Structure elucidation of sildenafil analogues in herbal products.
The structure of unknown compounds present in herbal products was elucidated using liquid chromatography-electrospray ionization-mass spectrometry, direct-infusion electrospray ionization-mass spectrometry, and nuclear magnetic resonance. Compounds 1-3 were identified as sildenafil analogues, 1 bearing an N-ethylpiperazine moiety instead of an N-methylpiperazine, and an acetyl group instead of the sulfonyl group, named acetildenafil, 2 bearing an N-ethylpiperazine moiety instead of an N-methylpiperazine (homosildenafil), and 3 bearing an N-hydroxylethylpiperazine moiety instead of an N-methylpiperazine, named hydroxyhomosildenafil. When analysing products marketed for penile erectile dysfunction or marketed as aphrodisiacs, attention should be given to the possible presence of these components.
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Centre for Quality of Chemical-Pharmaceutical Products, National Institute for Public Health and the Environment, PO Box 1, NL-3720 BA Bilthoven, The Netherlands.
Zomer
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Bakker
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Hartog
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Hamzink
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Ten Hove
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Vredenbregt
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De Kaste
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D002243:Carbolines / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods; D007093:Imidazoles / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008956:Models, Chemical; D010726:Phosphodiesterase Inhibitors / Q000737:chemistry*; D010879:Piperazines / Q000737:chemistry*; D028321:Plant Preparations / Q000737:chemistry*; D011687:Purines; D000068677:Sildenafil Citrate; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013450:Sulfones; D000068581:Tadalafil; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D014665:Vasodilator Agents / Q000737:chemistry*
D002243:Carbolines; D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D028321:Plant Preparations; D011687:Purines; D013450:Sulfones; D014227:Triazines; D014665:Vasodilator Agents; D000069058:Vardenafil Dihydrochloride; D000068581:Tadalafil; D000068677:Sildenafil Citrate