1. INTRODUCTION OF GLYCOSIDES
. Glycosides:are non reducing organic
comounds they can be hydrolyzed by acids ,
alkali & enzymes. On hydrolyesis they can
be divided into two parts:
2. INTRODUCTION OF GLYCOSIDES
On hydrolyesis they cab be divided into two parts:
Sugar part (glycone) :Which are formed with one or more units
of sugars.
Non sugar part (Aglycone) : this is also known as genin part,
which is responsible for pharmacological activity of crude
drug.
This is sugar part of glycosides are attached with non sugar or
aglycone part by acetal linkage or glycosidal linkage.
3. CLASSIFICATION OF GLYCOSIDES
Classes of glycosides according to chemical structure examples
1-cardioactive glycosides……………………………………....Digitalis, Convallaria.
2-antheraquinone glycosides……………………………….….Cascara , Senna, Aloe
3-saponine glycosides………………………………………... Glycyrrhiza
4- cyanophore glycosides……………………………….. . Amyadalin (lactril) , Prunisin
5- Isothiocynate glycosides…………………………………...Wild mustard
6-flavonoid glycosides………………………………………….Quercetin
7- Alcohol glycosides……………………………………………..Salicin
8- Aldehyde glycosides………………….........………Vanillin (Vanilla orchid)
9- lactone glycosides……………………………....….Sweet & Red clover
10- phenolic glycosides…………………………….….Uva Ursi,(arbutin)
11-Tanins glycosides polymerized by poly phenol oxidase .
5. ANTHRAQUINONE GLYCOSIDES
Anthraquinone are glycosides which
possess anthracene or their derivatives as
aglycone in which two keto group are
attached with the benzene ring .
Anthrone
Anthraguinone
anthracene
8. ANTHRAQUINONE GLYCOSIDES
not all Anthraquinone are strictly Quinone, for example
the sennosides are dianthrones consisting of two anthrone
units, each bearing only one carbonyl group(C=H), these
compounds considered as anthraquinon derivatives.
Quinone
9. ANTHRAGUINONE CHEMISTRY
Anthraquinones usually occure in plants as glycosides for example, the
sennosides from senna (cassia species)are O-glycosides and the aloins from Aloe
are C-glycosides.
10. ANTHRAGUINONE CHEMISTRY
Anthraquinones usually occure in plants as glycosides for example, the
sennosides from senna (cassia species)are O-glycosides and the aloins from Aloe
are C-glycosides. .
11. ANTHRAGUINONE CHEMISTRY
The cascarosides from cascara (Rhamnus
purshiana) are unusual molecules in that they
are C,O-glycosides, having one glucose
linked to acentral anthrone via acarbon atom
and asecond glucose linked via oxygen.
13. ANTHRAGUINONE CHEMISTRY
• *if aglycones are present in dried herbs, they are
always anthraquinones because anthrones are
too unstable in the free state.
• *Dianthrone glycosides such as the sennosides are
not found in the living plant , being formed on
harvesting and drying from monomeric anthrone
glycosides.
16. MEDICINAL USES OF ANTHRAQUINONE GLYCOSIDES
1- Many of anthraquinone glycosides possess antibacterial, antiparasitic ,
antiviral ,and ansecticidal , fungicidal, properities, and also used as
anticancer agents.
2- Anthraquinones are active components of many plant belonds which are
used as medicines and exhibit laxative , diuretic, and immunomodulatory
effects.
3- the main use of anthraquinone and related glycosids is stimulant cathartics
by increasing the tone of the smooth muscle in the wall of colon and
stimulate the secretion of water and electrolytes into the large intestine. .
17. MEDICINAL USES OF ANTHRAQUINONE GLYCOSIDES
4-Glycosides are hydrolysed in the colon by the action of the microflora
enzymes to the pharmacologically active free aglycones which usually
produce their effect in 8-12 hrs.
5- these agents are indicated for constipation in patient who do not respond
to milder drugs and for bowel evacuation before investigational procedure or
surgery.
6- stimulant laxative are habit forming so the long term use may result in
laxative dependence and less of normal bowel function .
18. MEDICINAL USES OF ANTHRAQUINONE GLYCOSIDES
7- the medication is taken by mouth or via the rectum .
It typically begins working in around 30 minutes when
given by rectum and within twelve hours when given
by mouth. It is aweaker laxative than bisacodyl or
castor oil.
19. MEDICINAL USES OF ANTHRAQUINONE GLYCOSIDES
8- The glycosides of anthranol and anthrones elicit a more
drastic reaction than do corresponding anthraquinone
glycosides and cause discomforting and gripping action like
aloin from Aloe vera. The drugs mostly used are cascara,
frangula,hypericum and senna.
Aloins Aloe vera plant
