The document provides an overview of secondary metabolites, focusing on steroids, cardiac glycosides, and triterpenoids such as liquorice, dioscorea, and digitalis. It details their biological sources, characteristics, cultivation, chemical constituents, uses, and marketed products. The information is tailored for third-year pharmacy students as per the PCI syllabus.

1. 1
UNIT II
INTRODUCTION TO SECONDARY
METABOLITE
STEROIDS, CARDIAC GLYCOSIDES
& TRITERPENOIDS:
LIQUORICE, DIOSCOREA, DIGITALIS
For Third Year B. Pharmacy as per PCI syllabus
Submitted by:
Mr. Lalit Bandu Patil
Roll No. 70
T.Y.B.Pharm (SEM: V) 2022-23
Under Guidance of:
Prof. Shubhangi R. Sonawane
PROF. RAVINDRA NIKAM COLLEGE OF PHARMACY,
GONDUR TAL. DIST. DHULE 424002

2. 2
 SECONDARY METABOLITES:
 Secondary metabolites, also called specialized metabolites, toxins,
secondary products, or natural products.
 They are organic compounds, produced by plants.
 They do not directly involved in the normal growth, development, or
reproduction of the organism.
 They plays an important role in defense mechanism of plant i.e.
protection of plants from insect attacks.
There are some types of secondary metabolites, as follow;
Secondary Metabolite
Alkaloid
Phenylpropanoids and
Flavonoids
Steroids, Cardiac
Glycosides & Triterpenoids
Volatile Oils
Tannins
Iridoids, other terpenoids
& Naphthaquinones
Glycosides
Resins

3. 3
 STEROIDS, CARDIAC GLYCOSIDES & TRITERPENOIDS:
1) Steroids:
 A steroid is a biologically active organic compound with four rings
arranged in a specific molecular configuration.
 The steroid core structure is composed of seventeen carbon atom,
bonded in four fused rings.
2) Cardiac Glycosides:
 Cardiac glycosides are a class of organic compounds that increase the
output force of the heart and increase its rate of contractions by acting
on the cellular sodium-potassium ATPase pump.
 Their beneficial medical uses as treatments for CHF and cardiac
arrhythmias.
 The most widely used cardiac glycoside is digoxin.
3) Triterpenes:
 These are a class of chemical compounds composed of three terpene
units with the molecular formula C30H48; they may also be thought
of as consisting of six isoprene units. Animals, plants and fungi all
produce triterpenes, including squalene, the precursor to all steroids.

4. 4
LIQUORICE
 Synonyms:
Radix Glycyrrhizae, Sweet liquorice.
 Biological Source:
Liquorice consists of peeled and unpeeled stolons, roots and
subterranean stems of Glycyrrhiza glabra Linn, and other species of
Glycyrrhiza.
Belonging to family Leguminosae.
 Geographical Source:
It is mainly found in China, Europe, India, Iraq, Japan, Kurdistan, Spain,
Turkey, and the United States.
 Characteristics:
1. Colour: unpeeled Liquorice-Externally,
yellowish brown or dark brown;
and externally, yellowish colour.
2. Odour: Faint and Characteristics
3. Taste: Sweet
4. Size: Length = 20 to 50cm; Diameter = 2cm.
5. Shape: Unpeeled drug-Straigt and nearly
cylindrical & Peeled drug-Mostly
angular.
6. Fracture: Fibrous in bark; and splintery in
the wood.
Length
20-50cm

5. 5
 Cultivation and Collection:
The plant requires a deep well cultivated fertile moisture-retentive soil
for good root production. Prefers a sandy soil with abundant moisture
and does not flourish in clay.
 Microscopy:
 The transverse section reveals several yellow-brown cork layers, and
a layer of phelloderm that is 1 to 3 cells thick.
 The cortex exhibits medullary rays, and obliterated sieve portions
radiate alternately.
Sun dried and Packed
Ollder stolon/roots are separated and washed with water
Parts are dibbled at about 4 inch under the soil
Cut parts into 6 inch long section
Plant parts are obtained from old plantation
Seedling are individually potted
Sown in a greenhouse in spring or autumn
Seeds are pre-soaked for 24 hrs in warm water
Propogated using seeds and roots

6. 6
 The phloem exhibits groups of phloem fibers, which are surrounded
by crystal cells, with thick but incompletely lignified walls.
 The vessels are accompanied by xylem fibers, which are surrounded
by crystal cells, and by xylem parenchyma cells.
 The parenchyma cells contain starch grains and often contain single
crystals of calcium oxalate
Transverse section of Liquorice Root
Cork
Phelloderm
Phloem Fibres
Phloem
parenchyma
Cambium
Vessels
Xylem fibres
Medullary ray
Pith

7. 7
 Chemical Constituents:
 The chief constituents of liquorice root is glycyrrhzin (6-8%),
obtainable in the form of a sweet, which is 50 times sweeter than
sucrose.
 Glycyrrhizic acid (triterpenoid saponin) having α-amyrine structure
on hydrolysis yields glycyrrhetic or glycyrrhetinic acids.
 The drug also contains sugar, starch(29%), gum, protein, fat ( 0.8%),
resin, asparagin (2-4%), atrace f tannin in the outer bark of the root,
yellow colouring matter, and 0.03% of volatile oil.
 Identification Test :
 When sulphuric acid (80%W/V) is added to a thick section of the
drug or powder it is instantly produced a deep yellow colour.

