-glucopyranosyl ester were isolated from E. perriniana cells treated with ferulic acid.     

Acceptor Specificity of Cyclodextrin Glycosyltransferase from Bacillus stearothermophilus and Synthesis of α-D-Glucosyl O-β-D-galactosyl-(1→4)-β-D-glucoside

Bacillus stearothermophilus CGTase had a wider acceptor specificity than Bacillus macerans CGTase did and produced large amounts of transfer products of various acceptors such as D-galactose, D-mannose, D-fructose, D- and L-arabinose, d- and L-fucose, L-rhamnose, D-glucosamine, and lactose, which were inefficient acceptors for B. macerans CGTase. The main component of the smallest transfer products of lactose was assumed to be α-D-glucosyl O-β-D-galactosyl-(l→4)-β-D-glucoside.     

Enzyme-Substrate Complex of p-Hydroxybenzoate Hydroxylase; One of the Activated Intermediates of the Overall Reaction

The transglucosidation reaction of brewer’s yeast α-glucosidase was examined under the co-existence of l-sorbose and phenyl-α-glucoside. As the transglucosidation products, three kinds of new disaccharide were chromatographically isolated. It was presumed that these disaccharides consisting of d-glucose and l-sorbose were 1-O-α-d-glucopyranosyl-l-sorbose ([α]_D+89.0), 3-O-α-d-glucopyranosyl-l-sorbose ([α]_D+69.1) and 4-O-α-d-glucopyranosyl-l-sorbose ([α]_D+81.0). The principal product formed in the enzyme reaction was 1-O-α-d-glucopyranosyl-l-sorbose.     

Synthesis of α-L-Mannopyranosyl-containing Disaccharides and Phenols as Substrates for the α-L-Mannosidase Activity of Commercial Naringinase

In order to clarify the substrate specificity of the α-L-mannosidase activity of naringinase (Sigma), the following disaccharides and phenol glycosides were freshly prepared: methyl 2-O-(α-L-mannopyranosyl)­β-D-glucoside (1), methyl 3-O-(α-L-mannopyranosyl)-α-D-glucoside (2), methyl 4-O-(α-L-mannopyranosyl)-α-D-glucoside (3), methyl 5-O-(α-L-mannopyranosyl)-β-D-glucoside (4), methyl 6-O-(α-L-mannopyranosyl)-α-D­glucoside (5), 6-O-(α-L-mannpyranosyl)-D-galactose (6), p-nitrophenyl α-L-mannoside (7), and 4-methyl umbelliferone α-L-mannoside (8).These compounds, except for 3 and 5, were hydrolyzed with naringinase.     

Characterization of an Extracellular Polysaccharide Elaborated by TX-1, a New Strain of Beijerinckia indica

An extracellular polysaccharide elaborated by a new species of Beijerinckia indica, named TX-1, was composed of D-glucose, L-fucose, D-glycero-D-manno-heptose, and D-glucuronic acid in a molar ratio of 5.0:1.0:2.0:0.9, in addition to 16.2% of the acetyl group. Among the polysaccharides of the Beijerinckia species, the present polysaccharide might be the first acidic type having an L-fucose residue. A methylation analysis, Smith degradation study and fragmentation analysis show that this polysaccharide consisted of non-reducing terminal D-glucose, O-4 substituted D-glucose, O-2 substituted D-glycero-D-manno-heptose, O-4 substituted D-glucuronic acid, O-3 and O-4 substituted D-glucose, and O-3 substituted L-fucose residues. A D-glucuronic acid residue was linked to the O-3 position of the L-fucose residue by an α-glycosidic linkage. Most of the D-glucose residues in the backbone chain were substituted at the O-3 position, with the side chain having non-reducing terminal D-glucose residues. It is suggested by the reaction with Con A that the anomeric configuration of the terminal D-glucose residues was β.     

Efficient Production and Purification of Extracellular 1,2-α-L-Fucosidase of Bacillus sp. K40T

When Bacillus sp. K40T was cultured in the presence of L-fucose, 1,2-α-L-fucosidase was found to be produced specifically in the culture fluid. The enzyme was purified to homogeneity from a culture containing only L-fucose by chromatography on hydroxylapatite and chromatofocusing. The molecular weight of the enzyme was estimated to be 200,000 by gel filtration on Sephadex G-200. The enzyme was optimal at pH 5.5–7.0 and was stable at pH 6.0–9.0. The enzyme hydrolyzed the α(1 → 2)-L-fucosidic linkages in various oligosaccharides and glycoproteins such as lacto-N-fucopentaose (LNF)-I 〈O-α-L-fucose-(1 → 2)-O-β-D-galactose-(1 → 3)-N-acetyl-O-β-D-glucosamine-(1 → 3)-O-β-D-galactose-(1 → 4)-D-glucose〉, porcine gastric mucin, and porcine submaxillary mucin. The enzyme also acted on human erythrocytes, which was confirmed by the hemagglutination test using Ulex anti-H lectin. The enzyme did not hydrolyze α(1 → 3)-, α-(1 → 4)- and α-(1 → 6)-L-fucosidic linkages in LNF-III 〈O-β-D-galactose-(1 → 4)[O-α-L-fucose-(1 → 3)-]-N-acetyl-O-β-D-glucosamine-(1 → 3)-O-β-D-galactose-(1 → 4)-D-glucose〉, LNF-II 〈O-β-D-galactose-(1 → 3)[O-α-L-fucose-(1 → 4)-]-N-acetyl-O-β-D-galactose-(1 → 3)-O-β-D-galactose-(1 → 4)-D-glucose〉 or 6-O-α-L-fucopyranosyl-N-acetylglucosamine.     

