1. Chemical nature of Crude drugs

2. On completion of this period, you would be able to know
Objectives
On completion of this period, you would be able to know
Glycosides
Different types of Glycosides

3. Glycosides
Glycosides are naturally occurring organic compounds in plants
On hydrolysis with an acid, alkali or enzyme
Gives a Non-sugar moity known as Aglycone OR Genin
A Sugar moity known as Glycone
Condensation products of Aglycone and Glycone

4. Glycosides Aglycone may be an alcohol an aldehyde a ketone
or even an amine
Glycone contains one or more sugars
Glucose
Galactose
Mannose
Rarely Rhamnose
Digitoxose
Cymarose are present

5. Glycosides Crystalline or amorphous components
Generally soluble in water
soluble in dilute alcohol
Insoluble in organic solvents.
Glycosides are optically laevorotatory

6. Classification of Glycosides
The glycosides can be classified on the basis of
The chemical nature of their aglycone
Coupled with physiological action

7. Classification of Glycosides
Saponin glycosides – Liquorice
Cardiac glycosides
Cardenolides _ Digitalis
Bufadienolides _ Squill
Cyanogenetic glycosides – Bitter almond
Isothiocyanate glycosides _ Black mustard
Phenolic glycosides
Simple phenolic _ Gaultheria
Anthroquinone _ Senna, Rhubarb
Coumarin _ Asafoetida
Flavone & flavonoid _ Senna, Liquorice
Anthocyanidin _ Rose, Purple grapes

8. Saponin glycosides These glycosides are characterized by
Property of producing froth when shaken with water
They also produce Haemolysis
Get precipitated with alcoholic solutions of sterols and higher alcohols.

9. Saponin glycosides They are lethal to lower organisms like
Fishes and earth worm
Saponins are powerful emulsifiers
Possess detergent properties
They are soluble in water
Insoluble in ether and light petroleum
The aglycone is termed as Sapogenin

10. Saponin glycosides Chemically saponins are of two types
Steroidal saponins
Triterpenoidal Saponins
The import triterpenoidal saponins include
Glycyrrhetic acid
Quillaic acid
Steroidal saponins used in synthesis of hormones like cortisones and progesterones

11. Cardiac Glycosides
The glycosides of this group are most important medicinally
Have action on cardiac / heart muscles
Increase force of contraction and thereby efficacy of heart

12. Cardiac glycosides The aglycone of Cardiac glycosides
Consists of steroid nucleus
All the Cardiac glycosides have
An unsaturated lactone at C17 position
The more common steroidal aglycone have5 membered unsaturated lactone ring
23 carbons containing steroids
They are known as CSardinolides
Bufadienolides have a 6 membered lactone ring at C17 position of steroidal nucleus

13. Cyanogenetic or Cyanophoric Glycosides
They produce hydrocyanic acid (HCN) as
One of the products of hydrolysis
They are glycosides and hydrolysed by enzymes
Yield one molecule of Hydocyanic acid in addition of glycone and aglycone
Examples of Prunasin from Prunus serotina
Amygdalin from Bitter almond

14. Isothiocyanate Glycosides
Isothiocyanate glycosides are
Glucosinolate compounds
Their aglycone contains Sulphur
They are present in many Plants of Cruciferae
family

15. Phenolic glycosides Simple phenolic glycosides
The phenolic glycosides comprises of
Largest group of glycosides of plant origin
Simple phenolic glycosides
Eg: Salicin from Salix species

16. Coumarin glycosides They are Benzopyrone derivatives
Possess aromatic smell
Alcoholic solution when made
alkaline show Green or Blue fluorescence

17. Coumarin glycosides
Its glycosides present in some plants of Rosaceae family
Coumarins have flavouring property
Harmful to liver
Coumarin compounds react with
Many other compounds
Possess carcinogenic action
Some countries banned its internal use

18. Summary In this class we learnt about What are Glycosides?
Examples of different types of Glycosides?

19. Quiz 1.Bufadienolides are otherwise called as C23 Glycosides

20. Quiz 2. Cardenolides are called as Aglycones C23Glycosides
All the above

21. Frequently Asked Questions
Classify Glycosides with examples?