Synthesis and Antioxidant and Antimicrobial Properties of β-Hydroxy Sulfides, Sulfoxides, and Sulfones Derived from Cardanol and Glycerol Derivatives

Natural and synthetic sulfur-bearing organic compounds have many applications in medicinal chemistry. This article reports the preparation of amphiphilic β-hydroxy sulfides, sulfoxides, and sulfones derived from cardanol and glycerol. Thiolysis of cardanol epoxide 3 with various thiols (4a-4j) in ethanol or water yielded the corresponding β-hydroxy sulfides 5a-5j (61-95%). Treatment with 30% H₂O₂ in acetic acid at ambient temperature completely converted these products into β-hydroxy sulfoxides 6a-6j and sulfones 7a, 7c-7f, 7h-7j. The synthesized compounds were characterized by ¹H nuclear magnetic resonance (NMR), ¹³C NMR, high-resolution mass spectroscopy (HRMS) and performed the in vitro evaluation antimicrobial activities against standard strains of Staphylococcus aureus and Escherichia coli. Compounds 5a, 5d-5f, and 5h-5j proved moderately active against S. aureus. None of the compounds were active against E. coli. β-Hydroxy-sulfides 5a-5j were also evaluated for antioxidant properties but failed to exhibit significant activity.

Keywords:
CNSL; cardanol; hydroxy sulfides; epoxide ring opening; antibacterial activity