Everything about The Amadori Rearrangement totally explained
The
Amadori rearrangement is an
organic reaction describing the
acid or base catalyzed isomerization or
rearrangement reaction of the N-
glycoside of an
aldose or the
glycosylamine to the corresponding 1-
amino-1-
deoxy-
ketose. The reaction is important in
carbohydrate chemistry.
The
reaction mechanism is demonstrated starting from the reaction of D-
mannose in its closed (
1) and open-form (
2) with
ammonia the 1,1-amino-alcohol
3 which is unstable and loses water to the
glycosylamine (again the open
imine (
5) and the closed form
hemiaminal (
4)) which is the starting point for the actual Amadori rearrangement.
By treatment of the glycosylamine with
pyridine and
acetic anhydride the imine group rearranges and the intermediate
enol in turn rearranges to the
ketone. In this particular reaction the all
alcohol and
amino groups are
acylated as well.
The reaction is associated with the
Maillard reaction with reagents naturally occurring sugars and
amino acids.
Amadori product
An
Amadori product is an intermediate in the production of an
advanced glycation end-product (AGE) as a result of
glycation.
The formation of an advanced glycation end-product involves the following steps:
- Formation of a Schiff base: For example the aldehyde group of a glucose molecule will combine with the amino group of a lysine molecule (in a protein) to form an imine or Schiff base, which is a double bond between the carbon atom of the glucose and the nitrogen atom of the lysine.
- Formation of an Amadori product: The Amadori product is a re-arrangement from the Schiff base wherein the hydrogen atom from the hydroxyl group adjacent to the carbon-nitrogen double bond moves to bond to the nitrogen, leaving a ketone.
- Formation of an advanced glycation end-product (AGE): The Amadori product is oxidized, most often by transition metal catalysis.
The first two steps in this reaction are both reversible, but the last step is irreversible.
Further Information
Get more info on 'Amadori Rearrangement'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://amadori_rearrangement.totallyexplained.com">Amadori rearrangement Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |