Temperature-Studies-Reaction-Month-Volume-Ml-Cm-f

The optimum reflects the limits of PAM catalyst structural and biological stability in combination with the requirement to control COS product solubility in order to prevent clogging of the packed bed. Using an axial flow rate of5 cm- 1, the COS were produced at ~ 5 gday and ≥ 95% substrate conversion (sucrose 0 mM). Fucosylated Lactose showed a stable composition of individual oligosaccharides up to cellohexaose, with cellobiose (48 mol%) and cellotriose (31 mol%) as the major components.CONCLUSIONS Continuous process technology for bottom-up biocatalytic production of soluble COS is demonstrated based on PAM immobilized E. coli cells that co-express BaScP, CuCbP and CcCdP in suitable absolute and relative activities.Conflict of interest statement The authors declare that they have no competing Selective bromoacetylation of alkyl hexopyranosides a facile preparation of intermediates for the synthesis of (1----6)-linked oligosaccharides.

Bromoacetylation of methyl beta-D-galacto- (1), alpha-D-galacto- (6), beta-D-gluco- (18), (22), and alpha-D-manno-pyranoside (31), and benzyl beta-D-glucopyranoside (27), gave the corresponding 6-O-bromoacetyl derivatives 2, 7, 19, 23, 32, and 28 in -% yields. Bromoacetylation of methyl 3-O-benzyl-beta-D-galactopyranoside (11) afforded methyl 3-O-benzyl-6-O-bromoacetyl-beta-D-galactopyranoside (12, %) as well as methyl 3-O-benzyl-2,6-di-O-bromoacetyl-beta-D-galactopyranoside (13, 14%). Compounds 2, 7, 19, 23, 32, 28, and 12 were benzoylated and the fully protected derivatives obtained were dehaloacetylated with thiourea to afford the methyl 2,3,4-tri-O-benzoyl-D-glycopyranosides of beta-galactose (5), alpha-galactose benzyl 2,3,4-tri-O-benzoyl-beta-D-glucopyranoside () and methyl 3-O-benzyl-2,4-di-O-benzoyl-beta-D-galactopyranoside (15). These compounds can be used as nucleophiles for the synthesis of (1----6)-linked oligosaccharides. Oligosaccharides ----5 could be performed without isolation of the intermediates. The treatment of bromoacetyl derivatives with benzoyl chloride in pyridine resulted in the benzoylation of the remaining free hydroxyl groups and the simultaneous substitution of bromine by chlorine, yielding the corresponding mono-O-chloroacetyl derivatives. Benzoylations with benzoyl bromide avoided this secondary event.

Glycosyl donors differentially substituted to allow further extension of the oligosaccharide chain at position 6 of D-glucose, D-galactose, and D-mannose, and sequentially at positions 6 and 3 in the case of the D-galactosyl donor derived from 15, were readily obtained by treatment of the appropriate, fully protected methyl glycosides with 1,1-dichloromethyl methyl ether in the presence of a catalytic amount of zinc chloride.Analysis of specific interactions of synthetic glycopolypeptides carrying N-acetyllactosamine and related compounds with lectins.Analysis of interactions of synthetic glycopolypeptides with lectins was performed with a biosensor based on surface plasmon resonance (SPR). A series of synthetic oligosaccharide-substituted poly(L-glutamic acid)s were immobilized on sensor surfaces via the gamma-carboxyl groups of their peptide moieties by the surface thiol coupling method. Artificial glycopolypeptides an N-acetyllactosamine-substituted polymer (1), an N-acetylisolactosamine-substituted polymer (2), a (GlcNAc)3-substituted polymer N-acetyl-beta-lactosaminide-substituted polymer (5), were used as the ligands. On analysis by SPR, surface-bound polymers 1 and 5 reacted with Erythrina cristagalli agglutinin (ECA), Lycopersicon esculentum agglutinin (LEA), Ricinus communis agglutinin-1 (RCA1), and wheat germ (Triticum vulgaris) agglutinin results indicate that beta-(1--4)-linked galactosyl residues are needed for binding to ECA and LEA. Polymer 3 reacted strongly with LEA and WGA, but polymer 4 reacted strongly only with WGA.

Affinity constants (KA) for surface-bound polymer 5-lectin interactions were also about 4-61 times as strong as those for surface-bound polymer 1-lectin interactions. These artificial glycopolypeptides were shown to be useful as tools and probes of carbohydrate recognition and modeling in the analysis of glycoprotein-lectin interactions.Cellulose Nanofibril Formulations Incorporating a Low-Molecular-Weight Alginate Oligosaccharide Modify Bacterial Biofilm Development.Jack AA(1), Nordli HR(2), Powell LC(1), Farnell DJJ(1), Pukstad B(2)(3), Rye School of Dentistry , Cardiff CF14 4XY , U.K.