pradeep sharma im isolating falvonoids from 80% methanol and fractionate the methanolic extract with petroleum ether, diethyl ether, and ethyl acetate. are its right or i change the solvent frm methanol to ethanol.?
dr Javed can u plz send me the book on isolation and identification of flavonoids. im working on corchorus.... my email id is firstname.lastname@example.org
Dear Kavisa Ghosh, you can try for lyophilization to get ur extract in powdered form..
Dear Dr. Javed please kindly send me the book(s) on isolation and identification of flavonoids. My email id is email@example.com
Test for Flavonoids
To the test Solution, add few fragments of Magnesium ribbon and add concentrated Hydrochloric acid drop wise, pink scarlet, crimson red or occasionally green to blue color appears after few minutes.
To the test solution add a mixture of Zinc dust and conc. Hydrochloric acid. It gives red color after few minutes.
To the test solution add few drops of sodium hydroxide solution; formation of an intense yellow color, which turns to Colorless on addition of few drops of dil. acid, indicates presence of Flavonoids.
in my opinon you apply paper chromatography or TLC on cellulose with sitable solvent system and best separation and isolation would be by prep tlc or plc the cheap and affordable technique also consult J B Harbone ( FLAVONOIS)or mabry( THE SYSTEMATIC IDENTIFICATION OF FLAVONOIDS) or Markham'( TECHNIQUES IN FLAVONOIDS) these are basic for the subject
For identification of flavonoids, take 2 ml of test sample (4 mg/ml) in which, add a pinch of magnesium metal powder and few drops of concentrated HCL and heat it. Green color sample turned into brick red color. It is the identification test for flavonoids (Harborne, 1988).
For isolation of flavonoids, do silica gel column chromatography with ethyl acetate or methanol plant extract.
Antonio Marcus de Andrade Paes
Universidade Federal do Maranhão
Dama L. B.
Dayanand Institutions, Solapu (Maharashtra), India.
Beatrice Kagai Amugune
University of Nairobi
National University of Science and Technology
Anna University, Chennai
Christian Alonso Becerra
National University of Colombia
Victor Yao Atsu Barku
University of Cape Coast
University Ibn Zohr - Agadir