TANNINS

INTRODUCTION

Tannins are complex organic non-nitrogenous, polyphenolic plant products showing astringent
and antioxidant property.

• The name 'tannin' is derived from the French 'tanin' (tanning substance) and is used for a range
of natural polyphenols.

• The term 'tannin' was first used by Seguin in 1796 to denote substances which have the ability
to combine with animal hides to convert them into leather which is known as tanning of the hide.

• This term was used to denote substances present in plant extract which react with protein of
animal hide, prevent their putrefaction (decay or rotting) and convert hide/skin into leather.

• They have a property to tan animal skin to convert to leather.

• Conversion imparts resistance to water, heat, and abrasives.

• They have property to precipitate gelatin & heavy metals.

• They can be extracted using water-acetone/alcohol mixture.

• Tannins are widely distributed in several plant species and are found in wood, bark, leaves and
fruits.

• Natural polyphenols - contain sufficient hydroxyl group and other suitable group (such as
carboxyl) to form a strong complex with protein and other macromolecules.

• Astringent property - precipitate proteins (Latin - Astringere which means to bind fast)

• Mostly high molecular weight compounds and are water soluble.

# PHYSICAL PROPERTIES

● State - Amorphous, non crystalline

● Molecular weight = 500 to >20,000 D

● Solubility

- Soluble in - water, alcohol, dilute alkali, glycerin, acetone

- Sparingly soluble in - Ethyl acetate
- Insoluble in - Organic solvent except acetone Form colloidal solution with water

● Taste - Astringent taste

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● Combine with skin/hide to form leather

# CHEMICAL PROPERTIES

(1) PRECIPITATION :-

● Tannin precipitates with protein, gelatin, alkaloids, glycosides and heavy metals.

● Tannin precipitates by salt of copper, tin, lead. (e.g. copper acetate, lead acetate)

● Precipitated by strong potassium dichromate or chromic acid solution.

(2) ANTIOXIDANT PROPERTY :-

● Antioxidants property (Free radicals which are highly reactive binds to cell and damages
cell so to prevent damage antioxidants bind with those free radicals) - polyhydroxy
phenolic compounds.

● Because of accumulation of OH group on small size nucleus, these agents have

antioxidant nature.

(3) ASTRINGENT PROPERTY :-

Tannins have the property to react with protein of the mucous membrane, shrink the cells there
and cause precipitation.

(4) Show acidic reaction due to phenolic group as they donate proton and form phenoxide ion
(Aqueous solution of tannin is acidic in nature)

(5) CARCINOGENICITY :-

● Prolong use of tannin containing plant material is hazardous because it causes cancer.

● Habitual use of Areca catechu can cause oral and esophageal cancer.

(6) REACTION WITH IRON/FERRIC SALTS :-

● Hydrolysable tannin + FeCl3 → Blue black color precipitates

● Condensed tannin + FeCl3 → Brownish green color precipitates

(7) REACTION WITH POTASSIUM FERRICYANIDE AND AMMONIA

● Tannin + potassium ferricyanide/ammonia → Deep red color formation

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CLASSIFICATION OF TANNINS

•The tannin compounds can be divided into two major groups on the basis of Goldbeater's skin
test.

•A group of tannins showing the positive tanning test may be regarded as true tannins, whereas
those, which are partly retained by the hide powder and fail to give the test, are called as pseudo
tannins.

(1) TRUE TANNINS :-

•Most of the true tannins are high molecular weight compounds.

•These compounds are complex polyphenolics, which are produced by polymerization of simple
polyphenols.
•They may form complex glycosides or remains as such which may be observed by their typical
hydrolytic reaction with the mineral acids and enzymes.
•Two major chemical classes of tannins are usually recognized based on this hydrolytic reaction
and the nature of phenolic nuclei involved in the tannins structure.
• The first class is referred to as hydrolysable tannins, whereas the other class is termed as
condensed tannins.

(a) Hydrolysable Tannins :-

• These tannins are hydrolysable by mineral acids or enzymes such as tannase.

• Their structures involve several molecules of polyphenolic acids such as gallic, hexahydroxy
diphenic, or ellagic acids, bounded through ester linkages to a central glucose molecule (ẞ
D-glucose).
• On the basis of the phenolic acids produced after the hydrolysis, these are categorized further
into Gallotannins and Ellagitannins.
• Gallotannins which on hydrolysis produce Gallic acid.
• Ellagitannins on hydrolysis produces Ellagic acid (Ellagic acid is formed by intraesterification
of hexahydroxy diphenic acid).
• Hydrolysable tannins are sometimes referred to as pyrogallol tannins as the components of
phenolic acids on dry distillation are converted to pyrogallol derivatives.
• The hydrolysable tannins are soluble in water, and their solution produces blue colour with
ferric chloride.

