Title
Enantiomers of triclabendazole sulfoxide: Analytical and semipreparative HPLC separation, absolute configuration assignment, and transformation into sodium salt
Author
Rosella Ferretti, Simone Carradori, Paolo Guglielmi, Marco Pierini, Adriano Casulli, Roberto Cirilli
Year
2017
Journal
Journal of Pharmaceutical and Biomedical Analysis
Abstract
Direct HPLC separation of the enantiomers of triclabendazole sulfoxide (TCBZ-SO), which is the main metabolite of the anthelmintic drug triclabendazole, was carried out using the polysaccharide-based Chiralpak AS-H and Chiralpak IF-3 chiral stationary phases (CSPs). The chromatographic behaviour of both CSPs was evaluated and compared using normal-phase and reversed-phase eluents at different column temperatures. The eluent mixture of n-hexane-2-propanol-trifluoroacetic acid 70:30:0.1 (v/v/v) and a column temperature of 40 °C were identified as the best operational conditions to carry out semipreparative enantioseparations on a 1-cm I.D. AS-H column. Under these conditions, 12.5 mg of racemic sample were resolved in a single chromatographic run within 15 min. Comparison of calculated and experimental chiroptical properties provided the absolute configuration assignment at the sulfur atom. The salification of the isolated enantiomers of TCBZ-SO by reaction with sodium hydroxide solution produced water-soluble Na salts which are potentially useful in the development of new anthelmintic enantiomerically pure formulations.
Instrument
J-700
Keywords
Circular dichroism, Stereochemistry, Pharmaceutical