I have done ethanolic extracts of four kind of berries 1:10. I concentrated the extracts with the rotary evaporator and transferred the liquids in vials which I left under cap to dry at room temperature. However, after 2 weeks the extracts are not completely dry yet. They look viscous at the bottom.
I need the extracts to test in an assay for inhibition of Acetyl CoA Carboxylase.
The idea was to store the dry extracts in the freezer and then prepare solutions with DMSO to use in the assay.
However I don't know how to get the dry extracts. Would it be possible to use the viscous extracts in the assays instead?
Unfortunately, the vacuum is not working in the lab so I can't freeze-dry... Any suggestions for drying?
Thank you
It is better to following common method of extraction. Firstly, extract with non-polar solvent ( hexane or petroleum ether ) to remove oils ( defatting) . If the plant part is leave remove chlorophyll, then with ethanol.
Our group are getting solid extract just by using rotary evaporator, it depends on the efficiency of the pump.
Another way , try to triturate with non- polar solvent in ice-bath.
The viscosity could be from fats or sugars (I read berries).
Try the trituration into hexanes or petroleum ether as described above, or perhaps a Kupchan partition.
The most important thing is to know which compounds are resposible for the main activity (inhibitory activity) if you already have to do liquid-liquid extraction. If the enzyme inhibition is affected by the compounds which can be extracted together with the fats then this cannot be recommended as a reliable method as it directly affects the final results. If the viscosity comes from carbohydrates, which is more likely if it is fresh berries, then you can use liquid-liquid extraction where a more polar solvent (for example water) will extract more polar compounds, including sugars, but only if the polar compounds are not responsible for the inhibitory activity of the enzyme.
Another idea would be to try dissolving these viscous extracts in ethanol at a certain concentration that will not affect the inhibition of the enzyme (you can check this by doing different controls with different concentrations of ethanol).
Hello Francesca Vidotto,
For drying,
You have transferred your extracts liquids in vials, so instead of vials you can spread your sample in the petri plates and place it on water bath and dry it out. At the end of your drying process you will get flakes form of your extracted sample, therefore you can scratch and take out. Why water bath drying means extracts should not dry in the direct heat, this will destroy the chemical constituents present within the sample.
Viscous extracts use,
You can't use the viscous extracts in your experiments because the sample preparation will become little difficult. If your sample powdery means it is easy to measure and etc.,
By the nature of your sample, I believe that you have removed the sugars and phenolic compounds from your sample, so the system will be viscous and will not be able to dehydrate them due to the hygroscopic capacity of the sugars. One option is SPE column fractionation
- Badges
- Science topic
- Similar topics
- Biological Science
- Botany
- Pharmaceutical Botany
- Plant Extracts