Differentiation between sulfoaildenafil and its analogs

Area of Science:

• Analytical Chemistry
• Pharmacology
• Forensic Science

Background:

• Dietary supplements for sexual enhancement may contain undeclared active pharmaceutical ingredients.
• Phosphodiesterase 5 (PDE5) inhibitors are commonly used for erectile dysfunction.
• Structural analogs of known drugs can pose risks due to uncharacterized pharmacological activity.

Purpose of the Study:

• To identify and characterize an unknown compound found in a dietary supplement.
• To determine if the identified compound is a structural analog of a PDE5 inhibitor.
• To develop methods for distinguishing the identified compound from similar known compounds.

Main Methods:

• Silica gel column chromatography for isolation.
• Nuclear Magnetic Resonance (NMR) spectrometry (13C and 1H) for structural elucidation.
• High-resolution Mass Spectrometry (MS) and X-ray crystallography for definitive identification.
• Ultra-performance Liquid Chromatography (UPLC)/MS, ion trap LC/MS/MS, and Gas Chromatography/MS (GC/MS) for distinguishing between similar compounds.

Main Results:

• An analog of aildenafil, identified as sulfoaildenafil (also known as thioaildenafil), was isolated and structurally confirmed.
• Sulfoaildenafil is structurally similar to thiohomosildenafil, making differentiation challenging.
• Specific mass fragments obtained via UPLC/MS, LC/IT-MS/MS, and GC/MS were identified as key identifiers for distinguishing sulfoaildenafil from thiohomosildenafil.

Conclusions:

• Dietary supplements can contain unlisted and potentially harmful drug analogs like sulfoaildenafil.
• Advanced analytical techniques, particularly mass spectrometry, are essential for accurate identification and differentiation of structurally similar compounds.
• The findings highlight the importance of rigorous testing of supplements to ensure consumer safety.