Are you looking for compounds with bio-activity?

Crude-->TLC-->CC-->TLC-->(R)HPLC

Run TLC of crude extract to check number of compounds.....run column of crude extract and run TLC of each fraction of column to check your compounds.....After TLC and CC....Identify your compounds in HPLC(if you have standards).

Purify your compounds with PrepTLC, PrepHPLC, flash chromatography...so...on...

Use resin for prilimanary purification. Then go for PrepTLC, PrepHPLC, flash chromatography...so...on...

gudluck

:)

Crude - TLC - Column chromatography - RP.HPLC

It depends the natural compound families. Various strategies are open. See some of our papers for some of them:

M. YOUSFI; A. DJERIDANE; I. BOMBARDA; C. HAMIA; B. DUHEM; E.M. GAYDOU

Isolation and Characterization of a New Hispolone Derivative From Antioxidant Extracts of Pistacia atlantica

Phytotherapy Res., 2009, 23, 1237-1242

L.M.M. LOUCHE, E.M. GAYDOU, J.-C. LESAGE.

Determination of Phlorin as Peel Marker in Orange (Citrus sinensis) Fruits and Juices.

J. Agric. Food Chem., 1998, 46(10), 4193-4197

P.P. MOULY, E.M. GAYDOU, R. FAURE, J.M. ESTIENNE.

Blood Orange Juice Authentication using Cinnamic Acid Derivatives. Variety Differentiations Associated to Flavanone Glycoside Content.

J. Agric. Food Chem., 1997, 45(1), 373-377

M. AKNIN, A. RUDI, Y. KASHMAN, J. VACELET, E.M. GAYDOU.

Plakinamine L: A New Steroidal Alkaloid from the Marine Sponge Corticium sp.

Natural Product Communications, 2010, 5(1), 33-34

E.M. GAYDOU. R. RANDRIAMIHARISOA, J.P. BIANCHINI.

Composition of the Essential Oil of Ylang-Ylang (Cananga odorata Hook Fil. et Thomson, forma genuina) from Madagascar.

J. Agric. Food Chem., 1986, 34(3), 481-487

J.P. AYCARD, F. KINI, B. KAM, E.M. GAYDOU, R. FAURE.

Isolation and Identification of Spicigera Lactone. Complete 1H and 13C Assignments using Two Dimensional NMR Experiments.

J. Nat. Products, 1993, 56(7), 1171-1173

B. RAMAROSON-RAONIZAFINIMANANA, E.M. GAYDOU, I. BOMBARDA.

Long-Chain Aliphatic b-Diketones from Epicuticular Wax of Vanilla Beans Species. Synthesis of Nervonoylacetone.

J. Agric. Food Chem., 2000, 48(10), 4739-4743.

My contribution to your question is similar to the one I gave to a similar question a few days ago: Isolation and purification of plants' secondary metabolites can be quite challenging. However, I believe that SUCCESSIVE partitioning of your crude extract into different solvents of increasing polarities (e.g hexane, ethyl acetate, butanol and methanol, in that order) or acid-base extractions followed by prep TLC of each fraction (after ascertaining a suitable solvent system using normal TLC) will increase the chances of isolating components. This method gives you an idea of the polarity property of components in each of the fractions. For instance, it is expected that the hexane fraction will contain non polar components, while the methanol fraction will contain highly polar component etc. Furthermore, you can use methods that are specific or selective to the component of interest. For instance, there are general methods for isolating flavonoids, saponins, alkaloids etc which are available in literature ( I suggest you consult J. B . Harborne's book). Two dimensional TLC of components obtained from prep TLC will help in the purification process. However, these are just guidelines.Secondary metabolites have a very wide diversity of properties, and one method may not apply successfully to all. Some may still require methods that are special and unique to them.I wish you the best.

Crude - TLC - Column chromatography - RP.HPLC (or HPTLC)

Try to fractionate your extract previous to TLC so that the constituents get separated at an early stage. Then check TLC profiles and proceed further with column chromatography. Once you get the compound isolated and if you have standards for comparision, I would strongly suggest to perform HPTLC instead of HPLC for confirmation of identity. This will give you a quantitative estimation also. You can further confirm using IR, NMR and Mass for final structural elucidation.

Run preparative TLC.followed by HPTLC.

Actualy there is no fixex methods for isolation of a secondary metabolites. It depends on compounds nature and laboratory facilities. Your mentioned methods all are suitable for specific metabolites. But firstly your use solvents for extraction and minimies impurities of your samples. Like polar solvents, nonpolar solvents, water missible or immisible solvents etc. After reduced impurities of your samples, then you will apply TLC. This TLC give you an idea, next what you will done?Chromatography, Solid Phase extraction (SPE)-for sample preparation before HPLC, analytical or preparative, it depends on samples amount. If you have enough samples, you must use preparative HPLC. Thank

Column

Thanks for your answers. Now I understood that Crude-TLC-column-TLC (separation) -TLC (purity check) - HPLC semiPrep to isolate single molecule based on your suggestions and my studies.