2. UNIT-III (6 Hours):
• Isolation, Identification and Analysis of Phytoconstituents
a) Terpenoids: Menthol, Citral, Artemisin
b) Glycosides: Glycyrhetinic acid & Rutin
c) Alkaloids: Atropine, Quinine, Reserpine, Caffeine
d) Resins: Podophyllotoxin, Curcumin
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3. Resins: Introduction
• Resins are amorphous solid or semisolid substances are regarded as the
end products of secondarymetabolism.
• They may contain volatile oil, oxygenated products of terpenes and carboxylic
acid
• Always water insoluble but mostly soluble in alcohol, volatile & fixed oil and
other non polar organic solvents.
• Physically they are found to be hard, translucent or transparent and fusible
i.e., upon heating they first get softened and ultimately melt.
• Chemically, they are complex mixtures of allied substances, like: resin acids,
resin alcohols (resinols), resinotannols, resin esters or glucoresins
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5. Podophyllotoxin - Introduction
• Podophyllotoxin is a resin found in the rhizomes of Podophyllum
hexandrum or Podophyllum emodi of the family Berberidaceae
growing in the Himalayan forest in Kashmir, Sikkim and parts of UP.
• Podophyllotoxin: 20% in American & 40% in Indian variety.
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7. Podophyllotoxin
• Chemicallyit is aryltetralinlactone lignan.
• It is a toxic, polycyclic antimitoticagent
• Formula:C22H22O8
• Molar mass: 414.405 g/mol
• Melting point: 183.3 to 184 °C
• Solubility:
• Very Soluble in chloroform and pure ethanol,
• Soluble in acetone or dichloromethane;
• insoluble or sparinglysoluble in water
• Insoluble in ethyl ether
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8. Extraction & Isolation
• Podophyllum root & rhizome powder is extracted using alcohol by
percolationmethod or soxhlet method
• The percolated extract is concentrated to syrup consistency by removing
alcohol by distillationmethod
• Acidifiedusing acidifiedwater (containing2% HCl) with continuous stirring
• Allowed to stand for two hours at 5oC to precipitate podophyllum resin
(approximately 40%)
• Filter under vacuum, washed with acidified water, cooled at 5oC, dissolved
in 90% alcohol.
• Alcohol is distilledoff to get residuedried at 80oC to a constant weight
• Use preparativeTLC to purify and crystallizethe product at 0oC
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12. Podophylllotoxin uses
• Used for its anti-tumor activity
• Used in production of semi-synthetic drug Etoposide & teniposide.
• Topical: as an antiviral treatment for genital warts.
• Traditionally/ earlier
• It is used as drastic but slow acting purgative
• Used with other purgatives to prevent gripping action
• anthelmintic
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14. Curcumin introduction
• Curcuminis a brightyellow chemical produced by Curcumalonga plants.
• It is the principal curcuminoid of turmeric (Curcumalonga), of family, Zingiberaceae.
• It is sold as an herbal supplement, cosmetics ingredient, food flavouring, and food
colouringagent.
• Chemically, curcumin is a diarylheptanoid, belonging to the group of curcuminoids, which
are natural phenols responsible for turmeric's yellowcolor.
• It is a tautomeric compound existing in enolic form in organic solvents and in keto form in
water.
• Curcumin is an oil-soluble pigment, practically insoluble in water at acidic and neutral pH,
and soluble in alkali, soluble in ethanol (10 mg/ml), DMSO (25 mg/ml), acetic
acid, 0.1M NaOH, 10mM Na2CO3, acetone, water (< 0.1 mg/ml), and
chloroform
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19. TLC identification and estimation
• Sample : Dissolve 1mg curcumin in 1ml methanol
• Stationary phase: Silica Gel G
• Mobile phase: Chloroform: Ethanol: glacial acetic acid(94:5:1)
• Detecting agent: Observation at UV 365nm
• Rf: 0. 79
• Color: bright yellow florescent
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20. Quantitative estimation of curcumin
• Spectrophotometric method
• Spectroscopic analysis was carried out using Double beam Shimadzu
recording UV-Visible Spectrophotometer (Kyoto, Japan) model 1601
with 10 mm path length matched quartz cells was used for analytical
purpose.
• Stock solutions of curcumin containing 10µg/ml were prepared in
methanol and evaluated in UV spectrophotometer.
• Showed the peak with maximum absorbance at 421 nm.
• The method is applied to the determination of curcumin in
pharmaceutical formulations.
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