Identification of a novel vardenafil analogue in herbal product

A new herbal health product marketed for enhancing erectile function, namely Power58 Platinum, was purchased over-the-counter in Hong Kong. The product was tested for adulteration with sildenafil, tadalafil, and vardenafil as well as their structurally modified analogues. A new analogue of vardenafil, in which the N-ethylpiperazine ring and the sulphonyl group were removed from the vardenafil structure, was identified in the product.