Identification of a new tadalafil analogue in an adulterated dietary supplement: Trans-Bisprehomotadalafil

- A new tadalafil analogue was identified from an adulterated dietary supplement.
- The structure of this tadalafil analogue was elucidated.
- This tadalafil analogue is a dimeric compound.
- This tadalafil analogue consists of an ethylamino group and two pretadalafil moieties.