A suspected sildenafil analogue (1) was firstly detected from dietary supplements, which claimed for energy enforcement, by TLC and UV method. The UV spectrum of this suspected compound showed close similar pattern to that of acetildenafil (2, sildenafil analogue). In order to identify this compound, separation and purification were carried out as well as structure determination was conducted by various NMR techniques, mass spectrum and IR. This new compound 1 had an acetyl group instead of sulfonyl-N-methylpiperazine moiety in sildenafil (3), and its structure was determined as 5-[2-ethoxy-5-acetyl-phenyl]-1-methyl-3-n-propyl-1,6- dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (molecular formula C19H22N4O3, molecular weight 354). So far no related report and literature to describe its pharmacological action and to provide related safety evaluation of this compound was published. The above results revealed that this compound was illegally adulterated into the dietary supplements, and has thus been included in our routine analysis list for public health.
Lin, M.-C.; Liu, Y.-C.; Lin, Y.-L.; and Lin, J.-H.
"Isolation and identification of a novel sildenafil analogue adulterated in dietary supplements,"
Journal of Food and Drug Analysis: Vol. 16
, Article 5.
Available at: https://doi.org/10.38212/2224-6614.2340