Synonyms: Glycyrrhiza, Liquorice root, Mulethi
Biological source: It consists of dried roots and stolons, whole or cut, peeled or unpeeled of Glycyrrhiza glabra Linn and other species of Glycyrrhiza.
Family: Leguminosae (Fabaceae)
Geographical source: Liquorice obtained from wild plants and from semi wild plants cultivated in Iraq, Syria, Afghanistan, Spain, Sicily and England.
Cultivation and Collection:
The liquorice is cultivated in Western Europe but the Russian variety and Persian varieties are obtained from wild plants Russia and Iran. Spanish variety is cultivated abundantly in Spain and Italy. The plant usually grows well in deep sandy soil but the soil should be fertile and near streams. The soil should be well prepared and added with farmyard manures.
Liquorice is usually propagated by replanting young pieces of stolons in the month of March.
Macroscopical Character:
Colour: Unpeeled drug is yellowish brown or dark brown in color externally and
yellowish colored internally but peeled liquorice is pale yellow in colour.
Odour: Typical odour, faint and characteristics.
Taste: Sweet.
Size: Stolons are several meter in length and are cut in pieces having 20-50 cm length
and 1 to 2 cm diameter fragments.
Shape: Cylindrical pieces sometimes straight or irregular peeled or unpeeled.
Fracture: Fibrous (bark), splintery (wood).
Chemical Constituents:
Liquorice owes most of its sweet taste due to glycyrrhizin or glycyrrhizic acid which is
potassium and calcium salt of glycyrrhizinic acid which has a triterpenoid structure.
Other hydroxyl and deoxy triterpenoid acid related to glycyrrhetinic acid or glycyrrhetic
acid have been isolated; the C-20 epimer of glycyrrhetinic acid is named liquiritic acid. The
yellow colour of liquorice is due to flavonoids which also having antigastric effect. Flavonoid
rich fraction included liquiritin, isoliquertin (a chalcone) which occurs as a glycoside and
during drying partly converted into liquiritin, liquiritigenin and isoliquiritigenin.
Chemical Test:
1. When 80 percent sulphuric acid is added on thick section of drug or on powdered drug it shows deep yellow colour.
2. A dark colour appears when aqueous extract of drug is treated with 5 percent ferric chloride solution (due to phenolic compounds).
3. Take aqueous extract and treat it with 5ml dilute potassium permagnate solution.Decolourisation of potassium permagnate indicates the presence of reducing sugars.
Uses:
Traditionally it is used as flavouring agent, demulcent and mild expectorant. It is used in
the preparation of cough syrups. The flavonoidal content of liquorice i.e. Isoliquiritin possess
antigastric activity so used in peptic ulcer treatment for healing purpose.