Factbites
 Where results make sense
About us   |   Why use us?   |   Reviews   |   PR   |   Contact us  

Topic: Glycosylamine


Related Topics

In the News (Sun 15 Nov 09)

  
  Uli.Iserloh.Blog » Birch Reactions on Carbohydrates
In N-linked glycopeptides 4, the asparagine carboxamide is glycosylated with a conserved (high mannose) pentasaccharide core structure.
Within the cellular context, this linkage is generated via glycosylation of the asparagine amide side-chain, while a common chemical synthesis approach involves peptide-bond formation between a glycosylamine 2 and the side-chain carboxylate of a uniquely disposed aspartate 3.
In many cases, the requisite glycosylamine 2 is generated via standard Kochetkov-Lansbury amination (NH O, 25° C) from the globally deprotected parent saccharide 1, featuring a free anomeric hydroxyl-group.
www.iserloh.com /chemistry/birch   (255 words)

  
 Info Archive Site   (Site not responding. Last check: 2007-10-29)
An attractive feature of the theory is that the reactants (sugars, amino acids etc.) are produced in abundance through the activities of microorganisms.
The glycosylamine subsequently undergoes to form the N-substituted-1-amino-deoxy-2-ketose.
This is subject to: fragmentation and formation of 3-carbon chain aldehydes and ketones, such as acetol, diacetyl etc.; dehydration and formation reductones and hydroxymethyl furfurals.
www.reach-for-life.com /MSprod/fulvic_formation.htm   (1042 words)

  
 ajay
positions to result in 4,6-O-ethylidene-D-glucopyranose and further it is condensed with a variety of aryl amines and ammonia to result in the corresponding glycosylamines.
  One of the glycosylamine derived from anthranilic acid and three different glycosylamine based Schiff base molecules were used in metal complexation reactions.
A.K. Sah, C.P. Rao, P.K. Saarenketo, E.K. Wegelius, K. Rissanen and E. Kolehmainen, “N-Glycoside of ortho substituted anilines of 4,6-O-Ethylideneglucopyranose:  Synthesis, characterization and structure of –COOH, -Cl and –F substituted glycosylamines and metal ion complexes of –COOH derivative”.
www.chem.iitb.ac.in /~cprao/STUDENTS_files/Ph.D/ajay-2002.htm   (549 words)

  
 Influence of Core Fucosylation on the Flexibility of a Biantennary N-Linked Oligosaccharide
Fluorescence energy transfer was used to study the conformation of each antenna of a complex biantennary oligosaccharide.
A core fucosylated biantennary oligosaccharide was converted to a glycosylamine which allowed coupling of a naphthyl donor fluorophore directly to the reducing-end GlcNAc 1.
After generating an aldehyde at C-6 of residue 6 or 6' using galactose oxidase, a dansyl ethylenediamine acceptor fluorophore was coupled to either antenna of the oligosaccharide resulting in two donor-acceptor pairs.
pubs.acs.org /cgi-bin/abstract.cgi/bichaw/1996/35/i03/abs/bi9513719.html   (323 words)

  
 Involvement of Hydrogen Peroxide in Collagen Cross-linking by High Glucose in Vitro and in Vivo -- Elgawish et al. 271 ...
In the presence of Amadori compounds, kinetic changes were dramatically increased and were preventable by addition of catalase to the medium.
This concept was challenged by Namiki (7) who found that sugar fragmentation can also occur at the stage of the glycosylamine, or Schiff base, i.e.
In the case of CML, both the presence of glycosylamine and Amadori products were major contributors to CML formation, most likely by a mechanism involving glyoxal formation (8, 9).
www.jbc.org /cgi/content/full/271/22/12964   (6248 words)

  
 Christianity and the Shroud of Turin Mystery
This is the result of a chemical change: the formation of a complex carbon-carbon double molecular bond within the coating.
There are two ways this could have happened chemically: 1) caramelization, whereby heat causes molecular breakdown into other volatile compounds and 2) a Maillard reaction in which a carbonyl group of sugars reacts with an amino group producing N-substituted glycosylamine.
The unstable glycosylamine undergoes Amadori rearrangement, forming ketosamines, which then form nitrogenous polymers and melanoidins.
www.historicaljesusquest.com /mandylion.htm   (3104 words)

  
 IIT Bombay - Electronic Theses and Dissertations   (Site not responding. Last check: 2007-10-29)
The thesis primarily deals with the synthesis and structure determination of a number of glycosylamines and glycosylimines based on D-glucose and D-ribose, and their metal ion complexes.
A total of nine glycosylamines of 4,6-O-butylidene-alpha-D-glucopyranose were synthesized using primary aromatic amines possessing various groups in their ortho- or para-positions.
All the complexes are neutral and dinuclear with the metal to the glycosylamine ratio being 1:1.
www.library.iitb.ac.in /~mnj/etd/che.html   (1388 words)

