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

View Article: PubMed Central - PubMed

ABSTRACT

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.

No MeSH data available.


Expanded Spectra 1H HR-MAS NMR of (A) (S)-enantiomer (13.0 mmol.L-1), (B) (R)-enantiomer (13.0 mmol.L-1), and (C) racemic mixture (13.0 mmol.L-1) in the presence of 1 mg of CSP-ID suspended in ACNd3/DEA (100:0.1, v/v).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5036802&req=5

pone.0162892.g005: Expanded Spectra 1H HR-MAS NMR of (A) (S)-enantiomer (13.0 mmol.L-1), (B) (R)-enantiomer (13.0 mmol.L-1), and (C) racemic mixture (13.0 mmol.L-1) in the presence of 1 mg of CSP-ID suspended in ACNd3/DEA (100:0.1, v/v).

Mentions: The spectrum of the racemic mixture (Fig 4C) shows the chemical shift for the protons located at H1 (δ = 2.55 ppm), H2 (δ = 1.14–1.13 ppm), H3 (δ = 2.65–2.80 ppm), H4 (δ = 2.91–3.31 ppm), H5 (δ = 6.60–6.71 ppm), H6 (δ = 6.79–6.71 ppm), H7 (δ = 6.75 ppm) and H8 (δ = 5.96 ppm), as assigned at the MDMA chemical structure (Fig 1). Changes in chemical shift can be perceived for the protons located at position H2, H3 and H4 when the spectra of Fig 4 are compared. These changes are better observed in the expanded spectra of both enantiomers shown in Fig 5. Major differences in chemical shift are observed for the (R)-enantiomers when compared to the other two spectra (B and C). This is an indicative that the (R)-enantiomer strongly interacts with CSP.


A High-Resolution Magic Angle Spinning NMR Study of the Enantiodiscrimination of 3,4-Methylenedioxymethamphetamine (MDMA) by an Immobilized Polysaccharide-Based Chiral Phase
Expanded Spectra 1H HR-MAS NMR of (A) (S)-enantiomer (13.0 mmol.L-1), (B) (R)-enantiomer (13.0 mmol.L-1), and (C) racemic mixture (13.0 mmol.L-1) in the presence of 1 mg of CSP-ID suspended in ACNd3/DEA (100:0.1, v/v).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036802&req=5

pone.0162892.g005: Expanded Spectra 1H HR-MAS NMR of (A) (S)-enantiomer (13.0 mmol.L-1), (B) (R)-enantiomer (13.0 mmol.L-1), and (C) racemic mixture (13.0 mmol.L-1) in the presence of 1 mg of CSP-ID suspended in ACNd3/DEA (100:0.1, v/v).
Mentions: The spectrum of the racemic mixture (Fig 4C) shows the chemical shift for the protons located at H1 (δ = 2.55 ppm), H2 (δ = 1.14–1.13 ppm), H3 (δ = 2.65–2.80 ppm), H4 (δ = 2.91–3.31 ppm), H5 (δ = 6.60–6.71 ppm), H6 (δ = 6.79–6.71 ppm), H7 (δ = 6.75 ppm) and H8 (δ = 5.96 ppm), as assigned at the MDMA chemical structure (Fig 1). Changes in chemical shift can be perceived for the protons located at position H2, H3 and H4 when the spectra of Fig 4 are compared. These changes are better observed in the expanded spectra of both enantiomers shown in Fig 5. Major differences in chemical shift are observed for the (R)-enantiomers when compared to the other two spectra (B and C). This is an indicative that the (R)-enantiomer strongly interacts with CSP.

View Article: PubMed Central - PubMed

ABSTRACT

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.

No MeSH data available.