TANNIN Flashcards
The term Tannin was first applied by _____ in _____ to denote substances present in plant extracts which were
able to combine with protein of animal hides, prevent their putrefaction and convert them into leather.
SEGUIN (1796)
was first applied by Seguin in 1796 to
denote substances present in plant extracts which were able to combine with protein of animal hides, prevent their putrefaction and convert them into leather.
TANNIN
Is a substance which is detected qualitatively by a Tannin Test (Goldbeater’s Skin Test) and is determined
quantitatively by its absorption on standard hide powder.
TANNINS
Tannin is a substance which is detected qualitatively by a ________ and is determined quantitatively by its absorption on standard hide powder.
TANNIN TEST ( GOLDBEATER’S SKIN TEST)
Many tannins are ______
GLYCOSIDES
Are source of fruit acids (Glycolic, Lactic, Mandelic, Malic, Tartaric and Citric acid)
TANNINS
Tannins are a source of fruit acids.
GLYCOLIC
LACTIC
MANDELIC
MALIC
TARTARIC
CITRIC ACID
Found in immature fruits
TANNINS
Found in specific plant parts (leaves, fruits, barks or stems)
TANNINS
Found in great quantities in dead or drying cells.
TANNINS
Occur in solution in cell sap, often in distinct vacuoles.
TANNINS
❑ Plant polyphenols
❑ “Tannin Extracts”
❑ Non-crystallizable
❑ Complex substance– a mixture of polyphenols and
non-crystallizable compounds
❑ Precipitate proteins
❑ Sharp “puckering” taste
TANNINS
a mixture of polyphenols and
non-crystallizable compounds
COMPLEX SUBSTANCE
This may be hydrolyzed by acids
or enzymes such as Tannase.
HYDROLYSABLE TANNINS
Hydrolysable Tannins may be hydrolyzed by acids or enzymes such as _____.
TANNASE
They form several molecules of phenolic acids as Gallic acid and Hexahydroxy-diphenic acid which are united by
ester linkages to a central glucose molecules.
HYDROLYSABLE TANNINS
They form several molecules of phenolic acids as _______ and ________ which are united by
ester linkages to a central glucose molecules.
GALLIC ACID
HEXAHYDROXY-DIPHENIC ACID
dry distillation, Gallic acid and similar components are converted to Pyrogallol.
FORMERLY KNOWN AS PYROGALLOL TANNINS
When treated with acids/enzymes– phenolic acids (Gallic acid, Ellagic Acid and Glucose)
HYDROLYSABLE TANNINS
Phenolic acids
GELLIC ACID
ELLAGIC ACID
GLUCOSE
Gallic acid
GALLITANNINS
Hexahydroxy-diphenic acid units
ELLAGITANNINS
Hydrolysable Tannins
(Ferric chloride)
BLUE
Hudrolysable Tannins
(Bromides)
No Precipitate
Condensed Tannins (Proanthocyanidins, Polyflavonoid, Catechol-type, Pyrocatecollic-type tannins)
NON-HYDROLYSABLE TANNINS
Are not readily hydrolyzed to simpler molecules and they do not contain a sugar moiety.
NON-HYDROLYSABLE TANNINS
Are related to the Flavonoid pigments and have polymeric Flavan-3-ol structures
NON-HYDROLYSABLE TANNINS
Catechins which also occur with the tannins and Flavan in the biosynthesis of the molecules..
NON-HYDROLYSABLE TANNINS
When treated with acids/enzymes– converted into red insoluble compounds known as Phlobaphenes– give the
characteristic color to many drugs (red cinchona bark)
NON-HYDROLYSABLE TANNINS
When subjected to dry distillation
CATECHOL CALLED AS CATECHOL TANNINS
Non-hydrolysable tannins
(Ferric Chloride)
Greenish
Non-hydrolysable tannins
(Bromides)
PRECIPITATE
Are compounds of lower molecular weight than true tannins and they do not respond to the Goldbeater’s skin test
PSEUDOTANNINS
It occur with the tannins
CATECHINS
It occur in the biosynthesis of the molecules
FLAVAN
It give characteristic color to many drugs (red cinchona bark)
PHLOBAPHENES
When subjected to dry distillation
CATECHOL CALLED AS CATECHOL TANNINS
Form by either linkages between two or more molecules of Phenolic acid:
DIGALLIC
CHLOROGENIC ACID
Derivatives of Falavan:
CATECHINS/CATECHOLS
Rhubarb and most materials which contains gallitannins
GALLIC ACID
Catechu, Acacia cutch, Kino, Cocoa, Guarana
CATECHINS
Unroasted coffee, Nux vomica
CHLOROGENIC ACID
Ipecacuanha
IPECACUANHA ACID
Examples of Catechins:
CATECHU
ACACIA CUTCH
KINO
COCOA
GUARANA
Examples of Chlorogenic Acid:
UNROASTED COFFEE
NUX VOMICA
Color obtained in Pseudotannins
CATECHOL TANNINS
PYROGALLOL TANNINS
Pyrocatechol/Phlobatannin
(Heated)
CATECHOL
Pyrocatechol/Phlobatannin
(Boiled with HCL)
INSOLUBLE RED PHLOBAPHENES
Pyrocatechol/Phlobatannin
(Treated with FeCL3 T.S.)
