Identification of a Sildenafil Analogue Adulterated in Two Herbal Food Supplements
MEI-CHIH LIN, YI-CHU LIU AND JER-HUEI LIN*
Bureau of Food and Drug Analysis, Department of Health, Executive Yuan, R.O.C.
161-2, Kuen Yang Street, Nankang, Taipei City 115, Taiwan, R.O.C.
(Received: November 18, 2005; Accepted: June 12, 2006)
ABSTRACT
Consumption of herbal supplements becomes more and more popular in the world. For the sake of public health, enhanced supervision on those products is needed. A novel sildenafil analogue is detected from two herbal dietary supplements in our laboratory. Its structure has been identified by various NMR techniques, mass spectrum, IR and X-ray diffraction. This compound is slightly different from sildenafil (Viagra) in the piperazine moiety, where N-methyl group in sildenafil is replaced by N-hydroxyethyl group. Thereby this compound is named as hydroxyhomosildenafil. Noticeably, this compound has not been approved as medication. Therefore, it is necessary to monitor diverse analogues besides the commercial chemical compounds.
Key words: Herbal supplements, NMR, Mass Spectrum, IR, X-ray Diffraction, sildenafil, hydroxyhomosildenafil