2. Introduction
Category – Anthraquinone glycoside
•They possess anthracene or their derivatives as aglycone
•Hydrolysis of these glycoside yields aglycone which are
di, tri, or tetra hydroxy anthraquinone
Anthraquinone Anthrone Anthranol
O O
OH
8 1 8 1
7 9 2 4H 7 9 2
6 10 3 6 10 3
5 4 5 H H 4
O H
O
2H
8 1
7 9 2
6 10 3
5 H 4
OH
Oxanthrone
Kratika Daniel (Ph.D)
3. Types of anthraquinone glycoside
1. O-glycosides where the aglycone moiety is 1,8
dihydroxyanthraquinone derivatives, e.g.,
Gl O O
OH O
1 Gl O OH Gl O O
OH
1 1
8 9 2 8 9 2 8 9 2
10
CH2 OH 10 10
5 4 COOH CH3
5 4 5 4
O
O O
Aloe-emodin-8-glycoside Rhein-8-glycoside Chrysophanol-8-glycoside
2. O-glycoside where the aglycone moiety partially reduced
1,8 dihydroxy anthraquinone, e.g., Oxanthrone-type.
Gl
OH OH
H O
7 8 9 1 2
6 10 3
5 4
Kratika Daniel (Ph.D)
Emodin-oxanthrone-9-glucoside O
4. 3. C-glycoside where the aglycone structure (anthrone der.)
O
OH OH
7 8 9 1 2
6 10 4 3
5 CH2 OH
H C6 H11 O5
Barbaloin
4. O-glycosides where the aglycone moiety is di-anthrone der. (i.e.,
dimmer) e.g., Sennosides where there is C-C bridge between the
anthranol units. Sennoside A&B
Gl O
O OH
7 8 9 1 2
6 10 4 3
COOH
5 H
H
COOH
Gl Kratika Daniel (Ph.D)
OH
O O
5. SOURCE
•Consists of the dried leaflet of Alexandrian or Khartoum
senna, Cassia senna (C.acutifolia), Tinnevelly senna
(C.angustifolia).
Constituents: - Dimeric anthracene glycosides
derived from two anthrones moieties which may be:
O
OH OH
1 O
OH OH
8 9 1
2
8 9 2
10
CH2 OH 10
5 4 COOH
5 4
Aloe-emodin anthrone
Rhein anthrone
Kratika Daniel (Ph.D)
6. 1.Similar anthrone moiety (Homo-dianthrones) i.e., 2 rhein anthrone
moieties condensate through two C-10 atomes. Thus it can be exist in
two optical forms, Sennoside A (L- form) & Sennoside B (meso form).
Gl O
O OH
7 8 9 1 2
6 10 4 3
COOH
5 H
H
COOH
Sennosides A &B
Gl O OH
O
2. Or different (Hetero-dianthrones) i.e., one rhein-anthrone & one
emodin anthrone, Sennoside CO(L- form) and Sennoside D (meso form).
Gl O OH
7 8 9 1 2
6 10 4 3
CH2 OH
5 H
H
COOH
Kratika Daniel (Ph.D)
Sennoside C&D
Gl OH
O O
7. Extraction & Isolation
I Dry Senna powdered
90% methanol or 50%
Acetone for 6 hrs.
Extraction with cold water for 4 hrs
17% of solid extract
Contain 60 – 65% sennoside
II Powdered Senna leaf
Citric acid in methanol
Extraction with methanol – toluene
Mixture & ammonia
Extract treated with CaCl2
Calcium salt of sennoside A & B
Kratika Daniel (Ph.D)
8. Senzyme
Biosynthesis O
O O O
O O O O
8 acetate unit
O CH3
O O O
Senzyme
O O O O
poly β - keto methylene acid
intramolecular condensation
CH3
COOH
OH O HO
Kratika Daniel (Ph.D)
chrysophanol anthrone
9. chrysophanol anthrone
-CO 2
O
HO CH3 HO CH3
COOH
OH O OH OH O
Emodin - 9 -anthrone Endocrocin
[O] O
HO CH3
O
HO CH3
[O] HO
OH
CH3
OH O OH
emodin
OH OH
Kratika Daniel (Ph.D) emodin dianthrone
10. Identification test
1. Borntrager’s test
3ml extract
+ Boil & filter To cold filtrate
Dil. H2SO4 Add benzene / CHCl3
& shake
Add NH3
Ammonia layer turns pink / red Separate the organic layer
2. Modified Borntrager’s test
5ml extract
+ Δ for 5 min. Boil & filter
5ml of FeCl3 To cold filtrate
Add benzene
+ / CHCl3
5ml of Dil. HCl. & shake
Ammonia layer turns Add NH
pink / red
3
Separate the organic layer
3. Magnesium acetate solution test: - in methanolic extract add magnesium
acetate solution give orange color.
Kratika Daniel (Ph.D)
11. TLC
Solvent system – dichloromethane: methanol: formamide(8:2:1)
ethyl acetate: n – propanol: water (4:4:3)
Detecting reagent – ammonia vapors or spectrophotometry.
Properties
1. Sennoside occurs as a brownish powder.
2. Sennoside soluble in alcohol but sparingly soluble in acetone
3. Purgative activity of senna is mainly due to sennoside A & B while
C & D exerts a powerful synergistic effect upon purgative activity.
Kratika Daniel (Ph.D)
12. SAR:
1. Glycosilation:The purgative action of anthracene bearing drugs is
owed to their anthracene glycosidal content rather than their content
of free anthracene aglycones (i.e., glycosylation is the main
requirement for activity, as the sugar moiety serve to transport the
aglycone to the site of action in the large intestine).
2. Hydroxylation:Hydroxylation of C-1, C-8 is essential for activity.
Increase hydroxylation leading to increase solubility.
3. Oxidation level:The degree of oxidation at positions C-9 & C-10
plays an important role in the pharmacological activity. Higher
oxidation level at C-9 & C-10 caused lowering of activity. i.e.,
anthrones and anthranols are more potent than their corresponding
oxanthrones, which in turn more active than their corresponding
anthraquinones. Complete reduction of C-10 &C-9 lead to complete
loss of activity. Kratika Daniel (Ph.D)
13. 4. The nature of substances at C-3:Derivative with CH2OH (as
in aloe emodin) are more active than those with CH3
substitution. The latter more active than derivative with
COOH substitution at C-3.
Anthraquinone glycosides containing adimer more active than
a monomer.
5. Effect of storage on the active of anthracene glycosides:
Prolonged storage of anthracene bearing drugs may bring
oxidation of anthranols and anthrones to give the less active
anthraquinones. Thus, the activity of drugs decreases by time.
However, anthraquinone glycosides do not cause any
griping action (like anthranol and anthone),
Senna preparations retain their activity for a long time
Kratika Daniel (Ph.D)
14. USE & ACTION
1. Used as effective cathartic agents for long time.
2. Their action is due to their anthracene constituents acting
on the large intestine. The sugar moiety helps to transport
anthracene aglycon intact to large intestine, where aglycon
is liberated by enzyme.
3. Anthracene derivative without sugar moiety are broken
down & only small amount reaches to intestine to exert
cathartic action.
4. It also used as purgative, cathartic, laxative & in acute
constipation.
5. Gripping action – occurs due to its resin or emodin
6. Used in haemhoridial, after anorectal operation, anal
fissure.
7. For evaluation X – ray Kratika Daniel (Ph.D) from intestine
contrast media