Alkaloids & Its Identification Tests

• Alkaloids & Its Identification Tests involve detecting nitrogenous plant compounds with therapeutic significance.
• Alkaloids & Its Identification Tests also confirm purity, pharmacological activity, and standardization of herbal drugs.

Definition

• Alkaloids are nitrogen-containing, basic organic compounds derived from amino acids.
• They have significant physiological effects on humans and animals.

Examples

• Morphine (Opium poppy – Papaver somniferum)
• Quinine (Cinchona bark – Cinchona officinalis)
• Nicotine (Tobacco – Nicotiana tabacum)

Properties of Alkaloids & Its Identification Test

• Mostly alkaline in nature.
• Soluble in organic solvents but sparingly soluble in water.
• Exhibit a bitter taste.
• Many alkaloids have pharmacological activity, e.g., analgesic, stimulant, or sedative effects.

Tests for Identification:

1. Dragendorff’s Test:

   • Reagent: Potassium bismuth iodide solution.
   • Positive Result: Orange or reddish-brown precipitate indicates the presence of alkaloids.

2. Mayer’s Test:

   • Reagent: Potassium mercuric iodide solution.
   • Positive Result: Cream-colored precipitate

3. Wagner’s Test:

   • Reagent: Iodine in potassium iodide solution.
   • Positive Result: Reddish-brown precipitate.

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