90-76-6

Diverse monosaccharide analysis methods have been established for a long time, but few methods are available for a complete monosaccharide analysis of glycosaminoglycans (GAGs) and certain acidolysis- resistant components derived from GAGs. In this report, a reversed-phase high-performance liquid chromatography (RP-HPLC) method with pre-column 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization was established for a complete monosaccharide analysis of GAGs. Good separation of glucosamine/ mannosamine (GlcN/ManN) and glucuronic acid/iduronic acid (GlcA/IdoA) was achieved. This method can also be applied to analyze the acidolysis-resistant disaccharides derived from GAGs, and the sequences of these disaccharides were confirmed by electrospray ionization-collision-induced dissociation- tandem mass spectrometry (ESI-CID-MS/MS). These unique disaccharides could be used as markers to distinguish heparin/heparan sulfate (HP/HS), chondroitin sulfate/dermatan sulfate (CS/DS), and hyaluronic acid (HA).

The present invention relates to the use of chondroitin as a transdermal carrier and slow-release system for active ingredients in pharmaceutical and cosmeceutical compositions.

Nineteen new highly oxygenated norbisabolane sesquiterpenoids, phyllanthacidoid acid methyl ester (1), and C-T (4-21), were isolated from Phyllanthus acidus Skeels, together with two known ones, phyllanthusols A (2) and B (3), whose sugar moiety was revised as glucosamine-N-acetate, rather than the previously assigned mannosamine-N-acetate. Compounds 2 and 3 were renamed respectively as phyllanthacidoids A (2) and B (3) to avoid confusion. All of the isolates except for 1 are glycosides, whose saccharide moieties possess a pentaoxy cyclohexane (scyllo quercitol) connecting with glucosamine-N-acetate or glucosyl moieties, which are first examples in natural products. Phyllanthacidoids N-R (15-19) with 8R configurations and/or 5,8-diketal skeleton, are unprecedented structures among norbisabolane sesquiterpenoids. Phyllanthacidoids S (20) and T (21) have the unusual tricyclo [3.1.1.1] oxygen bridge skeleton formed by a diketal system, of which the relative configurations of the aliphatic chain were assigned on the basis of heteronuclear coupling constants. The absolute configurations of compounds (1-21) were established by means of calculated electronic circular dichroism (ECD) and coupling constants. Compounds 1-5, 7-9, 10, and 14 displayed potential anti-hepatitis B virus (HBV) activities, with IC50 values of 0.8-36 μM against HBV surface antigen (HBsAg) and HBV excreted antigen (HBeAg), and the results indicated that the 5-ketal group and sugar moieties had contributions to the selectivity of HBsAg and HBeAg.

Cold-adapted bacteria are microorganisms that thrive at very low temperatures in permanently cold environments (0-10 °C). Their ability to survive under these harsh conditions is the result of molecular evolution and adaptations, which include the structural modification of the phospholipid membrane. To give insight into the role of the membrane in the mechanisms of adaptation to low temperature, the characterization of other cell-wall components is necessary. Among these components, the lipopolysaccharides are complex amphiphilic macromolecules embedded in the outer leaflet of the external membrane, of which they are the major constituents. The cold-adapted Colwellia psychrerythraea 34H bacterium, living in deep sea and Arctic and Antarctic sea ice, was cultivated at 4 °C. The lipooligosaccharide (LOS) was isolated and analysed by means of chemical analysis. Then it was degraded either by mild hydrazinolysis (O-deacylation) or hot KOH (4 M; N-deacylation). Both products were investigated in detail by 1H and 13C NMR spectroscopy and by ESI FT-ICR mass spectrometry. The oligosaccharide portion consists of a unique and very short species with the following general structure: α-L-Col-(1→2)-α-D-GalA-(1→2)-α-D-Man-[3-P-D-Gro] -(1→5)-α-D-Kdo-4-P-Lipid-A. The structural characterization of the lipooligosaccharide from the steno-psychrophilic bacterium Colwellia psychrerythraea strain 34H has been achieved by means of chemical analysis, mass spectrometry, and NMR spectroscopy experiments. The data revealed a very short, negatively charged, and unique oligosaccharide, lacking heptose residues. Copyright

A novel sugar adduct, 4,6-dimethoxy-1,3,5-triazin-2-yl-d-glucosaminide (GlcN-DMT), has been prepared by the reaction of d-glucosamine (GlcN) and 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-morpholinium chloride (DMT-MM). The adduct was recognized by exo-d-glucosaminidase (GlcNase) from Amycolatopsis orientalis and transferred the GlcN moiety, giving rise to the corresponding glucosaminides. This chemo-enzymatic process was successfully applied to d-galactosamine (GalN). GalN-DMT prepared directly from GalN and DMT-MM behaved as an efficient glycosyl donor for transfer of the GalN moiety catalyzed by the same enzyme. The introduction of the 4,6-dimethoxy-1,3,5-triazin-2-yl leaving group to the anomeric center significantly enhanced transglycosylating ability, resulting in the efficient glycosidase-catalyzed synthesis of glycosaminides.

