My crude fraction consists of alkaloids and phenolic compounds. I need to separate both phenolic compounds and alkaloids into separate fraction
Hi
Shake the crude extract with chloroform. Alkaloids will dissolve in chloroform and phenolic-rich fraction will be left behind which can be dissolved in 70% ethanol or methanol.
My crude extract is obtained from methanolic exraction still it is having some alkaloids in it
Couple of ways to do it...
1) Use extraction, make the aqueous layer acidic (0.1 N HCl). The alkaloids will form salts in the aqueous layer, the phenols should be left in the organic layer. The alkaloids can be recovered by making the organic layer basic and re-extracting into an organic solvent. I tend to use dichloromethane as the organic solvent.
2) Polyamide resin. I ran a gradient starting with water to 100% methanol, another gradient starting from methanol to 100% acetone, then acetone to 100% water containing 5% ammonium hydroxide (3 gradients total). The alkaloids shouldn't bind to the polyamide and should elute during the first gradient, although you may get some polyphenols there as well, but resolved from the alkaloids. The other gradients elute other phenolic compounds.
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