Flavonoids can be isolated from the ethanolic extract of plant material. It will be appropriate to fractionate the ethanolic extract with ether, ethylacetate and butanol respectively . Firest immerse the extract into water and fractionate with ether or pet ether or chloroform and then with ethyl acetate and butanol sequentially. Distiilled the respective solvent. Flavonoids will come in the ethyl acetate extract and butanol extracts. Butanol extract may contail flavonoid glycosides with 2 and more than two sugars. With the help of TLC flavonoids can be visualised by sprying different reagents. With Sulphuric acid yellow spots and with alcoholic feerric chloride bluish grey spots. By column chromatography using silica gel 100-230 mesh isolation is possible using chloroform and methanol mixture. After isolation of the compounds in pure state and by crystallization with the help of NMR and Mass spectral studies one can identify the flavonoids. Hope this information will be sufficient. If require any further information freely can ask.

You can use spray of NP-PEG to TLC, it is specific to "see" flavonoids spots. By column chromatography, you should avoid to use silica gel, you can lost part of flavonoids, that can be retained in silica, you need to use C18 or PVPP.

read Introduction to flavonoids by Bruce A. Bohm

Techniques of flavonoid identification by K. R. Markham

where you got all your answers

Weigh about 0.2 gm plant extract in separate test tubes and dissolved diluted Sodium hydroxide and add diluted Hydrochloride. And observe for yellow solutions that turn colorless. This indicates the presence of flavonoids

Color reagent

Obtained color

Observations

NaOH

Yellow

The presence of the yellow color indicates that the separated compound has a flavonoidic structure.

FeCl3

Green-blue

SbCl3

Yellow

The presence of the yellow color indicates that the separated compound has not a calchonic nature.

Mg+ HCl

Red

The presence of the red color indicates that the separated compound has a flavonolic nature.

Dr. Javed Intekhab has stated all the tests. You can also refer Plant Drug Analysis-a TLC Atlas by H. Wagner and S. Bladt. It gives various colour reagents and representative mobile phases for flavonoids with colour photographs.

OK OK i forget it

Springer

Plant Drug Analysis

A Thin Layer Chromatography Atlas

Go through books

you can refer SCIENCE OF FLAVANOIDS by Erich Grotewold!

Yes the qualitative test mentioned by Dr javed are very useful, if you use cellulose for coumn chromatography, wpuld be better for flavonoids however Prep. chromatography on whatman 3mm or TLC on cellulose is my favorite. Polyamide as adsorbant is also used, Consult Harbone and Mabry or Markham

Heart full thanks to all for kind suggestions

Hope all goes on well. Kindly share with us the outcome after trying the suggested methods. Best wishes.

Flavonoids can be isolated from the ethanolic extract of plant material. It will be appropriate to fractionate the ethanolic extract with ether, ethylacetate and butanol respectively . Firest immerse the extract into water and fractionate with ether or pet ether or chloroform and then with ethyl acetate and butanol sequentially. Distiilled the respective solvent. Flavonoids will come in the ethyl acetate extract and butanol extracts. Butanol extract may contail flavonoid glycosides with 2 and more than two sugars. With the help of TLC flavonoids can be visualised by sprying different reagents. With Sulphuric acid yellow spots and with alcoholic feerric chloride bluish grey spots. By column chromatography using silica gel 100-230 mesh isolation is possible using chloroform and methanol mixture. After isolation of the compounds in pure state and by crystallization with the help of NMR and Mass spectral studies one can identify the flavonoids. Hope this information will be sufficient. If require any further information freely can ask.

Hi, can you advise me on what protocol to use for flavonoids separation through HPLC? Some book chapter or review article I can refer to?

Flavonoid can be separated through reverse phase HPLC using acn--methanol and ACN acetate buffer mixture. But requirement of authentic samples is must for comparison

Hi ; I ‘m interested in the study of biological activities of two chemical families of phenolics : flavonoids and tannins. I would like to know if there are simple methods to extract total flavonoïds and tannins from plant materials

Tell me what do you really want, are you doing phd or want to increase your knowledge

Hi, DR Intekhab

First of all thank you to give importance to my requests

I’m not a PhD student, I’m professor Assistant in my institute. My research topic has as objective the valorization of the olive tree derivatives essentially the pruning by-products (leaves and twigs)

The flavonoids from olive leaves are known to have diverse biological activities. In a previous work we found that apigenine 7 glucoside are responsible for the differentiation and the inhibition of HL60 cells growth. So, in this context I would like first to extract flavonoids and tannins from leaves and twigs, respectively. Then test their biological activities

nice work, may ALLAH give you all the achievements which you want

I have several books on flavonoids if you want i will send you

Please send the books to me, thank you again

Mail add please here attachment is not possible

Dr. Javed, Kindly send me also the books on flavonoids . My email id is [email address deleted] . thanks and regards.

dear dr PRATIMA which book do you want, i have several

on isolation and identification of flavonoids..Thanks and regards

Flavonoids_Chemistry,_Biochemistry_and_Applications.Andersen.O.M&Markham.K.R.2006 need this

My a mail is [email address deleted]. Thanks

My email [email address deleted]

dear Leila Abaza kind send your email add on my mail

Dear Dr. Javed, Pls. can you kindly send me the book on isolation and identification of flavonoids. Am working on flavonoids in Zingiberaceae family.

My mail add: [email protected]

Thanks and regards

Nice discussions..........

I am also the one working on the isolation and identification of flavonoid. I have different fractions of ethyl acetate extract of a plant. I got those fractions after doing chormatography on silica gel. The second fraction is yellowish powder. It is to some extent soluble in methanol. But it is more soluble in chloroform and ethyl acetate. But it is not 100% soluble in neither of the above solvents. I took the dissolved portion of the extract in ethylacetate, and did the tlc on silica gel ( chloroform and ethyl acetate (9:1) as solvent system). It showed three spots. I am now in dilemma about how to proceed for isolation. If i do silica then i need to apply the sample in dry form as the sample is not 100% soluble in the solvents i do have. Would anybody suggest best alternative for the isolation. I will be highly thankful for the response.

Sir can you give me some idea of structural analysis of natural compound.

It is a plant leaf dye extracted in ethanol

I have problem in drying the plant ethanolic extract. Its like a sticky semisolid compound sticking to the glass wall! I need it in powder form to be able weigh it for my experimental works. please kindly help me!!!!

Dear Dr. Javed can you also sen me the books on isolation and identification of flavonoids. Am working on flavonoids in amaranthaceae and asteraceae family. my email id is [email protected]

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 [email protected] 

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 protected]

Test for Flavonoids

• Shinoda test (Magnesium Hydrochloride reduction test)

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.

• Zinc Hydrochloride reduction test

To the test solution add a mixture of Zinc dust and conc. Hydrochloric acid. It gives red color after few minutes.

• Alkaline reagent test

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.

Mrs Sundus Riaz can u plz send me the book on isolation and identification of flavonoids. I am working on medicinal plant. My email id is [email protected] 

I Hope you will send to me by e-mail

Pl Please can anyone be kind enough to send me the books on Isolation of flavonoids from Dr Javed? [email protected]

Thanks

all of you can download the book from here b-ok.org/dl/2227110/555f24