title: Isolation and structural elucidation of a new tadalafil analogue in health supplements: bisprenortadalafil.
abstract: A new tadalafil analogue was found, along with nortadalafil, using HPLC-DAD during the inspection of a health product sold without official approval. The analogue was separated using a semi-preparative HPLC system and its structure was determined by a combination of mass spectrometry and NMR spectroscopy. The compound was identified as a tadalafil analogue in which the N-methyl group of tadalafil was replaced with a tadalafil precursor moiety. Nuclear Overhauser effect spectroscopy experiments suggested a cis-relationship between the substituents on a piperidine ring in the tadalafil moiety.
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 , Cheongju-si , Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Lee
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 , Cheongju-si , Korea.
authors.forename: Han Na
authors.initials: HN
authors.lastname: Park
authors.affiliation: b College of Pharmacy , Kangwon National University , Chuncheon , Korea.
authors.forename: Bogonda
authors.initials: B
authors.lastname: Ganganna
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 , Cheongju-si , Korea.
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Jeong
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 , Cheongju-si , Korea.
authors.forename: Sung-Kwan
authors.initials: SK
authors.lastname: Park
authors.affiliation: b College of Pharmacy , Kangwon National University , Chuncheon , Korea.
authors.forename: Jongkook
authors.initials: J
authors.lastname: Lee
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 , Cheongju-si , Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Baek
mesh_terms: D002851:Chromatography, High Pressure Liquid; D019587:Dietary Supplements / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D058986:Phosphodiesterase 5 Inhibitors; D000068581:Tadalafil / Q000031:analogs & derivatives*
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; C000614363:bidprenortadalafil; D000068581:Tadalafil
keywords: PDE-5 inhibitor; Tadalafil analogue; bisprenortadalafil; dietary supplement; nortadalafil