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Clinical pharmacy PharmD program Third level Phytochemistry-1 (PG-504)

Test for flavonoids:

❖ Dissolve in alkalis giving yellow colored, disappear by acid

❖ Exhibit strong fluorescence under UV light, especially after exposure to ammonia vapors.

❖ Aluminum chloride test:

give yellow color ….

which fluoresces under UV with different colors.

Flavones................. Green.

Flavonols............... Yellowish to Yellowish-green

Chalcones............... Brown-pink.

Aurones.................. Pale brown

Shinoda’s test for flavonol

Flavonoidal compounds may be characterized through the investigation of their UV spectra, that
usually show two main bands; a band at higher wavelength (band I) which is attributed to the
cinnamoyl fraction of the flavonoidal structure, and a band at lower wavelength (band II) which
is due to the benzoyl fraction of the flavonoidal structure.

Ethyl acetate is the solvent of choice for the extraction of flavonoids from aqueous solutions.

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