GREEN COLOR
Pyrocatechol/Phlobatannin
(Treated with Bromine T.S.)
FORMED PRECIPITATE
Examples of Pyrocatechol/Phlobatannin
KINO
GAMBIR
Pyrogallol Tannins
(Heated)
Pyrogallol
Pyrogallol Tannins
(Boiled with HCL)
GALLIC ACID/ELLAGIC ACID
Pyrogallol Tannins
(Treated with FeCL3 T.S.)
BLUE COLOR
Treated with Bromine T.S.
NO PRECIPITATE
Examples of Pyrogallol Tannins
NUT GALL, OAK BARK, POMEGRANATE BARK
Uses or Pseudotannins:
ANTISEPTIC
ASTRINGENT
ANTIDOTE FOR ALKALOIDAL POISONING
PRESERVATIVE ON LEATHER
LABORATORY REAGENT FOR PROTEIN AND ALKALOID IDENTIFICATION
INK INDUSTRIES
CAUTION: CARCINOGENIC POTENTIAL
Other therapeutic activities of Pseudotannins
(Antioxidants)
LEUCOANTHOCYANIDINS
PROANTHOCYANIDINS
PYCNOGENOL
Grape seeds
VITIS VINIFERA
Needles and barks of pine trees
PINUS PINASTER
7 tests for Pseudontannins:
SOLUBILITY
REACTION WITH FERRIC SALTS
GOLDBEATER’S SKIN TEST
PHENAZONE TEST
GELATIN TEST
TEST FOR CATECHIN
TEST FOR CHLOROGENIC ACID
Plants rich sources of tannins:
Flowers
LIME
HAWTHORN
Flowers Rich Sources Of Tannins:
Fruits
CANBERRY
GRAPES
HAWTHORN
Flowers Rich Sources Of Tannins:
SEEDS
ARECA
CACAO
GUARANA
KOLA
Flowers Rich Sources Of Tannins:
Leaves
HAMAMELIS
HAWTHORN
Are classified to Polyhedric phenol from which they derived:
GALLITANNINS (GALLIC ACID)
ELLIGITANNINS (HEXAHYDROXY-DIPHENIC ACID)
Plants Rich Source of Tannins:
(BARKS)
ACACIA
CINNAMON
HAMAMELIS
OAK
WILLOW
WILD CHERRY
Plants Rich Source of Tannins:
(Roots and Rhizomes)
KRAMERIA
MALE FERN
Plants Rich Source of Tannins:
(Extracts and Dried Juices)
ACACIA CATECHU
MANGROVE
EAST INDIAN KINO
EUCALYPTUS KINO
BUTEA GUM
8 Plant Families of Tannins
COMBRETACEAE -QUISQUALIS
GERANIACEAE - GERANIUMS
LEGUMINOSAE - ACACIA, TAMARIND
MYRTACEAE - EUCALYPTUS, GUAVA
POLYGONACEAE - BUCKWHEAT
ROSACEAE - RED ROSE
RUBIACEAE - GAMBIR
THEACEAE - TEA
Quisqualis
COMBRETACEAE
Geraniums
GERANIACEAE
Acacia and Tamarind
LEGUMINOSAE
Eucalyptus and Guava
MYRTACEAE
Buckwheat
POLYGONACEAE
Red Rose
ROSACEAE
Gambir
RUBIACEAE
Tea
THEACEAE
High rates of oral esophageal cancer in India and South Africa.
HABITUAL CHEWING OF BETEL NUTS
Lower incidence of esophageal cancer in British than Dutch
ORDINARY DRINKING OF TEA