Yes I agree with Mario. Use Hexane or Petroleum ether. They won't affect phytochemical content of the plant, instead they will help remove the non polar compounds from the plant parts which will be useful later in the isolation process.

Pretroleum ether or n-Hexane are good choices.

Yes I agree with Mario. Use Hexane or Petroleum ether. They won't affect phytochemical content of the plant, instead they will help remove the non polar compounds from the plant parts which will be useful later in the isolation process.

Dear Barakat

I am attaching a slide which one of my phytochemistry friends presented in a training program. I hope it will be useful to you.

Good luck.

I would suggest you use 90% MeOH and n-hexane. I have used this solvent system in my studies and it was successful. 

Use organic solvents such as methanol or DMSO

Hexan will also take triterpenes, you can prepare hexane extract from the total alcohol extract then make saponification to separate the saponifiable matter (fatty material) from sterols and triterpenes

You can use Pet. ether or n-Hexane.

@Alireza Feizbaksh... Can you please provide any instance whereby authors have used methanol or DMSO for defatting of plant material. I am really concerned if methanol can be used for defatting, then there should be a lot of time saving during extraction process. There will be no need to defat with n-hexane/petroleum ether. Please elaborate on this, if possible. Thanks 

Dear  Tony Awany Barakat, Do not use Methanol or DMSO to Defat!!!! Please do not!!! Yes, Hexane or Pet ether will in some cases extract triterpenes in which case you could saponify if too oily before running a column.

triterpens present in plant in free form and glycosidic form as saponins and cardiac glycosides

for saponins you have deffat the plant material with n-hexan, then extract it with mthanol or methanol water mixture, concentrate the extract and add to it ethyl acetate which lead to precipitation of saponins, then you can perform acid hydrolysis for the PPt and fractionate against chloroform to seperate the sapogenins.

in case the plant contain free triterpen; you have to concentrate the methanolic extract and let it to be cooled over night the fixed oils, waxes will form forth layer which can be decanted  

Have you tried using methanol? 

To defatten your plant extract all you need is wash thoroughly with n-hexane or petroleum ether making sure to maximize the surface area of your plant extract. Am sure you will not loose the triterpenoids present.

I do agree with Nasir T. answer, since N-hexane or Pet. ether are at the top of the series of non-polar solvents. Also to be sure (100%) you can subject your filtrate (containing the n-Hexane used for defatting) to TLC studies thus checking if ever some terpenoids are found in it.