Oligonucleotides Containing Disaccharide Nucleosides: Synthesis,Physicochemical, and Substrate Properties

Abstract

The efficient synthesis of oligonucleotides containing 2′-O-β-D-ribofuranosyl (and β-D-ribopyranosyl)nucleosides, 2′-O-α-D-arabinofuranosyl (and α-L-arabinofuranosyl)nucleosides, 2′-O-β-D-erythrofuranosylnucleosides, and 2′-O-(5′-amino-5-deoxy-β-D-ribofuranosyl)nucleosides have been developed.     

Structures and Properties of a Diastereoisomeric Molecular Compound of (2S,3S)- and (2R,3S)-N-Acetyl-2-amino-3-methylpentanoic Acids

An X-ray crystal structural analysis revealed that (2S,3S)-N-acetyl-2-amino-3-methylpentanoic acid (N-acetyl-L-isoleucine; Ac-L-Ile) and (2R,3S)-N-acetyl-2-amino-3-methylpentanoic acid (N-acetyl-D-alloisoleucine; Ac-D-aIle) formed a molecular compound containing one Ac-L-Ile molecule and one Ac-D-aIle molecule as an unsymmetrical unit. This molecular compound is packed with strong hydrogen bonds forming homogeneous chains consisting of Ac-L-Ile molecules or Ac-D-aIle molecules and weak hydrogen bonds connecting these homogeneous chains in a fashion similar to that observed for Ac-L-Ile and Ac-D-aIle. Recrystallization of an approximately 1:1 mixture of Ac-L-Ile and Ac-D-aIle from water gave an equimolar molecular compound due to its lower solubility than that of Ac-D-aIle or especially Ac-L-Ile. The results suggest that the equimolar mixture of Ac-L-Ile and Ac-D-aIle could be obtained from an Ac-L-Ile-excess mixture by recystallization from water.     

Antitumor Activities and Immunochemical Properties of the Cell-wall Polysaccharides from Aureobasidium pullulans

Delipidated cell walls from Aureobasidium pullulans were fractionated systematically.

The cell surface heteropolysaccharide contains D-mannose, D-galactose, D-glucose, and D-glucuronic acid (ratio, 8.5:3.9:1.0:1.0). It consists of a backbone of (1→6)-α-linked D-mannose residues, some of which are substituted at O-3 with single or β-(1→6)-linked D-galactofuranosyl side chains, some terminated with a D-glucuronic acid residue, and also with single residues of D-glucopyranose, D-galactopyranose, and D-mannopyranose.

This glucurono-gluco-galactomannan interacted with antiserum against Elsinoe leucospila, which also reacted with its galactomannan, indicating that both polysaccharides contain a common epitope, i.e., at least terminal β-galactofuranosyl groups and also possibly internal β-(1→6)-linked galactofuranose residues.

It was further separated by DEAE-Sephacel column chromatography to gluco-galactomannan and glucurono-gluco-galactomannan.

The alkali-extracted β-D-glucan was purified by DEAE-cellulose chromatography to afford two antitumor-active (1→3)-β-D-glucans. One of the glucans (M_r, 1–2 × 10⁵) was a O-6-branched (1→3)-β-D-glucan with a single β-D-glucosyl residue, d.b., 1/7, and the other (M_r, 3.5–4.5 × 10⁵) had similar branched structure, but having d.b., 1/5. Side chains of both glucans contain small proportions of β-(1→6)-and β-(1→4)-D-glucosidic linkages.     

Synthesis of 3-O-β-N-Acetylglucosaminyl Cyclic Tetrasaccharide through a Lysozyme-catalyzed Transfer Reaction

Egg white lysozyme was found to catalyze the transfer of N-acetylglucosamine to cyclo{→6)-α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→3)-α-D-Glcp-(1→} (CTS). Structural analysis showed that the transfer product was3-O-β-N-acetylglucosaminyl CTS, cyclo{→6)-α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-[β-GlcNAc-(1→3)]-α-D-Glcp-(1→3)-α-D-Glcp-(1→}. This branched saccharide is anticipated to be a model compound of the sugar chains of glycoproteins.     

