Separation and structural elucidation of a novel analogue of vardenafil included as an adulterant in a dietary supplement by liquid chromatography-electrospray ionization mass spectrometry, infrared spectroscopy and nuclear magnetic resonance spectroscopy.
MEGATON, a dietary supplement, was analyzed in order to detect PDE-5 inhibitors and their analogues. A new analogue of vardenafil could be detected by high-performance liquid chromatography (HPLC) analysis with a photodiode array detector (PDA). This compound was compared with sildenafil, tadalafil, and vardenafil as well as their structurally modified analogues such as hongdenafil and homosildenafil. The structure of this compound was elucidated by mass spectrometry (MS), infrared (IR) spectroscopy and one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. When compared with vardenafil to verify the structural difference, this compound had an acetyl group instead of a sulfonyl group in the pyrazolopyrimidine portion without any substitution in the piperazine ring of the molecule. This compound was identified as 2-(2-ethoxy-5-(2-(4-ethylpiperazin-1-yl)acetyl)phenyl)-5-methyl-7-propyl-imidazo(5,1-f)-(1,2,4)triazin-4(3H)-one, which is also called acetylvardenafil.
Research Institute of Pharmaceutical Science, College of Pharmacy, Seoul National University, Gwanak_599, Gwanak-ro, Gwanak-gu, Seoul 151-742, South Korea.
Hwa-Mi
HM
Lee
Chang Soo
CS
Kim
Young Mi
YM
Jang
Sung Won
SW
Kwon
Bong-Jin
BJ
Lee
D002243:Carbolines / Q000737:chemistry; D002853:Chromatography, Liquid; D019587:Dietary Supplements / Q000009:adverse effects / Q000032:analysis*; D004340:Drug Contamination; D007172:Erectile Dysfunction / Q000188:drug therapy; D006801:Humans; D007093:Imidazoles / Q000032:analysis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D058986:Phosphodiesterase 5 Inhibitors / Q000032:analysis* / Q000737:chemistry*; D010879:Piperazines / Q000032:analysis* / Q000737:chemistry*; D011687:Purines / Q000032:analysis / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism; D000068677:Sildenafil Citrate; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013450:Sulfones / Q000032:analysis / Q000737:chemistry; D000068581:Tadalafil; D014227:Triazines / Q000032:analysis / Q000737:chemistry; D000069058:Vardenafil Dihydrochloride
C558258:2-(2-ethoxy-5-(2-(4-ethylpiperazin-1-yl)acetyl)phenyl)-5-methyl-7-propyl-imidazo(5,1-f)-(1,2,4)triazin-4(3H)-one; D002243:Carbolines; D007093:Imidazoles; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D000068581:Tadalafil; D000068677:Sildenafil Citrate