Are you running a gradient on your column?

I used a double gradient to remove the non-polar compounds; I did obtain a gum from this. I followed up the initial purification with C18.

One thing you may try is a precipitation. First, dissolve in a minimum of ethanol and add, dropwise, into a large volume of hexanes with vigorous stirring. I use 20 mL ethanol solution in 4 liters of hexanes (or petroleum ether). Then filter the solids.

http://www.isco.com/WebProductFiles/Applications/101/Poster_and_Paper_Reprints/Purification%20of%20Natural%20Products%20Using%20Mass%20Directed%20Fractionation.pdf

Thank you sir, I will try it ,

Best method for separation of curcumins from turmeric rhizome , first extract the crushed rizomes, then extract in methanol , remove solvent under vacuum & perform column chromatography using n-hexane as a eluent.