Quantitative stereoisomeric determination of phenylpropylamino alkaloids in khat (<i>Catha edulis</i> Forsk.) using chiral GC-MS
2008
Krizevski, Raz | Dudai, N. (Nativ) | Bar, Einat | Dessow, Ilana | Ravid, Uzi | Lewinsohn, Efraim
Khat (<i>Catha edulis</i> Forsk., Celastraceae) is a perennial shrub that was introduced to Israel by Yemenite immigrants. Its young leaves are chewed for their psycho-stimulating properties. Young khat leaves contain the phenylpropylamino alkaloids (-)-cathinone [(<i>S</i>)-α-aminopropiophenone], (+)-cathine [(1<i>S</i>)(2<i>S</i>)-norpseudoephedrine], and (-)-norephedrine [(1<i>R</i>)(2<i>S</i>)-norephedrine] as the main active principles. A novel GC-MS analysis method for the quantitative determination of phenylpropylamino alkaloids and their putative biosynthetic precursor 1-phenylpropane-1,2- dione in khat leaves was developed. We utilized an alkaline-organic extraction, coupled with gas chromatography and a chiral permethylated beta cyclodextrin phase, to allow a full separation between the two diastereoisomers (1<i>S</i>)(<i>2S</i>)-cathine and (1<i>R</i>)(<i>2</i> S)-norephedrine. We found a marked diversity in the phenylpropylamino alkaloid content and composition in three different locally grown accessions and the commercial cultivar ‘Mahanaim’.
显示更多 [+] 显示较少 [-]