Glycyrrhetinic Acid - Isolation, Identification, Analysis & Applications

Glycyrrhetinic acid is derived from Glycyrrhiza glabra (licorice) root.
It is the aglycone of glycyrrhizin, a triterpenoid saponin responsible for the sweet taste of licorice.

Extraction:
- Alcoholic Extraction: Dried licorice root is powdered and extracted with ethanol or methanol to obtain the glycosides.
Hydrolysis:
- Acid Hydrolysis: Glycyrrhizin is hydrolyzed under acidic conditions to yield glycyrrhetinic acid and glucose.
Purification:
- Liquid-Liquid Extraction: Using solvents like chloroform to separate glycyrrhetinics acid from aqueous phase.
- Recrystallization: Purifying the extracted acid by dissolving in suitable solvents and recrystallizing.
Chromatography:
- Column Chromatography: On silica gel to further purify glycyrrhetinic acid.

Physical Properties:
- Appearance: White crystalline powder.
- Melting Point: Approximately 295-297°C.
- Solubility: Soluble in organic solvents like ethanol and chloroform; sparingly soluble in water.
Spectroscopic Techniques:
- IR Spectroscopy: Identifies functional groups such as hydroxyl groups (~3400 cm⁻¹) and carbonyl groups (~1700 cm⁻¹).
- NMR Spectroscopy:
  - ¹H NMR and ¹³C NMR: Provide detailed structural information confirming the triterpenoid structure.
- Mass Spectrometry: Molecular ion peak at m/z 472 (as sodiated ion, [M+Na]^+).
Chromatographic Techniques:
- HPLC: Used for purity assessment.
- Thin-Layer Chromatography (TLC): For preliminary identification.

Quantitative Analysis:
- HPLC: Precise quantification in licorice extracts.
- Spectrophotometric Methods: Utilized with appropriate standards.
Quality Control:
- Verifying purity through spectral data.
- Assessing absence of contaminants.

Glycyrrhetinics acid exhibits anti-inflammatory, antiviral, and hepatoprotective activities.
It is used in the treatment of chronic hepatitis and as a flavoring agent in food products.