Search results for "Arid"

Influence of Nitrogen Content on Grape Non-Saccharomyces Glycosidic Activities

2019

This study investigated the influence of nitrogen content on both β-glucosidase and β-xylosidase activities from non-Saccharomyces yeasts. Enzymatic activities were induced by the presence of xylan polysaccharides in the medium. Results show that optimizing β-glucosidase and β-xylosidase enzymatic activities can be determined not only by sugar or ethanol content or pH, but also by the concentration of N in the medium. This is the first work studying the influence of N content on glycolytic enzymes produced by non-Saccharomyces yeasts.

A xyloglucan from persimmon fruit cell walls

1998

Persimmon (Diospyros kaki L.) fruit cell walls have been shown to contain a high proportion of xyloglucan. This hemicellulosic polysaccharide appears to play a crucial role in the softening process that accompanies fruit ripening. In the present work, xyloglucan from persimmon fruit cell walls was extracted, purified and chemically characterized from alkali-extracted hemicelluloses. Monosaccharide analysis of purified xyloglucan showed a molar ratio of Glc:Xyl:Gal:Fuc of 10.0:6.0:3.4:1.4. Linkage analysis showed a high proportion of terminal residues, indicating a low degree of polymerization of side-chains.

Chitin: A Structural Biopolysaccharide with Multiple Applications

2014

Chitin is a naturally occurring fibre-forming polymer that plays a protective role in many lower eukaryotes similar to that of cellulose in plants. Chemically it is a long-chain unbranched polysaccharide made of N-acetylglucosamine residues linked through β-1,4 covalent bonds; it is the second most abundant organic compound in nature, after cellulose. Taking into account the role played by chitin in different biological structures (i.e. fungal cell walls, insect peritrophic matrix, insect and crustacean cuticles, eggshells from nematodes, cyst wall of protozoa), its metabolism (biosynthesis and degradation) is essential for different morphogenetic events. Absent in vertebrates and plants, c…

An Uncommon Pathway in the Biosynthesis of Acetylenic Fatty Acids in Mosses

1995

Although more than 600 acetylenic compounds of various structures have been found in plants [1], hardly anything is known about the formation of the triple bonds. The acetylenes so far known from Bryophytes, have been identified as long chain fatty acids with a characteristic arrangement of one triple bond and one to three double bonds.

Carbohydrates from Chemical Pulps: Characterization by Capillary Zone Electrophoresis

2006

Capillary zone electrophoresis (CZE) is one of the novel separation techniques, being applicable, for example, to virtually all important biomass-derived monosaccharides. However, in spite of this fact the utilization of this technique in the pulp and paper industry is currently rather limited. In this chapter practical guidance and some application examples are given to show how carbohydrate material (polysaccharides, oligosaccharides, and neutral and acidic monosaccharides) in pulps and spent liquors can be analyzed by CZE. Emphasis is placed on sample preparation and separation conditions including comparison with other separation methods, such as gas chromatography (GC) and high-perform…

C1q

2000

Publisher Summary This chapter provides information to the physical properties, structure, and function of C1q protein. This protein is made up of three individual polypeptide chains, A, B and C, which are synthesized as pre-molecules with 22, 25, and 28 amino acid leader sequences, respectively. C1q has a characteristic appearance under the electron microscope, with six globular heads connected by six collagen-like stalks forming a central fibril stem. Glucosylgalactosyl disaccharide units are linked to certain hydroxylysine residues in the collagen regions of all three chains. C1q has a critical function in host defense and clearance of immune complexes. Antibody-independent activation of…

Dextran-Based Polycations: Thermodynamic Interaction with Water as Compared With Unsubstituted Dextran, 1 - Volumetric Properties and Light Scattering

2011

Synthesis of Protected Enantiopure Erythrulose Derivatives

1996

D- and l-Erythrulose derivatives 2–6 bearing protective O-silyl and O-benzyl groups in various positions were synthesized in enantiopure form from l-ascorbic acid, D-isoascorbic acid, and D-glucose.

Synthesis of 1,3- and 2,3-Diglycosylated Indoles as Potential Trisaccharide Mimetics

2012

Diglycosylated heteroaromatics may serve as metabolically stable mimetics of trisaccharides. Herein, the preparation of several 1,3- and 2,3-diglycosylindoles by direct C-glycosylation of monoglycosylated precursors is described.

Carbohydrates as Polyfunctional Scaffolds in Combinatorial Synthesis

2006

Carbohydrates are inexpensive, polyfunctional molecules which contain a high density of stereogenic centers. Taking advantage of these particular properties monosaccharides like glucose or mannose have been used for the construction of peptidomimetics which simulate recognition sites of somatostatin or RGD ligands of integrins. Due to their poly functionality, carbohydrates are considered promising scaffolds for combinatorial syntheses either in solution or on solid phase. The application of carbohydrate scaffolds, however, requires sets of orthogonally stable, selectively removable protecting groups, and the challenge in this combinatorial strategy increases with increasing number of hydro…