Evaluation of the effect of various drying techniques on the composition of the psychoactive phenylpropylamino alkaloids of khat (Catha edulis Forsk) chewing leaves

The study demonstrated that by freezing or drying under different conditions, cathinone could be detected in the khat (Catha edulis Forsk) samples that have been harvested for more than four months. Freeze drying or freezing in the refrigerator (-20 oC) yielded more than 73% of cathinone. Air drying, sun drying or oven drying at 60 oC resulted in a cathinone composition of 57%, 42% and 36%, respectively. The study confirmed that, freshly harvested tender leaves of khat contained exclusively of cathinone but upon sun drying, part of it decomposes to cathine and norephedrine leaving cathinone as a major component. Thus it is wrong to assume that sun drying the leaves can result complete conversion of cathinone to cathine and norephedrine. Furthermore, the results of the study confirmed that it was possible to preserve khat samples for longer periods after freeze drying or deep freezing without significant loss of cathinone. KEY WORDS: Khat, Alkaloids, Cathinone, Cathine, Norephedrine, Storage Bull. Chem. Soc. Ethiop. 2013, 27(3), 347-358.DOI: http://dx.doi.org/10.4314/bcse.v27i3.3