How to decolorize Aloe vera extract using for any herbal formulation? It need to be run in semi preparative hplc. I am scared the coloured compounds might spoil the column, i am not sure of it but. Can someone answer both the questions?
Have you tried active charcoal. If needed use centrifugation to separate charcoal particles.
Or use solid-phase sample preparation columns with C8 or C18 coupled to silica.
In addition to the charcoal suggestion above, also try a short polyamide cartridge to remove phenolic compounds. A guard column would work too, but I prefer using a C18 SPE column as mentioned in Jos' reply.
I tried charcoal and as mentioned by klaus it separated polysaccahrides and some antraquinones i checked them via dionex. But the extract obtained after passing through charcoal is not showing inhibitory activity for particular enzyme i am looking for as a result i am lookin for some other options.
Jack could elaborate about polyamide cartridge. i am also gonna try magnesium salt with some alkali like calcium hydroxide which forms color precipate which settles down. its new i ahvnt tried .Has anybody experience with this method?
@ Neha;
The easiest way to use the polyamide is to pack a very small column in methanol, dissolve your sample, run it through the column, and wash with methanol, combine the washing with the eluant. This method is useful for eliminating tannins which cause non-specific binding in some assays, but might capture some desired phenolic compounds. We generally ran our plant extracts through polyamide SPE cartridges to capture the tannins that interfered with our assays.
Given that the activity adsorbs on charcoal, I would try running the polyamide like a silica column. Pack it just like silica gel. I packed it in water and attached it to my flash chromatography system (CombiFlash Rf-200), I ran a gradient starting with water to 100% methanol, another gradient from methanol to methanol to 100% acetone, then acetone to 100% water containing 5% ammonium hydroxide (3 gradients total). This gives you a chance to recover the activity if it gets stuck on the column, and potentially identify the class of compounds.
if you use a glass column, this can be done with step gradients as well. The gradients give you a chance to recover the compounds that get adsorbed.
I would also try washing your used charcoal, if you still have it, with the solvents I mention for the polyamide column to see if you get your activity back.
The suggestions are all very valuable and I can only add a general recommendation. The final use of your product should be clearly in mind, before applying different physical, chemical or biological manufacturing process.
For example, if the final product is food, the undesirable compounds anthraquinones have to be removed. In this case, I suggest using the active charcoal, effective and well known in the industrial production.
Thankyou Jack the suggestions were really valuable. Will try doing both and get back to you.
An aqueous solution of aloe barbadensis can be prepared by taking
10 gm of gel from the fresh leaf of aloe plant and dissolve in 100
ml of distilled water. This solution kept on vertex for 15 min and
then clear colorless solution solution can filtered and keep at -20 for study purpose.
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