An analog of Sildenafil which has been used as an illegal adulterant in some dietary supplements.
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7H-Pyrazolo(4,3-d)pyrimidine-7-thione, 5-(5-(((3R,5S)-3,5-dimethyl-1-piperazinyl)sulfonyl)-2-ethoxyphenyl)-1,6-dihydro-1-methyl-3-propyl-, rel-
- Sildenafil thione
Sulfoaildenafil (thioaildenafil) is a synthetic chemical compound that is a structural analog of sildenafil (Viagra). It was first reported in 2005, and it is not approved by any health regulation agency. Like sildenafil, sulfoaildenafil is a phosphodiesterase type 5 inhibitor.
Sulfoaildenafil has been found as an adulterant in a variety of supplements which are sold as “natural” or “herbal” sexual enhancement products. A range of designer analogues of USA FDA-approved inhibitors of type-5 cGMP-specific phosphodiesterase (PDE5), such as sildenafil and vardenafil, have been detected in recent years as adulturants in over-the-counter herbal aphrodisiac products and dietary supplements, in an apparent attempt to circumvent both the legal restrictions on sale of erectile dysfunction drugs, which are prescription-onlymedicines in most Western countries, and the patent protection which prevents sale of these drugs by competitors except under license to their inventors.
These compounds have been demonstrated to display PDE5 inhibitory activity in vitro and presumably have similar effects when consumed, but have undergone no formal testing in either humans or animals, and as such represent a significant health risk to consumers of these products due to their unknown safety profile. Some attempts have been made to ban these drugs as unlicensed medicines, but progress has been slow so far, as even in those jurisdictions which have laws targeting designer drugs, the laws are drafted to ban analogues of illegal drugs of abuse, rather than analogues of prescription medicines. However at least one court case has resulted in a product being taken off the market.
In December 2010, the United States Food and Drug Administration (FDA) issued a warning to consumers about such products stating, “The FDA has found many products marketed as dietary supplements for sexual enhancement during the past several years that can be harmful because they contain active ingredients in FDA-approved drugs or variations of these ingredients.”
Volume 50, Issue 2, 8 September 2009, Pages 228–231
Phosphodiesterase type 5 (PDE-5) inhibitors represent a class of drugs used primarily in the treatment of erectile dysfunction. Currently, three PDE-5 inhibitors have been approved by the U.S. Food and Drug Administration (FDA) for use in the United States: sildenafil citrate, tadalafil, and vardenafil hydrochloride trihydrate. A bulk material, labeled as an ingredient for a dietary supplement, was analyzed for the presence of PDE-5 inhibitors. The compound that was detected displayed structural similarities to sildenafil, and was characterized further using LC–MSn, FTICRMS, X-ray crystallography and NMR. The compound was given the name sulfoaildenafil. When compared to sildenafil, sulfoaildenafil contains a sulfur atom substitution for the oxygen atom in the pyrazolopyrimidine portion of the molecule, and a 3,5-dimethyl substitution on the piperazine ring, rather than the 4-methyl moiety. The X-ray crystallographic data indicate that the material in this sample is comprised of two polymorphs, which may affect the chemical and/or biological properties of any product formulated with this compound.
A herbal supplement marketed to alleviate erectile dysfunction was recently submitted for testing in our laboratory because it was surprisingly effective considering it should only contain the traditional herbals utilized for this problem such as Oyster, 2-Deoxy-D Glucose, Barberry, Snow Lotus, Bombyx Mori L., Ginger Root, Salfron Crocus.
- Gratz, SR; Zeller, M; Mincey, DW; Flurer, CL (2009). “Structural characterization of sulfoaildenafil, an analog of sildenafil”. Journal of pharmaceutical and biomedical analysis 50 (2): 228–31. doi:10.1016/j.jpba.2009.04.003. PMID 19427155.
- Li, Shuxin; Ren, Jianping; Zhao, Yanjin; Lv, Qiujun; Guo, Jinhua. Pyrazolopyrimidinethione Derivatives, Salts and Solvates thereof, Preparation Methods and Use thereof. WO 2005058899
- Gryniewicz, CM; Reepmeyer, JC; Kauffman, JF; Buhse, LF (2009). “Detection of undeclared erectile dysfunction drugs and analogues in dietary supplements by ion mobility spectrometry”. Journal of pharmaceutical and biomedical analysis 49 (3): 601–6. doi:10.1016/j.jpba.2008.12.002. PMID 19150190.
- FDA warns consumers to avoid sexual enhancement pills, Sanjay Gupta, CNN, December 13th, 2010
- Reepmeyer JC, d’Avignon DA (January 2009). “Structure elucidation of thioketone analogues of sildenafil detected as adulterants in herbal aphrodisiacs”. Journal of Pharmaceutical and Biomedical Analysis 49 (1): 145–50. doi:10.1016/j.jpba.2008.10.007. PMID 19042103.
- Balayssac S, Trefi S, Gilard V, Malet-Martino M, Martino R, Delsuc MA (November 2008). “2D and 3D DOSY (1)H NMR, a useful tool for analysis of complex mixtures: Application to herbal drugs or dietary supplements for erectile dysfunction”. Journal of Pharmaceutical and Biomedical Analysis 50 (4): 602–12. doi:10.1016/j.jpba.2008.10.034. PMID 19108978.
- Zou P, Oh SS, Hou P, Low MY, Koh HL (February 2006). “Simultaneous determination of synthetic phosphodiesterase-5 inhibitors found in a dietary supplement and pre-mixed bulk powders for dietary supplements using high-performance liquid chromatography with diode array detection and liquid chromatography-electrospray ionization tandem mass spectrometry”. J Chromatogr A 1104 (1-2): 113–22. doi:10.1016/j.chroma.2005.11.103. PMID 16364350.
- Gratz SR, Gamble BM, Flurer RA (2006). “Accurate mass measurement using Fourier transform ion cyclotron resonance mass spectrometry for structure elucidation of designer drug analogs of tadalafil, vardenafil and sildenafil in herbal and pharmaceutical matrices”. Rapid Commun. Mass Spectrom. 20 (15): 2317–27. doi:10.1002/rcm.2594. PMID 16817245.
- Hou P, Zou P, Low MY, Chan E, Koh HL (September 2006). “Structural identification of a new acetildenafil analogue from pre-mixed bulk powder intended as a dietary supplement”. Food Addit Contam 23 (9): 870–5. doi:10.1080/02652030600803856. PMID 16901855.
- Oh, SS; Zou, P; Low, MY; Koh, HL (2006). “Detection of sildenafil analogues in herbal products for erectile dysfunction.”. Journal of toxicology and environmental health. Part A 69 (21): 1951–8.doi:10.1080/15287390600751355. PMID 16982533.
- Venhuis, BJ; Blok-Tip, L; De Kaste, D (2008). “Designer drugs in herbal aphrodisiacs.”. Forensic Science International 177 (2–3): e25–7. doi:10.1016/j.forsciint.2007.11.007. PMID 18178354.
- FDA warns consumers to avoid Man Up Now capsules, United States Food and Drug Administration, Dec. 15, 2010