This document discusses steroids, cardiac glycosides, and triterpenoids found in plants. It describes how these compounds are hydrolyzed to give aglycones and sugars. It then discusses specific examples including liquorice root and Dioscorea species. Liquorice root contains glycyrrhizin which gives it a sweet taste, and flavonoids which have antigastric effects. It is used as a flavoring agent and for its anti-inflammatory properties. Dioscorea species contain the steroidal sapogenin diosgenin, which is used to manufacture progesterone and other steroid drugs used as contraceptives and to treat various disorders.

1. SSBE’S
Nanded Pharmacy College, Nanded
Pharmacognosy & Phytochemistry –II
BP504 T
Dr M H Ghante

2. Unit-II.3
Contents
• General introduction,
• composition,
• chemistry & chemical classes,
• general methods of extraction
& analysis,
• biosources,
• therapeutic uses and
• commercial applications
1. Alkaloids: Vinca, Rauwolfia, Belladonna, Opium,
2. Phenylpropanoids and Flavonoids: Lignans, Tea, Ruta
3. Steroids, Cardiac Glycosides & Triterpenoids: Liquorice,
Dioscorea, Digitalis
4. Volatile oils: Mentha, Clove, Cinnamon, Fennel,
Coriander,
5. Tannins: Catechu, Pterocarpus
6. Resins: Benzoin, Guggul, Ginger, Asafoetida, Myrrh,
Colophony
7. Glycosides: Senna, Aloes, Bitter Almond
8. Iridoids, Other terpenoids & Naphthaquinones:
Gentian, Artemisia, taxus, carotenoids
• General introduction,
• composition,
• chemistry & chemical classes,
• general methods of extraction
& analysis,
• biosources,
• therapeutic uses and
• commercial applications
1. Alkaloids: Vinca, Rauwolfia, Belladonna, Opium,
2. Phenylpropanoids and Flavonoids: Lignans, Tea, Ruta
3. Steroids, Cardiac Glycosides & Triterpenoids: Liquorice,
Dioscorea, Digitalis
4. Volatile oils: Mentha, Clove, Cinnamon, Fennel,
Coriander,
5. Tannins: Catechu, Pterocarpus
6. Resins: Benzoin, Guggul, Ginger, Asafoetida, Myrrh,
Colophony
7. Glycosides: Senna, Aloes, Bitter Almond
8. Iridoids, Other terpenoids & Naphthaquinones:
Gentian, Artemisia, taxus, carotenoids
2
Compiled & edited by Dr Mahavir H Ghante

3. II-3
Steroids, Cardiac Glycosides &
Triterpenoids:
Liquorice, Dioscorea, Digitalis

4. • As glycosides they are hydrolysed by acids to give an aglycone (sapogenin)
and various sugars and related uronic acids.
• According to the structure of the aglycone or sapogenin, two kinds of
saponin are recognized
• —the steroidal (commonly tetracyclic triterpenoids)
– the pentacyclic triterpenoid types (see formulae below).
• Both of these have a glycosidal linkage at C-3 and have a common
biogenetic origin via mevalonic acid and isoprenoid units.
• Steroidal saponins are of great pharmaceutical importance because of
their relationship to compounds such as the sex hormones, cortisone,
diuretic steroids, vitamin D and the cardiac glycosides.
• As glycosides they are hydrolysed by acids to give an aglycone (sapogenin)
and various sugars and related uronic acids.
• According to the structure of the aglycone or sapogenin, two kinds of
saponin are recognized
• —the steroidal (commonly tetracyclic triterpenoids)
– the pentacyclic triterpenoid types (see formulae below).
• Both of these have a glycosidal linkage at C-3 and have a common
biogenetic origin via mevalonic acid and isoprenoid units.
• Steroidal saponins are of great pharmaceutical importance because of
their relationship to compounds such as the sex hormones, cortisone,
diuretic steroids, vitamin D and the cardiac glycosides.
4
Compiled & edited by Dr Mahavir H
Ghante

5. Liquorice Root
• The pharmacopoeial drug is now defined as
the dried unpeeled or peeled, whole or cut
root and stolons of
• Glyrrhiza glabra L. and/or of
• G. inflata Bat. and/or
• G. uralensis Fisch.
• The pharmacopoeial drug is now defined as
the dried unpeeled or peeled, whole or cut
root and stolons of
• Glyrrhiza glabra L. and/or of
• G. inflata Bat. and/or
• G. uralensis Fisch.
5
Compiled & edited by Dr Mahavir H
Ghante

