7. MONOSACCHARIDES AND OLIGOSACCHARIDES
327
M. NATURAL COMPOUNDS BETWEEN CARBOHYDRATES AND ACIDS
(EXCLUDING PHOSPHORIC)
In natural environments a number of mono- and disaccharides are
known to occur with one or more of their hydroxyl groups esterified
by carboxylic acid radicals. These radicals are acetyl, benzoyl, and trihydroxybenzoyl (galloyl). In addition pectic acid and gums are known
to contain monosaccharide units which are acetylated, but, owing to the
concomitant hydrolysis of the ester and glycosidic links, it has not been
possible to determine the position of these ester groupings in the parent
material. Birch wood xylan, which carries O-acetyl substituents has,
however, been investigated (166).* 2-Carboxyacetyl (malonyl) and
aminoformyl (carbamoyl) radicals are known to esterify carbohydrate
moieties in certain fungal products. The free carboxyl group in the
hydrogen malonyl esters confers acidic properties on the parent substances. (See also Section V,P.)
1. Hydrogen Sulfates
Hydrogen sulfate derivatives of polysaccharides are widespread. In
some of these the esterified positions have been established, but no
simple, or relatively simple, sulfated carbohydrates have been so far deTABLE I
SULFATED POLYSACCHARIDE TYPES
Main units
Name of polysaccharide
Source
References
D-Glucose
D-Glucose
L-Fucose, D-galactose,
D-mannose, D-galacturonic acid, D-glucosamine
D- and L-galactose
L-Fucose
D-Glucuronic and D-galacturonic acids D-G1UCOsamine and D-galactosamine
(?) Cellulose sulfate
Charonia lampas
a
(167)
(?) Cellulose sulfate
Busycon canaliculatum
a
(168)
Limacoitin sulfate
Japanese snail
Carrageenins
Fucoidins
Heparin
Keratosulfate
Chondroitin sulfates
Mactins
Red algae
Brown algae
ί
Animal connective
tissues
Clams
(169)
(170, 171)
(170, 171)
(172)
° Marine snails.
tected in a biological environment except the cerebroside sulfuric ester
of beef brain, which is essentially a glycoside of D-galactose-6-O-sulfate
(166a). Table I summarizes those monosaccharide units known to bear
acid sulfate groups.
* The acetyl groups are believed to occupy position 3 on the xylose units
(166).
327
M. NATURAL COMPOUNDS BETWEEN CARBOHYDRATES AND ACIDS
(EXCLUDING PHOSPHORIC)
In natural environments a number of mono- and disaccharides are
known to occur with one or more of their hydroxyl groups esterified
by carboxylic acid radicals. These radicals are acetyl, benzoyl, and trihydroxybenzoyl (galloyl). In addition pectic acid and gums are known
to contain monosaccharide units which are acetylated, but, owing to the
concomitant hydrolysis of the ester and glycosidic links, it has not been
possible to determine the position of these ester groupings in the parent
material. Birch wood xylan, which carries O-acetyl substituents has,
however, been investigated (166).* 2-Carboxyacetyl (malonyl) and
aminoformyl (carbamoyl) radicals are known to esterify carbohydrate
moieties in certain fungal products. The free carboxyl group in the
hydrogen malonyl esters confers acidic properties on the parent substances. (See also Section V,P.)
1. Hydrogen Sulfates
Hydrogen sulfate derivatives of polysaccharides are widespread. In
some of these the esterified positions have been established, but no
simple, or relatively simple, sulfated carbohydrates have been so far deTABLE I
SULFATED POLYSACCHARIDE TYPES
Main units
Name of polysaccharide
Source
References
D-Glucose
D-Glucose
L-Fucose, D-galactose,
D-mannose, D-galacturonic acid, D-glucosamine
D- and L-galactose
L-Fucose
D-Glucuronic and D-galacturonic acids D-G1UCOsamine and D-galactosamine
(?) Cellulose sulfate
Charonia lampas
a
(167)
(?) Cellulose sulfate
Busycon canaliculatum
a
(168)
Limacoitin sulfate
Japanese snail
Carrageenins
Fucoidins
Heparin
Keratosulfate
Chondroitin sulfates
Mactins
Red algae
Brown algae
ί
Animal connective
tissues
Clams
(169)
(170, 171)
(170, 171)
(172)
° Marine snails.
tected in a biological environment except the cerebroside sulfuric ester
of beef brain, which is essentially a glycoside of D-galactose-6-O-sulfate
(166a). Table I summarizes those monosaccharide units known to bear
acid sulfate groups.
* The acetyl groups are believed to occupy position 3 on the xylose units
(166).