Abstract
New analogues of Sildenafil (Viagra${\circledR}$)were identified in the imported Chinese herb drinks, which have been added illegally for affecting penile erectile dysfunction. In order to elucidate the chemical structures of Sildenafil analogues, separation and purification were carried out and followed by analysis of the routine 1D and 2D NMR spectroscopy and FAB mass spectrometry. Based on analytical data one compound was maned as Homosildenafil contains ethylpiperazine switched with methylpiperazine of Sildenafil and the other one was called an Hongdenafil contains ethylpiperazine switched with methylpiperazine and acetyl group instead of sulfonyl group of Sildenafil. As results, Homosildenafil and Hongdenafil were put on the list as new inspection items of the imported food for protectiong public health in Korea.