Deoxy sugar

Comparison of deoxy sugar and "normal" sugar

The deoxy sugar fucose [in the Fischer projection (open representation)] contains one less hydroxyl group in the 6-position than the “normal” sugar galactose (bottom).

For comparison, a "normal" sugar, here galactose, in the Fischer projection (open representation)

Deoxysugars are monosaccharides in which one or, more rarely, several hydroxyl groups have been replaced by hydrogen atoms. Most of the naturally occurring deoxy sugars are deoxyaldoses . Deoxy sugars are usually not free, but rather glycosidically bound.

In the monosaccharides, either a primary or a secondary hydroxyl group is missing , resulting in deoxy sugars with a terminal methyl group or a central methylene group .

Examples

Methyllose

The most common 6-deoxy - also Methylosen or methylpentose mentioned - is the L - rhamnose (6-deoxy- L -mannose). L - fucose (6-deoxy- L- galactose) is found in the blood group substances . The analogous ketohexose of fucose is fuculose . Methyl ethers of methyllose are also found in nature , e.g. B. D - digitalose (6-deoxy-3- O- methyl- D- galactose) contained in drugs .

nucleic acid

The deoxyribose is a constituent of deoxyribonucleic acid (DNA) and has no hydroxy group at the C2 atom, but two H atoms. In the RNA , the transcribed DNA, the ribose is not in the deoxy form and therefore has an HO group on the C2 atom.

Individual evidence

1. ^ Peter Nuhn: Naturstoffchemie , S. Hirzel Wissenschaftliche Verlagsgesellschaft, Stuttgart 1990, ISBN 3-7776-0473-9 , p. 578.
2. ^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag, Leipzig 1965, p. 277.
3. ↑ The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals , 9th Edition (Merck & Co., Inc.), Whitehouse Station, NJ, USA, 1976; ISBN 0-911910-26-3 , p. 417.