1. Saponins (cont’d) Pharmacognosy I
Mosul University/ College of Pharmacy
L.A. Dilbreen Barzanji

2. Pentacyclic triterpenoid saponins
This particular class of saponin essentially contains the sapogenin component with pentacyclic triterpenoid nuecleus, that is eventually linked with either sugar or uronic acids.
The sapogenin may further may be further classified into three major categories namely: α- amyrin, β-amyrin and lupeol.

4. Plant materials oftain contain these these saponins in considerable amounts. Thus, primula root contains about 5-10%; liquorice root about 2-12% of glycerrhizic acid (and a correspondingly larger amount of glycerrhizin, the potassium calcium salt); quillaia bark up to about 10% of the mixture known as ‘commercial saponin’ ; the seeds of horse chestnut up to 13% of aescin.
As some plants contain more than one saponin and purification is often difficult.

5. Liquorice root
The pharmacopoeial drug is now defined as the dried unpeel or peeled, whole or cut root and stolons of Glycerrhiza galbra.
In Western Europe liquorice is cultivated, but the ‘Russian’ and ‘Persian’ drugs are obtained from wild plants. In China, large-scale cultivation is replacing collection from wild.
The underground organs are developed into sufficient extent by the end of the third or fourth year, when they are dug up and washed, some are peeled and cut up into short lengths before drying, but much is now used unpeeled.

6. Glycerrhiza ows most of its sweet taste to glycerrhizin, the potassium and calcium salts of glycerrhizinic acid.
Glycerrhizinic acid is the diglucouronic acid of glycerrhetic (glycerrhetinic) acid, which has a tritepenoid structure.

7. The yellow colour of liquorice is due to flavonoids, which have antigastric effect, example of liquorice flavonoids: liquirtin.
Other active constituents of liquorice are polysaccharides with a pronounced activity on the reticuloendothelial system. e.g. glycerrhzan has been characterized as the representative polysaccharide with immunological activity.
The roots also contain about 5-15% of sugars (glucose, sucrose).

8. Action and uses of liquorice
Liquorice has been long been employed in pharmacy as a flavouring agent, demulcent, and mild expectorant.
The recognition of the deoxycortecosterone effects of liquorice extracts and glycerrhetinic acid has led to its use for the treatment of rheumatoid arthritis, Addison’s disease and various inflammatory conditions.
Unlike cortisone, liquorice may give symptomatic relief from peptic ulcer pain.

9. It has been reported that glycerrhizin gel can act as a useful vehicle for variuos drugs used topically; not only are the anti-inflammatory and antiviral effects relevant but also glycerrhizin enhances skin penetration by the drug.
Excessive consumption of liquorice leads to hypertension and hypokalaemic alkalosis.

10. Ivy
The drug consists of the whole or cut aerial leaves of Hedera helix, collected in the spring.
This familiar climber and creeper is widely distributed throughout Europe and Asia.

11. Important constituent of ivy are saponins involving the pentacyclic triterpenoid genins: hederagenin, bayogenin and oleanolic acid.
The BP/EP requires a minimum concentration of 3.0% heteracoside C.
Like most saponins, those of ivy are toxic in excess causing diarrhea, vomiting and allergy.

12. Uses of ivy
Ivy-leaf extract have been traditionally used as an expectorant for the treatment of various chest conditions, such as bronchitis and whooping cough; also for gout and rheumatic pains.
Externally ivy is used cosmetically and for a various of skin conditions.

13. QUIZ