139755-82-1Relevant articles and documents
Structure elucidation of phototransformation products of unapproved analogs of the erectile dysfunction drug sildenafil in artificial freshwater with UPLC-Q Exactive-MS
Acea, Jaume,Prez, Sandra,Gardinali, Piero,Abad, Jos Luis,Eichhorn, Peter,Heuett, Nubia,Barcel, Dami
, p. 1279 - 1289 (2014)
In this study, four unapproved analogues of Sildenafil (SDF) were photodegraded under synthetic sunlight in artificial freshwater. Homosildenafil (H-SDF), hydroxyhomo-sildenafil (HH-SDF), norneosildenafil (NR-SDF) and thiosildenafil (T-SDF) were selected because they are frequently detected as adulterants in natural herbal products. Using UPLC-Orbitrap (QExactive)-MS, six photoproducts common to H-SDF, HH-SDF and T-SDF and nine unique transformation products of different molecular weights were identified based on their high-resolution (+)ESI product ion spectra. Mass spectral analysis of deuterated H-SDF, labeled on the N-ethyl group, allowed to gain mechanistic insight into the fragmentation pathway of the substituted piperazine ring and to support the postulated photoproduct structures. The mass spectral fragmentation confirmed the stepwise destruction of the piperazine ring eventually producing a sulfonic acid derivative (C17H20N4O5S: 392.1151Da). In contrast, the photodegradation of NR-SDF, which lacks a piperazine ring in its structure, formed only two prominent photoproducts originating from N,Ndealkylation of the sulfonamide followed by hydrolysis. The current work constitutes the first study on the photodegradation of analogs of erectile dysfunction drugs and the first detection of two transformation products (m/z 449 and 489) in environmental samples.
Preparation of human drug metabolites using fungal peroxygenases
Poraj-Kobielska, Marzena,Kinne, Matthias,Ullrich, Rene,Scheibner, Katrin,Kayser, Gernot,Hammel, Kenneth E.,Hofrichter, Martin
experimental part, p. 789 - 796 (2012/07/14)
The synthesis of hydroxylated and O- or N-dealkylated human drug metabolites (HDMs) via selective monooxygenation remains a challenging task for synthetic organic chemists. Here we report that aromatic peroxygenases (APOs; EC 1.11.2.1) secreted by the agaric fungi Agrocybe aegerita and Coprinellus radians catalyzed the H2O2-dependent selective monooxygenation of diverse drugs, including acetanilide, dextrorphan, ibuprofen, naproxen, phenacetin, sildenafil and tolbutamide. Reactions included the hydroxylation of aromatic rings and aliphatic side chains, as well as O- and N-dealkylations and exhibited different regioselectivities depending on the particular APO used. At best, desired HDMs were obtained in yields greater than 80% and with isomeric purities up to 99%. Oxidations of tolbutamide, acetanilide and carbamazepine in the presence of H218O2 resulted in almost complete incorporation of 18O into the corresponding products, thus establishing that these reactions are peroxygenations. The deethylation of phenacetin-d1 showed an observed intramolecular deuterium isotope effect [(kH/kD) obs] of 3.1 ± 0.2, which is consistent with the existence of a cytochrome P450-like intermediate in the reaction cycle of APOs. Our results indicate that fungal peroxygenases may be useful biocatalytic tools to prepare pharmacologically relevant drug metabolites.
