Bachelor of Science in Pharmacy
1 TANNINS
MID
PHARMACOGNOSY AND PLANT CHEMISTRY
OUTLINE CLASSIFICATION OF TANNINS
Biosynthesis of Tannins based on Goldbeater’s skin test
Classes of Tannins
Extraction and Purification
Test for Tannins TRUE TANNIN PSEUDOTANNIN
Sources and Uses of Tannins
Positive tanning result Negative tanning result
INTRODUCTION Positive result with Goldbeater’s Skin Test?
Brown or Black (the color of leather)
Historically, tannin-containing drugs are
related to their tanning property. GENERAL TEST FOR TANNINS
GOLDBEATER’S SKIN TEST
ex: their ability to transform fresh hides
into imputrescible leather. soak a small piece of goldbeater’s skin in
animal skin + tannins = leather perish 2% hydrochloric acid
difficult to separate crystallize rinse with distilled water
astringent: precipitate proteins (ex. place in the solution to be tested for 5
Bayabas Psidium guajava) minutes
wash with distilled water
transfer to a 1% solution of ferrous
sulfate FeSO4
Brown or Black color on the skin denotes
the presence of tannins
⭐ NOTE: Goldbeater’s skin is a membrane
prepared from the intestine of the OX (Bos
taurus) and behaves similarly to an untanned
hide.
TRADITIONAL APPLICATIONS OF TANNINS
Pharmacological & Medicinal Nutritional Veterinarian
animal feed, treatment of fever,
gastrointestinal, respiratory, food ingredients of different
urinary, gastrointestinal, parasites,
urinary, inflammatory, skin dishes, revitalizing agents, and
external application on wounds
problems, sexual diseases, etc. food supplements, etc.
(usually to stop bleeding), etc.
, Bachelor of Science in Pharmacy
1 TANNINS
MID
PHARMACOGNOSY AND PLANT CHEMISTRY
Hydrolysable tannins on heating with
hydrochloric or sulfuric acids yield:
TRUE TANNINS Gallic acid and Ellagic acid
ELLAGIC
GALLIC
ACID ACID
Sources:
HYDROLYSABLE NON HYDROLYSABLE Myrobalan (Terminalia chebula) - Combretaceae
TANNINS TANNINS Bahera (Terminalia belerica) - Crombretaceae
Witch hazel - hamamelidaceae
blue-black greenish
ppt brown ppt
GENERAL TEST FOR TRUE TANNINS
FERRIC CHLORIDE TEST
A. Blue black
B, Greenish brown PHENOLIC ACIDS
HYDROLYSABLE TANNINS
Esters of sugars and phenolic acid
molecules
GALLIC ACID ELLAGIC ACID
tan
allotannin l agi nin
E
s
G
s
Gallotannins Sources Ellagitannins Sources
RGC PE
Rhubarb Pomegranate
DRY DISTILLATION ---> PYROGALLOL Rheum spp Punica granatum
Gall Eucalyptus
Tumor in plants Eucalyptus spp
Clove
Syzygium aromaticum
soluble in water
blue color with ferric
chloride
GALLOTANINS ELLAGITANNINS
1 TANNINS
MID
PHARMACOGNOSY AND PLANT CHEMISTRY
OUTLINE CLASSIFICATION OF TANNINS
Biosynthesis of Tannins based on Goldbeater’s skin test
Classes of Tannins
Extraction and Purification
Test for Tannins TRUE TANNIN PSEUDOTANNIN
Sources and Uses of Tannins
Positive tanning result Negative tanning result
INTRODUCTION Positive result with Goldbeater’s Skin Test?
Brown or Black (the color of leather)
Historically, tannin-containing drugs are
related to their tanning property. GENERAL TEST FOR TANNINS
GOLDBEATER’S SKIN TEST
ex: their ability to transform fresh hides
into imputrescible leather. soak a small piece of goldbeater’s skin in
animal skin + tannins = leather perish 2% hydrochloric acid
difficult to separate crystallize rinse with distilled water
astringent: precipitate proteins (ex. place in the solution to be tested for 5
Bayabas Psidium guajava) minutes
wash with distilled water
transfer to a 1% solution of ferrous
sulfate FeSO4
Brown or Black color on the skin denotes
the presence of tannins
⭐ NOTE: Goldbeater’s skin is a membrane
prepared from the intestine of the OX (Bos
taurus) and behaves similarly to an untanned
hide.
TRADITIONAL APPLICATIONS OF TANNINS
Pharmacological & Medicinal Nutritional Veterinarian
animal feed, treatment of fever,
gastrointestinal, respiratory, food ingredients of different
urinary, gastrointestinal, parasites,
urinary, inflammatory, skin dishes, revitalizing agents, and
external application on wounds
problems, sexual diseases, etc. food supplements, etc.
(usually to stop bleeding), etc.
, Bachelor of Science in Pharmacy
1 TANNINS
MID
PHARMACOGNOSY AND PLANT CHEMISTRY
Hydrolysable tannins on heating with
hydrochloric or sulfuric acids yield:
TRUE TANNINS Gallic acid and Ellagic acid
ELLAGIC
GALLIC
ACID ACID
Sources:
HYDROLYSABLE NON HYDROLYSABLE Myrobalan (Terminalia chebula) - Combretaceae
TANNINS TANNINS Bahera (Terminalia belerica) - Crombretaceae
Witch hazel - hamamelidaceae
blue-black greenish
ppt brown ppt
GENERAL TEST FOR TRUE TANNINS
FERRIC CHLORIDE TEST
A. Blue black
B, Greenish brown PHENOLIC ACIDS
HYDROLYSABLE TANNINS
Esters of sugars and phenolic acid
molecules
GALLIC ACID ELLAGIC ACID
tan
allotannin l agi nin
E
s
G
s
Gallotannins Sources Ellagitannins Sources
RGC PE
Rhubarb Pomegranate
DRY DISTILLATION ---> PYROGALLOL Rheum spp Punica granatum
Gall Eucalyptus
Tumor in plants Eucalyptus spp
Clove
Syzygium aromaticum
soluble in water
blue color with ferric
chloride
GALLOTANINS ELLAGITANNINS
