Sugar acid

With sugar acids refers to polyhydroxycarboxylic acids by oxidation of simple sugars ( monosaccharides ) are formed. The aldehyde group or the primary ( terminal ) or alcohol group at ketoses are the primary alcohol group is oxidized to a carboxyl group in aldose.

  • From aldoses arise as with mild oxidizing aldonic acids, in which the aldehyde group is oxidized ( for example, D -glucose → D - gluconic acid ).
  • , The primary alcohol group is oxidized in aldoses, one obtains uronic acids (such as D-glucose → D-glucuronic acid ).
  • For more energetic oxidation of aldoses aldaric arise ( for example, D -glucose → D- glucaric acid, the sugar acid in the narrow, technical sense ), bearing two carboxyl groups.
  • Ketoaldonic arise formally by oxidation of the primary alcohol group of ketoses, but technically by oxidation of a secondary alcohol group of Aldonic acids (eg, D -fructose → 2-oxo- D -gluconic acid ).

Watch Rules to the oxidation products of the monosaccharides

  • In the Fischer projection Where the underlying oxidized monosaccharides above, ie at C1, they are called onic acids ( Aldonic acids ), such as gluconic acid.
  • In the Fischer projection Where the underlying oxidized monosaccharides down, so on the last C, they are called uronic acids such as glucuronic acid.
  • In the Fischer projection Where the underlying oxidized monosaccharides up and down, so the C1 and the last C ( that is, everything is oxidized), they are called Arsäuren ( aldaric ), such as glucaric acid.

Properties

Sugar acids tend to lactone formation. Many sugar acids occur as metabolites or components of polymeric natural products (eg, pectins, the glycosaminoglycans of chondroitin sulfate, etc.).

Swell

  • Hermann Rompp ( Lim. ), Jürgen Falbe (ed. ), Manfred Regitz (ed.): Encyclopedia of chemistry Rompp. 10th edition. Thieme, Stuttgart 1999, ISBN 3-13-107720-4.
  • Hans Beyer, Wolfgang Walter: Textbook of Organic Chemistry. 20th edition. Hirzel, Stuttgart 1984, ISBN 3-7776-0406-2, p 398
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