Chapter 1: Basic Information of Carbohydrates
I. Types of Carbohydrates
Monosaccharides
Disaccharides
Oligosaccharides
around 10 carbohydrates but not specific
Polysaccharides
II. Monosaccharides
(i) Based on the functional groups:
Aldose: terminal aldehyde
Ketose: internal ketone
(ii) Based on the number of carbon atoms:
triose, tetrose, pentose, hexose etc.
CH2OH
CHO
O
H
OH
HO
H
H
H
OH
H
OH
H
OH
OH
CH2OH
CH2OH
Aldopentose
Ketohexose
1
(iii) Aldoses and Fisher Projection
CHO
H
CHO
OH
H
OH
CH2OH
CH2OH
D-Glyceraldehyde (Aldotriose)
CHO
HO
CHO
H
HO
H
CH2OH
CH2OH
L-Glyceraldehyde
CHO
CHO
H
OH
HO
H
H
OH
HO
H
H
OH
H
OH
H
OH
H
OH
CH2OH
CH2OH
D-Aldohexose
CHO
CHO
H
HO
H
HO
OH
H
OH
H
CH2OH
H
HO
H
HO
OH
H
OH
H
CH2OH
L-Aldohexose
2
CHO
Aldotetroses
CHO
H
OH
HO
H
HO
H
OH
HO
H
H
CH2OH
CH2OH
D-Erythrose
L-Erythrose
CHO
H
OH
H
OH
HO
H
OH
H
OH
H
D-Arabinose
H
H
HO
H
D-Xylose
H
OH
CH2OH
D-Lyxose
CHO
CHO
H
H
HO
H
HO
H
H
HO
H
HO
H
HO
HO
CH2OH
L-Arabinose
CHO
HO
CH2OH
HO
L-Ribose
OH
OH
CHO
OH
H
CHO
H
CH2OH
CH2OH
HO
CHO
H
OH
CH2OH
HO
CHO
OH
H
L-Threose
OH
D-Ribose
H
CH2OH
H
Aldopentoses
CHO
D-Threose
CHO
CH2OH
Aldohexoses
CHO
H
H
OH
OH
H
OH
H
HO
H
CH2OH
L-Xylose
CH2OH
L-Lyxose
CHO
CHO
H
OH
HO
H
OH
H
OH
HO
H
OH
H
OH
H
OH
H
OH
H
OH
H
OH
H
OH
H
OH
H
CH2OH
CH2OH
D-Allose
D-Altrose
CHO
OH
HO
H
OH
H
H
H
OH
CH2OH
D-Gulose
H
H
HO
H
D-Glucose
CH2OH
D-Mannose
H
CHO
OH
HO
H
HO
H
HO
H
H
HO
H
HO
H
CH2OH
3
H
OH
OH
D-Idose
HO
CHO
H
HO
OH
CH2OH
CHO
H
HO
H
CHO
H
OH
CH2OH
D-Galactose
H
OH
CH2OH
D-Talose
(iv) Ketoses and Fisher Projection
CH2OH
O
Ketotrioses
CH2OH
Dihydroxyacetone
CH2OH
CH2OH
O
Ketotetroses
H
O
OH
HO
H
CH2OH
D-Erythrulose
CH2OH
CH2OH
CH2OH
O
Ketopentoses
O
O
H
OH
HO
H
HO
H
OH
HO
H
H
CH2OH
D-Ribulose
CH2OH
CH2OH
L-Ribulose
CH2OH
O
Ketohexoses
L-Erythrulose
CH2OH
O
H
OH
H
OH
HO
H
OH
H
OH
H
D-Fructose
4
H
CH2OH
HO
CH2OH
HO
OH
L-Xylulose
CH2OH
O
H
H
CH2OH
OH
D-Psicose
OH
O
D-Xylulose
CH2OH
H
CH2OH
H
CH2OH
H
OH
HO
H
H
HO
H
OH
CH2OH
D-Sorbose
O
H
OH
CH2OH
D-Tagatose
III. Cyclic Structures of Monosaccharides
(i) Formation of cyclic hemiacetals from aldoses or hemiketals from ketoses
Five-membered ring: furanose
O
furan
Six-membered ring: pyranose
(Haworth projection is not good for pyranoses)
O
(ii) Cyclic hemiacetal of D-glucose
1
pyran
CHO
2
H
OH
3
HO
H
5-OH
5
5
O
HO
HO
4
H
OH
OH
1
OH
OH
+
O
HO
HO
1
OH
OH
OH
5
H
OH
6 CH OH
2
D-Glucose
1
-D-Glucopyranose
-D-Glucopyranose
CHO
2
H
OH
3
HO
H
4
H
OH
4-OH
HO
OH
O
4
HO
1
OH
+
4
HO
O
1
OH
5
H
OH
HO
OH
OH
OH
6 CH OH
2
D-Glucose
-D-Glucofuranose
5
-D- Glucofuranose
(iii) Important cyclic monosaccharides
OH
HO
HO
HO
O
OH
O
OH
OH
O
HO
HO
OH
Furanose
s
HO
OH
OH
D-Ribofuranose
HO
-D-Fluctofuranose
D-Glucofuranose
O
OH
OH
OH
OH
HO
D-Galactofuranose
OH
OH
O
OH
O
OH
OH
OH
HO
HO
D-Glucopyranose
D-Altropyranose
HO
HO
OH
OH
OH
O
OH
OH
O
O
HO
HO
OH
OH
OH
D-Mannopyranose
OH
D-Gulopyranose
HO
OH
OH
O
OH
O
OH
OH
D-Idopyranose
O
HO
HO
OH
HO
HO
OH
OH
OH
OH
OH
HO
O
HO
HO
L-Glucopyranose
O
OH
6
HO
O
OH
HO
HO
D-Arabinpyranose
OH
D-Xylopyranose
D-Talopyranose
D-Galactopyranose
OH
OH
OH
OH
D-Allopyranose
HO
O
HO
HO
Pyranose
s
OH
HO
OH
OH
L-Arabinpyranose
IV. Disaccharides and Trisaccharides
Name
Structure
1st Sugar
2nd Sugar
Glycosidic
bond
Glucose
Fructose
(1→2)
Galactose
Glucose
(1→4)
Glucose
Glucose
(1→4)
Glucose
Glucose
(1→1)
Glucose
Glucose
(1→4)
Galactose
Glucose
(1→6)
OH
O
HO
HO
OH
HO
Sucrose
O
O
HO
OH
HO
OH
HO
Lactose
OH
O
O
O
HO
HO
OH
OH
OH
Maltose
OH
O
HO
HO
OH
O
OH
O
HO
OH
OH
HO
OH
O
OH O
Trehalose
O
OH
OH
HO HO
OH
OH
Cellobiose
OH
O
O
HO
HO
O
HO
OH
OH
HO
OH
OH
O
HO
Melibiose
HO
O
HO
HO
O
OH
7
OH
OH
O
HO
HO
OH
HO
O
O
HO
OH
HO
O
O
HO
OH
OH
Maltotriose
OH
HO
HO
OH
O
O
HO
HO
OH
O
O
O
HO
HO
OH
Cellotriose
8
OH
V. Polysaccharide
Cellulose
OH
O
HO
OH
OH
O
HO
O
O
OH
OH
O
O
HO
HO
O
O
OH
OH
OH
OH
O
HO
OH
OH
O
HO
O
O
HO
O
OH
OH
O
HO
O
O
OH
OH
OH
OH
O
HO
OH
OH
O
HO
O
O
HO
O
OH
OH
O
HO
O
O
OH
OH
OH
9
Glycogen
OH
O
O
HO
OH
O
HO
OH
HO
O
O
HO
OH
O
HO
O
HO
HO
O
O
HO
O
O
HO
OH
HO
O
O
HO
OH
O
10
(i). Types of Unusual Sugars
Deoxysugars
H3C
O
HO
HO
OH
OH
Aminosugars
H3C
O
HO
H 2N
OH
OH
Branched-chain sugars
H3C
O
HO
HO
OH
OH
CH3
13
(i). Types of Unusual Sugars
Deoxysugars
H3C
O
HO
HO
OH
OH
Aminosugars
H3C
O
HO
H 2N
OH
OH
Branched-chain sugars
H3C
O
HO
HO
OH
OH
CH3
13