Pl. find attached some relevant literature about TLC including the TLC atlas by Wagner and Bladt. This would surely solve all your queries regarding thin layer chromatography, solvent selection according to the phytochemical category, methods involved and much more. 

TLC experiment helps you to identify the nature of your desire compound. It also helps you to choose the next separation techniques i.e chromatography and solvents. It is better, you use TLC. Its simple method. Thank

TLC in often performed as one step assay to keep a track on your compound(s) of interest or to make sure your extraction solvent is working properly. If you already have an idea of your marker compound in the extraction you expect to see that marker during TLC. If you don't see your compound, you need to dig and try to find the correct solvent to extract those compounds. If you are isolating new compounds, HPTLC is much better as you can quantify the compound of interest based on its spectra reading. Hyphenated techniques like HPLC/MS are usually avoided during the initial phases of plant extraction.

its known that polyphenols are very Good antioxidants and this class of natural compound can be identify by  with their known colors adsorption under UV  so i think that TLC will be good point for your activity

You can use also other technics like Hplc for confirmation and also for publishing the results

Hi, yes I agree with all previous comments. I think it is nice to do first preliminary experiment  by (HP)TLC; by (HP)TLC you can predict the chemical contents and antioxidant activities directly on (HP)TLC plates. You can search in the Camag TLC data base , the possible (HP)TLC system to separate your compounds. maybe someone has ever published it. After having good separation by (HP)TLC you can continue with LC (Qtof) MS   etc.

http://www.camag.com/en/tlc_hptlc/customer_magazine_cbs/ccbs_database.cfm

Agree with A.I. answer.

Dear Shital, it is equally important to know following things in your research scheme

1. Have you planned to work upon crude extracts of the plants in your study for the evaluation of their antioxidant activity?

2. Then which methods are you going to use for evaluation of antioxidant activity? For eg. In vitro methods involving spectrophotometer or Chromatographic method like TLC? (Nowadays antioxidant activity can be evaluated using TLC too by separating the components of your crude extracts on TLC plates and spraying the plate with the free radical solution like DPPH. This method is easily available online).

Along with the valuable suggestions by the peer researchers in this thread, I would like to add few things as follows;

1. Screen your different crude extracts using simple spectrophotometric assay like DPPH assay.

2. Develop a TLC method for the separation of components from your best crude extract (s) (in terms of antioxidant activity).

3. Use TLC-bio-autography technique to putatively know the most active component(s) of your best crude extract(s).

4. Use preparative TLC method for the isolation and characterization of the most active component(s) of your best crude extract (s). (In case if you are not trying isolation using column chromatographic technique).

5. Use cell-based assays or animal studies to confirm the antioxidant activity in the  biological system.

Good luck and all the best wishes for your research.

Thanks a lot all for your valuable comments and suggestions. @ bhavesh,  yes I have a planned to work with crude extract and will going to use different methods to evaluate antioxidant activity viz DPPH, FRAP,   NO, ABTS,  H2O2,  etc 

Hi Shital 

TLC gives you an indication about the constituents present in your extract qualitatively. You come to know how many compounds may be present in it which may increase when you perform the HPTLC which is more precise and accurate. Now the question is do you really require to do TLC if you have to find the antioxidant activity of your extracts. Actually it all depends upon your plan of work. Do you want to isolate and identify the antioxidant compound afterwards or just want to find which extract is best? You want to find which plant is best one among your selected plants. Then you can find it via antioxidant activity measurement only. NO need to do TLC. If you have plans to identify and isolate the active compounds or do quantitative analysis later, you have to perform TLC which is preliminary step in phytochemical analysis. If you want to do HPTLC then also you need a solvent system which you have to develop via TLC only unless you have previous reports about the plant.  If you need literature about the antioxidant activity and even TLC, I would be happy to share with you. Good Luck 

Regards

Thank you bhavesh and Alokji.. @Alokji.. As u told me pls share good literature with me as it may help me while doing work. 

Pl. find attached some relevant literature about TLC including the TLC atlas by Wagner and Bladt. This would surely solve all your queries regarding thin layer chromatography, solvent selection according to the phytochemical category, methods involved and much more. 

Hi Shital 

Here follows some good papers on antioxidant activity, different assays, method involved and their mechanisms. 

Hi Shital

Pl. find attached some more papers on DPPH activity, beta carotene linolenic acid model and in vivo approaches for this activity. 

Hope you will enjoy reading all these papers and would definitely come to a fruitful conclusion about your research plans. Good luck and regards 

Thanks a lot Alokji, it is really helpful for me. 

Its a nice work