title: Isolation and structural characterisation of a propoxyphenyl-linked thiohomosildenafil analogue found in a herbal product.
abstract: A propoxyphenyl-linked thiohomosildenafil analogue, one of the sildenafil analogues, was found in an herbal product. It was isolated by semi-preparative high-performance liquid chromatography (HPLC). The structure was established based on a comparison of chromatographic and spectroscopic behaviour with other sildenafil analogues using HPLC with diode array detection, quadrupole time-of-flight mass spectrometry (Q-TOF/MS), and nuclear magnetic resonance (NMR) spectroscopy. The HPLC analysis showed separation from known sildenafil analogues with a similar chromatographic retention time. An [M + H](+) ion at m/z 519.22 was detected by mass spectrometry corresponding to an empirical formula of C24H34N6O3S2. The structure was similar to that of thiohomosildenafil, except that the ethoxy group attached to the phenyl ring was substituted for a propoxy group. It was assigned as 5-[2-propoxy-5-(4-ethylpiperazin-4-ylsulfonyl)phenyl]-3-methyl-1-n-propyl-4,5,dihydro-1H-pyrazole[7,1,d]pyrimidin-4-thione and named as propoxyphenyl-thiohomosildenafil because the structure was considerably similar to thiohomosildenafil.
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 , Cheongwon-gun, Chungcheongbuk-do , Korea.
authors.forename: Nam Sook
authors.initials: NS
authors.lastname: Kim
authors.forename: Ji Hyune
authors.initials: JH
authors.lastname: Lee
authors.forename: Kyoung Moon
authors.initials: KM
authors.lastname: Han
authors.forename: Hyung Joo
authors.initials: HJ
authors.lastname: Kim
authors.forename: Sooyeul
authors.initials: S
authors.lastname: Cho
authors.forename: Soon Young
authors.initials: SY
authors.lastname: Han
authors.forename: Woo Seong
authors.initials: WS
authors.lastname: Kim
mesh_terms: D002851:Chromatography, High Pressure Liquid; D019587:Dietary Supplements / Q000009:adverse effects / Q000032:analysis; D005506:Food Contamination / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D058986:Phosphodiesterase 5 Inhibitors / Q000737:chemistry*; D010879:Piperazines / Q000737:chemistry*; D028321:Plant Preparations / Q000737:chemistry*; D011687:Purines / Q000737:chemistry; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000737:chemistry*
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D028321:Plant Preparations; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate