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Updated: Jun 26, 2026

NMR Spectroscopy as a Robust Tool for the Rapid Evaluation of the Lipid Profile of Fish Oil Supplements
Published on: May 1, 2017
2D and 3D DOSY 1H NMR, a useful tool for analysis of complex mixtures: application to herbal drugs or dietary
Stéphane Balayssac1, Saleh Trefi, Véronique Gilard
1Groupe de RMN Biomédicale, Laboratoire SPCMIB (UMR CNRS 5068), Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex, France.
Abstract:
Seventeen herbal dietary supplements, marketed as natural substances for the enhancement of sexual function, were analyzed by diffusion ordered spectroscopy (DOSY) (1)H NMR. The method allowed a global analysis of the samples with detection of both active and inactive ingredients present in these complex matrixes. Eight formulations contained compounds related to the synthetic phosphodiesterase-5 inhibitors. Sildenafil, tadalafil, vardenafil, hydroxyhomosildenafil, thiosildenafil, and the newly identified adulterant thiomethisosildenafil were detected. Quantification of these active ingredients was carried out by HPLC or NMR. In addition to these actives, about 30 compounds or excipients were characterized. This study ended up with a three-dimensional DOSY-COSY (1)H NMR experiment on a herbal formulation which provided both virtual separation and structural information.
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