Two-dimensional thin layer chromatographic separation of phenolic compounds from Eupatorium cannabinum extracts and their antioxidant activity.

Two dimensional thin layer chromatography on DIOL polar bonded stationary phase was performed to optimize the separation of some anioxidant phenolic compounds from Eupatorium cannabinum extracts. Ethyl-methyl ketone mixed with n-heptane and ethyl acetate mixed with n-heptane were used as non-aqueous mobile phases in normal phase separations (1st direction of development in 2D-HPTLC mode) and methanol mixed with water was used as a mobile phase in reversed phase (2nd direction of development in 2D-HPTLC mode). The plates were sprayed by use of Merck TLC sprayer using 2-(diphenylboryoxy)-ethylamine and PEG4000 (Merck, Darmstadt, Germany) or DPPH and photographed in Camag Cabinet UV lamp at 254 nm and 365 nm by use of Fuji 8 mpx camera. Satisfactory separations of antioxidant phenolic compounds in Eupatorium cannabinum extracts were obtained by use of optimized 2D-HPTLC systems.