O
O
O
H
O
O
Diosgenin
Progesterone
A
B
C
D
Spiroketal group
The most abundant starting material for the synthesis of progesterone is
diosgenin isolated from Dioscorea species, formerly supplied from
Mexico, and now from China. The spiroketal group attached to the D
ring of diosgenin can easily be removed. Other steroidal hormones, e.g.
cortisone and hydrocortisone, can be prepared from the starting material
hecogenin, which can be isolated from Sisal leaves found extensively in
East Africa.
O
O
O
H
O
O
O
O
OH
OH
Hecogenin
Cortisone
Spiroketal group
In triterpenoidal saponins, the aglycone is a triterpene. Most aglycones of
triterpenoidal saponins are pentacyclic compounds derived from one of the
three basic structural classes represented by a-amyrin, b-amyrin and lupeol.
However, tetracyclic triterpenoidal aglycones are also found, e.g. ginsenosides. These glycosides occur abundantly in many plants, e.g. liquorice and
ginseng roots contain glycyrrhizinic acid derivatives and ginsenosides,
respectively. Most crude drugs containing triterpenoid saponins are usually
used as expectorants. Three major sources of triterpenoidal glycosides along
with their uses are summarized below.
Plants Botanical names (Family)
Main constituents
Uses
Liquorice root Glycyrrhiza
Glycyrrhizinic acid
In addition to expectorant
glabra (Fabaceae)
derivatives
action, it is also used as a
flavouring agent.
Quillaia bark Quillaja
Several complex
Tincture of this plant is
saponaria (Rosaceae)
triterpenoidal saponins,
used as an emulsifying
e.g. senegin II
agent.
Ginseng Panax ginseng
Ginsenosides
As a tonic, and to
(Araliaceae)
promote the feeling of
well being.
326
CH6 NATURAL PRODUCT CHEMISTRY
O
O
H
O
O
Diosgenin
Progesterone
A
B
C
D
Spiroketal group
The most abundant starting material for the synthesis of progesterone is
diosgenin isolated from Dioscorea species, formerly supplied from
Mexico, and now from China. The spiroketal group attached to the D
ring of diosgenin can easily be removed. Other steroidal hormones, e.g.
cortisone and hydrocortisone, can be prepared from the starting material
hecogenin, which can be isolated from Sisal leaves found extensively in
East Africa.
O
O
O
H
O
O
O
O
OH
OH
Hecogenin
Cortisone
Spiroketal group
In triterpenoidal saponins, the aglycone is a triterpene. Most aglycones of
triterpenoidal saponins are pentacyclic compounds derived from one of the
three basic structural classes represented by a-amyrin, b-amyrin and lupeol.
However, tetracyclic triterpenoidal aglycones are also found, e.g. ginsenosides. These glycosides occur abundantly in many plants, e.g. liquorice and
ginseng roots contain glycyrrhizinic acid derivatives and ginsenosides,
respectively. Most crude drugs containing triterpenoid saponins are usually
used as expectorants. Three major sources of triterpenoidal glycosides along
with their uses are summarized below.
Plants Botanical names (Family)
Main constituents
Uses
Liquorice root Glycyrrhiza
Glycyrrhizinic acid
In addition to expectorant
glabra (Fabaceae)
derivatives
action, it is also used as a
flavouring agent.
Quillaia bark Quillaja
Several complex
Tincture of this plant is
saponaria (Rosaceae)
triterpenoidal saponins,
used as an emulsifying
e.g. senegin II
agent.
Ginseng Panax ginseng
Ginsenosides
As a tonic, and to
(Araliaceae)
promote the feeling of
well being.
326
CH6 NATURAL PRODUCT CHEMISTRY