8. 8
 Uses:
 Glycyrrhizia is widely used as a sweetening agent and in bronchial
problems such as catarrah, bronchitis, cold, flu and coughs.
 It reduces irritation of the throat and yet has an expectorant action,
demulcent and expectorant effects. It is used in releving stress.
 It is potent healing agent for tuberculosis.
 Glycyrrhiza is also effective in helping to reduce fevers (glycyrretinic
acid has an effective like aspirin), and it may have an antibacterial
action as well.
 It is used in the treatment of chronic inflammation such as arthritis
and rheumatic disease, chronic skin cordition and autoimmune
diseases in general.
 Marketed products:
It is one of the ingredients of the preparations known as Herbolex,
Koflet, Regurin (Himalaya Drug Company), Eladi Bati, Madhumehari
(Baidyanath), J. P. Nikhar oil, J. P. Kasantak (Jamuna pharma).

9. 9
DIOSCOREA
 Synonyms:
Yam, wild yam.
 Biological source:
Dioscorea is the dried rhizome of several species of Dioscorea,
belonging to family Dioscoreaceae.
 Geographical Sources:
It is mainly found in North America, Mexico, India (Himalayas from
Kashmir and Punjab up to an altitude of 3000m), Nepal and China.
 Characteristics
1. Colour: Slightly brown
2. Odour: Odourless
3. Taste: Bitter
4. Size: Varies depending upon age
of rhizomes
 Cultivation and Collection:
 The plant prefers sandy, loamy and clay soils and requires well-
drained soil.
 The plant prefers acid, neutral and basic (alkaline) and moist soils. It
can grow in semishade or no shade.
Dioscorea Tubers

10. 10
 Microscopic Characteristics:
 Epidermis is brown and thin.
 Cork consist of few layers of sclerenchyma tissue.
 Vascular tissues, xylem and phloem together present in pith.
Dried and they loose 50% weight after drying.
fresh tubers are harvested by deep ploughing after two years of crop.
Irrigation done every 10 days
Manures and organic fertilizers are supplied.
they required support for optimum growth as veins are weak and
tender.
after 2-3 month of growth transplanted in field at distance of 30-
60cm.
after 30-40 day tubers sprout.(germinate)
Tubers are sown in nursery bed.
Cultivated from tubers with crown of about 70-80 gm in weight.

11. 11
 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%).

12. 12
 Chemical Test:
Foam Test:
1 gm of drug add 10-20ml of water, shake for few minutes, formation of
foam which persist for 60 to 120 seconds.
 Uses:
 Diosgenin is widely used to manufacture progesterone and other
steroid drugs.
 Some species of dioscorea are used for the extraction of starch.
 Use for menstrual cramps, discomfort and stomach cramps.
 Anti-spasmod-ic, anti-inflammatory, anti-rheumatic, diuretic and
exportant.
 Marketed Products:
It is one of the ingredient of the preparations known as wild yam root,
wild yam (herb pharm), Mexican wild yam.

13. 13
DIGITALIS
 `Synonyms:
Digitalis leaves, Fox glove, finger flower, Fox glove leaves.
 Biological Source:
Digitalis consist of dried leaves of Digitalis Purpurea Linn.,
belonging to family Scrophulariaceae.
 Geographical Source:
It is mainly found in England, Germany, France, North America,
India, Iraq, Japan, Kurdistan, Mexico, Nepal, Spain, Turkey, etc.
 Characteristics:
1. Colour: Dark grayish green
2. Odour: Odourless
3. Taste: Distinctly bitter
4. Size: Length 10-30 cm
Width 04-10 cm
5. Shape: Ovate, lancolate, petiolate.
Length
10-30cm

14. 14
 Cultivation and Collection:
 It requires Calcareous, acidic, sandy soil for growth.
Dried leaves are packed in air tight container with suitable
dehydrating agent
Leaves are dried in vaccum dryer at temp below 60oC
Leaves collected in second year in afternoon during
August/September
In the first year plant bears rosette leaves and in second year sessile
leaves
Plant flowers in April and is followed by fruiting
Young seedlings are transplanted in September/November
Seeds are mixed with fine sand and sown in nursery in March/April
It is propagated by seeds

15. 15
 Microscopic characteristics:
 It is dorsivental leaf.
 It has anomocytic stomata.
 Covering and glandular trichomes on both sides
 Trichomes and stomata are more in lower surface.
 Chemical constituents:
 Digitalis contain 0.2 to 0.45% of both primary and secondary
glycosides.
 Primary glycosides- Purpurea glycosides A and B. glucogetaloxin and
Secondary are digitoxin, gitoxin and getaloxin.
 Primary glycosides are less stable and less significant than secondary
glycosides.

16. 16
Digitoxin
 Chemical tests:
1. Baljet Test: To a thick section of leaf sodium picrate reagent is
added. Yellow to orange colour indicates the presence of glycoside.
2. Killer-Killiani Test: Isolated glycoside is dissolved in glacial acetic
acid and a drop of ferric chloride solution is added followed by
addition of sulphuric acid, forms lower layer. A reddish brown colour
is seen in between two liquids.
 Uses:
 Digitalis increases excitability of cardiac muscles and increases
contractions.
 It is effective in congestive cardiac failure.
 It is also used as diuretics.

17. 17
 Marketed products:
It is one of the ingredients of preparations known as Lanoxin Tablets
(Glaxo Smith Kline).
References used:
1. Text book of Pharmacognosy by C.K. Kokate, Purohit, Gokhale
(2007), 37th
Edition, Nirali Prakashan.
2. Text book of Pharmacognosy and Phytochemistry by Biren Shah
and A.K. Seth (2009), Second Edition, CBS Publishers.