hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydro ...
group replaced with a
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
atom.
Examples include:
*
Deoxyribose
Deoxyribose, or more precisely 2-deoxyribose, is a monosaccharide with idealized formula H−(C=O)−(CH2)−(CHOH)3−H. Its name indicates that it is a deoxy sugar, meaning that it is derived from the sugar ribose by loss of a hydroxy group. D ...
, or 2-deoxy-D-
ribose
Ribose is a simple sugar and carbohydrate with molecular formula C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H. The naturally-occurring form, , is a component of the ribonucleotides from which RNA is built, and so this compo ...
Fucose
Fucose is a hexose deoxy sugar with the chemical formula C6H12O5. It is found on ''N''-linked glycans on the mammalian, insect and plant cell surface. Fucose is the fundamental sub-unit of the seaweed polysaccharide fucoidan. The α(1→3) li ...
, or 6-deoxy-L-
galactose
Galactose (, '' galacto-'' + ''-ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecu ...
, main component of
fucoidan
Fucoidan is a long chain sulfated polysaccharide found in various species of brown algae. Commercially available fucoidan is commonly extracted from the seaweed species '' Fucus vesiculosus'', ''Cladosiphon okamuranus'', ''Laminaria japonica'' and ...
of
brown algae
Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and p ...
, and present in
N-linked glycan
The terms glycans and polysaccharides are defined by IUPAC as synonyms meaning "compounds consisting of a large number of monosaccharides linked glycosidically". However, in practice the term glycan may also be used to refer to the carbohydrate ...
s
*
Fuculose
Fuculose or 6-deoxy-tagatose is a ketohexose deoxy sugar
Deoxy sugars are sugars that have had a hydroxyl group replaced with a hydrogen atom.
Examples include:
* Deoxyribose, or 2-deoxy-D- ribose, a constituent of DNA
* Fucose, or 6-deo ...
, or 6-deoxy-L-
tagatose
Tagatose is a hexose monosaccharide. It is found in small quantities in a variety of foods, and has attracted attention as an alternative sweetener. It is often found in dairy products, because it is formed when milk is heated. It is similar in t ...
, one of the important components of
avian influenza virus
Avian influenza, known informally as avian flu or bird flu, is a variety of influenza caused by viruses adapted to birds.Rhamnose, or 6-deoxy-L-
mannose
Mannose is a sugar monomer of the aldohexose series of carbohydrates. It is a C-2 epimer of glucose. Mannose is important in human metabolism, especially in the glycosylation of certain proteins. Several congenital disorders of glycosylation ...
, present in plant
glycoside
In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycoside ...
s
In ''
Escherichia coli
''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Esc ...
'' bacteria, deoxyribose sugars are synthesized via two different pathways - one pathway involves
aldol condensation
An aldol condensation is a condensation reaction in organic chemistry in which two carbonyl moieties (of aldehydes or ketones) react to form a β-hydroxyaldehyde or β-hydroxyketone (an aldol reaction), and this is then followed by dehydration to ...
, whereas the other pathway is conversion of a ribose sugar into a deoxyribose sugar by means of changes on the nucleotide or nucleoside level. Deoxyribose is synthesized through the reduction of ribose. Deoxyribose is derived from the same precursor as ribose being that the reduction of the sugar with the extra hydroxyl group results in the deoxy-sugar, which has its hydroxyl group replaced with a hydrogen atom.
Dideoxy sugars
Some biologically important dideoxy sugars, sugars that have had two
hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydro ...
groups replaced with hydrogen atoms, include
colitose
Colitose is a mannose-derived 3,6-dideoxysugar produced by certain bacteria. It is a constituent of the lipopolysaccharide. It is the enantiomer of abequose.
Biological role
Colitose is found in the O-antigen of certain Gram-negative bacteria s ...
and
abequose
Abequose is a hexose and a 3,6-dideoxysugar. It is a constituent of the in O‐specific chains in lipopolysaccharides that occur in certain serotypes of ''Salmonella'' and ''Citrobacter'' bacteria. It is the enantiomer
In chemistry, an enant ...