title: Identification of thioketone analogues of sildenfil using gas chromatography-mass spectrometry.
abstract: Sildenafil analogues have been found adulterated in herbal preparations and food products that claim to have natural aphrodisiacs. In this study, a gas chromatography-mass spectrometry (GC-MS) assay was developed for the screening and identification of thioketone analogues of sildenafil. Thiopyrazolopyrimidine, a precursor or a cleavage product of thioketone analogue, exhibited characteristic fragment ions of m/z 328 and m/z 299 was found to be the best marker to screen the presence of general thioketone analogues. Identification by GC-MS assay was rapid and specific as all the studied thioketones showed characteristic mass fragmentations including their intact molecular ions. The developed GC-MS assay had successfully identified thiosildenafil, thiohomosildenafil and thiodimethylsildenafil in herbal preparation and food products.
authors.affiliation: National Poison Centre, Universiti Sains Malaysia, 11800 Penang, Malaysia. kaknin337@yahoo.com
authors.forename: Che Nin
authors.initials: CN
authors.lastname: Man
authors.forename: Norjuliana Mohd
authors.initials: NM
authors.lastname: Noor
authors.forename: Razak
authors.initials: R
authors.lastname: Lajis
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007659:Ketones / Q000737:chemistry* / Q000302:isolation & purification; D010879:Piperazines / Q000737:chemistry* / Q000302:isolation & purification; D011687:Purines / Q000737:chemistry / Q000302:isolation & purification; D011743:Pyrimidines / Q000737:chemistry* / Q000302:isolation & purification; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000737:chemistry* / Q000302:isolation & purification; D013696:Temperature
chemical_list: D007659:Ketones; D010879:Piperazines; D011687:Purines; D011743:Pyrimidines; D013450:Sulfones; D000068677:Sildenafil Citrate; C539492:thiosildenafil