Fundamentals of Medicinal Chemistry

O

CH 2 OH

H

H

OH

H

H

OH

OH

H

H

HO

OH

O

H

H

OH

OH

H

α-D-Xylopyranose

(α-D-xylose)

CHO

OH

OH

CH 2 OH

H

H

CH 2 OH

CH 2 OH

H

H

OH

CO

OH

CO

CH 2 OH

H

CH 2 OH

OH

H OH

HO H

H OH

D-gluco-Hexose

(D-Glucose)

D-xylo-Hexulose

(D-Fructose)

D-gluco-Heptulose

D-erythro-Pentulose

(D-Ribulose)

(D-Ribose)

D-erythro-Tetrose

(D-Erythrose)

β-D-Glucopyranose

(β-D-glucose)

β-D-Ribofuranose

(β-D-ribose)

OH

O

H

H

H

H

3 

OH

5 

2 

4  1 

HOCH 2

H

β-D-Deoxyribofuranose

(β-D-Deoxyribose)

H

OH

H

H

HOCH (^2) O OH
H
OH
(a)
(b)
HO H
HOH
H
H OH
CHO
CH 2 OH
OH
HO
OH
H
C
H
H OH
O
CH 2 OH
CH 2 OH
Figure 1.16 Monosaccharide nomenclature. Commonly used trivial names are given in the
brackets

monosaccharides are based on a stem name indicating the number of carbon

atoms, a prefix indicating the configuration of the hydroxy group and either the

suffix-ose(aldoses) or-ulose(ketoses). In addition the name is also prefixed by

the D or L as appropriate (Figure 1.16(a)). Five membered ring monosacchar-

ides have the stem namefuranosewhilst six membered ring compounds have the

stem namepyranose together with the appropriate configurational prefixes

indicating the stereochemistry of the anomers (Figure 1.16(b)). Monosacchar-

ides in which one of the hydroxy groups has been replaced by a hydrogen atom

have the prefixdeoxy-with the appropriate locant, except if it is at position 2,

when no locant is given.

1.4.3 Glycosides

Many endogenous compounds occur as glycosides. These are compounds

which consist of a carbohydrate residue, known generally as aglycone, bonded

to a non-sugar residue, known generally as an aglycone, by a so called

glycosidic linkto the anomeric carbon of the glycone. Since the glycosidic

link is formed to the anomeric carbon botha- andb-isomers of a glycoside

are known. The structures of glycosidic links vary, the most common being

an ether group (oxygen glycosidic links) but amino (nitrogen glycosidic

CARBOHYDRATES 15