“Gallic acid”

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“Pyrogallol”

“Ellagic acid”

Gallic acid + Iron salts → Blue fluorescence

Ellagic acid + Iron salts → Blue fluorescence

Biosynthetically, gallic acid (= 3,4,5- trihydroxybenzoic acid) arises from the metabolism of
shikimic acid.

• Hydrolysable tannin or pyrogallol-type tannin is a type of tannin that, on heating with

hydrochloric or sulfuric acids, yields gallic or ellagic acids.

(b) Condensed/Non hydrolysable Tannins :-

Are not readily hydrolysable to simpler molecules with mineral acids and enzymes, thus they are
also referred to as non hydrolysable tannins.

• Also known as Proanthocyanidins.

• Contain only phenolic nuclei which are biosynthetically derived from flavonoids (Flavanol,
Catechin, Flavan-3,4-diol these are polymers of flavanoid).

• When treated with acids or enzymes, they tend to polymerize (self condensate) yielding
insoluble red coloured products known as phlobaphens.

• The phlobaphenes give characteristic red colour to many drugs such as cinchona and wild
cherry bark.

• On dry distillation, they yield catechol derivatives.

• Condensed tannins are also soluble in water and produce green colour with ferric chloride.

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“Catechol”

“Glucogallin”

Catechol solution + Iron salts → Green fluorescence

Condensed tannins + Iron salts → Green fluorescence

• E.g. Cocoa bean, Pterocarpus, Cinchona, Cinnamon bark, Black catechu, Pale catechu, Wild
cherry, Cinchona barks.

• They consist of flavan-3-ol units linked together by carbon-carbon bonds, most often 48 or 46,
which result from coupling between the electrophilic C-4 of a flavanyl unit from a flavan-4-ol or
flavan-3,4-diol and a nucleophilic position (C8, less commonly C- 6) of another unit, generally a
flavan-3-ol.

• Unlike hydrolysable tannins, these are not readily hydrolysable to simpler molecules and they
do not contain a sugar moiety.

• Biosynthetically, flavonoids are derived from acetate and shikimate pathways.

• Polymers may include up to 50 monomer units.

• Condensed tannins occur due to polymerization (condensation) reactions between flavonoids.

• Non-hydrolysable tannins on heating with hydrochloric acid yield phlobaphenes like

phloroglucinol.

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Examples in detail

● Barks - Cinnamon, wild cherry, cinchona, willow, acacia, oak & hamamelis
● Roots and rhizomes - Krameria (rhatany) and male fern
● Flowers - Lime and hawthorn
● Seeds - Cocoa, guarana, kola
● Leaves - Hamamelis, hawthorn and tea, especially green tea
● Extracts and dried juices - catechu, acacia and mangrove cutches

(2) PSEUDO TANNINS :-

• These are not as such a separate group of tannins, but may be treated as subgroups because they
do not obey Goldbeater's skin test and are low molecular weight compounds.

• Chlorogenic acid in coffee and nux vomica, ipecacuanhic acid in ipecacuanha and catechins in
cocoa are examples of pseudo tannins.

• The detection test for chlorogenic acid is carried out by extracting the drug with water and
treating this extract with ammonia solution, followed by exposure to air, which leads slowly to
formation of green colour.

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HYDROLYSABLE TANNINS

# AMLA

• Synonyms :- Emblica, Indian gooseberry, Amalki

• Biological Source :-

This consists of dried, as well as fresh fruits of the plant Emblica officinalis Gaertn Phyllanthus
emblica Linn.
belonging to the family Euphorbiaceae.
It contains not less than 1.0 per cent w/w of gallic acid calculated on a dry basis.

• Geographical Source :-

It is a small or medium size tree found in all deciduous forests of India.

It is also found in Sri Lanka and Myanmar.
The leaves are feathery with small oblong pinnately arranged leaflets. The tree is characteristic
greenish-grey with smooth bark.

• Cultivation and Collection :-

Intolerant to frost or drought, it is grown by seed germination; besides, Amla can also be
propagated by budding or cutting. It does not tolerate the frost or drought. It is normally found
up to an altitude of 1500 m. Commercially, it is collected from wild plants.

