Isolation & identification of atropine & Quinine

Isolation & identification of Atropine


Isolation: 

  1. Moisten the powdered bark with an aqueous solution of sodium carbonate and extract it with ether or benzene. The free alkaloids are extracted from the solvent and acidified with acetic acid. Discard the aqueous layer.
  2. Add sodium hydroxide to the organic layer to precipitate atropine sulfate. Filter, recrystallize, and purify the crystals with activated charcoal.
  3. Dissolve the atropine sulfate in dilute sulfuric acid and make it alkaline with ammonia. Atropine will precipitate as crystals. Wash and dry them at 45-55°C.


Identification: 

Vitali-Morin Test:
  • Atropine + Small Amount of Con. HNO3 
  • Evaporated to dryness in Waterbath.
  • Residue is dissolved in 1 ml Acetone and few drops of freshly prepared Alcoholic KOH, 
  • Observation: Violet Colour (Tropane Neuclus) 

Isolation & identification of Quinine 

Isolation 


Here are some steps for isolating quinine from cinchona bark:
  • Mix the powdered bark with calcium hydroxide or calcium oxide and sodium hydroxide solution. Let it stand for a few hours.
  • Extract the alkaloids with benzene in a Soxhlet apparatus. 
  • Filter the benzene extract and add sulfuric acid to separate the aqueous and organic layers. Discard the benzene layer.
  • Add sodium hydroxide to the aqueous layer to precipitate quinine sulfate. Filter, recrystallize, and purify the crystals with activated charcoal.
  • Dissolve the quinine sulfate in dilute sulfuric acid and make it alkaline with ammonia.
  • Quinine will precipitate as crystals. Wash and dry them at 45-55°C.


Identification 


  • Thalleoquin Test:
    • Bromine Water and Ammonium solution is added to a small amount of Sample 
    • Emerald Green colour confirms the presence of Quinine. 

  • Thin layer chromatography (TLC): Quinine can be separated and identified by TLC using silica gel as the stationary phase and pure chloroform as the mobile phase. Quinine shows three spots for the free drug and two metabolites under UV light. The Rf value of quinine is 0-0.1.

Comments

Post a Comment

Popular posts from this blog

Image
 Photosynthesis  Light Dependent Reactions  The light-dependent reactions of photosynthesis take place in the thylakoid membranes of chloroplasts. They use light energy to split water molecules into hydrogen and oxygen, and to produce ATP and NADPH. Stage 1: Light energy is absorbed by chlorophyll molecules, which are the green pigments in chloroplasts. This energy is used to excite electrons, which are then transferred to a series of electron carriers. Stage 2:  The electron carriers transfer the electrons to NADP+ , which is reduced to NADPH.   The electrons also transfer protons to the stroma, which creates a proton gradient. The proton gradient is used to drive the synthesis of ATP from ADP and Pi. The light-dependent reactions of photosynthesis are essential for the production of ATP and NADPH, which are used in the Calvin cycle to fix carbon dioxide into glucose. Light Independent Reactions The light-independent reactions of photosynthesis, also known as the Calvin cycle , take p
Read more
Image
  LIQUORICE Biological Source Plant Part – Peeled and un peeled stolons, root and stem Scientific Name – Glycyrrhiza glabra Family – Leguminosae Morphology Odour : Characteristic   Taste : Sweet Shape : Cylindrical   Chemical Constituents *        Saponin glycoside: Glycyrrhizin and glycyrrhizin acid *        Coumarin derivatives – Umbellirerone       Chemical Tests Salkowski test   few drops of con. H 2 SO 4 + liquorice powder ¯ Reddish Brown colour liquorice contains glycyrrhizin Uses 1.       Demulcent and Expectorants 2.     
Read more
Image
Shikimate Pathway  The shikimate pathway is a metabolic pathway that synthesizes aromatic amino acids, such as phenylalanine, tyrosine, and tryptophan, and a variety of other aromatic compounds, such as quinones, flavonoids, and lignin. Stages  Stage 1: The synthesis of shikimate from phosphoenolpyruvate (PEP) and erythrose 4-phosphate. This step is catalyzed by the enzyme 3-dehydroquinate synthase (DHS).  DHS condenses PEP and erythrose 4-phosphate to form 3-dehydroquinate. 3-dehydroquinate is then reduced to shikimate by the enzyme shikimate dehydrogenase (SDH). Stage 2: The conversion of shikimate to chorismate. The key enzymes in this stage are shikimate kinase (SK), 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), chorismate synthase (CS), and chorismate mutase (CM). Stage 3: The conversion of chorismate to aromatic amino acids and other aromatic compounds. Chorismate can be converted to a variety of aromatic amino acids and other aromatic compounds, including phenylalanine,
Read more