Detection and structure elucidation of hydroxythiovardenafil as an adulterant in a herbal dietary supplement

  • J Pharm Biomed Anal. 2013 Feb 23:74:83-91. doi: 10.1016/j.jpba.2012.10.013.
Péter Jankovics  1 ,  Szilvia Lohner ,  András Darcsi ,  Júlia Németh-Palotás ,  Szabolcs Béni
Affiliations
  • 1. National Institute of Pharmacy, Zrínyi u. 3., PO Box 450, H-1051 Budapest, Hungary. [email protected]
PMID: 23245238 DOI: 10.1016/j.jpba.2012.10.013
Abstract

A new derivative of vardenafil was detected in an alleged herbal dietary supplement and identified as 2-(2-ethoxy-5-(4-(2-hydroxyethyl)piperazin-1-ylsulfonyl)phenyl)-5-methyl-7-propyl-imidazo[1,5-f][1,2,4]triazin-4(3H)-thione. Structure elucidation was carried out by LC-UV-MS/MS and NMR. Results obtained with high resolution MS and IR spectroscopy confirmed the proposed chemical structure. The compound was distinguished from hydroxyvardenafil, a second active substance identified in the same product, by the conversion of the oxo group to a thio group on the imidazo-triazin moiety. Hydroxythiovardenafil was therefore suggested as a proprietary name for the new molecule. This is the first paper to describe a thio-analog of vardenafil in a commercially available product.

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