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Plant bears male and female flowers separately. Male flowers are reported in the axil of the leaf,
in bunches while the solitary female flowers are in the axil of the branches. The extent of
fertilization is 25 - 30 percent of flowers. Cultivated plants bear comparatively large fruits. The
tree flowers in hot season and the fruits ripen during the winter.

Alternative crops to the extent of 7 - 8 years age of Amla trees can be undertaken. Black gram,
tomato, gaur, sunflower, ground nut etc. are the common alternative crops of choice. Each plant
can bear 175-300 kg of fruits and each healthy fruit weighs approximately 25 - 35 gm.

Plant hormones like Gibberlic acid or planofix in the range of 30 - 50 ppm are most useful to
increase the yield per hectare.

• Macroscopic Characters :-

● Colour - The green colour changes to light yellow or brick red at maturity
● Odour - Odourless
● Taste - The taste of Amla is sore and astringent
● Size - The average size of an Amla is between 1.5 and 2.5 cm in diameter.
● Shape - The fruits are depressed, globular.

• Extra Features :-

Fruits are fleshy obscurely 4 lobed with 6-trigonus seeds.

They are very hard and smooth in appearance.

• Chemical Constituents :-

Amla fruit is a rich natural source of vitamin C (Ascorbic acid) and contains 600 750 mg per 100
g of the fresh pulp.
Furthermore, fruits also contain about 0.5 per cent fat, phyllemblin and 5 per cent tannin.
Amla fruits are also rich in mineral matters like phosphorus, iron and calcium. It contains an
appreciable amount of pectin. The fresh fruits contain about 75 per cent moisture. The fruits are
dehydrated and stored. It is found that vitamin content of dried fruits is not lost considerably.
It may be due to the presence of tannins, which retards oxidation of vitamin C.

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• Chemical Tests :-

1. Alcoholic or aqueous extract of the drug gives blue colour with ferric chloride solution.
2. Adding gelatin and sodium chloride in aqueous extract produces milky white colour.
3. In the aqueous extract of Amla add lead acetate to remove precipitate by filtration. To the
filtrate adds a solution of 2: 6 dichlorophenol - indophenols; the colour disappears.

• Uses :-

● Amla fruits are largely used in Indian medicines. It is used as an acrid, diuretic,
refrigerant and laxative.
● Dried fruits are given in diarrhoea and dysentery.
● They are also administered in jaundice, dyspepsia and anemia along with iron
compounds.
● Fruits are also used in preparation of inks, hair oils and shampoo.
● Seeds of the fruits are given in treatment of asthma and bronchitis.
● Alcoholic extract of the fruit is anti-viral.
● It is a popular ingredient of 'Triphala' and 'Chyawanprash'. Amla, being a rich source of
vitamin C.

# BAHERA

• Synonyms :-

Belleric myrobalan, Baheda, Bibhitak are other names of Bahera.

• Biological Source :-

It consists of dried ripe fruits of the plant Terminalia belerica Linn. belonging to family
Combretaceae, and should contain not less than 0.3 percent of ellagic acid and 0.75 percent of
gallic acid in dried form.

• Geographical Source :-

The tree is found in all the deciduous forests of India, up to an altitude of 1000 m. It is found in
abundance in Madhya Pradesh, Uttar Pradesh, Punjab; Maharashtra and in Sri Lanka and Malaya
as well.

• Cultivation and Collection :-

Cultivation of Baher, though not done on a commercial scale, can be carried out by sowing the
seeds. The seeds can retain the viability for a year and their rate of germination is about 80 per
cent. The plant can also be raised by transplantation. It takes about 15-30 days for germination of
seed. The maximum height of the plant is about 40 m and the girth is 2-3 m. The stem of the

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plant is straight and the leaves are broadly elliptic and clustered towards the end of the branches.
Flowers are simple, solitary and in auxiliary spikes.

• Macroscopic Characters :-

● Colour - Fruits are dark brown to black

● Odour - None
● Taste - Astringent
● Size - 1.3-2 cm in length.
● Shape - Fruits are globular and obscurely 5 angled
The fruits are pulpy with hard and stony seeds.

• Chemical Constituents :-

The fruits contain about 20 - 30 percent of tannins and 40 - 45 percent water-soluble extractives.
It also contains colouring matter besides gallic acid, ellagic acid, phyllemblin, and ethyl gallate
and galloyl glucose. The seeds contain non-edible oil. The plant produces gum. It also contains
most of the sugars as reported in myrobalan.

