10.4.2 Coumarins
Coumarins and its derivatives are found in so many plants. Coumarin is ubiquitously available in about 150 species of 30 different families. They are available in
the families mainly Solanaceae, Rubiaceae, Leguminosae, Oleaceae, Umbelliferae,
Caprifoliaceae, etc. The important source of coumarin compounds is sweet clover
belonging to Melilotus spp., tonka bean (scientific name: Dipteryx odorata), and
sweet woodruff (scientific name: Galium odoratum) (Hoffmann 2003). They are the
derivatives of benzo-a-pyrone, also known as lactone of o-hydroxycinnamic acid,
i.e., cyclic ester of phenolic compound (Hoffmann 2003). Aesculetin, aesculin,
herniarin, fraxin, umbelliferone, scopolin, and scopoletin are popular coumarin
compounds having benzo-a-pyrone nucleus available both in the free state and as
glycosides also (Fig. 10.13). Plants having coumarin derivatives are belladonna
(Atropa belladonna), Datura (Datura stramonium) belonging to the family
Solanaceae, February daphne (Daphne mezereum belonging to the family
Thymeliaceae), common rue (Ruta graveolens belonging to the family
Umbelliferae), and Horse chestnut (A. hippocastanum belonging to the family
Hippocastanaceae) and certain Rosaceae (Evans 2009).
Furanocoumarin derivatives are also available in bergamot oil, bael fruit, psoralea, etc. These compounds are formed by the fusion of furan ring with coumarin at
6 and 7 positions and 7 and 8 positions, respectively (Bruni et al. 2019). These
CO
O
Coumarin
3
4
5
6
7
8
1
2
CO
O
O
H
O
H
Aesculetin
CO
O
H 3 CO
O
H
O-Glu
Fraxin
CO
O
H 3 CO
CO
O
H 3 CO
O
H
CO
O
O
H
Herniarin
Scopoletin
Umbelliferone
O
O
H
O
O
C
H 3
C
H 3
CH 3
Psoralidin
Fig. 10.13 The chemical structures of some important coumarin drugs of plant sources
10 Secondary Metabolites from Plant Sources
345
Coumarins and its derivatives are found in so many plants. Coumarin is ubiquitously available in about 150 species of 30 different families. They are available in
the families mainly Solanaceae, Rubiaceae, Leguminosae, Oleaceae, Umbelliferae,
Caprifoliaceae, etc. The important source of coumarin compounds is sweet clover
belonging to Melilotus spp., tonka bean (scientific name: Dipteryx odorata), and
sweet woodruff (scientific name: Galium odoratum) (Hoffmann 2003). They are the
derivatives of benzo-a-pyrone, also known as lactone of o-hydroxycinnamic acid,
i.e., cyclic ester of phenolic compound (Hoffmann 2003). Aesculetin, aesculin,
herniarin, fraxin, umbelliferone, scopolin, and scopoletin are popular coumarin
compounds having benzo-a-pyrone nucleus available both in the free state and as
glycosides also (Fig. 10.13). Plants having coumarin derivatives are belladonna
(Atropa belladonna), Datura (Datura stramonium) belonging to the family
Solanaceae, February daphne (Daphne mezereum belonging to the family
Thymeliaceae), common rue (Ruta graveolens belonging to the family
Umbelliferae), and Horse chestnut (A. hippocastanum belonging to the family
Hippocastanaceae) and certain Rosaceae (Evans 2009).
Furanocoumarin derivatives are also available in bergamot oil, bael fruit, psoralea, etc. These compounds are formed by the fusion of furan ring with coumarin at
6 and 7 positions and 7 and 8 positions, respectively (Bruni et al. 2019). These
CO
O
Coumarin
3
4
5
6
7
8
1
2
CO
O
O
H
O
H
Aesculetin
CO
O
H 3 CO
O
H
O-Glu
Fraxin
CO
O
H 3 CO
CO
O
H 3 CO
O
H
CO
O
O
H
Herniarin
Scopoletin
Umbelliferone
O
O
H
O
O
C
H 3
C
H 3
CH 3
Psoralidin
Fig. 10.13 The chemical structures of some important coumarin drugs of plant sources
10 Secondary Metabolites from Plant Sources
345