6. • Liquorice owes most of its sweet taste to glycyrrhizin, the potassium and
calcium salts of glycyrrhizinic acid.
• Glycyrrhizinic acid is the diglucopyranosiduronic acid of glycyrrhetic
(glycyrrhetinic) acid, which has a triterpenoid structure
• Other hydroxy- and deoxy-triterpenoid acids related to glycyrrhetic acid
have been isolated; the C-20 epimer of glycyrrhetic acid is named
liquiritic acid.
• The yellow colour of liquorice is due to flavonoids, which received further
considerable study when in 1978 the antigastric effect of flavonoid-rich
fractions was recognized.
• They include liquiritin, isoliquiritin (a chalcone, which occurs as a
glycoside), liquiritigenin, isoliquiritigenin (chalcone form) and other
compounds.
• Isoliquiritigenin is reported to be an aldose-reductase inhibitor and may
be effective in preventing diabetic complications.
• Rhamnoliquiritin was isolated from the roots in 1968.
• Liquorice owes most of its sweet taste to glycyrrhizin, the potassium and
calcium salts of glycyrrhizinic acid.
• Glycyrrhizinic acid is the diglucopyranosiduronic acid of glycyrrhetic
(glycyrrhetinic) acid, which has a triterpenoid structure
• Other hydroxy- and deoxy-triterpenoid acids related to glycyrrhetic acid
have been isolated; the C-20 epimer of glycyrrhetic acid is named
liquiritic acid.
• The yellow colour of liquorice is due to flavonoids, which received further
considerable study when in 1978 the antigastric effect of flavonoid-rich
fractions was recognized.
• They include liquiritin, isoliquiritin (a chalcone, which occurs as a
glycoside), liquiritigenin, isoliquiritigenin (chalcone form) and other
compounds.
• Isoliquiritigenin is reported to be an aldose-reductase inhibitor and may
be effective in preventing diabetic complications.
• Rhamnoliquiritin was isolated from the roots in 1968.
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Ghante

7. • Many flavonoids and isoprenoid-substituted flavonoids from G. glabra of
various origins have since been reported.
• These include the pyranoisoflavan, glabridin and, more recently, two
minor isoflavones, glabriso flavone A and B, and glabrocoumarone .
• Various 2-methylisoflavones have been isolated from indigenous Indian
roots together with an unusual coumarin (liqcoumarin), 6-acetyl-
5-hydroxy-4-methyl-coumarin.
• An examination of liquorice from five countries has shown the flavonoid
content to be geographically consistent, varying only in the relative
proportions of constituents.
• Japanese traditional (kampo) extracts prepared by boiling show a high
content of flavonoid aglycones which may be pharmacologically more
active than the parent glycosides.
• Other active constituents of liquorice are polysaccharides with a
pronounced activity on the reticuloendothelial system.
• The roots also contain about 5–15% of sugars (glucose, sucrose); about 1–
2% of asparagine (amide of aspartic or aminosuccinic acid); 0.04–0.06%
volatile compounds; β-sitosterol; starch; protein; bitter principles
(glycyramarin).
• Many flavonoids and isoprenoid-substituted flavonoids from G. glabra of
various origins have since been reported.
• These include the pyranoisoflavan, glabridin and, more recently, two
minor isoflavones, glabriso flavone A and B, and glabrocoumarone .
• Various 2-methylisoflavones have been isolated from indigenous Indian
roots together with an unusual coumarin (liqcoumarin), 6-acetyl-
5-hydroxy-4-methyl-coumarin.
• An examination of liquorice from five countries has shown the flavonoid
content to be geographically consistent, varying only in the relative
proportions of constituents.
• Japanese traditional (kampo) extracts prepared by boiling show a high
content of flavonoid aglycones which may be pharmacologically more
active than the parent glycosides.
• Other active constituents of liquorice are polysaccharides with a
pronounced activity on the reticuloendothelial system.
• The roots also contain about 5–15% of sugars (glucose, sucrose); about 1–
2% of asparagine (amide of aspartic or aminosuccinic acid); 0.04–0.06%
volatile compounds; β-sitosterol; starch; protein; bitter principles
(glycyramarin).
7
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Ghante

