title: Isolation and identification of novel propoxyphenyl thiosildenafil found in natural health food product.
abstract: A novel phosphodiesterase-5 (PDE-5) inhibitor was found in a natural health food product. The previously unknown sildenafil analogue was isolated using preparative HPLC. The structure of the compound was elucidated using HPLC with diode array detection (DAD), time-of-flight mass spectrometry (TOF/MS), and nuclear magnetic resonance spectroscopy (NMR). An [M + H](+) ion was detected at m/z 505.2077 by LC-TOF/MS that was consistent with C23H32N6O3S2 (-0.98 ppm). By NMR analysis, the analogue was identified as 1-methyl-5-(5-(4-methylpiperazin-1-ylsulfonyl)-2-propoxyphenyl)-3-propyl-1H-pyrazolo[4,3-d]pyrimidine-7(6H)-thione. In this structure, the ethoxy group of thiosildenafil was substituted by a propoxy group of the unknown compound. Therefore, this novel thiosildenafil analogue was named propoxyphenyl thiosildenafil.
authors.affiliation: a Advanced Analysis Team, Toxicological Evaluation and Research Department , National Institute of Food and Drug Safety Evaluation , Ministry of Food and Drug Safety , Cheongwon-gun , Korea.
authors.forename: Kyoung Moon
authors.initials: KM
authors.lastname: Han
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Hyoung-Joon
authors.initials: HJ
authors.lastname: Park
authors.forename: Insun
authors.initials: I
authors.lastname: Hwang
authors.forename: Ok-Soon
authors.initials: OS
authors.lastname: Heo
authors.forename: Woo Seong
authors.initials: WS
authors.lastname: Kim
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005506:Food Contamination / Q000032:analysis*; D058870:Food, Organic / Q000009:adverse effects / Q000032:analysis*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D015394:Molecular Structure; D058986:Phosphodiesterase 5 Inhibitors / Q000009:adverse effects / Q000737:chemistry / Q000302:isolation & purification*; D011743:Pyrimidines / Q000009:adverse effects / Q000737:chemistry / Q000302:isolation & purification*; D056910:Republic of Korea; D021241:Spectrometry, Mass, Electrospray Ionization; D013450:Sulfones / Q000009:adverse effects / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; D011743:Pyrimidines; D013450:Sulfones; C539492:thiosildenafil