Differentiation between sulfoaildenafil and its analogs.
An analog of aildenafil, which is a potent and highly selective inhibitor of phosphodiesterase 5, was found in a dietary supplement marketed for enhancement of sexual function. The compound was isolated by silica gel column chromatography, and its structure was identified by means of 13C-NMR spectrometry, 1H-NMR spectrometry, high-resolution MS, and X-ray structure determination. The compound was identified to be sulfoaildenafil (other names: thioaildenafil, dimethyl sildenafil thione, and thiomethisosildenafil). Sulfoaildenafil is very similar to the compound thiohomosildenafil. As it is difficult to distinguish between them by LC-photodiode array detector analysis, ultra-performance LC (UPLC)/MS, ion trap LC/MS/MS (LC/IT-MS/MS), and GC/MS were performed. The mass spectra of thiohomosildenafil by UPLC/MS and LC/IT-MS/MS showed mass fragments of m/z 58, 72, and 355, and the mass spectrum by GC/MS showed mass fragments of m/z 56, 72, and 420. Some of these fragments had low intensities, but they were useful for distinguishing between the two compounds. The relationship between aildenafil (other names: dimethylsildenafil and methisosildenafil) and homosildenafil is similar to that between sulfoaildenafil and thiohomosildenafil. Therefore, these compounds were also examined.
Tokyo Metropolitan Institute of Public Health, Department of Pharmaceutical Sciences, 24-1 Hyakunincho 3-chome Shinjuku-ku, Tokyo 169-0073, Japan. moriyasu0520@gmail.com
Takako
T
Moriyasu
Keiko
K
Minowa
Miho
M
Sakamoto
Kiyoko
K
Kishimoto
Hideo
H
Kadoi
Jun'ichi
J
Nakajima
Ken'ichiro
K
Mori
Shuzo
S
Ogino
Haruhiko
H
Fukaya
Yasuo
Y
Shida
D002853:Chromatography, Liquid / Q000379:methods; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5 / Q000032:analysis; D019587:Dietary Supplements / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D058986:Phosphodiesterase 5 Inhibitors / Q000032:analysis; D010879:Piperazines / Q000032:analysis*; D013450:Sulfones / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods
D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D013450:Sulfones; C543174:sulfoaildenafil; C570473:thiohomosildenafil; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5