• Uses :-

Bahera is used as an astringent and in the treatment of dyspepsia and diarrhoea. It is a constituent
of triphala. The purgative property of half ripe fruit is due to the presence of fixed oil. The oil on
hydrolysis yields an irritant recipe. Gum is used as a demulcent and purgative. Oil is used for the
manufacture of soap.

CONDENSED TANNINS

# AMAR

• Synonym :- Mango, Aam

• Biological Source :-

Amra consists of dried stem bark of Mangifera indica Linn. family Anacardiaceae, a tree found
wild or cultivated throughout the country. It contains not less than 1.5 percent of mangiferin on a
dried basis.

• Description :-

(a) Macroscopic

● Colour - Greyish to dark brown externally and yellowish-white to reddish internally

● Odour - Pleasant
● Taste - Astringent

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● Size and Shape - Drug occurs in pieces of variable size and thickness
● Extra features - Surface rough due to longitudinal cracks, fissures and scattered, raised
lenticels.

(b) Microscopic

Mature bark has a wide cork consisting of tangentially elongated cells, few outer layers brown
and inner lighter in colour, at few places lenticels; secondary cortex absent; secondary phloem
wide, consisting of sieve elements, parenchyma and phloem fibres, traversed by medullary rays,
resin canals and yellow coloured elongated; tannin sacs abundantly scattered throughout phloem;
stone cells thick walled, lignified, rectangular with wide lumen starch grains and prismatic
crystals of calcium oxalate present in phloem cells; phloem fibres in groups of 2-15 or more
cells, long and thick walled, phloem rays 1-3 seriate, containing crystals of calcium oxalate and
starch grins.

• Chemical Constituents :-

Mango bark contains 10-20 per cent tannins, namely protocatechuic acid and catechin.
Additionally it also contains mangiferin, alanine, glycine, aminobutyric acid, kainic acid and
Shikimic acid. Mangiferin is a polyphenolic compound and is an antimicrobial, analgesic and
antioxidant.

• Standards :-

● Foreign organic matter - Not more than 2 per cent

● Total ash - Not more than 9 per cent
● Acid-insoluble ash - Not more than 2 per cent
● Alcohol-soluble extractive - Not less than 20 per cent
● Water-soluble extractive - Not less than 14 per cent

• Identification by TLC :-

TLC of the alcoholic extract on Silica gel 'G' plate using n-Butanol: Acetic acid: Water (4:1:5)
shows under:

(1) UV (366 nm) three violet spots at Rr. 0.12, 0.73 and 0.87.
(2) On exposure to iodine vapour four yellow coloured spots appear at Rt. 0.33, 0.51, 0.74 and
0.88.
(3) On spraying with 5 percent Methanolic-sulphuric acid reagent and after heating the plate at
105°C for ten minutes, three grey coloured spots appear at Rr. 0.49, 0.69 and 0.88.

• Uses :-

Amra-bark is used as an astringent, antioxidant and also in the treatment of diarrhoea, dysentery
and rheumatism. Fruits are edible, sweet, delicious and a rich source of nutrients. Fixed oil
obtained from mango-stone is valuable industrially.

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# BLACK CATECHU

• Synonyms :-

Kattha, Cutch, Khadir-catechu, Catechu

• Biological Source :-

It consists of dried aqueous extract prepared from the heartwood of Acacia catechu wild and
Acacia chundra willd family Leguminosae.

• Geographical Source :-

Plants used for preparation of catechu are grown in India and Myanmar.

• Manufacture of Black Catechu :-

In the traditional method, the separated heartwood is boiled in earthen vessels, fired by sap
wood, till all the soluble portion is extracted from it. It is cooled naturally till it is converted to
semi- solid mass. On cooling, a less soluble fraction separates out. The latter is removed as
kattha and semi solid mass as cutch. It is transferred to rectangular pits, at the bottom of which
sand and clay are placed. It is kept for several days, till the clutch part is absorbed by clay and
solid mass, called kattha, is taken out and moulded into blocks.

In modern methods, the red heart wood obtained by felling the tree and separating the bark and
sapwood, is cut into chips mechanically and put into extractors. The steam is passed through the
drug for maximum extraction. The extract is concentrated under vacuum and is cooled by
refrigeration. It is then centrifuged to isolate the cake of kattha. The cake is moulded in desired
sizes and dried in proper condition. By this way, a good quality marketable kattha, ready for
market is obtained. The mother liquor, left behind during centrifugation is concentrated, which
on cooling gives a clutch.