8. 8
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Ghante

9. • Action and uses. Liquorice has long been employed in pharmacy
as a flavouring agent, demulcent and mild expectorant.
• The recognition of the deoxycorticosterone effects of liquorice extracts and
glycyrrhetinic acid has led to its use for the treatment of rheumatoid arthritis,
Addison’s disease and various inflammatory conditions.
• Interestingly, the flavonoid component of the root, which possesses
antimicrobial properties, also exerts spasmolytic and ntiulcerogenic activity.
• A Japanese patent (Chem. Abs., 1992, 117, 55948) describes the formulation
of a liquiritin cream as beneficial, with no adverse effects, for the removal of
skin stains in patients with chloasma, senile melanoderma, etc.
• Unlike cortisone, liquorice may give symptomatic relief from peptic ulcer pain.
It has been reported that glycyrrhizin gel can act as a useful vehicle for various
drugs used topically;
• not only are the anti-inflammatory and antiviral effects relevant but also
glycyrrhizin enhances skin penetration by the drug.
• Excessive consumption of liquorice leads to hypertension and hypokalaemic
alkosis; the hospitalization of an individual taking 200 g liquorice daily was
reported
• in 1998. Most of the liquorice imported is used in the tobacco trade and in
confectionery.
• Action and uses. Liquorice has long been employed in pharmacy
as a flavouring agent, demulcent and mild expectorant.
• The recognition of the deoxycorticosterone effects of liquorice extracts and
glycyrrhetinic acid has led to its use for the treatment of rheumatoid arthritis,
Addison’s disease and various inflammatory conditions.
• Interestingly, the flavonoid component of the root, which possesses
antimicrobial properties, also exerts spasmolytic and ntiulcerogenic activity.
• A Japanese patent (Chem. Abs., 1992, 117, 55948) describes the formulation
of a liquiritin cream as beneficial, with no adverse effects, for the removal of
skin stains in patients with chloasma, senile melanoderma, etc.
• Unlike cortisone, liquorice may give symptomatic relief from peptic ulcer pain.
It has been reported that glycyrrhizin gel can act as a useful vehicle for various
drugs used topically;
• not only are the anti-inflammatory and antiviral effects relevant but also
glycyrrhizin enhances skin penetration by the drug.
• Excessive consumption of liquorice leads to hypertension and hypokalaemic
alkosis; the hospitalization of an individual taking 200 g liquorice daily was
reported
• in 1998. Most of the liquorice imported is used in the tobacco trade and in
confectionery. 9
Compiled & edited by Dr Mahavir H
Ghante

10. Dioscorea species
• Tubers of many of the dioscoreas (yams) have long been used forfood, as they are
rich in starch.
• In addition to starch, some species contain steroidal saponins, others alkaloids.
• From a suitable source the sapogenins are isolated by acid hydrolysis of the
saponin.
• The water-insoluble sapogenin is then extracted with a suitable organic solvent.
the tubers reach maturity in 3–5 years and on average, yield
• 1–8% of total sapogenin.
• Until 1970 diosgenin isolated from the Mexican yam was the sole source for
steroidal contraceptive manufacture.
• With the nationalization of the Mexican industry, however, prices were increased
to such an extent that manufacturers switched to hecogenin for corticosteroids, to
other sources of diosgenin and to the use of the steroidal alkaloids of Solanum
species.
• Total synthesis also became economically feasible and is now much used.
• More recently, the economics of steroid production have again changed in that
China is now exporting large quantities of diosgenin;
• Tubers of many of the dioscoreas (yams) have long been used forfood, as they are
rich in starch.
• In addition to starch, some species contain steroidal saponins, others alkaloids.
• From a suitable source the sapogenins are isolated by acid hydrolysis of the
saponin.
• The water-insoluble sapogenin is then extracted with a suitable organic solvent.
the tubers reach maturity in 3–5 years and on average, yield
• 1–8% of total sapogenin.
• Until 1970 diosgenin isolated from the Mexican yam was the sole source for
steroidal contraceptive manufacture.
• With the nationalization of the Mexican industry, however, prices were increased
to such an extent that manufacturers switched to hecogenin for corticosteroids, to
other sources of diosgenin and to the use of the steroidal alkaloids of Solanum
species.
• Total synthesis also became economically feasible and is now much used.
• More recently, the economics of steroid production have again changed in that
China is now exporting large quantities of diosgenin;
10
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Ghante

11. DIOSCOREA
• Synonym- Yam.
• Biological Source
Dioscorea is the dried rhizome of several species of
Dioscorea like
• D. villosa,
• D. prazeri Prain and Burk;
• D. composite;
• D.spiculiflora;
• D. deltoidea and
• D. floribunda,
belonging to family Dioscoreaceae.
• Synonym- Yam.
• Biological Source
Dioscorea is the dried rhizome of several species of
Dioscorea like
• D. villosa,
• D. prazeri Prain and Burk;
• D. composite;
• D.spiculiflora;
• D. deltoidea and
• D. floribunda,
belonging to family Dioscoreaceae.
11
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Ghante

