Chiral separation of 3,4-methylenedioxymethamphetamine (MDMA) enantiomers using batch chromatography with peak shaving recycling and its effects on oxidative stress status in rat liver

Development of enantioselective high-performance liquid chromatography-tandem mass spectrometry method for the quantitative determination of 3,4-methylenedioxy-methamphetamine (MDMA) and its phase-1 metabolites in human biological fluids

In the present study enantioselective high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were developed for the quantitative determination of 3,4-methylenedioxy-methamphetamine (MDMA) and its major phase-1 metabolites 4-hydroxy-3-methoxyamphetamine (HMA), 4-hydroxy-3-methoxymethamphetamine (HMMA) and 3,4-methylenedioxyamphetamine (MDA) in human plasma, sweat, oral fluid (OF) and urine. The simultaneous separation of all these compounds and their respective enantioseparation was accomplished on two polysaccharide-based chiral columns. The Lux AMP column with a proprietary chiral selector enabled baseline separation of the enantiomers of MDMA, HMA and HMMA while MDA enantiomers could not be separated with this column under the experimental conditions used in this study. The Lux i-Amylose-3 column based on amylose tris(5-chloro-3-methylphenylcarbamate) as chiral selector baseline-separated the enantiomers of MDMA, HMMA and MDA while the enantiomers of HMA could not be separated. Thus, the various samples were analyzed by using both columns alternatively in combinations with acetonitrile containing 25% (v/v) 5 mM ammonium bicarbonate buffer at pH 11.0 as mobile phase. Analysis time was less than 4 min with the Lux AMP column and less than 6 min with the Lux i-Amylose-3 column. Both methods were validated and applied to the enantioselective determination of MDMA and its phase-I metabolites in human biological fluids, and enantioselective metabolism of MDMA was confirmed.

Swim in the Chiral Pool: MDMA and MDA Enantiomers from Alanine-Derived Precursors

A divergent two-step process has provided access to optically pure enantiomers of MDMA and MDA, clinically relevant phenylisopropylamine entactogens. Target compounds were synthesized from commercially available alanine-derived aziridines. Critical process parameters were identified, and the reactions were optimized to avoid chromatographic purifications toward gram-scale isolations, providing (R)-(-)-MDMA, (S)-(+)-MDMA, (R)-(-)-MDA, and (S)-(+)-MDA each in greater than 98% purity by UPLC, >99% enantiomeric excess, and net yields between 50 and 60% for the complete process.

Chiral Separations in Preparative Scale: A Medicinal Chemistry Point of View

Enantiomeric separation is a key step in the development of a new chiral drug. Preparative liquid chromatography (LC) continues to be the technique of choice either during the drug discovery process, to achieve a few milligrams, or to a scale-up during the clinical trial, needing kilograms of material. However, in the last few years, instrumental and technical developments allowed an exponential increase of preparative enantioseparation using other techniques. Besides LC, supercritical fluid chromatography (SFC) and counter-current chromatography (CCC) have aroused interest for preparative chiral separation. This overview will highlight the importance to scale-up chiral separations in Medicinal Chemistry, especially in the early stages of the pipeline of drugs discovery and development. Few examples within different methodologies will be selected, emphasizing the trends in chiral preparative separation. The advantages and drawbacks will be critically discussed.

Sympathomimetic amine compounds and hepatotoxicity: Not all are alike-Key distinctions noted in a short review

Sympathomimetic amine compounds are often pooled together and incorrectly assumed to be interchangeable with respect to potential adverse effects. A brief and specific review of sympathomimetic compounds and one instance (i.e., hepatotoxicity) where these compounds have been improperly grouped together is covered. A review of the proposed mechanisms through which known hepatotoxic sympathomimetic agents (e.g., 3,4-methylenedioxymethamphetamine or MDMA, methamphetamine and amphetamine) cause liver injury, along with a corresponding review of in vitro data, interventional data, animal model studies and observational data allow for a comparison/contrast of different agents and reveals a lack of potential toxicity for some agents (e.g., pseudoephedrine, phenylephrine, ephedrine, 1,3-dimethylamylamine, phentermine) in this broad category. Data show that compounds within the broad group of sympathomimetics display divergent pharmacological and toxicological profiles and can be clearly distinguished with respect to liver injury. These data serve as a reminder to clinicians and others, that even small structural differences between molecules can lead to drastically different pharmacological/toxicological profiles and that one should not assume that all sympathomimetic agents are hepatotoxic. Such assumptions could lead to diagnostic errors and incorrect or insufficient treatment.

