Journal of Mass Spectrometry
June 1, 2003
Frank T. Peters, Simone Schaëfer, Roland F. Staack et al.
171 citations
A method was developed to screen for and simultaneously quantify classical stimulants (amphetamine, methamphetamine, ethylamphetamine, MDA, MDMA, MDEA, BDB, MBDB) and newer designer drugs (4-methylthioamphetamine, p-methoxyamphetamine, p-methoxymethamphetamine, and several piperazine derivatives) along with two metabolites in human blood plasma. The technique uses gas chromatography/mass spectrometry with selected-ion monitoring after solid-phase extraction and derivatization. The method was linear from 5 to 1000 µg/L for all analytes, with a limit of quantification of 5 µg/L. Accuracy and precision met required limits except for MDBP. The assay was validated and applicable for confirming immunoassay results positive for amphetamines or ecstasy-type designer drugs.
Journal of Analytical Toxicology
November 1, 2003
Frank T. Peters, Nele Samyn, Martin Wahl et al.
65 citations
The pharmacological effects of amphetamine, methamphetamine, MDA, MDMA, and MDEA depend on their mirror-image molecular forms (enantiomers), which differ in how they act in the body. Analysis of plasma from clinical toxicology cases and from drivers suspected of drug impairment showed that concentrations of most enantiomers were lower in routine screening samples than in intoxication or driving-under-the-influence cases. Drivers under the influence had higher levels of both amphetamine enantiomers than intoxicated patients. Differences in the ratio of R to S enantiomers for several drugs between groups suggest these ratios can help distinguish recent from past use. In one MDMA poisoning, the R form cleared more slowly (half-life 6.0 hours) than the S form (4.1 hours), and the ratio of R to S rose over time.
Journal of mass spectrometry : JMS
June 1, 2005
Vilma Habrdova, Frank T. Peters, Denis S Theobald et al.
61 citations
A new method using gas chromatography/mass spectrometry was developed to screen and quantify seven 2C-series designer drugs (2C-D, 2C-E, 2C-P, 2C-B, 2C-I, 2C-T-2, 2C-T-7) and mescaline in human blood plasma. The method involves solid-phase extraction and derivatization, and was validated per international guidelines. Validation for 2C-T-2 and 2C-T-7 was unacceptable; for the other analytes, the method was linear from 5 to 500 microg/L with accuracy and precision within acceptable limits. This addresses the scarcity of data on analyzing these substances in blood or plasma.
Clinical Chemistry
August 11, 2005
Frank T. Peters, Nele Samyn, C. T. J. Lamers et al.
49 citations
An assay was developed to measure the enantiomers of the designer drugs MDA, MDMA, and MDEA in small plasma volumes (0.2 mL or less). After extraction and derivatization, the enantiomers were separated by gas chromatography and detected by mass spectrometry within 17 minutes. The method was linear for MDA at 1–50 μg/L and for MDMA and MDEA at 5–250 μg/L per enantiomer, with extraction yields of 82.1%–95.3%. Applied to samples from a controlled study after a single 75 mg dose of racemic MDMA, the assay showed that R-(−)-MDMA concentrations significantly exceeded those of S-(+)-MDMA, with ratios always above 1.0 and increasing over time. S-(+)-MDA concentrations exceeded those of R-(−)-MDA, with ratios also increasing but remaining below 1.0.
Clinical Chemistry
March 2, 2007
Frank T. Peters, Nele Samyn, Thomas Kræmer et al.
36 citations
A gas chromatography–mass spectrometry method using negative-ion chemical ionization was developed to separately measure the left- and right-handed forms (enantiomers) of amphetamine, methamphetamine, MDA, MDMA, and MDEA in oral fluid. After adding a buffer and a derivatizing agent, the enantiomers were extracted and analyzed. The method was linear from 5–250 μg/L per enantiomer for MDA and from 25–1250 μg/L per enantiomer for the other drugs. Recoveries and precision were acceptable except for MDEA. When applied to samples from a controlled MDMA study and real driving-under-the-influence cases, the oral fluid concentrations and enantiomer ratios did not reliably predict plasma levels.
Toxicology Letters
October 8, 2009
Markus R Meyer, Frank T. Peters, Hans H Maurer
The human liver enzymes CYP2D6 and CYP3A4 are primarily responsible for breaking down the chiral designer drugs MDA and BDB, which are also metabolites of MDMA (Ecstasy) and related compounds. The enzymes preferentially process the S-enantiomer of these substances. This metabolic step, called demethylenation, converts the drugs into catecholamines. The findings help clarify how these substances are cleared from the body and may inform understanding of their effects and toxicity in recreational users.
Biochemical Pharmacology
June 1, 2009
Markus R Meyer, Frank T. Peters, Hans H Maurer
Cytochrome P450 isozymes responsible for metabolizing the designer drug MBDB (Eden) were identified for the first time. The main metabolites produced are DHMBB and BDB. Dealkylation is primarily catalyzed by CYP2B6 and CYP2C19, while demethylenation also involves CYP1A2, CYP2D6, and CYP3A4. After in vitro-in vivo correlation, CYP2D6 is the most abundant isozyme for total MBDB metabolism, and CYP2C19 is the most enantioselective, metabolizing the S-enantiomer at a higher rate at low substrate concentrations. Inhibition studies with quinidine confirmed CYP2D6's dominant role. These findings align with results for similar amphetamines.