12. • Chemical Constituents
• The roots contain diosgenin (4–6%) a steroidal sapogenin and its
glycoside smilagenin, epismilagenin and beta isomer yammogenin.
• It also contains sapogenase (enzyme), phenolic compounds and
starch (75%).
• Uses
• It is a main source of diosgenin. This is widely used in modern
medicine in order to manufacture progesterone and other steroid
drugs.
• These are used as contraceptives and in the treatment of various
disorders of the genitary organs as well as in a host of other
diseases such as asthma and arthritis.
• Marketed Products
• It is one of the ingredients of the preparations known as
Explode (Herbotech Pharmaceuticals).
• Chemical Constituents
• The roots contain diosgenin (4–6%) a steroidal sapogenin and its
glycoside smilagenin, epismilagenin and beta isomer yammogenin.
• It also contains sapogenase (enzyme), phenolic compounds and
starch (75%).
• Uses
• It is a main source of diosgenin. This is widely used in modern
medicine in order to manufacture progesterone and other steroid
drugs.
• These are used as contraceptives and in the treatment of various
disorders of the genitary organs as well as in a host of other
diseases such as asthma and arthritis.
• Marketed Products
• It is one of the ingredients of the preparations known as
Explode (Herbotech Pharmaceuticals).
12
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Ghante

13. 13
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Ghante

14. 14
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Ghante

15. DIGITALIS LEAVES
• Synonyms
• Digitalis, purple foxglove, finger flower, lady’s glove, Foxglove
Leaves, Folia Digitalis.
• Biological Sources
• Digitalis consists of dried leaves of Digitalis purpurea Linn.,
belonging to family Scrophulariaceae.
• Geographical Sources
• It is mainly found in England, Germany, France, North
America, India, Iraq, Japan, Kurdistan, Mexico, Nepal, Spain,
Turkey
• Synonyms
• Digitalis, purple foxglove, finger flower, lady’s glove, Foxglove
Leaves, Folia Digitalis.
• Biological Sources
• Digitalis consists of dried leaves of Digitalis purpurea Linn.,
belonging to family Scrophulariaceae.
• Geographical Sources
• It is mainly found in England, Germany, France, North
America, India, Iraq, Japan, Kurdistan, Mexico, Nepal, Spain,
Turkey
15
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Ghante

16. • Chemical Constituents
• Digitalis leaves contains 0.2–0.45% of both primary and secondary glycosides.
• Purpurea glycosides A and B and glucogitoloxin are primary glycosides.
• Because of greater stability of secondary glycosides, and lesser absorption of primary
glycosides a higher content of primary glycosides are not considered ideal and secondary
glycosides are used.
• Purpurea glycosides A and B are present in fresh leaves and by their hydrolysis digitoxin and
glucose or gitoxin and glucose are obtained respectively.
• Hydrolysis of purpurea glycosides can take place by digipuridase (enzyme) present in the
leaves.
• Digitoxin yields on hydrolysis digitoxigenin and three digitoxose.
• By hydrolysis of verodoxin, gitaloxigenin and digitalose are obtained.
• Digitalis leaves also contains glycosides like odoroside-H, gitaloxin, verodoxin and
glucoverodoxin.
• Verodoxin was found to potentiate the activity of digitoxin by synergism.
• Digitoxose and digitalose are desoxy sugars found only in cardiac glycosides and answers
Keller–Killiani test.
• The important saponins include digitonin, tigonin and gitonin, and luteolin, a flavone
responsible for the colour of the drug are also present in the leaves.
• Chemical Constituents
• Digitalis leaves contains 0.2–0.45% of both primary and secondary glycosides.
• Purpurea glycosides A and B and glucogitoloxin are primary glycosides.
• Because of greater stability of secondary glycosides, and lesser absorption of primary
glycosides a higher content of primary glycosides are not considered ideal and secondary
glycosides are used.
• Purpurea glycosides A and B are present in fresh leaves and by their hydrolysis digitoxin and
glucose or gitoxin and glucose are obtained respectively.
• Hydrolysis of purpurea glycosides can take place by digipuridase (enzyme) present in the
leaves.
• Digitoxin yields on hydrolysis digitoxigenin and three digitoxose.
• By hydrolysis of verodoxin, gitaloxigenin and digitalose are obtained.
• Digitalis leaves also contains glycosides like odoroside-H, gitaloxin, verodoxin and
glucoverodoxin.
• Verodoxin was found to potentiate the activity of digitoxin by synergism.
• Digitoxose and digitalose are desoxy sugars found only in cardiac glycosides and answers
Keller–Killiani test.
• The important saponins include digitonin, tigonin and gitonin, and luteolin, a flavone
responsible for the colour of the drug are also present in the leaves.
16
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Ghante

