ABSTRACT
A novel tadalafil analogue found in a dietary supplement by routine drug-adulteration screening was isolated by column chromatography and HPLC. On the basis of extensive 1D- and 2D-nuclear magnetic resonance (NMR), infrared (IR) and mass spectral analyses, the structure of the new compound YJ-02 was established as 6‐(benzo[d][1,3]dioxol‐5‐yl)‐2,3,6,7,12,12a‐hexahydro‐2‐(1E,2E)‐3‐phenylallylidene)amino)pyrazino[1ʹ,2ʹ:1,6]pyrido[3,4‐b]indole‐1,4‐dione. Its common name is N-phenylpropenyltadalafil.