Transglycosylation of Glycosyl Residues to Cyclic Tetrasaccharide by Bacillus stearothermophilus Cyclomaltodextrin Glucanotransferase Using Cyclomaltodextrin as the Glycosyl Donor

Cyclomaltodextrin glucanotransferase (EC 2.4.1.19, abbreviated as CGTase) derived from Bacillus stearothermophilus produced a series of transfer products from a mixture of cyclomaltohexaose and cyclic tetrasaccharide (cyclo{→6)-α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→3)-α-D-Glcp-(1→}, CTS). Of the transfer products, only two components, saccharides A and D, remained and accumulated after digestion with glucoamylase. The total combined yield of the saccharides reached 63.4% of total sugars, and enzymatic and instrumental analyses revealed the structures of both saccharides. Saccharide A was identified as4-mono-O-α-glucosyl-CTS, {→6)-[α-D-Glcp-(1→4)]-α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→3)-α-D-Glcp-(1→}, and sachharide D was 4,4′-di-O-α-glucosyl-CTS, {→6)-[α-D-Glcp-(1→4)]-α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-[α-D-Glcp-(1→4)]-α-D-Glcp-(1→3)-α-D-Glcp-(1→}. These structures led us to conclude that the glycosyltransfer catalyzed by CGTase was specific to the C4-OH of the 6-linked glucopyranosyl residues in CTS.     

Improvement of Gene Targeting in Aspergillus nidulans with Excess Non-Homologous Fragments

An α-glucosidase was purified in an electrophoretically pure state from an extract of koji culture of Aspergillus sp. KT-11. This enzyme was found to have a transferring activity when the reaction was done in a high concentration of leucrose at pH 4.5. Two kinds of transfer products, fractions I and II, were obtained from leucrose by the enzyme and they were identified as [(α-D-glucopyranosyl-(1 →6)-α-D-glucopyranosyl-(1 →6)- α -D-glucopyranosyl-(1→5)-D-fructopyranose] and [α-D-glucopyranosyl-(1 →6)-α-D-glucopyranosyl-(1→5)-D- fructopyranose], respectively. These are considered to be novel oligosaccharides     

Screening of the regioselectivity of acetyl xylan esterase from Bacillus pumilus as a catalyst for the deacetylation of glycoside acetates

Regioselective deacetylations of nine glycosides catalyzed by acetyl xylan esterase from Bacillus pumilus have been studied. The glycosides were methyl and benzyl glycosides of the tetraacetates of α-D-glucopyranose, α-D-galactopyranose and α-D-mannopyranose, and the methyl glycosides of tetra-O-acetyl-β-D-glucopyranose, tetra-O-acetyl-β-D-galactopyranose and tetra-O-acetyl-α-D-glucopyranose. The kinetics of successive deacetylations was monitored by GLC and 21 sugar acetates have been identified.     

Structural Analysis of an Extracellular Polysaccharide Bioflocculant of Klebsiella pneumoniae

The glycoside composition and sequence of an extracellular polysaccharide flocculant of Klebsiella pneumoniae H12 was analyzed. GC and HPLC analysis of the acid-hydrolysate identified its constituent monosaccharides as D-Glc, D-Man, D-Gal, and D-GlcA in an approximate molar ratio of 3.9:1.0:2.3:3.6. To analyze the glycoside sequence, the polysaccharide was partially hydrolyzed by acid and enzyme treatment. GC, HPLC, TLC, MALDI-TOF/MS, and 1H- and 13C- NMR spectroscopy characterized the obtained oligosaccharides.

The results clarified the partial structure of H12 polysaccharide as a linear polymer of a unit of pentasaccharide with a side chain of one D-GlcA to D-Glc moiety (see below). Although the existence of other sequences or other constituent glycosides could not be fully excluded, H12 polysaccharide must be a novel types as such a complicated unit for a polymer has not so far been reported. The partial structure of a H12 polysaccharide flocculant is also discussed in this report.

→4)- α-D-Glcp-(1→2)-α-D-Manp-(1→3)-4,6-Pyr-β-D- 3 Galp-(1→4)-β-D-Galp-(1→ ↓

1 β-D-GlcpA     

Practical Production of 6-O-Octanoyl-D-allose and Its Biological Activity on Plant Growth

The transesterification of D-allose (the C-3 epimer of D-glucose) with vinyl octanoate using Candida antarctica lipase in tetrahydrofuran proceeded with high regioselectivity to produce 6-O-octanoyl-D-allose with nearly complete conversion. The growth-inhibiting activity of 6-O-octanoyl-D-allose on lettuce seedlings was about 6-fold greater than that of D-allose.     

Characterization of a Thermostable Endo-β-1,4-D-galactanase from the Hyperthermophile Thermotoga maritima

A putative endo-β-1,4-D-galactanase gene of Thermotoga maritima was cloned and overexpressed in Escherichia coli. The recombinant enzyme hydrolyzed pectic galactans and produced D-galactose, β-1,4-D-galactobiose, β-1,4-D-galactotriose, and β-1,4-D-galactotetraose. The enzyme displayed optimum activity at 90 °C and pH 7.0. It was slowly inactivated above pH 8.0 and below pH 5.0 and stable at temperatures up to 80 °C.