4-hydroxy-3-methoxymethamphetamine and atrolactic-acid

Different pharmacokinetic properties are known for the two enantiomers of the entactogen 3,4-methylendioxy-methamphetamine (MDMA), most likely due to enantioselective metabolism. The aim of the present work was 1) the investigation of the main sulfotransferases (SULT) isoenzymes involved in the sulfation of the main MDMA phase I metabolites 3,4-dihydroxymethamphetamine (DHMA) and 4-hydroxy-3-methoxymethamphetamine (HMMA) and 2) the evaluation of a possible enantioselectivity of this phase II metabolic step. Therefore, racemic DHMA and HMMA were incubated with heterologously expressed SULTs, and quantification of the sulfates by liquid chromatography-high-resolution mass spectrometry was conducted. Because separation of DHMA and HMMA sulfate could not be achieved by liquid chromatography, enantioselective kinetic parameters were determined using the substrate-depletion approach with enantioselective quantification of substrate consumption by gas chromatography-negative ion chemical ionization mass spectrometry. SULT1A1 and SULT1A3 catalyzed sulfation of DHMA, and SULT1A3 and SULT1E1 catalyzed sulfation of HMMA. SULT1A1 and SULT1E1 revealed classic Michaelis-Menten kinetics, whereas SULT1A3 kinetics showed deviation from the typical Michaelis-Menten kinetics, resulting in a concentration-dependent self-inhibition. SULT1A3 showed the highest affinity and capacity of the SULT isoforms. Marked enantioselectivity could be observed for S-DHMA sulfation by SULT1A3 and in human liver cytosol, whereas no differences were observed for HMMA sulfation. Finally, comparison of K(m) and V(max) values calculated using achiral product formation and chiral substrate depletion showed good correlation within 2-fold of each other. In conclusion, preferences for S-enantiomers were observed for DHMA sulfation, but not for HMMA sulfation.

Topics: Chromatography, Gas; Chromatography, Liquid; Humans; Isoenzymes; Kinetics; Lactates; Mandelic Acids; Mass Spectrometry; Metabolic Detoxication, Phase I; Metabolic Detoxication, Phase II; Methamphetamine; N-Methyl-3,4-methylenedioxyamphetamine; Sulfates; Sulfotransferases

In order to clarify the mechanism of drug incorporation into hair, disposition of 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine (MDEA), 3-methoxy-4,5-methylenedioxyamphetamine (MMDA) and metabolites of MDMA, 4-hydroxy-3-methoxyamphetamine (HMAP) and 4-hydroxy-3-methoxymethamphetamine (HMMA), into hair was investigated with an animal model. After the intraperitoneal administration of those six drugs to pigmented hairy rats (5 mg/kg/day, 10 days, n = 3), the parent compounds and their metabolites in the rat plasma (5, 15, 30, 60, 120, 360 min after administration) and in the newly grown rat hair for 4 weeks were determined by GC/MS-SIM. When the ratio of hair concentration to area under the concentration versus time curves (AUCs) in plasma was represented as an index of incorporation rate (ICR) of drugs into hair, the order of ICRs was HMAP < MDA < HMMA < MDMA < MDEA < MMDA. In the comparison between MDA, MDMA and MDEA, their ICRs increased according to the length of carbon branches from proton to ethyl at the N position. From the point of view that the ICRs of MMDA was 2.3 times as much as that of MDA, the methoxy group on the benzene ring seemed to serve as a positive factor for the ICR. However, the ICRs of 4-hydroxy-3-methoxy compounds, HMAP and HMMA, were lower in comparison with those of MDA and MDMA, respectively. On the other hand, the ICRs of MDA, MDMA and MDEA were 5.5-6.1 times larger than those of amphetamine, methamphetamine and ethylamphetamine, suggesting that the methylenedioxy group on the benzene ring raises their ICRs very positively. Moreover, in order to apply the results from the animal experiments to human cases, the scalp hair samples of seven MDMA abusers were analyzed. MDMA and its metabolites, MDA; were simultaneously detected in all the samples by GC/MS. In the two samples, MDEA was found in addition to MDMA and MDA. It was shown that a hair sample is a good specimen for the confirmation of retrospective use of methylenedioxyamphetamines.

Topics: 3,4-Methylenedioxyamphetamine; Amphetamines; Animals; Gas Chromatography-Mass Spectrometry; Hair; Hallucinogens; Humans; Lactates; Male; Methamphetamine; N-Methyl-3,4-methylenedioxyamphetamine; Rats; Substance Abuse Detection; Substance-Related Disorders