The invention relates to novel hybrid compounds comprising at least one polyon entity (Po)—for example oligomer or polymer—in which at least one of the hydroxyl functions of Po is substituted by at least one entity A that can be of a variable nature, for example polymer (e.g. polyorganosiloxane-POS), hydrocarbonated or mineral. The bond Ro between the entity Po and the entity A is obtained by means of “click chemistry” and corresponds to formula (II.1) or (II.2), Z representing —CH— or —N—. A is an entity selected from the group comprising the various polyols of Po, polyorganosiloxanes (POS), polyalkylene glycols, polyamides, polyesters, polystyrenes, alkyls, alkenyls, alkynyls, aryls, and combinations thereof, in addition to mineral materials such as silica and the combinations thereof. Said hybrid components can be used as emulsifiers, especially for cosmetics.

We report herein a bacterial N-acetylhexosamine kinase, NahK, with broad substrate specificity towards structurally modified GalNAc analogues, and the production of a GalNAc-1-phosphate library using this kinase.

Disclosed is a process for the preparation of a glucosamine acid addition salt from fructose and ammonia or an ammonia source such as an ammonium compound by contacting fructose and ammonia or an ammonia source in the presence of (i) a solvent comprising about 25 to 100 weight percent water and 75 to 0 weight percent of an inert, organic, water-miscible solvent at a WWpH or SWpH of about 1 to 6; or (ii) a solvent comprising about 75 to 100 weight percent of an inert, organic, water-miscible solvent and 0 to 25 weight percent water at a WWpH or SWpH of about 1 to 10. A mannosamine acid addition salt also is produced as a co-product of the process.

A combination of enzyme preparations from Trichoderma atroviride and Serratia marcescens was able to completely degrade high concentrations (100 g/L) of chitin from langostino crab shells to N-acetylglucosamine (78%), glucosamine (2%), and chitobiose (10%). The result was achieved at 32°C in 12 days with no pre-treatment (size reduction or swelling) of the substrate and without removal of the inhibitory end-products from the mixture. Enzymatic degradation of three forms of chitin by Serratia/Trichoderma and Streptomyces/Trichoderma blends was carried out according to a simplex-lattice mixture design. Fitted polynomial models indicated that there was synergy between prokaryotic and fungal enzymes for both hydrolysis of crab chitin and reduction of turbidity of colloidal chitin (primarily endo-type activity). Prokaryotic/fungal enzymes were not synergistic in degrading chitosan. Enzymes from prokaryotic sources had much lower activity against chitosan than enzymes from T. atroviride.

We report the synthesis of a novel compound for chitinase assays, p-nitrophenyl 2-acetamido-4-O-(2-amino-2-deoxy-β-D-glucopyranosyl)-2-deoxy-β-D-glucopyranoside [GlcNGlcNAc-pNP] by selective N-deacetylation of p-nitrophenyl 2-acetamido-4-O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-2-deoxy-β-D-glucopyranoside [(GlcNAc)2-pNP] using a purified chitin deacetylase isolated from Colletotrichum lindemuthianum ATCC 56676. FABMS, 1H NMR, and 13C NMR analyses confirmed the structure of this new compound. This disaccharide derivative can be used to distinguish special chitinases that effectively remove partially deacetylated parts of substrates within a mixture of chitinases which degrades (GlcNAc)2-pNP. Copyright (C) 1999 Elsevier Science Ltd.

-

A new, mild method for the splitting of N-linked oligosaccharides from glycoproteins includes treatment of glycoproteins (ovomucoid, flavoprotein, ribonuclease B, hemagglutinin, or transferrin) with 2 M LiBH4 in 25 mM LiOH - 50 mM Li citrate - 70percent aqueous tert-butyl alcohol (5 h, 45 deg C), followed by hydrolysis of the resulting glycosylamine with aqueous acetic acid.The oligosaccharides formed were easily isolated by gel filtration and cation-exchange chromatography in 60-80 percent yields.The reaction was accompanied by the intense reductive cleavage of peptide bonds with formation of amino alcohols, but N-deacetylation of hexosamine was completely excluded.The optimal conditions of this reaction were chosen by use of a model glycopeptide, 2-acetamido-4-O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-1-N-(4-L-aspartoyl)-2-deoxy-β-D-glucopyranosylamine

The reaction of 2-amino-2-deoxy-D-glucose hydrochloride with 5,5-dimethyl-2-phenylaminomethylene-1,3-cyclohexanedione in MeOH in the presence of Et3N afforded 2-deoxy-2--D-glucose (6) in yields >75percen

-

By a combination of chemical, 1H and 13C NMR, and mass spectrometric studies, the structures of the five major components of the antibiotic teicoplanin, produced by Actinoplanes teichomyceticus, have been elucidated.The components all have structures closely related to those of the glycopeptide antibiotics of the vancomycin group.The teicoplanin components are differentiated from one another by the presence of various N-acylglucosamine moieties, where the acyl group is a C10 or C11 fatty acid.Such groups are not present in any other known member of the vancomycin group.