Coumarin Glycosides and Related Compounds Coumarins are derivatives of benzo--pyrone, or lactones of o-hydroxycinnamic acid (o-coumaric acid). The parent compound is coumarin, umbelliferone is the 7-OH derivative of Coumrin. The glycoside of umbelliferone is called skimmin. These compounds are used to protect skin from UV light as they absorb short wave length (280- 315 nm).

Dicoumarol Uses: anticoagulant and rodenticide. It is a phytoalexin formed due to fungal effect on Melilotus officinalis (Red Clover) It is a dimer of 4-hydroxycoumarin that is now produced synthetically under the trade name of Dicoumarol. Uses: anticoagulant and rodenticide.

Furanocoumarins They are coumarin derivatives with additional furan ring. Ammi majus contain a group of furanocoumarins, the parent compound is called Psoralene. They are used for the treatment of psoriases and leucodermia.

Furanochromones They are benzo--pyrone derivatives resist alkalis. Ammi visnaga contain furanochromones, the major is Khellin. Khellinis a smooth muscle relaxant used as: Bronchodilator. Antispasmodic. Renal colic. Coronary vasodilator.

Flavonoidal Glycosides Flavonoids are C-15 compounds. Flavonoids, constitute one of the most diverse and widespread group of natural products. They are one of the most important constituents of the human diet. They are found in fruits, vegetables, nuts, seeds, stems, flowers and common drinks e.g. tea. Flavonoids bind to a range of cellular receptor sites and show a wide range of biological activities. They are classified into many groups based on the oxidation level at ring C. They are benzo--pyrone derivatives so not open by alkalis. They are responsible for the colours of flowers and fruits.

General Tests: Blue colour with FeCl3. Yellow colour with Alkalis. Yellow colour with AlCl3.

1- Diosmin Source: Buchu leaves. Nature: Flavone glycoside. Uses: Diuretic- Diaphoretic- varicose veins (vasoprotective)

2- Hesperidin Source: Citrus fruits. Nature: Flavanone glycoside. Uses: Diuretic- Diaphoretic- varicose veins (vasoprotective)

3- Rutin Source: Ruta graveolens and Nicotiana tabacum Nature: Flavonol glycoside. Uses: Cold- Influenza- varicose veins (vasoprotective). Essential for vit C absorption.

4- Genistein and Genistin Source: Andria spp. (Genistein) Genista and Lupinus spp. Nature: Isoflavone & it Glycoside. Uses: Estrogenic activity.

5- Anthocyanidin Source: Grape and Berries. Nature: Anthocyanidins. Uses: Antioxidant.

6- Rotenone Source: Derris Roots. Nature: Rotenoids (Isoflavone derivatives). Uses: Insecticides.

7- Amentoflavone Source: Ginkgo biloba. Nature: Biflavones. Uses: Uterine antispasmodic- Enhance cerebral circulation- Delaying diabetic cataract and Diabetic neuropathies.

Flavono-lignans 1- Silymarin Source: Silybum marianum. Nature: Condensation product of flavones with hemilignans. Silymarin is a mixture of isomers the major isomer is Silybin. Uses: Very effective hepatoprotective and antihepatotoxic agent.

Mechanism of Action: Antioxidant so protect liver cells from free radicals. Stimulate liver cell regeneration. Anti-fibrotic and anti-cirrhotic activity.

Lignans 1- Podophyllotoxin Source: Podophyllum Rhizomes. Nature: Lignan derivatives. Lignans are C18 compounds resulted from condensation of two hemilignans C9. Uses: Anticancer.

Semisynthetic Derivatives: Side Effects: GIT upset, Nausea and Vomiting. Semisynthetic Derivatives: Etoposide: Lung and testicular cancer Teniposide: Leukaemia and brain cancer in children.