• Description :-

● Colour - Light brown to black

● Odour - None
● Taste - Very astringent
● Size - About 2.5-5 cm
● Shape - Cube or irregular fragments of broken cubes or brick shaped pieces.

• Extra Feature :-

The cubes as well as brick shaped pieces of catechu show the presence of vegetable debris and
break with a short fracture. The broken pieces are angular with pale cinnamon-brown colour. It is
friable and porous.

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• Chemical Constituents :-

Black catechu contains about 10 percent of acacatechin. It is diastereoisomer of 5, 7, 3', 4'

tetrahydroxy flavan-3-ols. Acacatechin is also known as acacia catechin. Acacatechin undergoes
oxidation to catechu tannic acid in presence of water and the latter constitutes about 30 percent
of the drug. The other contents of black catechu are catechu red, quercetin, gum and quercitrin.
Black catechu does not contain chlorophyll and also the fluorescent- substance present in pale
catechu.

• Chemical Tests :-

(1) Because of the presence of catechin, black catechu gives pink or red colour with vanillin and
hydrochloric acid.

(2) Catechin when treated with hydrochloric acid produces phloroglucinol, which burns along
with lignin to give purple or magenta colour. For this purpose, tannin extract is taken on match
sticks dipped in hydrochloric acid and heated near the flame.

(3) Lime water when added to aqueous extract of black catechu gives brown colour, which turns
to red precipitate on standing for some time.

(4) Green colour is produced when ferric ammonium sulphate is added to dilute the solution of
black catechu. By the addition of sodium hydroxide, the green colour turns to purple.

• Standards :-

● Ash value - not more than 6 percent w/w

● Water insoluble residue - not more than 25 percent w/w
● Alcohol insoluble residue - not more than 90 percent w/w

• Uses :-

Kattha is used as an astringent externally for boils, skin eruptions and ulcers. It is also used in
Cough and diarrhoea. Kattha has cooling and digestive properties
Cutch is not much used medicinally, but for other purposes like dyeing and colouring, water
softening, reducing the viscosity of drill mud, removal of mercaptans from gasoline, protective
agent for fishing nets and in the manufacture of ion-exchange resins.

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ISOLATION

● Both hydrolysable and condensed tannins are highly soluble in water and alcohol but
insoluble in organic solvents such as solvent ether, chloroform, and benzene.

● Tannin compounds can be easily extracted by water or alcohol.

● The general method for the extraction of tannic acid from various galls is either with
water-saturated ether, or with mixture of water, alcohol, and ether.

● In such cases, free acids such as Gallic and ellagic acid go along with ether, whereas true
tannin gets extracted in water.

● If the drug consists of chlorophyll or pigment, it may be removed by ether.

● After extraction, the aqueous and ethereal layers are separately concentrated, dried, and
subjected to further isolation and purification using various separation techniques of
chromatography.

IDENTIFICATION TEST

(1) Goldbeater's skin test (main test) :-

Goldbeater's skin is a membrane produced from the intestine of Ox. It behaves just like an
untanned animal hide.
↓
A piece of goldbeater's skin previously soaked in 2% hydrochloric acid
↓
washed with distilled water is placed in a solution of tannin for 5 minutes.
↓
then washed with distilled water and transferred to 1% ferrous sulphate solution.
↓
change of the colour of the goldbeater's skin to brown or black indicates the presence of tannin.

(2) Gelatin test :-

1% gelatin solution + 10% NaCl solution + 1% tannin solution

↓
White buff colour precipitate
↓
Tannins cause precipitation of gelatin from solution.

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(3) Phenazone test :-

5 ml aq. tannin solution + 0.5 gm Sodium acid phosphate/ sodium hydrogen phosphate
↓
Warm Cool & filter it
↓
Filtrate + 2% phenazone soln
↓
Bulky coloured precipitates produced.

(4) Test for Chlorogenic acid :-

Aq. tannin solution + aq. ammonia

↓
Expose it to air
↓
Green colour appears gradually due to the presence of chlorogenic acid.

(5) Vanillin HCL acid test :-

Sample solution
+
Vanillin HCl reagent (1 g vanillin + 10 ml alcohol + 10 ml dil. HCl solution)
↓
Pink or red colour due to formation of phloroglucinol

(6) Test for Catechin (Matchstick test) :-

Catechin test is the modification of the well-known phloroglucinol test for lignin.
Matchsticks contain lignin.

