The genus Cinnamomum

R
OH
4
HO
O
O
O
OH
Chemistry of Cinnamon and Cassia 109
I II
OH
Cinncassiol C1
R = OH
Cinncassiol C1 glucoside
R = O Glu
HO
HO
6
HO
8
HO
O
O
O
Cinncassiol C 3
O H
Cinncassiol D3
OH
OH
OH
OH
19
OH
O
Cinnamon bark also contains large amounts of condensed tannins. Morimoto et al.
(1986a,b) suggested that condensed tannin is the main component responsible for the
medicinal effect of cinnamon bark. Tannins form a large group of poly-phenolic
compounds, and are generally classified into two groups – (1) hydrolysable tannins
which are esters composed of polyphenolic acids (eg: gallic acid and hexahydroxydiphenic
acid) and glucose (or some other sugar or polyalcohol); and (2) condensed
tannins, which are condensates of flavan units, such as ()-catechin and ()-epicatechin.
Cinnamon and cassia barks contain condensed tannins, which are also known as
OR′
18
20
RO
13
17
O
HO
HO
7
OH
OH
OH
HO
5 Cinncassiol C2
R = H
Cinncassiol C2 glucoside
R = Glu
HO
H
O H
R
Cinncassiol D 1
R, R′ = H
Cinncassiol D1 glucoside
R = H , R′ = glu
Cinncassiol D2
R = OH , R′ = H
Cinncassiol D 2 glucoside
R = OH, R′ = glu
HO
OH
11
12
14
7
8
OH
O
6
10
9
16
Cinncassiol E I
Figure 3A.2 Secondary metabolites from barks of cinnamon and cassia (see text for explanation).
9
5
OH
4
OH
1
OH
15
OH
2
3