  
 D0001: Semicarbazide Derivatives of Monosaccharides as Models for Oligosaccharide/Amine Interactions   (Site not responding. Last check: 2007-10-29)
We view these structures as potential model systems for the linkages between oligosaccharides and the biotin-linked hydrazide labeling agents used in carbohydrate-protein recognition studies [1].
In the macromolecular systems in which these agents are used, the product of the reaction between the oligosaccharide and the hydrazide labeling agent could be an open-chain hydrazone or a cyclic glycosylamine.
Although an equilibrium between these two forms of the corresponding small molecules may exist in solution, the compounds we have isolated in the solid state upon reaction of these three particular monosaccharides with semicarbazide are all glycopyranosylamines (structure of the D-glucose derivative shown below).
aca.hwi.buffalo.edu /ACA01/abstracts/text/D0001.html   (230 words)

  
 Nelson and Bozich, July, 1996   (Site not responding. Last check: 2007-10-29)
C, small increases were observed up to 48 h but a large increase was observed after 168 h.
Contributors to increased NDF seemed due to changes in protein solubility and glycosylamine formation when fresh forage was stored at 60
C, formation of adducts with arabinose and glucose from nonstructural carbohydrates as well as polymerization and fragmentation of cell wall monosaccharides probably contributed to altered NDF content of alfalfa.
www.asas.org /jas/papers/1996/jul/jul1689abs.html   (208 words)

  
 ScottBrosCoffee.com_Magic
At high heat, from 185 to 240 degrees Celsius, sugars combine with amino acids, peptides and proteins according to a well-known caramelization process called Maillard's reaction.
The end products are brownish, bittersweet glycosylamine and melanoidins — which give rise to coffee's dominant taste — along with carbon dioxide (up to 12 liters per kilogram of roasted coffee).
Simultaneously, a wide variety of lower-mass aromatic molecules emerge; these volatile compounds give coffee its familiar fragrance.
www.scottbroscoffee.com /whybuy/whybuy_magic.htm   (879 words)

  
 CAP - Clinical Abstracts - September 2005
MG is the most reactive AGE precursor, and its concentration is increased in diabetics.
MG reacts irreversibly with lysine to form glycosylamine protein cross-links and with arginine to give imidazolone derivatives.
AGEs are associated with complications of rheumatoid arthritis, Alzheimer's disease, and diabetes.
www.cap.org /apps/cap.portal?_nfpb=true&cntvwrPtlt_actionOverride=/portlets/contentViewer/show&_windowLabel=cntvwrPtlt&cntvwrPtlt{actionForm.contentReference}=cap_today/clinical_abstracts/Clinical_0905.html&_state=maximized&_pageLabel=cntvwr   (2666 words)

  
 Making Flavour Chemicals At Home   (Site not responding. Last check: 2007-10-29)
It is a complicated reaction with many steps, so I'm going to look at the first step in which a carbonyl group of a reducing sugar is condensed with a free amino group of a protein or amino acid.
This loses a molecule of water to form N-substituted glycosylamine:
The final products of the reaction are brown nitrogenous polymers and copolymers called melanoidins.
www.chem.shef.ac.uk /chm131-2003/chb03jb/maillard.html   (296 words)

  
 [No title]   (Site not responding. Last check: 2007-10-29)
¡Zê!Zÿÿþ$ÿÿþ-Œÿÿþª,)“ó 'Ÿ¨ Carbohydrates¡ÿÿþŸ¨¡Chemical Reactions of Sugars Maillard Reaction Basics Reactions: The aldehyde form of the aldose binds to the amino acid or protein to form a glycosylamine.
Through enolization (reaction between an alkene and ketone) and dehydration melanoidins are formed producing colored pigments.
Glycosylamines and the further products produce characteristic flavors depending upon the saccharide and amino acids involved.
www.csuchico.edu /nfsc/04fall/120carbohydrates1.ppt   (1138 words)

  
 Previous Exam 1   (Site not responding. Last check: 2007-10-29)
Describe three (3) ways to minimize Maillard browning in foods and explain why each method or treatment is effective.
Draw and label an example (the entire reaction) of the formation of a glycosylamine in the initial stages of Maillard browning.
List three (3) examples of structures containing a glycosidic bonds (two must involve non-carbohydrate materials) (6 pts).
www.uky.edu /Ag/FoodScience/test1-434.html   (292 words)

  
 Abstract Details
The experimental mass profile of tryptic digested glycodelin and glycan from the full scan were then submitted for the mass peptide fingerprinting (MFP) using the protein database (www.matrixscience.com) and for glycan compositions mapping using the GlycoMol shareware (www.expasy.org).
The identification of each N-glycosylation site was based on the 0.98-Da mass increase observed upon hydrolysis by the amidase PNGase F of the glycosylamine linkage of each N-glycosylated asparagine, which formed an aspartic acid residue.
The proposed peptide sequence and its potential N-glycosylation sites were verified using both micro-LC- and MALDI-tandem mass spectrometry under low-energy collision-induced dissociation.
www.asms.org /Desktopmodules/inmergeabstractsearch/programprintview.aspx?sess=WP20   (8962 words)

Try your search on: Qwika (all wikis)

Factbites
  About us   |   Why use us?   |   Reviews   |   Press   |   Contact us  
Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.