title: Structure elucidation of a novel analogue of sildenafil detected as an adulterant in an herbal dietary supplement.
abstract: A new analogue of sildenafil was detected in an herbal dietary supplement, which was sold over the internet and promoted as a product for the enhancement of sexual performance. The structure of the compound was established using LC-MS, UV spectroscopy, MS-MS, and NMR. In addition, the compound was cleaved at its sulfonamide S-N bond yielding a sulfonic acid and an amine, which were independently characterized using LC-MS, GC-MS, and derivatization. The compound, named methisosildenafil, is a novel synthetic analogue of sildenafil in which the N-methylpiperazine moiety has been replaced with 2,6-dimethylpiperazine.
authors.affiliation: US Food and Drug Administration, Division of Pharmaceutical Analysis, St. Louis, MO 63101, USA. john.reepmeyer@fda.hhs.gov
authors.forename: John C
authors.initials: JC
authors.lastname: Reepmeyer
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Woodruff
authors.forename: D André
authors.initials: DA
authors.lastname: d'Avignon
mesh_terms: D002853:Chromatography, Liquid; D015198:Designer Drugs / Q000032:analysis / Q000737:chemistry; D019587:Dietary Supplements / Q000032:analysis*; D007172:Erectile Dysfunction / Q000178:diet therapy; D005506:Food Contamination; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013058:Mass Spectrometry; D015394:Molecular Structure; D010726:Phosphodiesterase Inhibitors / Q000737:chemistry; D010879:Piperazines / Q000032:analysis / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis*; D028321:Plant Preparations / Q000032:analysis / Q000737:chemistry; D011687:Purines / Q000032:analysis / Q000737:chemistry; D000068677:Sildenafil Citrate; D013056:Spectrophotometry, Ultraviolet; D013450:Sulfones / Q000032:analysis / Q000737:chemistry*
chemical_list: D015198:Designer Drugs; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D010936:Plant Extracts; D028321:Plant Preparations; D011687:Purines; D013450:Sulfones; C520362:methisosildenafil; D000068677:Sildenafil Citrate