I need to remove the color of the crude extracts because im going to test the crude extract for MIC test , I dont want to use chemicals that might affect on the result, please suggest to me a method that will not affect the result.
Dry the plant material completely and keep it in open air for some time , with the passage of time chlorophyll material will degrade itself after this when you prepare its extract it will contain no deep color or if color still persists then treat your extract with activated charcoal, kaolin or other clay or a small amount of powder CaO/Ca(OH)2 plus heat at 50-60C for few minutes, shake well and filter, it will clear your extract within seconds
Thank you for answeing my question. But does these chemicals will affect on my results since Im going to use it for antibacterial activity. ?
U can also remove pigments by cold extraction processes like solvent extractn
CaO or CaOH2 may affect the pH of aqueous extract but in other organic solvents it is not soluble and you can remove by filtration. How ever if you don't want to do this then pass through a short length silica gel column eluting with EtOH or MeOH
I suggest dry flash chromatography with silica gel and mixture of hexane and ether or methanol as a eluent.
Have anyone tested leaves extract for antibacterial activity ? For MIC I need the extract to be clear in order to detect the growth or inhibition of bacteria. So that I am concern that CaO may afffect on the growth or it will not?
As you purify the extract to determine the active compounds, the color will be removed, unless, of course, the colored compound is the source of your activity. Column chromatography will remove colored compounds.
the impurities are trapped within the growing calcium carbonate crystals, often
distorting the crystals, rather than being adsorbed onto thesurface after precipitation. Any kind of colour body that hassome acidic (anionic) character and is capable of forming aweak linkage with calcium .Sometimes activated charcoal works,if active compound is other than pigments,u have to check all these things.column chromatographic fractionation might be helpful for you.
Chlorophil may be extracted by cold acetone.
Green leaf richly has lipoic acid/thioctic acid, which has yellow colour and may be essential for Photosynthesis. Lipoic acid can be adsorved to avidin-affinity HPLC-column (please see file; Lipoic acid Avidin).
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