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Planta Med 2012; 78(08): 838-842
DOI: 10.1055/s-0031-1298430
Analytical Studies
Original Papers
Georg Thieme Verlag KG Stuttgart · New York

Naturally Occurring Norephedrine Oxazolidine Derivatives in Khat (Catha edulis)

Raz Krizevski
1   Department of Aromatic, Medicinal and Spice Crops, Newe Yaʼar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
2   The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, Israel
,
Einat Bar
1   Department of Aromatic, Medicinal and Spice Crops, Newe Yaʼar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
,
Nativ Dudai
1   Department of Aromatic, Medicinal and Spice Crops, Newe Yaʼar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
,
Asaf Levy
1   Department of Aromatic, Medicinal and Spice Crops, Newe Yaʼar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
,
Efraim Lewinsohn
1   Department of Aromatic, Medicinal and Spice Crops, Newe Yaʼar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
,
Yaron Sitrit
2   The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, Israel
,
Shimon Ben-Shabat
3   Department of Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
› Author Affiliations
Further Information

Publication History

received 29 November 2011
revised 14 March 2012

accepted 15 March 2012

Publication Date:
11 April 2012 (online)

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Abstract

Khat (Catha edulis Forsk.) is a perennial shrub whose young leaves are chewed for their psychostimulating and anorectic properties. The main active principles of khat are believed to be the phenylpropylamino alkaloids, primarily (−)-cathinone [(S)-α-aminopropiophenone], (+)-cathine [(1S)(2S)-norpseudoephedrine], and (−)-norephedrine [(1R)(2S)-norephedrine]. GC-MS analyses of young leaf extracts indicated the presence of two oxazolidine derivatives, 2,4-dimethyl-5-phenyloxazolidine and 4-methyl-2-(trans-1-pentenyl)-5-phenyloxazolidine. To ascertain the chemical identity of these compounds, we synthesized the putative compounds by condensation of norephedrine and acetaldehyde or trans-2-hexenal, respectively. Spectroscopic analyses (GC-MS, NMR) of the structures of these synthetic compounds showed them to have identical retention indexes and mass spectra characteristic to 2,4-dimethyl-5-phenyloxazolidine and 4-methyl-2-(trans-1-pentenyl)-5-phenyloxazolidine. Marked differences in the ratios between each of these two norephedrine oxazolidine derivatives and total phenylpropylamino alkaloids were found among thirteen different khat accessions further indicating polymorphism in alkaloid ratios and content in C. edulis.

Key words

Khat (Catha edulis - Celastraceae) - norephedrine - phenylpropylamino alkaloids - phenyloxazolidine alkaloids - GC-MS
 

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