title: Structure determination of new analogues of vardenafil and sildenafil in dietary supplements.
abstract: New analogues of vardenafil and sildenafil illegally added to dietary supplements were detected by high-performance liquid chromatography (HPLC) analysis with a photodiode array detector (PDA). These compounds were isolated and their structures elucidated by mass spectrometry (MS), infrared (IR) spectroscopy, one- and two-dimensional nuclear magnetic resonance (NMR). One of the new analogues given the trivial name pseudovardenafil (compound 1) was structurally elucidated and shown to be 1-[[3-(1,4-dihydro-5-methyl-4-oxo-7-propylimidazo[5,1-f][1,2,4]triazin-2-yl)-4-ethoxyphenyl]sulfonyl]-piperidine. It was a vardenafil analogue isolated from a dietary supplement capsule. Compared with vardenafil, the piperidine ring was substituted for the ethylpiperazine group. The second new analogue, trivially named hydroxyhongdenafil (compound 2), was separated from bulk powder used as a raw material for a dietary supplement. The piperazine and phenyl groups were connected through an acetyl group instead of a sulfonyl group, and hydroxyethylpiperazine was substituted for the methylpiperazine of sildenafil. It was structurally elucidated as 5-[2-ethoxy-5-[[4-(2-hydroxyethyl)-1-piperazinyl]acetyl]phenyl]-1,4-dihydro-1-methyl-3-propyl-7H-pyrazolo[4,3-d]pyrimidin-7-one.
authors: College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, 151-742. Korea.
authors: H J
authors: HJ
authors: Park
authors: H K
authors: HK
authors: Jeong
authors: M I
authors: MI
authors: Chang
authors: M H
authors: MH
authors: Im
authors: J Y
authors: JY
authors: Jeong
authors: D M
authors: DM
authors: Choi
authors: K
authors: K
authors: Park
authors: M K
authors: MK
authors: Hong
authors: J
authors: J
authors: Youm
authors: S B
authors: SB
authors: Han
authors: D J
authors: DJ
authors: Kim
authors: J H
authors: JH
authors: Park
authors: S W
authors: SW
authors: Kwon
mesh_terms: D019587:Dietary Supplements / Q000032:analysis*; D005506:Food Contamination; D007093:Imidazoles / Q000032:analysis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010726:Phosphodiesterase Inhibitors / Q000032:analysis* / Q000737:chemistry; D010879:Piperazines / Q000032:analysis* / Q000737:chemistry; D011687:Purines / Q000032:analysis / Q000737:chemistry; D000068677:Sildenafil Citrate; D013057:Spectrum Analysis; D013450:Sulfones / Q000032:analysis* / Q000737:chemistry; D014227:Triazines / Q000032:analysis / Q000737:chemistry; D000069058:Vardenafil Dihydrochloride
chemical_list: D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D000068677:Sildenafil Citrate