17. 17
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Ghante

18. • Chemical Tests
• Digitalis glycosides having five membered lactone ring answers positive for
the following tests which are due to the intact lactone
1. Baljet Test: To a thick section of the leaf sodium picrate reagent is added.
Yellow to orange colour indicates the presence of glycoside.
2. Legal Test: Glycoside is dissolved in pyridine and sodium nitroprusside
solution is added to it and made alkaline. Pink to red colour is produced.
3. Keller–Killiani Test: The isolated glycoside is dissolved in glacial acetic acid
and a drop of ferric chloride solution is added followed by the addition of
sulphuric acid which forms the lower layer.
A reddish-brown colour is seen in between two liquids and the upper layer
becomes bluish green.
• If the powdered leaves are used, 1 gm of the powdered leaves is extracted
with 10 ml of 70% alcohol for couple of minutes, filtered and to 5 ml of
filtrate 10 ml of water and 0.5 ml of strong solution of lead acetate is added
and filtered and the filtrate is shaken with 5 ml of chloroform. Chloroform
layer is separated in a porcelain dish and the test is carried out as
mentioned above.
• Chemical Tests
• Digitalis glycosides having five membered lactone ring answers positive for
the following tests which are due to the intact lactone
1. Baljet Test: To a thick section of the leaf sodium picrate reagent is added.
Yellow to orange colour indicates the presence of glycoside.
2. Legal Test: Glycoside is dissolved in pyridine and sodium nitroprusside
solution is added to it and made alkaline. Pink to red colour is produced.
3. Keller–Killiani Test: The isolated glycoside is dissolved in glacial acetic acid
and a drop of ferric chloride solution is added followed by the addition of
sulphuric acid which forms the lower layer.
A reddish-brown colour is seen in between two liquids and the upper layer
becomes bluish green.
• If the powdered leaves are used, 1 gm of the powdered leaves is extracted
with 10 ml of 70% alcohol for couple of minutes, filtered and to 5 ml of
filtrate 10 ml of water and 0.5 ml of strong solution of lead acetate is added
and filtered and the filtrate is shaken with 5 ml of chloroform. Chloroform
layer is separated in a porcelain dish and the test is carried out as
mentioned above. 18
Compiled & edited by Dr Mahavir H
Ghante

19. • Uses
• The foxglove is a widely used herbal medicine with a recognized
stimulatory effect upon the heart.
• It is also used in allopathic medicine in the treatment of heart complaints.
• It has a profound tonic effect upon a diseased heart, enabling the heart to
beat more slowly, powerfully and regularly without requiring more oxygen.
• At the same time it stimulates the flow of urine which lowers the volume
of the blood and lessens the load on the heart.
• It has also been employed in the treatment of internal haemorrhage, in
inflammatory diseases, in delirium tremens, in epilepsy, in acute mania and
various other diseases.
• Digitalis has a cumulative effect in the body, so the dose has to be decided
very carefully.
• Marketed Products
It is one of the ingredients of the preparation known as Lanoxin tablets
(Glaxo Smith Kline).
• Uses
• The foxglove is a widely used herbal medicine with a recognized
stimulatory effect upon the heart.
• It is also used in allopathic medicine in the treatment of heart complaints.
• It has a profound tonic effect upon a diseased heart, enabling the heart to
beat more slowly, powerfully and regularly without requiring more oxygen.
• At the same time it stimulates the flow of urine which lowers the volume
of the blood and lessens the load on the heart.
• It has also been employed in the treatment of internal haemorrhage, in
inflammatory diseases, in delirium tremens, in epilepsy, in acute mania and
various other diseases.
• Digitalis has a cumulative effect in the body, so the dose has to be decided
very carefully.
• Marketed Products
It is one of the ingredients of the preparation known as Lanoxin tablets
(Glaxo Smith Kline).
19
Compiled & edited by Dr Mahavir H
Ghante

