title: Structure elucidation of a novel analog of sildenafil detected as an adulterant in a dietary supplement using LC-UV and LC/MS.
abstract: A sildenafil-related compound was detected in a dietary supplement marketed as an aphrodisiac. The compound was detected during analysis of the dietary supplement using LC-UV and LC/electrospray ionization-MS. The structure of the compound was established using high resolution MS, NMR spectrometry, and X-ray crystal structure analysis. The compound was identified as 5-(5-((3,5-dimethylpiperazin-1-yl)sulfonyl)-2-ethoxyphenyl)-l-methyl-7-((1-methyl-4-nitro-1H-imidazol-5-yl)thio)-3-propyl-1H-pyrazolo[4,3-d] pyrimidine. Based on this structure, the compound was named nitroprodenafil. The dietary supplement was found to contain 90 mg nitroprodenafil/capsule. This article describes the structural characterization of a new sildenafil-related compound. The compound was detected during analysis of a dietary supplement using LC-UV and LC/electrospray ionization (ESI)-MS. The structure was established using high resolution MS (HRMS), NMR spectrometry, and X-ray crystal structure analysis. The structures of methisosildenafil, thiomethisosildenafil, and this new analog, named nitroprodenafil (21), are shown in Figure 1. In the Demizu et al. report, the compound is named mutaprodenafil instead ofnitroprodenafil. Considering the naming right, the authors of this paper think the use of mutaprodenafil is appropriate as the compound name, although nitroprodenafil is used.
authors.affiliation: Tokyo Metropolitan Institute of Public Health, Department of Pharmaceutical Sciences, 24-1 Hyakunincho 3-chome, Shinjuku-ku, Tokyo 169-0073, Japan. Miho_Sakamoto@member.metro.tokyo.jp
authors.forename: Miho
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Takako
authors.initials: T
authors.lastname: Moriyasu
authors.forename: Keiko
authors.initials: K
authors.lastname: Minowa
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Kishimoto
authors.forename: Hideo
authors.initials: H
authors.lastname: Kadoi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Hamano
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Fukaya
mesh_terms: D002214:Capsules; D002623:Chemistry Techniques, Analytical / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D018360:Crystallography, X-Ray / Q000379:methods; D019587:Dietary Supplements / Q000032:analysis*; D004340:Drug Contamination; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods*; D008956:Models, Chemical; D010879:Piperazines / Q000032:analysis* / Q000737:chemistry; D011687:Purines / Q000032:analysis / Q000737:chemistry; D015203:Reproducibility of Results; D000068677:Sildenafil Citrate; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013450:Sulfones / Q000032:analysis* / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: C575533:5-(5-((3,5-dimethylpiperazin-1-yl)sulfonyl)-2-ethoxyphenyl)-l-methyl-7-((1-methyl-4-nitro-1H-imidazol-5-yl)thio)-3-propyl-1H-pyrazolo(4,3-d)pyrimidine; D002214:Capsules; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate