Isolation, Identification And Analysis Of Atropine

The isolation, identification, and analysis of atropine, a tropane alkaloid primarily sourced from plants like belladonna (Atropa belladonna), involve a series of systematic steps. Initially, the plant material is dried and powdered, followed by solvent extraction using alcohol or water to separate the alkaloid from other compounds. The liquid extract is then filtered and concentrated through evaporation, yielding a crude extract that contains atropine. Identification is achieved through techniques like thin-layer chromatography (TLC) or high-performance liquid chromatography (HPLC), which help separate atropine for further analysis. Confirmatory methods such as infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS) provide detailed structural information and confirm its identity. For quantification, HPLC is employed to measure atropine concentration against a standard curve, while purity can be assessed through additional chromatographic methods. Finally, pharmacological assays may be conducted to evaluate atropine’s biological activity, such as its effects on heart rate. Collectively, these methods ensure a comprehensive understanding of atropine's properties and potential medicinal applications.

1. PHARMACOGNOSY AND PHYTOCHEMISTRY - II ISOLATION, IDENTIFICATION AND ANALYSIS OF ATROPINE BY, DAKSHINESH P B. Pharm V semester

2. ALKALOIDS Alkaloids are basic chemical compounds, obtained from plants. Chemically, one nitrogen atom is always present in the 5 - or 6 -membered ring structure of alkaloids. Their basic nature is due to this N -atom only. They are valuable to the body‘s physiological system. Ladenburg defined alkaloids as, ‘Compounds originated from plants with a basic nature, having one or more nitrogen atom in its ring structure.’ After development in the research work related to chemistry of alkaloids, alkaloids are defined as ‘ Physiologically active basic compounds of plant origin in which at least one nitrogen atom forms part of a cyclic system .’

3. ATROPINE Atropine is a tropane alkaloid. Tropane alkaloids are a class of bicyclic alkaloids and secondary metabolites that contain a tropane ring in their chemical structure. 

4. ATROPINE Family: Solanaceae Biological source: Obtained from the fresh or dried leaves and flowering tops of Atropa belladonna (deadly nightshade), Datura stramonium (thorn apple), Hyoscyamus niger (henbane)

5. ISOLATION Required quantity of coarse powder is taken and moistens with sodium carbonate solution. The blended mixture is extracted in petroleum ether and filters it. To the filtrate aqueous acetic acid is added and extracted with ether to remove coloring matter. Both fraction are separated by separating funnel and discard solvent ether fraction.

6. Aqueous (Acidic fraction) is made alkaline with sodium carbonate solution to obtain precipitates of tropane alkaloids. The precipitate is filtered and dry to obtain residue. The residue is dissolved in diethyl ether, filtered it and concentrated the filtrate. Atropine crystals will be separated out. The crystals are filtered and dissolve in alcohol containing sodium hydroxide solution (Hyocyamine is converted to atropine). The atropine sulphate is recrystallized from acetone and crystals of atropine are separated

7. PROPERTIES Appearance: Colorless crystal or white crystalline powder Odor: Odorless Taste: Bitter taste Solubility: Easily soluble in water, soluble in ethanol, but insoluble in ether and chloroform

8. IDENTIFICATION Vitali–Morin test: Small quantity of the solid atropine is taken and added 2 drops of Conc. nitric acid in an evaporating dish and evaporated to dryness on water bath. Then the residue is dissolved in 1ml of acetone and few drops of freshly prepared alcoholic potassium hydroxide solution is added. Violet coloration takes place due to tropane nucleus.

9. ANALYSIS THIN LAYER CHROMATOGRAPHY (TLC) Sample preparation : 1mg of Atropine is dissolved in 1ml of chloroform Standard sample : Atropine Stationary phase : Pre-coated Silica gel Mobile phase : Toluene: Ethyl acetate: Diethyl amine (70:20:10) Detecting agent : Dragendorff’s reagent RF Value : 0.70 Color spot : Yellow orange spot

10. USES Antispasmodic – Drug used to relieve spasm of involuntary muscle. Mydriatic - Agent that induces dilation of the pupil. Antidote in opium poisoning.

11. SUMMARY Atropine is tropane alkaloid. Obtained from the fresh or dried leaves and flowering tops of Atropa belladonna, Datura stramonium and Hyoscyamus niger , belongs to family – Solanaceae. Isolated by general method. Identified by Vitali–Morin test which give positive violet color. Analysis by Thin Layer Chromatography (TLC).

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