Ecstasy induces reactive oxygen species, kidney water absorption and rhabdomyolysis in normal rats. Effect of N-acetylcysteine and Allopurinol in oxidative stress and muscle fiber damage

BACKGROUND

Ecstasy (Ec) use produces hyperthermia, excessive sweating, intense thirst, an inappropriate antidiuretic hormone secretion (SIADH) and a multisystemic toxicity due to oxidative stress (OS). Intense thirst induces high intake of pure water, which associated with SIADH, usually develops into acute hyponatremia (Hn). As Hn is induced rapidly, experiments to check if Ec acted directly on the Inner Medullary Collecting Ducts (IMCD) of rats were conducted. Rhabdomyolysis and OS were also studied because Ec is known to induce Reactive Oxygen Species (ROS) and tissue damage. To decrease OS, the antioxidant inhibitors N-acetylcysteine (NAC) and Allopurinol (Allo) were used.

METHODS

Rats were maintained on a lithium (Li) diet to block the Vasopressin action before Ec innoculation. AQP2 (Aquaporin 2), ENaC (Epitheliun Sodium Channel) and NKCC2 (Sodium, Potassium, 2 Chloride) expression were determined by Western Blot in isolated IMCDs. The TBARS (thiobarbituric acid reactive substances) and GSH (reduced form of Glutathione) were determined in the Ec group (6 rats injected with Ec-10mg/kg), in Ec+NAC groups (NAC 100mg/Kg/bw i.p.) and in Allo+Ec groups (Allo 50mg/Kg/i.p.).

RESULTS

Enhanced AQP2 expression revealed that Ec increased water transporter expression, decreased by Li diet, but the expression of the tubular transporters did not change. The Ec, Ec+NAC and Allo+Ec results showed that Ec increased TBARS and decreased GSH, showing evidence of ROS occurrence, which was protected by NAC and Allo. Rhabdomyolysis was only protected by Allo.

CONCLUSION

Results showed that Ec induced an increase in AQP2 expression, evidencing another mechanism that might contribute to cause rapid hyponatremia. In addition, they showed that NAC and Allo protected against OS, but only Allo decreased rhabdomyolysis and hyperthermia.

A High-Resolution Magic Angle Spinning NMR Study of the Enantiodiscrimination of 3,4-Methylenedioxymethamphetamine (MDMA) by an Immobilized Polysaccharide-Based Chiral Phase

This paper reports the investigation of the chiral interaction between 3,4-methylenedioxy-methamphetamine (MDMA) enantiomers and an immobilized polysaccharide-based chiral phase. For that, suspended-state high-resolution magic angle spinning nuclear magnetic resonance spectroscopy (1H HR-MAS NMR) was used. 1H HR-MAS longitudinal relaxation time and Saturation Transfer Difference (STD NMR) titration experiments were carried out yielding information at the molecular level of the transient diastereoisomeric complexes of MDMA enantiomers and the chiral stationary phase. The interaction of the enantiomers takes place through the aromatic moiety of MDMA and the aromatic group of the chiral selector by π-π stacking for both enantiomers; however, a stronger interaction was observed for the (R)-enantiomer, which is the second one to elute at the chromatographic conditions.

Enantiomeric separations of illicit drugs and controlled substances using cyclofructan-based (LARIHC) and cyclobond I 2000 RSP HPLC chiral stationary phases

Recently a novel class of chiral stationary phases (CSPs) based on cyclofructan (CF) has been developed. Cyclofructans are cyclic oligosaccharides that possess a crown ether core and pendent fructofuranose moieties. Herein, we evaluate the applicability of these novel CSPs for the enantiomeric separation of chiral illicit drugs and controlled substances directly without any derivatization. A set of 20 racemic compounds were used to evaluate these columns including 8 primary amines, 5 secondary amines, and 7 tertiary amines. Of the new cyclofructan-based LARIHC columns, 14 enantiomeric separations were obtained including 7 baseline and 7 partial separations. The LARIHC CF6-P column proved to be the most useful in separating illicit drugs and controlled substances accounting for 11 of the 14 optimized separations. The polar organic mode containing small amounts of methanol in acetonitrile was the most useful solvent system for the LARIHC CF6-P CSP. Furthermore, the LARIHC CF7-DMP CSP proved to be valuable for the separation of the tested chiral drugs resulting in four of the optimized enantiomeric separations, whereas the CF6-RN did not yield any optimum separations. The broad selectivity of the LARIHC CF7-DMP CSP is evident as it separated primary, secondary and tertiary amine containing chiral drugs. The compounds that were partially or un-separated using the cyclofructan based columns were screened with a Cyclobond I 2000 RSP column. This CSP provided three baseline and six partial separations.