Isolation and identification of two novel PDE-5 inhibitors illegally added to pressed candies.

Two novel phosphodiesterase 5 (PDE-5) inhibitors were detected in pressed candy using high-performance liquid chromatography (HPLC)-diode array detection. Following extraction with acetonitrile and sonication, the compounds were isolated and purified semi-preparative liquid chromatography. Structural characterisation was achieved through high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectroscopy.

Isolation and characterisation of N-benzyl tadalafil as a novel adulterant in a coffee-based dietary supplement.

A new tadalafil analogue was detected via high-performance liquid chromatography (HPLC)-diode array detection (DAD) during routine screening of health foods suspected of adulteration with erectile dysfunction drugs. The UV absorption spectrum of the unknown was almost identical to that of tadalafil. The analogue was purified by preparative HPLC and structural elucidation carried out by mass spectrometric and NMR spectroscopic experiments.