Enantioselective quantitation of the ecstasy compound (R)- and (S)-N-ethyl-3,4-methylenedioxyamphetamine and its major metabolites in human plasma and urine.
An enantioselective HPLC method has been developed and validated for the stereospecific analysis of N-ethyl-3,4-methylenedioxyamphetamine (MDE) and its major metabolites N-ethyl-4-hydroxy-3-methoxyamphetamine (HME) and 3,4-methylenedioxyamphetamine (MDA). These compounds have been analyzed both from human plasma and urine after administration of 70 mg pure MDE-hydrochloride enantiomers to four subjects. The samples were prepared by hydrolysis of the o-glucuronate and sulfate conjugates using beta-glucuronidase/arylsulfatase and solid-phase extraction with a cation-exchange phase. A chiral stationary protein phase (chiral-CBH) was used for the stereoselective determination of MDE, HME and MDA in a single HPLC run using sodium dihydrogenphosphate, ethylendiaminetetraacetic acid disodium salt and isopropanol as the mobile phase (pH 6.44) and fluorimetric detection (lambda(ex) 286 nm, lambda(em) 322 nm). Moreover, a suitable internal standard (N-ethyl-3,4-methylenedioxybenzylamine) was synthesized and qualified for quantitation purposes. The method showed high recovery rates (>95%) and limits of quantitation for MDE and MDA of 5 ng/ml and for HME of 10 ng/ml. The RSDs for all working ranges of MDE, MDA and HME in plasma and urine, respectively, were less than 1.5%. After validation of the analytical methods in plasma and urine samples pharmacokinetic parameters were calculated. The plasma concentrations of (R)-MDE exceeded those of the S-enantiomer (ratio R:S of the area under the curve, 3.1) and the plasma half time of (R)-MDE was longer than that of (S)-MDE (7.9 vs. 4.0 h). In contrast, the stereochemical disposition of the MDE metabolites HME and MDA was reversed. Concentrations of the (S)-metabolites in plasma of volunteers were much higher than those of the (R)-enantiomers.
Buechler
Jochen
J
Department of Pharmaceutical Analysis, University of Tuebingen, Auf der Morgenstelle 8, D-72076, Tuebingen, Germany.
Schwab
Matthias
M
Mikus
Gerd
G
Fischer
Beate
B
Hermle
Leo
L
Marx
Claudia
C
Grön
Georg
G
Spitzer
Manfred
M
Kovar
Karl Artur
KA
D015104:3,4-Methylenedioxyamphetamine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D000328:Adult; D002851:Chromatography, High Pressure Liquid; D018592:Cross-Over Studies; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence; D013237:Stereoisomerism
D015104:3,4-Methylenedioxyamphetamine; C051800:3,4-methylenedioxyethamphetamine