Dip the matchstick in aq. solution of tannin/plant extract

↓
Dry it near the flame
↓
Moisten with Conc. HCI
↓
Warm it near the flame Matchstick turns Pink or Red in colour due to phloroglucinol formation.

(Catechin in the presence of acid produces phloroglucinol which stains the lignified wood pink
or red)

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(7) Ferric chloride test :-

Tannin solution + FeCl3

↓
Blue colour

Confirms presence of Hydrolysable tannins (Gallic acid, Ellagic acid)

Tannin solution + FeCl3

↓
Brownish green colour

Confirms presence of Condensed tannins (Catechol solution)

ANALYSIS BY
THIN LAYER CHROMATOGRAPHY (TLC)

1. Sample Preparation :-

● Dissolve tannin extract in methanol or water-methanol mixture.

2. Stationary Phase :-

● Use silica gel-coated TLC plates.

3. Mobile Phase :-

● Commonly used solvents: Ethyl acetate:Formic acid:Water (8:1:1).

4. Application :-

● Apply spots of tannin extracts on the TLC plate.

5. Development and Detection :-

● Develop the plate in a chamber saturated with the mobile phase.

● Dry the plate and spray with a detecting agent like ferric chloride.

● Spots appear as dark blue, green, or red depending on the type of tannin.

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MEDICINAL PROPERTIES AND USES

● Tannins occur in crude drugs either as a major active constituent as in oak bark,
hamamelis leaves, and bearberry leaves, etc. or as a subsidiary component as in clove,
cinnamon, peppermint, or garden sage.

● In many cases, they synergistically increase the effectiveness of active principles.

● Tannins are medicinally significant due to their astringent properties.

● They promote rapid healing and the formation of new tissues on wounds and inflamed
mucosa.

● Tannins are used in the treatment of varicose ulcers, haemorrhoids, minor burns, frostbite,
as well as inflammation of gums

● Internally tannins are administered in cases of diarrhoea, intestinal catarrh, and in cases
of heavy metal poisoning as an antidote.

● In recent years, these compounds have demonstrated their antiviral activities for
treatment of viral diseases including AIDS.

● Tannins are used as mordant in dyeing, manufacture of ink, sizing paper and silk, and for
printing fabrics.

● It is used along with gelatine and albumin for manufacture of imitation horn and tortoise
shell.

● They are widely used in the leather industry for conversion of hide into leather, the
process being known as tanning.

● Tannins are also used for clarifying beer or wine, in photography or as a coagulant in
rubber manufacture.

● Tannins are used for the manufacture of gallic acid and pyrogallol, and sometimes as a
reagent in analytical chemistry.

• Importance of tannins :-

# Medicinal uses

● Antidote
● Antiseptic
● Algicidals
● Astringents

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● Anti-carcinogenic
● Antibiotic, Herbicides, Insecticides

# Biological activities :-

● Inhibition of lipid peroxidation

● Decrease in blood urea nitrogen content
● Inhibition of plasma Lipolysis in fat cells

# Industrial uses :-

● Ink manufacturer
● Vegetable tanning
● Preservatives
● Flavouring agent
● Perfumery agent

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• References :-

● W.C.Evans, Trease and Evans Pharmacognosy, 16th edition, W.B. Sounders & Co.,
London, 2009.

● Mohammad Ali. Pharmacognosy and Phytochemistry, CBS Publishers & Distribution,

New Delhi.

● Textbook of Pharmacognosy by C.K. Kokate, Purohit, Gokhlae (2007), 37th Edition,

Nirali Prakashan, New Delhi.

● Herbal drug industry by R.D. Choudhary (1996), Ist Edn, Eastern Publisher, New Delhi.

● Essentials of Pharmacognosy, Dr.SH.Ansari, IInd edition, Birla publications, New Delhi,

2007

● Herbal Cosmetics by H.Pande, Asia Pacific Business press, Inc, New Delhi.

● A.N. Kalia, Textbook of Industrial Pharmacognosy, CBS Publishers, New Delhi, 2005.

● R Endress, Plant cell Biotechnology, Springer-Verlag, Berlin, 1994.

● Pharmacognosy & Pharmacobiotechnology. James Bobbers, Marilyn KS, VE Tylor.

● The formulation and preparation of cosmetic, fragrances and flavours.

● Remington's Pharmaceutical sciences.

● TextBook of Biotechnology by Vyas and Dixit.

● TextBook of Biotechnology by R.C. Dubey.

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