20. DIGITALIS LANATA
• Synonym
• Grecian Foxglove.
• Biological Source
• It consists of the dried leaves of
• Digitalis lanata J. F. Ehrh.,
belonging to family Scrophulariaceae.
• Geographical Source
• It is mainly found in Central and Southern Europe, England,
California and India.
• Synonym
• Grecian Foxglove.
• Biological Source
• It consists of the dried leaves of
• Digitalis lanata J. F. Ehrh.,
belonging to family Scrophulariaceae.
• Geographical Source
• It is mainly found in Central and Southern Europe, England,
California and India.
20
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Ghante

21. • Chemical Constituents
• Digitalis lanata contains cardiac glycosides like lanatoside A, B, C and E.
Lanatosides A and B are acetyl derivatives of purpurea glycosides A and B
respectively.
• Hydrolysis of Lanatoside C yields digoxin, a crystalline active glycoside.
• Uses
• It has gained much importance in recent years because of the less
cumulative effect and three to four times greater activity than D.
purpurea.
• They have the same actions as that of the D. purpurea.
• It is the commercial source of digoxin.
• Employed in the treatment of auricular fibrillation and congestive heart
failure.
• Their use should always be supervised by a qualified practitioner since in
excess they cause nausea, vomiting, slow pulse, visual disturbance,
anorexia and fainting.
• Chemical Constituents
• Digitalis lanata contains cardiac glycosides like lanatoside A, B, C and E.
Lanatosides A and B are acetyl derivatives of purpurea glycosides A and B
respectively.
• Hydrolysis of Lanatoside C yields digoxin, a crystalline active glycoside.
• Uses
• It has gained much importance in recent years because of the less
cumulative effect and three to four times greater activity than D.
purpurea.
• They have the same actions as that of the D. purpurea.
• It is the commercial source of digoxin.
• Employed in the treatment of auricular fibrillation and congestive heart
failure.
• Their use should always be supervised by a qualified practitioner since in
excess they cause nausea, vomiting, slow pulse, visual disturbance,
anorexia and fainting.
21
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Ghante

22. Uses and applications
• Digitalis probably acts in competition with K+ ions for specific receptor enzyme
(ATPase) sites in the cell membranes of cardiac muscle and is particularly
successful during the depolarization phase of the muscle when there is an influx
of Na+ ions.
• The clinical effect in cases of congestive heart failure is to increase the force of
myocardial contraction (the positive inotropic effect) resulting in a complete
emptying of the ventricles.
• As a result of depression of conduction in the bundle of His, the atrioventricular
conduction time is increased, resulting in an extended P–R interval on
the electrocardiogram.
• Arising from their vagus effects, the digitalis glycosides are also used to control
supraventricular (atrial) cardiac arrhythmias.
• The diuretic action of digitalis, important in the treatment of dropsy, arises from
the improved circulatory effect.
• However, following the introduction of safer diuretics in the 1950s, diuretic
therapy for heart failure has become much more important and in some cases can
replace digitalis treatment.
• Digitalis probably acts in competition with K+ ions for specific receptor enzyme
(ATPase) sites in the cell membranes of cardiac muscle and is particularly
successful during the depolarization phase of the muscle when there is an influx
of Na+ ions.
• The clinical effect in cases of congestive heart failure is to increase the force of
myocardial contraction (the positive inotropic effect) resulting in a complete
emptying of the ventricles.
• As a result of depression of conduction in the bundle of His, the atrioventricular
conduction time is increased, resulting in an extended P–R interval on
the electrocardiogram.
• Arising from their vagus effects, the digitalis glycosides are also used to control
supraventricular (atrial) cardiac arrhythmias.
• The diuretic action of digitalis, important in the treatment of dropsy, arises from
the improved circulatory effect.
• However, following the introduction of safer diuretics in the 1950s, diuretic
therapy for heart failure has become much more important and in some cases can
replace digitalis treatment.
22
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Ghante

23. Reference & Credits
• Textbook of Pharmacognosy and
Phytochemistry, Shah and Seth, First Edition,
ELSEVIER-A division of Reed Elsevier India
Private Limited, 2010.
• Pharmacognosy, Trease and Evans, William
Charles Evans, Daphne Evans, SIXTEENTH
EDITION, Saunders, ELSEVIER, 2009.
• Textbook of Pharmacognosy and
Phytochemistry, Shah and Seth, First Edition,
ELSEVIER-A division of Reed Elsevier India
Private Limited, 2010.
• Pharmacognosy, Trease and Evans, William
Charles Evans, Daphne Evans, SIXTEENTH
EDITION, Saunders, ELSEVIER, 2009.
23
Compiled & edited by Dr Mahavir H
Ghante